Move png header files in place; add documentationsyslinux-3.06

5 files changed, 5192 insertions, 4856 deletions

diff --git a/com32/lib/libpng/libpng.3 b/com32/lib/libpng/libpng.3
new file mode 100644
index 00000000..1feceee3
--- /dev/null
+++ b/com32/lib/libpng/libpng.3
@@ -0,0 +1,4022 @@
+.TH LIBPNG 3 "December 3, 2004"
+.SH NAME
+libpng \- Portable Network Graphics (PNG) Reference Library 1.2.8
+.SH SYNOPSIS
+\fI\fB
+
+\fB#include <png.h>\fP
+
+\fI\fB
+
+\fBpng_uint_32 png_access_version_number \fI(void\fP\fB);\fP
+
+\fI\fB
+
+\fBint png_check_sig (png_bytep \fP\fIsig\fP\fB, int \fInum\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_chunk_error (png_structp \fP\fIpng_ptr\fP\fB, png_const_charp \fIerror\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_chunk_warning (png_structp \fP\fIpng_ptr\fP\fB, png_const_charp \fImessage\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_convert_from_struct_tm (png_timep \fP\fIptime\fP\fB, struct tm FAR * \fIttime\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_convert_from_time_t (png_timep \fP\fIptime\fP\fB, time_t \fIttime\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_charp png_convert_to_rfc1123 (png_structp \fP\fIpng_ptr\fP\fB, png_timep \fIptime\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_infop png_create_info_struct (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_structp png_create_read_struct (png_const_charp \fP\fIuser_png_ver\fP\fB, png_voidp \fP\fIerror_ptr\fP\fB, png_error_ptr \fP\fIerror_fn\fP\fB, png_error_ptr \fIwarn_fn\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_structp png_create_read_struct_2(png_const_charp \fP\fIuser_png_ver\fP\fB, png_voidp \fP\fIerror_ptr\fP\fB, png_error_ptr \fP\fIerror_fn\fP\fB, png_error_ptr \fP\fIwarn_fn\fP\fB, png_voidp \fP\fImem_ptr\fP\fB, png_malloc_ptr \fP\fImalloc_fn\fP\fB, png_free_ptr \fIfree_fn\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_structp png_create_write_struct (png_const_charp \fP\fIuser_png_ver\fP\fB, png_voidp \fP\fIerror_ptr\fP\fB, png_error_ptr \fP\fIerror_fn\fP\fB, png_error_ptr \fIwarn_fn\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_structp png_create_write_struct_2(png_const_charp \fP\fIuser_png_ver\fP\fB, png_voidp \fP\fIerror_ptr\fP\fB, png_error_ptr \fP\fIerror_fn\fP\fB, png_error_ptr \fP\fIwarn_fn\fP\fB, png_voidp \fP\fImem_ptr\fP\fB, png_malloc_ptr \fP\fImalloc_fn\fP\fB, png_free_ptr \fIfree_fn\fP\fB);\fP
+
+\fI\fB
+
+\fBint png_debug(int \fP\fIlevel\fP\fB, png_const_charp \fImessage\fP\fB);\fP
+
+\fI\fB
+
+\fBint png_debug1(int \fP\fIlevel\fP\fB, png_const_charp \fP\fImessage\fP\fB, \fIp1\fP\fB);\fP
+
+\fI\fB
+
+\fBint png_debug2(int \fP\fIlevel\fP\fB, png_const_charp \fP\fImessage\fP\fB, \fP\fIp1\fP\fB, \fIp2\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_destroy_info_struct (png_structp \fP\fIpng_ptr\fP\fB, png_infopp \fIinfo_ptr_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_destroy_read_struct (png_structpp \fP\fIpng_ptr_ptr\fP\fB, png_infopp \fP\fIinfo_ptr_ptr\fP\fB, png_infopp \fIend_info_ptr_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_destroy_write_struct (png_structpp \fP\fIpng_ptr_ptr\fP\fB, png_infopp \fIinfo_ptr_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_error (png_structp \fP\fIpng_ptr\fP\fB, png_const_charp \fIerror\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_free (png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fIptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_free_chunk_list (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_free_default(png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fIptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_free_data (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fInum\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_byte png_get_bit_depth (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_uint_32 png_get_bKGD (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_color_16p \fI*background\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_byte png_get_channels (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_uint_32 png_get_cHRM (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, double \fP\fI*white_x\fP\fB, double \fP\fI*white_y\fP\fB, double \fP\fI*red_x\fP\fB, double \fP\fI*red_y\fP\fB, double \fP\fI*green_x\fP\fB, double \fP\fI*green_y\fP\fB, double \fP\fI*blue_x\fP\fB, double \fI*blue_y\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_uint_32 png_get_cHRM_fixed (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fP\fI*white_x\fP\fB, png_uint_32 \fP\fI*white_y\fP\fB, png_uint_32 \fP\fI*red_x\fP\fB, png_uint_32 \fP\fI*red_y\fP\fB, png_uint_32 \fP\fI*green_x\fP\fB, png_uint_32 \fP\fI*green_y\fP\fB, png_uint_32 \fP\fI*blue_x\fP\fB, png_uint_32 \fI*blue_y\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_byte png_get_color_type (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_byte png_get_compression_type (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_byte png_get_copyright (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_voidp png_get_error_ptr (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_byte png_get_filter_type (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_uint_32 png_get_gAMA (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, double \fI*file_gamma\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_uint_32 png_get_gAMA_fixed (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fI*int_file_gamma\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_byte png_get_header_ver (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_byte png_get_header_version (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_uint_32 png_get_hIST (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_16p \fI*hist\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_uint_32 png_get_iCCP (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_charpp \fP\fIname\fP\fB, int \fP\fI*compression_type\fP\fB, png_charpp \fP\fIprofile\fP\fB, png_uint_32 \fI*proflen\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_uint_32 png_get_IHDR (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fP\fI*width\fP\fB, png_uint_32 \fP\fI*height\fP\fB, int \fP\fI*bit_depth\fP\fB, int \fP\fI*color_type\fP\fB, int \fP\fI*interlace_type\fP\fB, int \fP\fI*compression_type\fP\fB, int \fI*filter_type\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_uint_32 png_get_image_height (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_uint_32 png_get_image_width (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_byte png_get_interlace_type (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_voidp png_get_io_ptr (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_byte png_get_libpng_ver (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_voidp png_get_mem_ptr(png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_uint_32 png_get_oFFs (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fP\fI*offset_x\fP\fB, png_uint_32 \fP\fI*offset_y\fP\fB, int \fI*unit_type\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_uint_32 png_get_pCAL (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_charp \fP\fI*purpose\fP\fB, png_int_32 \fP\fI*X0\fP\fB, png_int_32 \fP\fI*X1\fP\fB, int \fP\fI*type\fP\fB, int \fP\fI*nparams\fP\fB, png_charp \fP\fI*units\fP\fB, png_charpp \fI*params\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_uint_32 png_get_pHYs (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fP\fI*res_x\fP\fB, png_uint_32 \fP\fI*res_y\fP\fB, int \fI*unit_type\fP\fB);\fP
+
+\fI\fB
+
+\fBfloat png_get_pixel_aspect_ratio (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_uint_32 png_get_pixels_per_meter (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_voidp png_get_progressive_ptr (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_uint_32 png_get_PLTE (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_colorp \fP\fI*palette\fP\fB, int \fI*num_palette\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_byte png_get_rgb_to_gray_status (png_structp \fIpng_ptr)
+
+\fBpng_uint_32 png_get_rowbytes (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_bytepp png_get_rows (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_uint_32 png_get_sBIT (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_color_8p \fI*sig_bit\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_bytep png_get_signature (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_uint_32 png_get_sPLT (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_spalette_p \fI*splt_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_uint_32 png_get_sRGB (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fI*intent\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_uint_32 png_get_text (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_textp \fP\fI*text_ptr\fP\fB, int \fI*num_text\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_uint_32 png_get_tIME (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_timep \fI*mod_time\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_uint_32 png_get_tRNS (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_bytep \fP\fI*trans\fP\fB, int \fP\fI*num_trans\fP\fB, png_color_16p \fI*trans_values\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_uint_32 png_get_unknown_chunks (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_unknown_chunkpp \fIunknowns\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_voidp png_get_user_chunk_ptr (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_uint_32 png_get_user_height_max( png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_voidp png_get_user_transform_ptr (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_uint_32 png_get_user_width_max (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_uint_32 png_get_valid (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIflag\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_int_32 png_get_x_offset_microns (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_int_32 png_get_x_offset_pixels (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_uint_32 png_get_x_pixels_per_meter (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_int_32 png_get_y_offset_microns (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_int_32 png_get_y_offset_pixels (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_uint_32 png_get_y_pixels_per_meter (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_uint_32 png_get_compression_buffer_size (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBint png_handle_as_unknown (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fIchunk_name\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_init_io (png_structp \fP\fIpng_ptr\fP\fB, FILE \fI*fp\fP\fB);\fP
+
+\fI\fB
+
+\fBDEPRECATED: void png_info_init (png_infop \fIinfo_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBDEPRECATED: void png_info_init_2 (png_infopp \fP\fIptr_ptr\fP\fB, png_size_t \fIpng_info_struct_size\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_voidp png_malloc (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fIsize\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_voidp png_malloc_default(png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fIsize\fP\fB);\fP
+
+\fI\fB
+
+\fBvoidp png_memcpy (png_voidp \fP\fIs1\fP\fB, png_voidp \fP\fIs2\fP\fB, png_size_t \fIsize\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_voidp png_memcpy_check (png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fP\fIs1\fP\fB, png_voidp \fP\fIs2\fP\fB, png_uint_32 \fIsize\fP\fB);\fP
+
+\fI\fB
+
+\fBvoidp png_memset (png_voidp \fP\fIs1\fP\fB, int \fP\fIvalue\fP\fB, png_size_t \fIsize\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_voidp png_memset_check (png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fP\fIs1\fP\fB, int \fP\fIvalue\fP\fB, png_uint_32 \fIsize\fP\fB);\fP
+
+\fI\fB
+
+\fBDEPRECATED: void png_permit_empty_plte (png_structp \fP\fIpng_ptr\fP\fB, int \fIempty_plte_permitted\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_process_data (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_bytep \fP\fIbuffer\fP\fB, png_size_t \fIbuffer_size\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_progressive_combine_row (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIold_row\fP\fB, png_bytep \fInew_row\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_read_destroy (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_infop \fIend_info_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_read_end (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_read_image (png_structp \fP\fIpng_ptr\fP\fB, png_bytepp \fIimage\fP\fB);\fP
+
+\fI\fB
+
+\fBDEPRECATED: void png_read_init (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBDEPRECATED: void png_read_init_2 (png_structpp \fP\fIptr_ptr\fP\fB, png_const_charp \fP\fIuser_png_ver\fP\fB, png_size_t \fP\fIpng_struct_size\fP\fB, png_size_t \fIpng_info_size\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_read_info (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_read_png (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fP\fItransforms\fP\fB, png_voidp \fIparams\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_read_row (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIrow\fP\fB, png_bytep \fIdisplay_row\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_read_rows (png_structp \fP\fIpng_ptr\fP\fB, png_bytepp \fP\fIrow\fP\fB, png_bytepp \fP\fIdisplay_row\fP\fB, png_uint_32 \fInum_rows\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_read_update_info (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fB#if \fI!defined(PNG_1_0_X)
+
+\fBvoid png_set_add_alpha (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fP\fIfiller\fP\fB, int \fIflags\fP\fB);\fP
+
+\fI\fB#endif
+
+\fI\fB
+
+\fBvoid png_set_background (png_structp \fP\fIpng_ptr\fP\fB, png_color_16p \fP\fIbackground_color\fP\fB, int \fP\fIbackground_gamma_code\fP\fB, int \fP\fIneed_expand\fP\fB, double \fIbackground_gamma\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_bgr (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_bKGD (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_color_16p \fIbackground\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_cHRM (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, double \fP\fIwhite_x\fP\fB, double \fP\fIwhite_y\fP\fB, double \fP\fIred_x\fP\fB, double \fP\fIred_y\fP\fB, double \fP\fIgreen_x\fP\fB, double \fP\fIgreen_y\fP\fB, double \fP\fIblue_x\fP\fB, double \fIblue_y\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_cHRM_fixed (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fP\fIwhite_x\fP\fB, png_uint_32 \fP\fIwhite_y\fP\fB, png_uint_32 \fP\fIred_x\fP\fB, png_uint_32 \fP\fIred_y\fP\fB, png_uint_32 \fP\fIgreen_x\fP\fB, png_uint_32 \fP\fIgreen_y\fP\fB, png_uint_32 \fP\fIblue_x\fP\fB, png_uint_32 \fIblue_y\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_compression_level (png_structp \fP\fIpng_ptr\fP\fB, int \fIlevel\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_compression_mem_level (png_structp \fP\fIpng_ptr\fP\fB, int \fImem_level\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_compression_method (png_structp \fP\fIpng_ptr\fP\fB, int \fImethod\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_compression_strategy (png_structp \fP\fIpng_ptr\fP\fB, int \fIstrategy\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_compression_window_bits (png_structp \fP\fIpng_ptr\fP\fB, int \fIwindow_bits\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_crc_action (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fIcrit_action\fP\fB, int \fIancil_action\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_dither (png_structp \fP\fIpng_ptr\fP\fB, png_colorp \fP\fIpalette\fP\fB, int \fP\fInum_palette\fP\fB, int \fP\fImaximum_colors\fP\fB, png_uint_16p \fP\fIhistogram\fP\fB, int \fIfull_dither\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_error_fn (png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fP\fIerror_ptr\fP\fB, png_error_ptr \fP\fIerror_fn\fP\fB, png_error_ptr \fIwarning_fn\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_expand (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_filler (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fP\fIfiller\fP\fB, int \fIflags\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_filter (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fImethod\fP\fB, int \fIfilters\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_filter_heuristics (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fIheuristic_method\fP\fB, int \fP\fInum_weights\fP\fB, png_doublep \fP\fIfilter_weights\fP\fB, png_doublep \fIfilter_costs\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_flush (png_structp \fP\fIpng_ptr\fP\fB, int \fInrows\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_gamma (png_structp \fP\fIpng_ptr\fP\fB, double \fP\fIscreen_gamma\fP\fB, double \fIdefault_file_gamma\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_gAMA (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, double \fIfile_gamma\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_gAMA_fixed (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIfile_gamma\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_gray_1_2_4_to_8(png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_gray_to_rgb (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_hIST (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_16p \fIhist\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_iCCP (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_charp \fP\fIname\fP\fB, int \fP\fIcompression_type\fP\fB, png_charp \fP\fIprofile\fP\fB, png_uint_32 \fIproflen\fP\fB);\fP
+
+\fI\fB
+
+\fBint png_set_interlace_handling (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_invalid (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fImask\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_invert_alpha (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_invert_mono (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_IHDR (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fP\fIwidth\fP\fB, png_uint_32 \fP\fIheight\fP\fB, int \fP\fIbit_depth\fP\fB, int \fP\fIcolor_type\fP\fB, int \fP\fIinterlace_type\fP\fB, int \fP\fIcompression_type\fP\fB, int \fIfilter_type\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_keep_unknown_chunks (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fIkeep\fP\fB, png_bytep \fP\fIchunk_list\fP\fB, int \fInum_chunks\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_mem_fn(png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fP\fImem_ptr\fP\fB, png_malloc_ptr \fP\fImalloc_fn\fP\fB, png_free_ptr \fIfree_fn\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_oFFs (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fP\fIoffset_x\fP\fB, png_uint_32 \fP\fIoffset_y\fP\fB, int \fIunit_type\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_packing (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_packswap (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_palette_to_rgb(png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_pCAL (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_charp \fP\fIpurpose\fP\fB, png_int_32 \fP\fIX0\fP\fB, png_int_32 \fP\fIX1\fP\fB, int \fP\fItype\fP\fB, int \fP\fInparams\fP\fB, png_charp \fP\fIunits\fP\fB, png_charpp \fIparams\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_pHYs (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fP\fIres_x\fP\fB, png_uint_32 \fP\fIres_y\fP\fB, int \fIunit_type\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_progressive_read_fn (png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fP\fIprogressive_ptr\fP\fB, png_progressive_info_ptr \fP\fIinfo_fn\fP\fB, png_progressive_row_ptr \fP\fIrow_fn\fP\fB, png_progressive_end_ptr \fIend_fn\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_PLTE (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_colorp \fP\fIpalette\fP\fB, int \fInum_palette\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_read_fn (png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fP\fIio_ptr\fP\fB, png_rw_ptr \fIread_data_fn\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_read_status_fn (png_structp \fP\fIpng_ptr\fP\fB, png_read_status_ptr \fIread_row_fn\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_read_user_transform_fn (png_structp \fP\fIpng_ptr\fP\fB, png_user_transform_ptr \fIread_user_transform_fn\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_rgb_to_gray (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fIerror_action\fP\fB, double \fP\fIred\fP\fB, double \fIgreen\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_rgb_to_gray_fixed (png_structp \fP\fIpng_ptr\fP\fB, int error_action png_fixed_point \fP\fIred\fP\fB, png_fixed_point \fIgreen\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_rows (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_bytepp \fIrow_pointers\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_sBIT (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_color_8p \fIsig_bit\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_sCAL (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_charp \fP\fIunit\fP\fB, double \fP\fIwidth\fP\fB, double \fIheight\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_shift (png_structp \fP\fIpng_ptr\fP\fB, png_color_8p \fItrue_bits\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_sig_bytes (png_structp \fP\fIpng_ptr\fP\fB, int \fInum_bytes\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_sPLT (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_spalette_p \fP\fIsplt_ptr\fP\fB, int \fInum_spalettes\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_sRGB (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fIintent\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_sRGB_gAMA_and_cHRM (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fIintent\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_strip_16 (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_strip_alpha (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_swap (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_swap_alpha (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_text (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_textp \fP\fItext_ptr\fP\fB, int \fInum_text\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_tIME (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_timep \fImod_time\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_tRNS (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_bytep \fP\fItrans\fP\fB, int \fP\fInum_trans\fP\fB, png_color_16p \fItrans_values\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_tRNS_to_alpha(png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_uint_32 png_set_unknown_chunks (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_unknown_chunkp \fP\fIunknowns\fP\fB, int \fP\fInum\fP\fB, int \fIlocation\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_unknown_chunk_location(png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fP\fIchunk\fP\fB, int \fIlocation\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_read_user_chunk_fn (png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fP\fIuser_chunk_ptr\fP\fB, png_user_chunk_ptr \fIread_user_chunk_fn\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_user_limits (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fP\fIuser_width_max\fP\fB, png_uint_32 \fIuser_height_max\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_user_transform_info (png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fP\fIuser_transform_ptr\fP\fB, int \fP\fIuser_transform_depth\fP\fB, int \fIuser_transform_channels\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_write_fn (png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fP\fIio_ptr\fP\fB, png_rw_ptr \fP\fIwrite_data_fn\fP\fB, png_flush_ptr \fIoutput_flush_fn\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_write_status_fn (png_structp \fP\fIpng_ptr\fP\fB, png_write_status_ptr \fIwrite_row_fn\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_write_user_transform_fn (png_structp \fP\fIpng_ptr\fP\fB, png_user_transform_ptr \fIwrite_user_transform_fn\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_compression_buffer_size(png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fIsize\fP\fB);\fP
+
+\fI\fB
+
+\fBint png_sig_cmp (png_bytep \fP\fIsig\fP\fB, png_size_t \fP\fIstart\fP\fB, png_size_t \fInum_to_check\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_start_read_image (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_warning (png_structp \fP\fIpng_ptr\fP\fB, png_const_charp \fImessage\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_chunk (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIchunk_name\fP\fB, png_bytep \fP\fIdata\fP\fB, png_size_t \fIlength\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_chunk_data (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIdata\fP\fB, png_size_t \fIlength\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_chunk_end (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_chunk_start (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIchunk_name\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_destroy (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_end (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_flush (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_image (png_structp \fP\fIpng_ptr\fP\fB, png_bytepp \fIimage\fP\fB);\fP
+
+\fI\fB
+
+\fBDEPRECATED: void png_write_init (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBDEPRECATED: void png_write_init_2 (png_structpp \fP\fIptr_ptr\fP\fB, png_const_charp \fP\fIuser_png_ver\fP\fB, png_size_t \fP\fIpng_struct_size\fP\fB, png_size_t \fIpng_info_size\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_info (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_info_before_PLTE (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_png (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fP\fItransforms\fP\fB, png_voidp \fIparams\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_row (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fIrow\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_rows (png_structp \fP\fIpng_ptr\fP\fB, png_bytepp \fP\fIrow\fP\fB, png_uint_32 \fInum_rows\fP\fB);\fP
+
+\fI\fB
+
+\fBvoidpf png_zalloc (voidpf \fP\fIpng_ptr\fP\fB, uInt \fP\fIitems\fP\fB, uInt \fIsize\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_zfree (voidpf \fP\fIpng_ptr\fP\fB, voidpf \fIptr\fP\fB);\fP
+
+\fI\fB
+
+.SH DESCRIPTION
+The
+.I libpng
+library supports encoding, decoding, and various manipulations of
+the Portable Network Graphics (PNG) format image files.  It uses the
+.IR zlib(3)
+compression library.
+Following is a copy of the libpng.txt file that accompanies libpng.
+.SH LIBPNG.TXT
+libpng.txt - A description on how to use and modify libpng
+
+ libpng version 1.2.8 - December 3, 2004
+ Updated and distributed by Glenn Randers-Pehrson
+ <glennrp at users.sourceforge.net>
+ Copyright (c) 1998-2004 Glenn Randers-Pehrson
+ For conditions of distribution and use, see copyright
+ notice in png.h.
+
+ based on:
+
+ libpng 1.0 beta 6  version 0.96 May 28, 1997
+ Updated and distributed by Andreas Dilger
+ Copyright (c) 1996, 1997 Andreas Dilger
+
+ libpng 1.0 beta 2 - version 0.88  January 26, 1996
+ For conditions of distribution and use, see copyright
+ notice in png.h. Copyright (c) 1995, 1996 Guy Eric
+ Schalnat, Group 42, Inc.
+
+ Updated/rewritten per request in the libpng FAQ
+ Copyright (c) 1995, 1996 Frank J. T. Wojcik
+ December 18, 1995 & January 20, 1996
+
+.SH I. Introduction
+
+This file describes how to use and modify the PNG reference library
+(known as libpng) for your own use.  There are five sections to this
+file: introduction, structures, reading, writing, and modification and
+configuration notes for various special platforms.  In addition to this
+file, example.c is a good starting point for using the library, as
+it is heavily commented and should include everything most people
+will need.  We assume that libpng is already installed; see the
+INSTALL file for instructions on how to install libpng.
+
+Libpng was written as a companion to the PNG specification, as a way
+of reducing the amount of time and effort it takes to support the PNG
+file format in application programs.
+
+The PNG specification (second edition), November 2003, is available as
+a W3C Recommendation and as an ISO Standard (ISO/IEC 15948:2003 (E)) at
+<http://www.w3.org/TR/2003/REC-PNG-20031110/
+The W3C and ISO documents have identical technical content.
+
+The PNG-1.2 specification is available at
+<http://www.libpng.org/pub/png/documents/>
+
+The PNG-1.0 specification is available
+as RFC 2083 <http://www.libpng.org/pub/png/documents/> and as a
+W3C Recommendation <http://www.w3.org/TR/REC.png.html>. Some
+additional chunks are described in the special-purpose public chunks
+documents at <http://www.libpng.org/pub/png/documents/>.
+
+Other information
+about PNG, and the latest version of libpng, can be found at the PNG home
+page, <http://www.libpng.org/pub/png/>.
+
+Most users will not have to modify the library significantly; advanced
+users may want to modify it more.  All attempts were made to make it as
+complete as possible, while keeping the code easy to understand.
+Currently, this library only supports C.  Support for other languages
+is being considered.
+
+Libpng has been designed to handle multiple sessions at one time,
+to be easily modifiable, to be portable to the vast majority of
+machines (ANSI, K&R, 16-, 32-, and 64-bit) available, and to be easy
+to use.  The ultimate goal of libpng is to promote the acceptance of
+the PNG file format in whatever way possible.  While there is still
+work to be done (see the TODO file), libpng should cover the
+majority of the needs of its users.
+
+Libpng uses zlib for its compression and decompression of PNG files.
+Further information about zlib, and the latest version of zlib, can
+be found at the zlib home page, <http://www.info-zip.org/pub/infozip/zlib/>.
+The zlib compression utility is a general purpose utility that is
+useful for more than PNG files, and can be used without libpng.
+See the documentation delivered with zlib for more details.
+You can usually find the source files for the zlib utility wherever you
+find the libpng source files.
+
+Libpng is thread safe, provided the threads are using different
+instances of the structures.  Each thread should have its own
+png_struct and png_info instances, and thus its own image.
+Libpng does not protect itself against two threads using the
+same instance of a structure.  Note: thread safety may be defeated
+by use of some of the MMX assembler code in pnggccrd.c, which is only
+compiled when the user defines PNG_THREAD_UNSAFE_OK.
+
+.SH II. Structures
+
+There are two main structures that are important to libpng, png_struct
+and png_info.  The first, png_struct, is an internal structure that
+will not, for the most part, be used by a user except as the first
+variable passed to every libpng function call.
+
+The png_info structure is designed to provide information about the
+PNG file.  At one time, the fields of png_info were intended to be
+directly accessible to the user.  However, this tended to cause problems
+with applications using dynamically loaded libraries, and as a result
+a set of interface functions for png_info (the png_get_*() and png_set_*()
+functions) was developed.  The fields of png_info are still available for
+older applications, but it is suggested that applications use the new
+interfaces if at all possible.
+
+Applications that do make direct access to the members of png_struct (except
+for png_ptr->jmpbuf) must be recompiled whenever the library is updated,
+and applications that make direct access to the members of png_info must
+be recompiled if they were compiled or loaded with libpng version 1.0.6,
+in which the members were in a different order.  In version 1.0.7, the
+members of the png_info structure reverted to the old order, as they were
+in versions 0.97c through 1.0.5.  Starting with version 2.0.0, both
+structures are going to be hidden, and the contents of the structures will
+only be accessible through the png_get/png_set functions.
+
+The png.h header file is an invaluable reference for programming with libpng.
+And while I'm on the topic, make sure you include the libpng header file:
+
+#include <png.h>
+
+.SH III. Reading
+
+We'll now walk you through the possible functions to call when reading
+in a PNG file sequentially, briefly explaining the syntax and purpose
+of each one.  See example.c and png.h for more detail.  While
+progressive reading is covered in the next section, you will still
+need some of the functions discussed in this section to read a PNG
+file.
+
+.SS Setup
+
+You will want to do the I/O initialization(*) before you get into libpng,
+so if it doesn't work, you don't have much to undo.  Of course, you
+will also want to insure that you are, in fact, dealing with a PNG
+file.  Libpng provides a simple check to see if a file is a PNG file.
+To use it, pass in the first 1 to 8 bytes of the file to the function
+png_sig_cmp(), and it will return 0 if the bytes match the corresponding
+bytes of the PNG signature, or nonzero otherwise.  Of course, the more bytes
+you pass in, the greater the accuracy of the prediction.
+
+If you are intending to keep the file pointer open for use in libpng,
+you must ensure you don't read more than 8 bytes from the beginning
+of the file, and you also have to make a call to png_set_sig_bytes_read()
+with the number of bytes you read from the beginning.  Libpng will
+then only check the bytes (if any) that your program didn't read.
+
+(*): If you are not using the standard I/O functions, you will need
+to replace them with custom functions.  See the discussion under
+Customizing libpng.
+
+
+    FILE *fp = fopen(file_name, "rb");
+    if (!fp)
+    {
+        return (ERROR);
+    }
+    fread(header, 1, number, fp);
+    is_png = !png_sig_cmp(header, 0, number);
+    if (!is_png)
+    {
+        return (NOT_PNG);
+    }
+
+
+Next, png_struct and png_info need to be allocated and initialized.  In
+order to ensure that the size of these structures is correct even with a
+dynamically linked libpng, there are functions to initialize and
+allocate the structures.  We also pass the library version, optional
+pointers to error handling functions, and a pointer to a data struct for
+use by the error functions, if necessary (the pointer and functions can
+be NULL if the default error handlers are to be used).  See the section
+on Changes to Libpng below regarding the old initialization functions.
+The structure allocation functions quietly return NULL if they fail to
+create the structure, so your application should check for that.
+
+    png_structp png_ptr = png_create_read_struct
+       (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr,
+        user_error_fn, user_warning_fn);
+    if (!png_ptr)
+        return (ERROR);
+
+    png_infop info_ptr = png_create_info_struct(png_ptr);
+    if (!info_ptr)
+    {
+        png_destroy_read_struct(&png_ptr,
+           (png_infopp)NULL, (png_infopp)NULL);
+        return (ERROR);
+    }
+
+    png_infop end_info = png_create_info_struct(png_ptr);
+    if (!end_info)
+    {
+        png_destroy_read_struct(&png_ptr, &info_ptr,
+          (png_infopp)NULL);
+        return (ERROR);
+    }
+
+If you want to use your own memory allocation routines,
+define PNG_USER_MEM_SUPPORTED and use
+png_create_read_struct_2() instead of png_create_read_struct():
+
+    png_structp png_ptr = png_create_read_struct_2
+       (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr,
+        user_error_fn, user_warning_fn, (png_voidp)
+        user_mem_ptr, user_malloc_fn, user_free_fn);
+
+The error handling routines passed to png_create_read_struct()
+and the memory alloc/free routines passed to png_create_struct_2()
+are only necessary if you are not using the libpng supplied error
+handling and memory alloc/free functions.
+
+When libpng encounters an error, it expects to longjmp back
+to your routine.  Therefore, you will need to call setjmp and pass
+your png_jmpbuf(png_ptr).  If you read the file from different
+routines, you will need to update the jmpbuf field every time you enter
+a new routine that will call a png_*() function.
+
+See your documentation of setjmp/longjmp for your compiler for more
+information on setjmp/longjmp.  See the discussion on libpng error
+handling in the Customizing Libpng section below for more information
+on the libpng error handling.  If an error occurs, and libpng longjmp's
+back to your setjmp, you will want to call png_destroy_read_struct() to
+free any memory.
+
+    if (setjmp(png_jmpbuf(png_ptr)))
+    {
+        png_destroy_read_struct(&png_ptr, &info_ptr,
+           &end_info);
+        fclose(fp);
+        return (ERROR);
+    }
+
+If you would rather avoid the complexity of setjmp/longjmp issues,
+you can compile libpng with PNG_SETJMP_NOT_SUPPORTED, in which case
+errors will result in a call to PNG_ABORT() which defaults to abort().
+
+Now you need to set up the input code.  The default for libpng is to
+use the C function fread().  If you use this, you will need to pass a
+valid FILE * in the function png_init_io().  Be sure that the file is
+opened in binary mode.  If you wish to handle reading data in another
+way, you need not call the png_init_io() function, but you must then
+implement the libpng I/O methods discussed in the Customizing Libpng
+section below.
+
+    png_init_io(png_ptr, fp);
+
+If you had previously opened the file and read any of the signature from
+the beginning in order to see if this was a PNG file, you need to let
+libpng know that there are some bytes missing from the start of the file.
+
+    png_set_sig_bytes(png_ptr, number);
+
+.SS Setting up callback code
+
+You can set up a callback function to handle any unknown chunks in the
+input stream. You must supply the function
+
+    read_chunk_callback(png_ptr ptr,
+         png_unknown_chunkp chunk);
+    {
+       /* The unknown chunk structure contains your
+          chunk data: */
+           png_byte name[5];
+           png_byte *data;
+           png_size_t size;
+       /* Note that libpng has already taken care of
+          the CRC handling */
+
+       /* put your code here.  Return one of the
+          following: */
+
+       return (-n); /* chunk had an error */
+       return (0); /* did not recognize */
+       return (n); /* success */
+    }
+
+(You can give your function another name that you like instead of
+"read_chunk_callback")
+
+To inform libpng about your function, use
+
+    png_set_read_user_chunk_fn(png_ptr, user_chunk_ptr,
+        read_chunk_callback);
+
+This names not only the callback function, but also a user pointer that
+you can retrieve with
+
+    png_get_user_chunk_ptr(png_ptr);
+
+At this point, you can set up a callback function that will be
+called after each row has been read, which you can use to control
+a progress meter or the like.  It's demonstrated in pngtest.c.
+You must supply a function
+
+    void read_row_callback(png_ptr ptr, png_uint_32 row,
+       int pass);
+    {
+      /* put your code here */
+    }
+
+(You can give it another name that you like instead of "read_row_callback")
+
+To inform libpng about your function, use
+
+    png_set_read_status_fn(png_ptr, read_row_callback);
+
+.SS Width and height limits
+
+The PNG specification allows the width and height of an image to be as
+large as 2^31-1 (0x7fffffff), or about 2.147 billion rows and columns.
+Since very few applications really need to process such large images,
+we have imposed an arbitrary 1-million limit on rows and columns.
+Larger images will be rejected immediately with a png_error() call. If
+you wish to override this limit, you can use
+
+   png_set_user_limits(png_ptr, width_max, height_max);
+
+to set your own limits, or use width_max = height_max = 0x7fffffffL
+to allow all valid dimensions (libpng may reject some very large images
+anyway because of potential buffer overflow conditions).
+
+You should put this statement after you create the PNG structure and
+before calling png_read_info(), png_read_png(), or png_process_data().
+If you need to retrieve the limits that are being applied, use
+
+   width_max = png_get_user_width_max(png_ptr);
+   height_max = png_get_user_height_max(png_ptr);
+
+.SS Unknown-chunk handling
+
+Now you get to set the way the library processes unknown chunks in the
+input PNG stream. Both known and unknown chunks will be read.  Normal
+behavior is that known chunks will be parsed into information in
+various info_ptr members; unknown chunks will be discarded. To change
+this, you can call:
+
+    png_set_keep_unknown_chunks(png_ptr, keep,
+        chunk_list, num_chunks);
+    keep       - 0: do not handle as unknown
+                 1: do not keep
+                 2: keep only if safe-to-copy
+                 3: keep even if unsafe-to-copy
+               You can use these definitions:
+                 PNG_HANDLE_CHUNK_AS_DEFAULT   0
+                 PNG_HANDLE_CHUNK_NEVER        1
+                 PNG_HANDLE_CHUNK_IF_SAFE      2
+                 PNG_HANDLE_CHUNK_ALWAYS       3
+    chunk_list - list of chunks affected (a byte string,
+                 five bytes per chunk, NULL or '\0' if
+                 num_chunks is 0)
+    num_chunks - number of chunks affected; if 0, all
+                 unknown chunks are affected.  If nonzero,
+                 only the chunks in the list are affected
+
+Unknown chunks declared in this way will be saved as raw data onto a
+list of png_unknown_chunk structures.  If a chunk that is normally
+known to libpng is named in the list, it will be handled as unknown,
+according to the "keep" directive.  If a chunk is named in successive
+instances of png_set_keep_unknown_chunks(), the final instance will
+take precedence.  The IHDR and IEND chunks should not be named in
+chunk_list; if they are, libpng will process them normally anyway.
+
+.SS The high-level read interface
+
+At this point there are two ways to proceed; through the high-level
+read interface, or through a sequence of low-level read operations.
+You can use the high-level interface if (a) you are willing to read
+the entire image into memory, and (b) the input transformations
+you want to do are limited to the following set:
+
+    PNG_TRANSFORM_IDENTITY      No transformation
+    PNG_TRANSFORM_STRIP_16      Strip 16-bit samples to
+                                8 bits
+    PNG_TRANSFORM_STRIP_ALPHA   Discard the alpha channel
+    PNG_TRANSFORM_PACKING       Expand 1, 2 and 4-bit
+                                samples to bytes
+    PNG_TRANSFORM_PACKSWAP      Change order of packed
+                                pixels to LSB first
+    PNG_TRANSFORM_EXPAND        Perform set_expand()
+    PNG_TRANSFORM_INVERT_MONO   Invert monochrome images
+    PNG_TRANSFORM_SHIFT         Normalize pixels to the
+                                sBIT depth
+    PNG_TRANSFORM_BGR           Flip RGB to BGR, RGBA
+                                to BGRA
+    PNG_TRANSFORM_SWAP_ALPHA    Flip RGBA to ARGB or GA
+                                to AG
+    PNG_TRANSFORM_INVERT_ALPHA  Change alpha from opacity
+                                to transparency
+    PNG_TRANSFORM_SWAP_ENDIAN   Byte-swap 16-bit samples
+
+(This excludes setting a background color, doing gamma transformation,
+dithering, and setting filler.)  If this is the case, simply do this:
+
+    png_read_png(png_ptr, info_ptr, png_transforms, NULL)
+
+where png_transforms is an integer containing the logical OR of
+some set of transformation flags.  This call is equivalent to png_read_info(),
+followed the set of transformations indicated by the transform mask,
+then png_read_image(), and finally png_read_end().
+
+(The final parameter of this call is not yet used.  Someday it might point
+to transformation parameters required by some future input transform.)
+
+You must use png_transforms and not call any png_set_transform() functions
+when you use png_read_png().
+
+After you have called png_read_png(), you can retrieve the image data
+with
+
+   row_pointers = png_get_rows(png_ptr, info_ptr);
+
+where row_pointers is an array of pointers to the pixel data for each row:
+
+   png_bytep row_pointers[height];
+
+If you know your image size and pixel size ahead of time, you can allocate
+row_pointers prior to calling png_read_png() with
+
+   if (height > PNG_UINT_32_MAX/png_sizeof(png_byte))
+      png_error (png_ptr,
+         "Image is too tall to process in memory");
+   if (width > PNG_UINT_32_MAX/pixel_size)
+      png_error (png_ptr,
+         "Image is too wide to process in memory");
+   row_pointers = png_malloc(png_ptr,
+      height*png_sizeof(png_bytep));
+   for (int i=0; i<height, i++)
+      row_pointers[i]=png_malloc(png_ptr,
+         width*pixel_size);
+   png_set_rows(png_ptr, info_ptr, &row_pointers);
+
+Alternatively you could allocate your image in one big block and define
+row_pointers[i] to point into the proper places in your block.
+
+If you use png_set_rows(), the application is responsible for freeing
+row_pointers (and row_pointers[i], if they were separately allocated).
+
+If you don't allocate row_pointers ahead of time, png_read_png() will
+do it, and it'll be free'ed when you call png_destroy_*().
+
+.SS The low-level read interface
+
+If you are going the low-level route, you are now ready to read all
+the file information up to the actual image data.  You do this with a
+call to png_read_info().
+
+    png_read_info(png_ptr, info_ptr);
+
+This will process all chunks up to but not including the image data.
+
+.SS Querying the info structure
+
+Functions are used to get the information from the info_ptr once it
+has been read.  Note that these fields may not be completely filled
+in until png_read_end() has read the chunk data following the image.
+
+    png_get_IHDR(png_ptr, info_ptr, &width, &height,
+       &bit_depth, &color_type, &interlace_type,
+       &compression_type, &filter_method);
+
+    width          - holds the width of the image
+                     in pixels (up to 2^31).
+    height         - holds the height of the image
+                     in pixels (up to 2^31).
+    bit_depth      - holds the bit depth of one of the
+                     image channels.  (valid values are
+                     1, 2, 4, 8, 16 and depend also on
+                     the color_type.  See also
+                     significant bits (sBIT) below).
+    color_type     - describes which color/alpha channels
+                         are present.
+                     PNG_COLOR_TYPE_GRAY
+                        (bit depths 1, 2, 4, 8, 16)
+                     PNG_COLOR_TYPE_GRAY_ALPHA
+                        (bit depths 8, 16)
+                     PNG_COLOR_TYPE_PALETTE
+                        (bit depths 1, 2, 4, 8)
+                     PNG_COLOR_TYPE_RGB
+                        (bit_depths 8, 16)
+                     PNG_COLOR_TYPE_RGB_ALPHA
+                        (bit_depths 8, 16)
+
+                     PNG_COLOR_MASK_PALETTE
+                     PNG_COLOR_MASK_COLOR
+                     PNG_COLOR_MASK_ALPHA
+
+    filter_method  - (must be PNG_FILTER_TYPE_BASE
+                     for PNG 1.0, and can also be
+                     PNG_INTRAPIXEL_DIFFERENCING if
+                     the PNG datastream is embedded in
+                     a MNG-1.0 datastream)
+    compression_type - (must be PNG_COMPRESSION_TYPE_BASE
+                     for PNG 1.0)
+    interlace_type - (PNG_INTERLACE_NONE or
+                     PNG_INTERLACE_ADAM7)
+    Any or all of interlace_type, compression_type, of
+    filter_method can be NULL if you are
+    not interested in their values.
+
+    channels = png_get_channels(png_ptr, info_ptr);
+    channels       - number of channels of info for the
+                     color type (valid values are 1 (GRAY,
+                     PALETTE), 2 (GRAY_ALPHA), 3 (RGB),
+                     4 (RGB_ALPHA or RGB + filler byte))
+    rowbytes = png_get_rowbytes(png_ptr, info_ptr);
+    rowbytes       - number of bytes needed to hold a row
+
+    signature = png_get_signature(png_ptr, info_ptr);
+    signature      - holds the signature read from the
+                     file (if any).  The data is kept in
+                     the same offset it would be if the
+                     whole signature were read (i.e. if an
+                     application had already read in 4
+                     bytes of signature before starting
+                     libpng, the remaining 4 bytes would
+                     be in signature[4] through signature[7]
+                     (see png_set_sig_bytes())).
+
+
+    width            = png_get_image_width(png_ptr,
+                         info_ptr);
+    height           = png_get_image_height(png_ptr,
+                         info_ptr);
+    bit_depth        = png_get_bit_depth(png_ptr,
+                         info_ptr);
+    color_type       = png_get_color_type(png_ptr,
+                         info_ptr);
+    filter_method    = png_get_filter_type(png_ptr,
+                         info_ptr);
+    compression_type = png_get_compression_type(png_ptr,
+                         info_ptr);
+    interlace_type   = png_get_interlace_type(png_ptr,
+                         info_ptr);
+
+
+These are also important, but their validity depends on whether the chunk
+has been read.  The png_get_valid(png_ptr, info_ptr, PNG_INFO_<chunk>) and
+png_get_<chunk>(png_ptr, info_ptr, ...) functions return non-zero if the
+data has been read, or zero if it is missing.  The parameters to the
+png_get_<chunk> are set directly if they are simple data types, or a pointer
+into the info_ptr is returned for any complex types.
+
+    png_get_PLTE(png_ptr, info_ptr, &palette,
+                     &num_palette);
+    palette        - the palette for the file
+                     (array of png_color)
+    num_palette    - number of entries in the palette
+
+    png_get_gAMA(png_ptr, info_ptr, &gamma);
+    gamma          - the gamma the file is written
+                     at (PNG_INFO_gAMA)
+
+    png_get_sRGB(png_ptr, info_ptr, &srgb_intent);
+    srgb_intent    - the rendering intent (PNG_INFO_sRGB)
+                     The presence of the sRGB chunk
+                     means that the pixel data is in the
+                     sRGB color space.  This chunk also
+                     implies specific values of gAMA and
+                     cHRM.
+
+    png_get_iCCP(png_ptr, info_ptr, &name,
+       &compression_type, &profile, &proflen);
+    name            - The profile name.
+    compression     - The compression type; always
+                      PNG_COMPRESSION_TYPE_BASE for PNG 1.0.
+                      You may give NULL to this argument to
+                      ignore it.
+    profile         - International Color Consortium color
+                      profile data. May contain NULs.
+    proflen         - length of profile data in bytes.
+
+    png_get_sBIT(png_ptr, info_ptr, &sig_bit);
+    sig_bit        - the number of significant bits for
+                     (PNG_INFO_sBIT) each of the gray,
+                     red, green, and blue channels,
+                     whichever are appropriate for the
+                     given color type (png_color_16)
+
+    png_get_tRNS(png_ptr, info_ptr, &trans, &num_trans,
+                     &trans_values);
+    trans          - array of transparent entries for
+                     palette (PNG_INFO_tRNS)
+    trans_values   - graylevel or color sample values of
+                     the single transparent color for
+                     non-paletted images (PNG_INFO_tRNS)
+    num_trans      - number of transparent entries
+                     (PNG_INFO_tRNS)
+
+    png_get_hIST(png_ptr, info_ptr, &hist);
+                     (PNG_INFO_hIST)
+    hist           - histogram of palette (array of
+                     png_uint_16)
+
+    png_get_tIME(png_ptr, info_ptr, &mod_time);
+    mod_time       - time image was last modified
+                    (PNG_VALID_tIME)
+
+    png_get_bKGD(png_ptr, info_ptr, &background);
+    background     - background color (PNG_VALID_bKGD)
+                     valid 16-bit red, green and blue
+                     values, regardless of color_type
+
+    num_comments   = png_get_text(png_ptr, info_ptr,
+                     &text_ptr, &num_text);
+    num_comments   - number of comments
+    text_ptr       - array of png_text holding image
+                     comments
+    text_ptr[i].compression - type of compression used
+                 on "text" PNG_TEXT_COMPRESSION_NONE
+                           PNG_TEXT_COMPRESSION_zTXt
+                           PNG_ITXT_COMPRESSION_NONE
+                           PNG_ITXT_COMPRESSION_zTXt
+    text_ptr[i].key   - keyword for comment.  Must contain
+                         1-79 characters.
+    text_ptr[i].text  - text comments for current
+                         keyword.  Can be empty.
+    text_ptr[i].text_length - length of text string,
+                 after decompression, 0 for iTXt
+    text_ptr[i].itxt_length - length of itxt string,
+                 after decompression, 0 for tEXt/zTXt
+    text_ptr[i].lang  - language of comment (empty
+                         string for unknown).
+    text_ptr[i].lang_key  - keyword in UTF-8
+                         (empty string for unknown).
+    num_text       - number of comments (same as
+                     num_comments; you can put NULL here
+                     to avoid the duplication)
+    Note while png_set_text() will accept text, language,
+    and translated keywords that can be NULL pointers, the
+    structure returned by png_get_text will always contain
+    regular zero-terminated C strings.  They might be
+    empty strings but they will never be NULL pointers.
+
+    num_spalettes = png_get_sPLT(png_ptr, info_ptr,
+       &palette_ptr);
+    palette_ptr    - array of palette structures holding
+                     contents of one or more sPLT chunks
+                     read.
+    num_spalettes  - number of sPLT chunks read.
+
+    png_get_oFFs(png_ptr, info_ptr, &offset_x, &offset_y,
+       &unit_type);
+    offset_x       - positive offset from the left edge
+                     of the screen
+    offset_y       - positive offset from the top edge
+                     of the screen
+    unit_type      - PNG_OFFSET_PIXEL, PNG_OFFSET_MICROMETER
+
+    png_get_pHYs(png_ptr, info_ptr, &res_x, &res_y,
+       &unit_type);
+    res_x          - pixels/unit physical resolution in
+                     x direction
+    res_y          - pixels/unit physical resolution in
+                     x direction
+    unit_type      - PNG_RESOLUTION_UNKNOWN,
+                     PNG_RESOLUTION_METER
+
+    png_get_sCAL(png_ptr, info_ptr, &unit, &width,
+       &height)
+    unit        - physical scale units (an integer)
+    width       - width of a pixel in physical scale units
+    height      - height of a pixel in physical scale units
+                 (width and height are doubles)
+
+    png_get_sCAL_s(png_ptr, info_ptr, &unit, &width,
+       &height)
+    unit        - physical scale units (an integer)
+    width       - width of a pixel in physical scale units
+    height      - height of a pixel in physical scale units
+                 (width and height are strings like "2.54")
+
+    num_unknown_chunks = png_get_unknown_chunks(png_ptr,
+       info_ptr, &unknowns)
+    unknowns          - array of png_unknown_chunk
+                        structures holding unknown chunks
+    unknowns[i].name  - name of unknown chunk
+    unknowns[i].data  - data of unknown chunk
+    unknowns[i].size  - size of unknown chunk's data
+    unknowns[i].location - position of chunk in file
+
+    The value of "i" corresponds to the order in which the
+    chunks were read from the PNG file or inserted with the
+    png_set_unknown_chunks() function.
+
+The data from the pHYs chunk can be retrieved in several convenient
+forms:
+
+    res_x = png_get_x_pixels_per_meter(png_ptr,
+       info_ptr)
+    res_y = png_get_y_pixels_per_meter(png_ptr,
+       info_ptr)
+    res_x_and_y = png_get_pixels_per_meter(png_ptr,
+       info_ptr)
+    res_x = png_get_x_pixels_per_inch(png_ptr,
+       info_ptr)
+    res_y = png_get_y_pixels_per_inch(png_ptr,
+       info_ptr)
+    res_x_and_y = png_get_pixels_per_inch(png_ptr,
+       info_ptr)
+    aspect_ratio = png_get_pixel_aspect_ratio(png_ptr,
+       info_ptr)
+
+   (Each of these returns 0 [signifying "unknown"] if
+       the data is not present or if res_x is 0;
+       res_x_and_y is 0 if res_x != res_y)
+
+The data from the oFFs chunk can be retrieved in several convenient
+forms:
+
+    x_offset = png_get_x_offset_microns(png_ptr, info_ptr);
+    y_offset = png_get_y_offset_microns(png_ptr, info_ptr);
+    x_offset = png_get_x_offset_inches(png_ptr, info_ptr);
+    y_offset = png_get_y_offset_inches(png_ptr, info_ptr);
+
+   (Each of these returns 0 [signifying "unknown" if both
+       x and y are 0] if the data is not present or if the
+       chunk is present but the unit is the pixel)
+
+For more information, see the png_info definition in png.h and the
+PNG specification for chunk contents.  Be careful with trusting
+rowbytes, as some of the transformations could increase the space
+needed to hold a row (expand, filler, gray_to_rgb, etc.).
+See png_read_update_info(), below.
+
+A quick word about text_ptr and num_text.  PNG stores comments in
+keyword/text pairs, one pair per chunk, with no limit on the number
+of text chunks, and a 2^31 byte limit on their size.  While there are
+suggested keywords, there is no requirement to restrict the use to these
+strings.  It is strongly suggested that keywords and text be sensible
+to humans (that's the point), so don't use abbreviations.  Non-printing
+symbols are not allowed.  See the PNG specification for more details.
+There is also no requirement to have text after the keyword.
+
+Keywords should be limited to 79 Latin-1 characters without leading or
+trailing spaces, but non-consecutive spaces are allowed within the
+keyword.  It is possible to have the same keyword any number of times.
+The text_ptr is an array of png_text structures, each holding a
+pointer to a language string, a pointer to a keyword and a pointer to
+a text string.  The text string, language code, and translated
+keyword may be empty or NULL pointers.  The keyword/text
+pairs are put into the array in the order that they are received.
+However, some or all of the text chunks may be after the image, so, to
+make sure you have read all the text chunks, don't mess with these
+until after you read the stuff after the image.  This will be
+mentioned again below in the discussion that goes with png_read_end().
+
+.SS Input transformations
+
+After you've read the header information, you can set up the library
+to handle any special transformations of the image data.  The various
+ways to transform the data will be described in the order that they
+should occur.  This is important, as some of these change the color
+type and/or bit depth of the data, and some others only work on
+certain color types and bit depths.  Even though each transformation
+checks to see if it has data that it can do something with, you should
+make sure to only enable a transformation if it will be valid for the
+data.  For example, don't swap red and blue on grayscale data.
+
+The colors used for the background and transparency values should be
+supplied in the same format/depth as the current image data.  They
+are stored in the same format/depth as the image data in a bKGD or tRNS
+chunk, so this is what libpng expects for this data.  The colors are
+transformed to keep in sync with the image data when an application
+calls the png_read_update_info() routine (see below).
+
+Data will be decoded into the supplied row buffers packed into bytes
+unless the library has been told to transform it into another format.
+For example, 4 bit/pixel paletted or grayscale data will be returned
+2 pixels/byte with the leftmost pixel in the high-order bits of the
+byte, unless png_set_packing() is called.  8-bit RGB data will be stored
+in RGB RGB RGB format unless png_set_filler() or png_set_add_alpha()
+is called to insert filler bytes, either before or after each RGB triplet.
+16-bit RGB data will be returned RRGGBB RRGGBB, with the most significant
+byte of the color value first, unless png_set_strip_16() is called to
+transform it to regular RGB RGB triplets, or png_set_filler() or
+png_set_add alpha() is called to insert filler bytes, either before or
+after each RRGGBB triplet.  Similarly, 8-bit or 16-bit grayscale data can
+be modified with
+png_set_filler(), png_set_add_alpha(), or png_set_strip_16().
+
+The following code transforms grayscale images of less than 8 to 8 bits,
+changes paletted images to RGB, and adds a full alpha channel if there is
+transparency information in a tRNS chunk.  This is most useful on
+grayscale images with bit depths of 2 or 4 or if there is a multiple-image
+viewing application that wishes to treat all images in the same way.
+
+    if (color_type == PNG_COLOR_TYPE_PALETTE)
+        png_set_palette_to_rgb(png_ptr);
+
+    if (color_type == PNG_COLOR_TYPE_GRAY &&
+        bit_depth < 8) png_set_gray_1_2_4_to_8(png_ptr);
+
+    if (png_get_valid(png_ptr, info_ptr,
+        PNG_INFO_tRNS)) png_set_tRNS_to_alpha(png_ptr);
+
+These three functions are actually aliases for png_set_expand(), added
+in libpng version 1.0.4, with the function names expanded to improve code
+readability.  In some future version they may actually do different
+things.
+
+PNG can have files with 16 bits per channel.  If you only can handle
+8 bits per channel, this will strip the pixels down to 8 bit.
+
+    if (bit_depth == 16)
+        png_set_strip_16(png_ptr);
+
+If, for some reason, you don't need the alpha channel on an image,
+and you want to remove it rather than combining it with the background
+(but the image author certainly had in mind that you *would* combine
+it with the background, so that's what you should probably do):
+
+    if (color_type & PNG_COLOR_MASK_ALPHA)
+        png_set_strip_alpha(png_ptr);
+
+In PNG files, the alpha channel in an image
+is the level of opacity.  If you need the alpha channel in an image to
+be the level of transparency instead of opacity, you can invert the
+alpha channel (or the tRNS chunk data) after it's read, so that 0 is
+fully opaque and 255 (in 8-bit or paletted images) or 65535 (in 16-bit
+images) is fully transparent, with
+
+    png_set_invert_alpha(png_ptr);
+
+PNG files pack pixels of bit depths 1, 2, and 4 into bytes as small as
+they can, resulting in, for example, 8 pixels per byte for 1 bit
+files.  This code expands to 1 pixel per byte without changing the
+values of the pixels:
+
+    if (bit_depth < 8)
+        png_set_packing(png_ptr);
+
+PNG files have possible bit depths of 1, 2, 4, 8, and 16.  All pixels
+stored in a PNG image have been "scaled" or "shifted" up to the next
+higher possible bit depth (e.g. from 5 bits/sample in the range [0,31] to
+8 bits/sample in the range [0, 255]).  However, it is also possible to
+convert the PNG pixel data back to the original bit depth of the image.
+This call reduces the pixels back down to the original bit depth:
+
+    png_color_8p sig_bit;
+
+    if (png_get_sBIT(png_ptr, info_ptr, &sig_bit))
+        png_set_shift(png_ptr, sig_bit);
+
+PNG files store 3-color pixels in red, green, blue order.  This code
+changes the storage of the pixels to blue, green, red:
+
+    if (color_type == PNG_COLOR_TYPE_RGB ||
+        color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+        png_set_bgr(png_ptr);
+
+PNG files store RGB pixels packed into 3 or 6 bytes. This code expands them
+into 4 or 8 bytes for windowing systems that need them in this format:
+
+    if (color_type == PNG_COLOR_TYPE_RGB)
+        png_set_filler(png_ptr, filler, PNG_FILLER_BEFORE);
+
+where "filler" is the 8 or 16-bit number to fill with, and the location is
+either PNG_FILLER_BEFORE or PNG_FILLER_AFTER, depending upon whether
+you want the filler before the RGB or after.  This transformation
+does not affect images that already have full alpha channels.  To add an
+opaque alpha channel, use filler=0xff or 0xffff and PNG_FILLER_AFTER which
+will generate RGBA pixels.
+
+Note that png_set_filler() does not change the color type.  If you want
+to do that, you can add a true alpha channel with
+
+    if (color_type == PNG_COLOR_TYPE_RGB ||
+           color_type == PNG_COLOR_TYPE_GRAY)
+    png_set_add_alpha(png_ptr, filler, PNG_FILLER_AFTER);
+
+where "filler" contains the alpha value to assign to each pixel.
+This function was added in libpng-1.2.7.
+
+If you are reading an image with an alpha channel, and you need the
+data as ARGB instead of the normal PNG format RGBA:
+
+    if (color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+        png_set_swap_alpha(png_ptr);
+
+For some uses, you may want a grayscale image to be represented as
+RGB.  This code will do that conversion:
+
+    if (color_type == PNG_COLOR_TYPE_GRAY ||
+        color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+          png_set_gray_to_rgb(png_ptr);
+
+Conversely, you can convert an RGB or RGBA image to grayscale or grayscale
+with alpha.
+
+    if (color_type == PNG_COLOR_TYPE_RGB ||
+        color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+          png_set_rgb_to_gray_fixed(png_ptr, error_action,
+             int red_weight, int green_weight);
+
+    error_action = 1: silently do the conversion
+    error_action = 2: issue a warning if the original
+                      image has any pixel where
+                      red != green or red != blue
+    error_action = 3: issue an error and abort the
+                      conversion if the original
+                      image has any pixel where
+                      red != green or red != blue
+
+    red_weight:       weight of red component times 100000
+    green_weight:     weight of green component times 100000
+                      If either weight is negative, default
+                      weights (21268, 71514) are used.
+
+If you have set error_action = 1 or 2, you can
+later check whether the image really was gray, after processing
+the image rows, with the png_get_rgb_to_gray_status(png_ptr) function.
+It will return a png_byte that is zero if the image was gray or
+1 if there were any non-gray pixels.  bKGD and sBIT data
+will be silently converted to grayscale, using the green channel
+data, regardless of the error_action setting.
+
+With red_weight+green_weight<=100000,
+the normalized graylevel is computed:
+
+    int rw = red_weight * 65536;
+    int gw = green_weight * 65536;
+    int bw = 65536 - (rw + gw);
+    gray = (rw*red + gw*green + bw*blue)/65536;
+
+The default values approximate those recommended in the Charles
+Poynton's Color FAQ, <http://www.inforamp.net/~poynton/>
+Copyright (c) 1998-01-04 Charles Poynton <poynton at inforamp.net>
+
+    Y = 0.212671 * R + 0.715160 * G + 0.072169 * B
+
+Libpng approximates this with
+
+    Y = 0.21268 * R    + 0.7151 * G    + 0.07217 * B
+
+which can be expressed with integers as
+
+    Y = (6969 * R + 23434 * G + 2365 * B)/32768
+
+The calculation is done in a linear colorspace, if the image gamma
+is known.
+
+If you have a grayscale and you are using png_set_expand_depth(),
+png_set_expand(), or png_set_gray_to_rgb to change to truecolor or to
+a higher bit-depth, you must either supply the background color as a gray
+value at the original file bit-depth (need_expand = 1) or else supply the
+background color as an RGB triplet at the final, expanded bit depth
+(need_expand = 0).  Similarly, if you are reading a paletted image, you
+must either supply the background color as a palette index (need_expand = 1)
+or as an RGB triplet that may or may not be in the palette (need_expand = 0).
+
+    png_color_16 my_background;
+    png_color_16p image_background;
+
+    if (png_get_bKGD(png_ptr, info_ptr, &image_background))
+        png_set_background(png_ptr, image_background,
+          PNG_BACKGROUND_GAMMA_FILE, 1, 1.0);
+    else
+        png_set_background(png_ptr, &my_background,
+          PNG_BACKGROUND_GAMMA_SCREEN, 0, 1.0);
+
+The png_set_background() function tells libpng to composite images
+with alpha or simple transparency against the supplied background
+color.  If the PNG file contains a bKGD chunk (PNG_INFO_bKGD valid),
+you may use this color, or supply another color more suitable for
+the current display (e.g., the background color from a web page).  You
+need to tell libpng whether the color is in the gamma space of the
+display (PNG_BACKGROUND_GAMMA_SCREEN for colors you supply), the file
+(PNG_BACKGROUND_GAMMA_FILE for colors from the bKGD chunk), or one
+that is neither of these gammas (PNG_BACKGROUND_GAMMA_UNIQUE - I don't
+know why anyone would use this, but it's here).
+
+To properly display PNG images on any kind of system, the application needs
+to know what the display gamma is.  Ideally, the user will know this, and
+the application will allow them to set it.  One method of allowing the user
+to set the display gamma separately for each system is to check for a
+SCREEN_GAMMA or DISPLAY_GAMMA environment variable, which will hopefully be
+correctly set.
+
+Note that display_gamma is the overall gamma correction required to produce
+pleasing results, which depends on the lighting conditions in the surrounding
+environment.  In a dim or brightly lit room, no compensation other than
+the physical gamma exponent of the monitor is needed, while in a dark room
+a slightly smaller exponent is better.
+
+   double gamma, screen_gamma;
+
+   if (/* We have a user-defined screen
+       gamma value */)
+   {
+      screen_gamma = user_defined_screen_gamma;
+   }
+   /* One way that applications can share the same
+      screen gamma value */
+   else if ((gamma_str = getenv("SCREEN_GAMMA"))
+      != NULL)
+   {
+      screen_gamma = (double)atof(gamma_str);
+   }
+   /* If we don't have another value */
+   else
+   {
+      screen_gamma = 2.2; /* A good guess for a
+           PC monitor in a bright office or a dim room */
+      screen_gamma = 2.0; /* A good guess for a
+           PC monitor in a dark room */
+      screen_gamma = 1.7 or 1.0;  /* A good
+           guess for Mac systems */
+   }
+
+The png_set_gamma() function handles gamma transformations of the data.
+Pass both the file gamma and the current screen_gamma.  If the file does
+not have a gamma value, you can pass one anyway if you have an idea what
+it is (usually 0.45455 is a good guess for GIF images on PCs).  Note
+that file gammas are inverted from screen gammas.  See the discussions
+on gamma in the PNG specification for an excellent description of what
+gamma is, and why all applications should support it.  It is strongly
+recommended that PNG viewers support gamma correction.
+
+   if (png_get_gAMA(png_ptr, info_ptr, &gamma))
+      png_set_gamma(png_ptr, screen_gamma, gamma);
+   else
+      png_set_gamma(png_ptr, screen_gamma, 0.45455);
+
+If you need to reduce an RGB file to a paletted file, or if a paletted
+file has more entries then will fit on your screen, png_set_dither()
+will do that.  Note that this is a simple match dither that merely
+finds the closest color available.  This should work fairly well with
+optimized palettes, and fairly badly with linear color cubes.  If you
+pass a palette that is larger then maximum_colors, the file will
+reduce the number of colors in the palette so it will fit into
+maximum_colors.  If there is a histogram, it will use it to make
+more intelligent choices when reducing the palette.  If there is no
+histogram, it may not do as good a job.
+
+   if (color_type & PNG_COLOR_MASK_COLOR)
+   {
+      if (png_get_valid(png_ptr, info_ptr,
+         PNG_INFO_PLTE))
+      {
+         png_uint_16p histogram = NULL;
+
+         png_get_hIST(png_ptr, info_ptr,
+            &histogram);
+         png_set_dither(png_ptr, palette, num_palette,
+            max_screen_colors, histogram, 1);
+      }
+      else
+      {
+         png_color std_color_cube[MAX_SCREEN_COLORS] =
+            { ... colors ... };
+
+         png_set_dither(png_ptr, std_color_cube,
+            MAX_SCREEN_COLORS, MAX_SCREEN_COLORS,
+            NULL,0);
+      }
+   }
+
+PNG files describe monochrome as black being zero and white being one.
+The following code will reverse this (make black be one and white be
+zero):
+
+   if (bit_depth == 1 && color_type == PNG_COLOR_TYPE_GRAY)
+      png_set_invert_mono(png_ptr);
+
+This function can also be used to invert grayscale and gray-alpha images:
+
+   if (color_type == PNG_COLOR_TYPE_GRAY ||
+        color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+      png_set_invert_mono(png_ptr);
+
+PNG files store 16 bit pixels in network byte order (big-endian,
+ie. most significant bits first).  This code changes the storage to the
+other way (little-endian, i.e. least significant bits first, the
+way PCs store them):
+
+    if (bit_depth == 16)
+        png_set_swap(png_ptr);
+
+If you are using packed-pixel images (1, 2, or 4 bits/pixel), and you
+need to change the order the pixels are packed into bytes, you can use:
+
+    if (bit_depth < 8)
+       png_set_packswap(png_ptr);
+
+Finally, you can write your own transformation function if none of
+the existing ones meets your needs.  This is done by setting a callback
+with
+
+    png_set_read_user_transform_fn(png_ptr,
+       read_transform_fn);
+
+You must supply the function
+
+    void read_transform_fn(png_ptr ptr, row_info_ptr
+       row_info, png_bytep data)
+
+See pngtest.c for a working example.  Your function will be called
+after all of the other transformations have been processed.
+
+You can also set up a pointer to a user structure for use by your
+callback function, and you can inform libpng that your transform
+function will change the number of channels or bit depth with the
+function
+
+    png_set_user_transform_info(png_ptr, user_ptr,
+       user_depth, user_channels);
+
+The user's application, not libpng, is responsible for allocating and
+freeing any memory required for the user structure.
+
+You can retrieve the pointer via the function
+png_get_user_transform_ptr().  For example:
+
+    voidp read_user_transform_ptr =
+       png_get_user_transform_ptr(png_ptr);
+
+The last thing to handle is interlacing; this is covered in detail below,
+but you must call the function here if you want libpng to handle expansion
+of the interlaced image.
+
+    number_of_passes = png_set_interlace_handling(png_ptr);
+
+After setting the transformations, libpng can update your png_info
+structure to reflect any transformations you've requested with this
+call.  This is most useful to update the info structure's rowbytes
+field so you can use it to allocate your image memory.  This function
+will also update your palette with the correct screen_gamma and
+background if these have been given with the calls above.
+
+    png_read_update_info(png_ptr, info_ptr);
+
+After you call png_read_update_info(), you can allocate any
+memory you need to hold the image.  The row data is simply
+raw byte data for all forms of images.  As the actual allocation
+varies among applications, no example will be given.  If you
+are allocating one large chunk, you will need to build an
+array of pointers to each row, as it will be needed for some
+of the functions below.
+
+.SS Reading image data
+
+After you've allocated memory, you can read the image data.
+The simplest way to do this is in one function call.  If you are
+allocating enough memory to hold the whole image, you can just
+call png_read_image() and libpng will read in all the image data
+and put it in the memory area supplied.  You will need to pass in
+an array of pointers to each row.
+
+This function automatically handles interlacing, so you don't need
+to call png_set_interlace_handling() or call this function multiple
+times, or any of that other stuff necessary with png_read_rows().
+
+   png_read_image(png_ptr, row_pointers);
+
+where row_pointers is:
+
+   png_bytep row_pointers[height];
+
+You can point to void or char or whatever you use for pixels.
+
+If you don't want to read in the whole image at once, you can
+use png_read_rows() instead.  If there is no interlacing (check
+interlace_type == PNG_INTERLACE_NONE), this is simple:
+
+    png_read_rows(png_ptr, row_pointers, NULL,
+       number_of_rows);
+
+where row_pointers is the same as in the png_read_image() call.
+
+If you are doing this just one row at a time, you can do this with
+a single row_pointer instead of an array of row_pointers:
+
+    png_bytep row_pointer = row;
+    png_read_row(png_ptr, row_pointer, NULL);
+
+If the file is interlaced (interlace_type != 0 in the IHDR chunk), things
+get somewhat harder.  The only current (PNG Specification version 1.2)
+interlacing type for PNG is (interlace_type == PNG_INTERLACE_ADAM7)
+is a somewhat complicated 2D interlace scheme, known as Adam7, that
+breaks down an image into seven smaller images of varying size, based
+on an 8x8 grid.
+
+libpng can fill out those images or it can give them to you "as is".
+If you want them filled out, there are two ways to do that.  The one
+mentioned in the PNG specification is to expand each pixel to cover
+those pixels that have not been read yet (the "rectangle" method).
+This results in a blocky image for the first pass, which gradually
+smooths out as more pixels are read.  The other method is the "sparkle"
+method, where pixels are drawn only in their final locations, with the
+rest of the image remaining whatever colors they were initialized to
+before the start of the read.  The first method usually looks better,
+but tends to be slower, as there are more pixels to put in the rows.
+
+If you don't want libpng to handle the interlacing details, just call
+png_read_rows() seven times to read in all seven images.  Each of the
+images is a valid image by itself, or they can all be combined on an
+8x8 grid to form a single image (although if you intend to combine them
+you would be far better off using the libpng interlace handling).
+
+The first pass will return an image 1/8 as wide as the entire image
+(every 8th column starting in column 0) and 1/8 as high as the original
+(every 8th row starting in row 0), the second will be 1/8 as wide
+(starting in column 4) and 1/8 as high (also starting in row 0).  The
+third pass will be 1/4 as wide (every 4th pixel starting in column 0) and
+1/8 as high (every 8th row starting in row 4), and the fourth pass will
+be 1/4 as wide and 1/4 as high (every 4th column starting in column 2,
+and every 4th row starting in row 0).  The fifth pass will return an
+image 1/2 as wide, and 1/4 as high (starting at column 0 and row 2),
+while the sixth pass will be 1/2 as wide and 1/2 as high as the original
+(starting in column 1 and row 0).  The seventh and final pass will be as
+wide as the original, and 1/2 as high, containing all of the odd
+numbered scanlines.  Phew!
+
+If you want libpng to expand the images, call this before calling
+png_start_read_image() or png_read_update_info():
+
+    if (interlace_type == PNG_INTERLACE_ADAM7)
+        number_of_passes
+           = png_set_interlace_handling(png_ptr);
+
+This will return the number of passes needed.  Currently, this
+is seven, but may change if another interlace type is added.
+This function can be called even if the file is not interlaced,
+where it will return one pass.
+
+If you are not going to display the image after each pass, but are
+going to wait until the entire image is read in, use the sparkle
+effect.  This effect is faster and the end result of either method
+is exactly the same.  If you are planning on displaying the image
+after each pass, the "rectangle" effect is generally considered the
+better looking one.
+
+If you only want the "sparkle" effect, just call png_read_rows() as
+normal, with the third parameter NULL.  Make sure you make pass over
+the image number_of_passes times, and you don't change the data in the
+rows between calls.  You can change the locations of the data, just
+not the data.  Each pass only writes the pixels appropriate for that
+pass, and assumes the data from previous passes is still valid.
+
+    png_read_rows(png_ptr, row_pointers, NULL,
+       number_of_rows);
+
+If you only want the first effect (the rectangles), do the same as
+before except pass the row buffer in the third parameter, and leave
+the second parameter NULL.
+
+    png_read_rows(png_ptr, NULL, row_pointers,
+       number_of_rows);
+
+.SS Finishing a sequential read
+
+After you are finished reading the image through either the high- or
+low-level interfaces, you can finish reading the file.  If you are
+interested in comments or time, which may be stored either before or
+after the image data, you should pass the separate png_info struct if
+you want to keep the comments from before and after the image
+separate.  If you are not interested, you can pass NULL.
+
+   png_read_end(png_ptr, end_info);
+
+When you are done, you can free all memory allocated by libpng like this:
+
+   png_destroy_read_struct(&png_ptr, &info_ptr,
+       &end_info);
+
+It is also possible to individually free the info_ptr members that
+point to libpng-allocated storage with the following function:
+
+    png_free_data(png_ptr, info_ptr, mask, seq)
+    mask - identifies data to be freed, a mask
+           containing the logical OR of one or
+           more of
+             PNG_FREE_PLTE, PNG_FREE_TRNS,
+             PNG_FREE_HIST, PNG_FREE_ICCP,
+             PNG_FREE_PCAL, PNG_FREE_ROWS,
+             PNG_FREE_SCAL, PNG_FREE_SPLT,
+             PNG_FREE_TEXT, PNG_FREE_UNKN,
+           or simply PNG_FREE_ALL
+    seq  - sequence number of item to be freed
+           (-1 for all items)
+
+This function may be safely called when the relevant storage has
+already been freed, or has not yet been allocated, or was allocated
+by the user and not by libpng,  and will in those
+cases do nothing.  The "seq" parameter is ignored if only one item
+of the selected data type, such as PLTE, is allowed.  If "seq" is not
+-1, and multiple items are allowed for the data type identified in
+the mask, such as text or sPLT, only the n'th item in the structure
+is freed, where n is "seq".
+
+The default behavior is only to free data that was allocated internally
+by libpng.  This can be changed, so that libpng will not free the data,
+or so that it will free data that was allocated by the user with png_malloc()
+or png_zalloc() and passed in via a png_set_*() function, with
+
+    png_data_freer(png_ptr, info_ptr, freer, mask)
+    mask   - which data elements are affected
+             same choices as in png_free_data()
+    freer  - one of
+               PNG_DESTROY_WILL_FREE_DATA
+               PNG_SET_WILL_FREE_DATA
+               PNG_USER_WILL_FREE_DATA
+
+This function only affects data that has already been allocated.
+You can call this function after reading the PNG data but before calling
+any png_set_*() functions, to control whether the user or the png_set_*()
+function is responsible for freeing any existing data that might be present,
+and again after the png_set_*() functions to control whether the user
+or png_destroy_*() is supposed to free the data.  When the user assumes
+responsibility for libpng-allocated data, the application must use
+png_free() to free it, and when the user transfers responsibility to libpng
+for data that the user has allocated, the user must have used png_malloc()
+or png_zalloc() to allocate it.
+
+If you allocated your row_pointers in a single block, as suggested above in
+the description of the high level read interface, you must not transfer
+responsibility for freeing it to the png_set_rows or png_read_destroy function,
+because they would also try to free the individual row_pointers[i].
+
+If you allocated text_ptr.text, text_ptr.lang, and text_ptr.translated_keyword
+separately, do not transfer responsibility for freeing text_ptr to libpng,
+because when libpng fills a png_text structure it combines these members with
+the key member, and png_free_data() will free only text_ptr.key.  Similarly,
+if you transfer responsibility for free'ing text_ptr from libpng to your
+application, your application must not separately free those members.
+
+The png_free_data() function will turn off the "valid" flag for anything
+it frees.  If you need to turn the flag off for a chunk that was freed by your
+application instead of by libpng, you can use
+
+    png_set_invalid(png_ptr, info_ptr, mask);
+    mask - identifies the chunks to be made invalid,
+           containing the logical OR of one or
+           more of
+             PNG_INFO_gAMA, PNG_INFO_sBIT,
+             PNG_INFO_cHRM, PNG_INFO_PLTE,
+             PNG_INFO_tRNS, PNG_INFO_bKGD,
+             PNG_INFO_hIST, PNG_INFO_pHYs,
+             PNG_INFO_oFFs, PNG_INFO_tIME,
+             PNG_INFO_pCAL, PNG_INFO_sRGB,
+             PNG_INFO_iCCP, PNG_INFO_sPLT,
+             PNG_INFO_sCAL, PNG_INFO_IDAT
+
+For a more compact example of reading a PNG image, see the file example.c.
+
+.SS Reading PNG files progressively
+
+The progressive reader is slightly different then the non-progressive
+reader.  Instead of calling png_read_info(), png_read_rows(), and
+png_read_end(), you make one call to png_process_data(), which calls
+callbacks when it has the info, a row, or the end of the image.  You
+set up these callbacks with png_set_progressive_read_fn().  You don't
+have to worry about the input/output functions of libpng, as you are
+giving the library the data directly in png_process_data().  I will
+assume that you have read the section on reading PNG files above,
+so I will only highlight the differences (although I will show
+all of the code).
+
+png_structp png_ptr;
+png_infop info_ptr;
+
+ /*  An example code fragment of how you would
+     initialize the progressive reader in your
+     application. */
+ int
+ initialize_png_reader()
+ {
+    png_ptr = png_create_read_struct
+        (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr,
+         user_error_fn, user_warning_fn);
+    if (!png_ptr)
+        return (ERROR);
+    info_ptr = png_create_info_struct(png_ptr);
+    if (!info_ptr)
+    {
+        png_destroy_read_struct(&png_ptr, (png_infopp)NULL,
+           (png_infopp)NULL);
+        return (ERROR);
+    }
+
+    if (setjmp(png_jmpbuf(png_ptr)))
+    {
+        png_destroy_read_struct(&png_ptr, &info_ptr,
+           (png_infopp)NULL);
+        return (ERROR);
+    }
+
+    /* This one's new.  You can provide functions
+       to be called when the header info is valid,
+       when each row is completed, and when the image
+       is finished.  If you aren't using all functions,
+       you can specify NULL parameters.  Even when all
+       three functions are NULL, you need to call
+       png_set_progressive_read_fn().  You can use
+       any struct as the user_ptr (cast to a void pointer
+       for the function call), and retrieve the pointer
+       from inside the callbacks using the function
+
+          png_get_progressive_ptr(png_ptr);
+
+       which will return a void pointer, which you have
+       to cast appropriately.
+     */
+    png_set_progressive_read_fn(png_ptr, (void *)user_ptr,
+        info_callback, row_callback, end_callback);
+
+    return 0;
+ }
+
+ /* A code fragment that you call as you receive blocks
+   of data */
+ int
+ process_data(png_bytep buffer, png_uint_32 length)
+ {
+    if (setjmp(png_jmpbuf(png_ptr)))
+    {
+        png_destroy_read_struct(&png_ptr, &info_ptr,
+           (png_infopp)NULL);
+        return (ERROR);
+    }
+
+    /* This one's new also.  Simply give it a chunk
+       of data from the file stream (in order, of
+       course).  On machines with segmented memory
+       models machines, don't give it any more than
+       64K.  The library seems to run fine with sizes
+       of 4K. Although you can give it much less if
+       necessary (I assume you can give it chunks of
+       1 byte, I haven't tried less then 256 bytes
+       yet).  When this function returns, you may
+       want to display any rows that were generated
+       in the row callback if you don't already do
+       so there.
+     */
+    png_process_data(png_ptr, info_ptr, buffer, length);
+    return 0;
+ }
+
+ /* This function is called (as set by
+    png_set_progressive_read_fn() above) when enough data
+    has been supplied so all of the header has been
+    read.
+ */
+ void
+ info_callback(png_structp png_ptr, png_infop info)
+ {
+    /* Do any setup here, including setting any of
+       the transformations mentioned in the Reading
+       PNG files section.  For now, you _must_ call
+       either png_start_read_image() or
+       png_read_update_info() after all the
+       transformations are set (even if you don't set
+       any).  You may start getting rows before
+       png_process_data() returns, so this is your
+       last chance to prepare for that.
+     */
+ }
+
+ /* This function is called when each row of image
+    data is complete */
+ void
+ row_callback(png_structp png_ptr, png_bytep new_row,
+    png_uint_32 row_num, int pass)
+ {
+    /* If the image is interlaced, and you turned
+       on the interlace handler, this function will
+       be called for every row in every pass.  Some
+       of these rows will not be changed from the
+       previous pass.  When the row is not changed,
+       the new_row variable will be NULL.  The rows
+       and passes are called in order, so you don't
+       really need the row_num and pass, but I'm
+       supplying them because it may make your life
+       easier.
+
+       For the non-NULL rows of interlaced images,
+       you must call png_progressive_combine_row()
+       passing in the row and the old row.  You can
+       call this function for NULL rows (it will just
+       return) and for non-interlaced images (it just
+       does the memcpy for you) if it will make the
+       code easier.  Thus, you can just do this for
+       all cases:
+     */
+
+        png_progressive_combine_row(png_ptr, old_row,
+          new_row);
+
+    /* where old_row is what was displayed for
+       previously for the row.  Note that the first
+       pass (pass == 0, really) will completely cover
+       the old row, so the rows do not have to be
+       initialized.  After the first pass (and only
+       for interlaced images), you will have to pass
+       the current row, and the function will combine
+       the old row and the new row.
+    */
+ }
+
+ void
+ end_callback(png_structp png_ptr, png_infop info)
+ {
+    /* This function is called after the whole image
+       has been read, including any chunks after the
+       image (up to and including the IEND).  You
+       will usually have the same info chunk as you
+       had in the header, although some data may have
+       been added to the comments and time fields.
+
+       Most people won't do much here, perhaps setting
+       a flag that marks the image as finished.
+     */
+ }
+
+
+
+.SH IV. Writing
+
+Much of this is very similar to reading.  However, everything of
+importance is repeated here, so you won't have to constantly look
+back up in the reading section to understand writing.
+
+.SS Setup
+
+You will want to do the I/O initialization before you get into libpng,
+so if it doesn't work, you don't have anything to undo. If you are not
+using the standard I/O functions, you will need to replace them with
+custom writing functions.  See the discussion under Customizing libpng.
+
+    FILE *fp = fopen(file_name, "wb");
+    if (!fp)
+    {
+       return (ERROR);
+    }
+
+Next, png_struct and png_info need to be allocated and initialized.
+As these can be both relatively large, you may not want to store these
+on the stack, unless you have stack space to spare.  Of course, you
+will want to check if they return NULL.  If you are also reading,
+you won't want to name your read structure and your write structure
+both "png_ptr"; you can call them anything you like, such as
+"read_ptr" and "write_ptr".  Look at pngtest.c, for example.
+
+    png_structp png_ptr = png_create_write_struct
+       (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr,
+        user_error_fn, user_warning_fn);
+    if (!png_ptr)
+       return (ERROR);
+
+    png_infop info_ptr = png_create_info_struct(png_ptr);
+    if (!info_ptr)
+    {
+       png_destroy_write_struct(&png_ptr,
+         (png_infopp)NULL);
+       return (ERROR);
+    }
+
+If you want to use your own memory allocation routines,
+define PNG_USER_MEM_SUPPORTED and use
+png_create_write_struct_2() instead of png_create_write_struct():
+
+    png_structp png_ptr = png_create_write_struct_2
+       (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr,
+        user_error_fn, user_warning_fn, (png_voidp)
+        user_mem_ptr, user_malloc_fn, user_free_fn);
+
+After you have these structures, you will need to set up the
+error handling.  When libpng encounters an error, it expects to
+longjmp() back to your routine.  Therefore, you will need to call
+setjmp() and pass the png_jmpbuf(png_ptr).  If you
+write the file from different routines, you will need to update
+the png_jmpbuf(png_ptr) every time you enter a new routine that will
+call a png_*() function.  See your documentation of setjmp/longjmp
+for your compiler for more information on setjmp/longjmp.  See
+the discussion on libpng error handling in the Customizing Libpng
+section below for more information on the libpng error handling.
+
+    if (setjmp(png_jmpbuf(png_ptr)))
+    {
+       png_destroy_write_struct(&png_ptr, &info_ptr);
+       fclose(fp);
+       return (ERROR);
+    }
+    ...
+    return;
+
+If you would rather avoid the complexity of setjmp/longjmp issues,
+you can compile libpng with PNG_SETJMP_NOT_SUPPORTED, in which case
+errors will result in a call to PNG_ABORT() which defaults to abort().
+
+Now you need to set up the output code.  The default for libpng is to
+use the C function fwrite().  If you use this, you will need to pass a
+valid FILE * in the function png_init_io().  Be sure that the file is
+opened in binary mode.  Again, if you wish to handle writing data in
+another way, see the discussion on libpng I/O handling in the Customizing
+Libpng section below.
+
+    png_init_io(png_ptr, fp);
+
+.SS Write callbacks
+
+At this point, you can set up a callback function that will be
+called after each row has been written, which you can use to control
+a progress meter or the like.  It's demonstrated in pngtest.c.
+You must supply a function
+
+    void write_row_callback(png_ptr, png_uint_32 row,
+       int pass);
+    {
+      /* put your code here */
+    }
+
+(You can give it another name that you like instead of "write_row_callback")
+
+To inform libpng about your function, use
+
+    png_set_write_status_fn(png_ptr, write_row_callback);
+
+You now have the option of modifying how the compression library will
+run.  The following functions are mainly for testing, but may be useful
+in some cases, like if you need to write PNG files extremely fast and
+are willing to give up some compression, or if you want to get the
+maximum possible compression at the expense of slower writing.  If you
+have no special needs in this area, let the library do what it wants by
+not calling this function at all, as it has been tuned to deliver a good
+speed/compression ratio. The second parameter to png_set_filter() is
+the filter method, for which the only valid values are 0 (as of the
+July 1999 PNG specification, version 1.2) or 64 (if you are writing
+a PNG datastream that is to be embedded in a MNG datastream).  The third
+parameter is a flag that indicates which filter type(s) are to be tested
+for each scanline.  See the PNG specification for details on the specific filter
+types.
+
+
+    /* turn on or off filtering, and/or choose
+       specific filters.  You can use either a single
+       PNG_FILTER_VALUE_NAME or the logical OR of one
+       or more PNG_FILTER_NAME masks. */
+    png_set_filter(png_ptr, 0,
+       PNG_FILTER_NONE  | PNG_FILTER_VALUE_NONE |
+       PNG_FILTER_SUB   | PNG_FILTER_VALUE_SUB  |
+       PNG_FILTER_UP    | PNG_FILTER_VALUE_UP   |
+       PNG_FILTER_AVE   | PNG_FILTER_VALUE_AVE  |
+       PNG_FILTER_PAETH | PNG_FILTER_VALUE_PAETH|
+       PNG_ALL_FILTERS);
+
+If an application
+wants to start and stop using particular filters during compression,
+it should start out with all of the filters (to ensure that the previous
+row of pixels will be stored in case it's needed later), and then add
+and remove them after the start of compression.
+
+If you are writing a PNG datastream that is to be embedded in a MNG
+datastream, the second parameter can be either 0 or 64.
+
+The png_set_compression_*() functions interface to the zlib compression
+library, and should mostly be ignored unless you really know what you are
+doing.  The only generally useful call is png_set_compression_level()
+which changes how much time zlib spends on trying to compress the image
+data.  See the Compression Library (zlib.h and algorithm.txt, distributed
+with zlib) for details on the compression levels.
+
+    /* set the zlib compression level */
+    png_set_compression_level(png_ptr,
+        Z_BEST_COMPRESSION);
+
+    /* set other zlib parameters */
+    png_set_compression_mem_level(png_ptr, 8);
+    png_set_compression_strategy(png_ptr,
+        Z_DEFAULT_STRATEGY);
+    png_set_compression_window_bits(png_ptr, 15);
+    png_set_compression_method(png_ptr, 8);
+    png_set_compression_buffer_size(png_ptr, 8192)
+
+extern PNG_EXPORT(void,png_set_zbuf_size)
+
+.SS Setting the contents of info for output
+
+You now need to fill in the png_info structure with all the data you
+wish to write before the actual image.  Note that the only thing you
+are allowed to write after the image is the text chunks and the time
+chunk (as of PNG Specification 1.2, anyway).  See png_write_end() and
+the latest PNG specification for more information on that.  If you
+wish to write them before the image, fill them in now, and flag that
+data as being valid.  If you want to wait until after the data, don't
+fill them until png_write_end().  For all the fields in png_info and
+their data types, see png.h.  For explanations of what the fields
+contain, see the PNG specification.
+
+Some of the more important parts of the png_info are:
+
+    png_set_IHDR(png_ptr, info_ptr, width, height,
+       bit_depth, color_type, interlace_type,
+       compression_type, filter_method)
+    width          - holds the width of the image
+                     in pixels (up to 2^31).
+    height         - holds the height of the image
+                     in pixels (up to 2^31).
+    bit_depth      - holds the bit depth of one of the
+                     image channels.
+                     (valid values are 1, 2, 4, 8, 16
+                     and depend also on the
+                     color_type.  See also significant
+                     bits (sBIT) below).
+    color_type     - describes which color/alpha
+                     channels are present.
+                     PNG_COLOR_TYPE_GRAY
+                        (bit depths 1, 2, 4, 8, 16)
+                     PNG_COLOR_TYPE_GRAY_ALPHA
+                        (bit depths 8, 16)
+                     PNG_COLOR_TYPE_PALETTE
+                        (bit depths 1, 2, 4, 8)
+                     PNG_COLOR_TYPE_RGB
+                        (bit_depths 8, 16)
+                     PNG_COLOR_TYPE_RGB_ALPHA
+                        (bit_depths 8, 16)
+
+                     PNG_COLOR_MASK_PALETTE
+                     PNG_COLOR_MASK_COLOR
+                     PNG_COLOR_MASK_ALPHA
+
+    interlace_type - PNG_INTERLACE_NONE or
+                     PNG_INTERLACE_ADAM7
+    compression_type - (must be
+                     PNG_COMPRESSION_TYPE_DEFAULT)
+    filter_method  - (must be PNG_FILTER_TYPE_DEFAULT
+                     or, if you are writing a PNG to
+                     be embedded in a MNG datastream,
+                     can also be
+                     PNG_INTRAPIXEL_DIFFERENCING)
+
+    png_set_PLTE(png_ptr, info_ptr, palette,
+       num_palette);
+    palette        - the palette for the file
+                     (array of png_color)
+    num_palette    - number of entries in the palette
+
+    png_set_gAMA(png_ptr, info_ptr, gamma);
+    gamma          - the gamma the image was created
+                     at (PNG_INFO_gAMA)
+
+    png_set_sRGB(png_ptr, info_ptr, srgb_intent);
+    srgb_intent    - the rendering intent
+                     (PNG_INFO_sRGB) The presence of
+                     the sRGB chunk means that the pixel
+                     data is in the sRGB color space.
+                     This chunk also implies specific
+                     values of gAMA and cHRM.  Rendering
+                     intent is the CSS-1 property that
+                     has been defined by the International
+                     Color Consortium
+                     (http://www.color.org).
+                     It can be one of
+                     PNG_sRGB_INTENT_SATURATION,
+                     PNG_sRGB_INTENT_PERCEPTUAL,
+                     PNG_sRGB_INTENT_ABSOLUTE, or
+                     PNG_sRGB_INTENT_RELATIVE.
+
+
+    png_set_sRGB_gAMA_and_cHRM(png_ptr, info_ptr,
+       srgb_intent);
+    srgb_intent    - the rendering intent
+                     (PNG_INFO_sRGB) The presence of the
+                     sRGB chunk means that the pixel
+                     data is in the sRGB color space.
+                     This function also causes gAMA and
+                     cHRM chunks with the specific values
+                     that are consistent with sRGB to be
+                     written.
+
+    png_set_iCCP(png_ptr, info_ptr, name, compression_type,
+                      profile, proflen);
+    name            - The profile name.
+    compression     - The compression type; always
+                      PNG_COMPRESSION_TYPE_BASE for PNG 1.0.
+                      You may give NULL to this argument to
+                      ignore it.
+    profile         - International Color Consortium color
+                      profile data. May contain NULs.
+    proflen         - length of profile data in bytes.
+
+    png_set_sBIT(png_ptr, info_ptr, sig_bit);
+    sig_bit        - the number of significant bits for
+                     (PNG_INFO_sBIT) each of the gray, red,
+                     green, and blue channels, whichever are
+                     appropriate for the given color type
+                     (png_color_16)
+
+    png_set_tRNS(png_ptr, info_ptr, trans, num_trans,
+       trans_values);
+    trans          - array of transparent entries for
+                     palette (PNG_INFO_tRNS)
+    trans_values   - graylevel or color sample values of
+                     the single transparent color for
+                     non-paletted images (PNG_INFO_tRNS)
+    num_trans      - number of transparent entries
+                     (PNG_INFO_tRNS)
+
+    png_set_hIST(png_ptr, info_ptr, hist);
+                    (PNG_INFO_hIST)
+    hist           - histogram of palette (array of
+                     png_uint_16)
+
+    png_set_tIME(png_ptr, info_ptr, mod_time);
+    mod_time       - time image was last modified
+                     (PNG_VALID_tIME)
+
+    png_set_bKGD(png_ptr, info_ptr, background);
+    background     - background color (PNG_VALID_bKGD)
+
+    png_set_text(png_ptr, info_ptr, text_ptr, num_text);
+    text_ptr       - array of png_text holding image
+                     comments
+    text_ptr[i].compression - type of compression used
+                 on "text" PNG_TEXT_COMPRESSION_NONE
+                           PNG_TEXT_COMPRESSION_zTXt
+                           PNG_ITXT_COMPRESSION_NONE
+                           PNG_ITXT_COMPRESSION_zTXt
+    text_ptr[i].key   - keyword for comment.  Must contain
+                 1-79 characters.
+    text_ptr[i].text  - text comments for current
+                         keyword.  Can be NULL or empty.
+    text_ptr[i].text_length - length of text string,
+                 after decompression, 0 for iTXt
+    text_ptr[i].itxt_length - length of itxt string,
+                 after decompression, 0 for tEXt/zTXt
+    text_ptr[i].lang  - language of comment (NULL or
+                         empty for unknown).
+    text_ptr[i].translated_keyword  - keyword in UTF-8 (NULL
+                         or empty for unknown).
+    num_text       - number of comments
+
+    png_set_sPLT(png_ptr, info_ptr, &palette_ptr,
+       num_spalettes);
+    palette_ptr    - array of png_sPLT_struct structures
+                     to be added to the list of palettes
+                     in the info structure.
+    num_spalettes  - number of palette structures to be
+                     added.
+
+    png_set_oFFs(png_ptr, info_ptr, offset_x, offset_y,
+        unit_type);
+    offset_x  - positive offset from the left
+                     edge of the screen
+    offset_y  - positive offset from the top
+                     edge of the screen
+    unit_type - PNG_OFFSET_PIXEL, PNG_OFFSET_MICROMETER
+
+    png_set_pHYs(png_ptr, info_ptr, res_x, res_y,
+        unit_type);
+    res_x       - pixels/unit physical resolution
+                  in x direction
+    res_y       - pixels/unit physical resolution
+                  in y direction
+    unit_type   - PNG_RESOLUTION_UNKNOWN,
+                  PNG_RESOLUTION_METER
+
+    png_set_sCAL(png_ptr, info_ptr, unit, width, height)
+    unit        - physical scale units (an integer)
+    width       - width of a pixel in physical scale units
+    height      - height of a pixel in physical scale units
+                  (width and height are doubles)
+
+    png_set_sCAL_s(png_ptr, info_ptr, unit, width, height)
+    unit        - physical scale units (an integer)
+    width       - width of a pixel in physical scale units
+    height      - height of a pixel in physical scale units
+                 (width and height are strings like "2.54")
+
+    png_set_unknown_chunks(png_ptr, info_ptr, &unknowns,
+       num_unknowns)
+    unknowns          - array of png_unknown_chunk
+                        structures holding unknown chunks
+    unknowns[i].name  - name of unknown chunk
+    unknowns[i].data  - data of unknown chunk
+    unknowns[i].size  - size of unknown chunk's data
+    unknowns[i].location - position to write chunk in file
+                           0: do not write chunk
+                           PNG_HAVE_IHDR: before PLTE
+                           PNG_HAVE_PLTE: before IDAT
+                           PNG_AFTER_IDAT: after IDAT
+
+The "location" member is set automatically according to
+what part of the output file has already been written.
+You can change its value after calling png_set_unknown_chunks()
+as demonstrated in pngtest.c.  Within each of the "locations",
+the chunks are sequenced according to their position in the
+structure (that is, the value of "i", which is the order in which
+the chunk was either read from the input file or defined with
+png_set_unknown_chunks).
+
+A quick word about text and num_text.  text is an array of png_text
+structures.  num_text is the number of valid structures in the array.
+Each png_text structure holds a language code, a keyword, a text value,
+and a compression type.
+
+The compression types have the same valid numbers as the compression
+types of the image data.  Currently, the only valid number is zero.
+However, you can store text either compressed or uncompressed, unlike
+images, which always have to be compressed.  So if you don't want the
+text compressed, set the compression type to PNG_TEXT_COMPRESSION_NONE.
+Because tEXt and zTXt chunks don't have a language field, if you
+specify PNG_TEXT_COMPRESSION_NONE or PNG_TEXT_COMPRESSION_zTXt
+any language code or translated keyword will not be written out.
+
+Until text gets around 1000 bytes, it is not worth compressing it.
+After the text has been written out to the file, the compression type
+is set to PNG_TEXT_COMPRESSION_NONE_WR or PNG_TEXT_COMPRESSION_zTXt_WR,
+so that it isn't written out again at the end (in case you are calling
+png_write_end() with the same struct.
+
+The keywords that are given in the PNG Specification are:
+
+    Title            Short (one line) title or
+                     caption for image
+    Author           Name of image's creator
+    Description      Description of image (possibly long)
+    Copyright        Copyright notice
+    Creation Time    Time of original image creation
+                     (usually RFC 1123 format, see below)
+    Software         Software used to create the image
+    Disclaimer       Legal disclaimer
+    Warning          Warning of nature of content
+    Source           Device used to create the image
+    Comment          Miscellaneous comment; conversion
+                     from other image format
+
+The keyword-text pairs work like this.  Keywords should be short
+simple descriptions of what the comment is about.  Some typical
+keywords are found in the PNG specification, as is some recommendations
+on keywords.  You can repeat keywords in a file.  You can even write
+some text before the image and some after.  For example, you may want
+to put a description of the image before the image, but leave the
+disclaimer until after, so viewers working over modem connections
+don't have to wait for the disclaimer to go over the modem before
+they start seeing the image.  Finally, keywords should be full
+words, not abbreviations.  Keywords and text are in the ISO 8859-1
+(Latin-1) character set (a superset of regular ASCII) and can not
+contain NUL characters, and should not contain control or other
+unprintable characters.  To make the comments widely readable, stick
+with basic ASCII, and avoid machine specific character set extensions
+like the IBM-PC character set.  The keyword must be present, but
+you can leave off the text string on non-compressed pairs.
+Compressed pairs must have a text string, as only the text string
+is compressed anyway, so the compression would be meaningless.
+
+PNG supports modification time via the png_time structure.  Two
+conversion routines are provided, png_convert_from_time_t() for
+time_t and png_convert_from_struct_tm() for struct tm.  The
+time_t routine uses gmtime().  You don't have to use either of
+these, but if you wish to fill in the png_time structure directly,
+you should provide the time in universal time (GMT) if possible
+instead of your local time.  Note that the year number is the full
+year (e.g. 1998, rather than 98 - PNG is year 2000 compliant!), and
+that months start with 1.
+
+If you want to store the time of the original image creation, you should
+use a plain tEXt chunk with the "Creation Time" keyword.  This is
+necessary because the "creation time" of a PNG image is somewhat vague,
+depending on whether you mean the PNG file, the time the image was
+created in a non-PNG format, a still photo from which the image was
+scanned, or possibly the subject matter itself.  In order to facilitate
+machine-readable dates, it is recommended that the "Creation Time"
+tEXt chunk use RFC 1123 format dates (e.g. "22 May 1997 18:07:10 GMT"),
+although this isn't a requirement.  Unlike the tIME chunk, the
+"Creation Time" tEXt chunk is not expected to be automatically changed
+by the software.  To facilitate the use of RFC 1123 dates, a function
+png_convert_to_rfc1123(png_timep) is provided to convert from PNG
+time to an RFC 1123 format string.
+
+.SS Writing unknown chunks
+
+You can use the png_set_unknown_chunks function to queue up chunks
+for writing.  You give it a chunk name, raw data, and a size; that's
+all there is to it.  The chunks will be written by the next following
+png_write_info_before_PLTE, png_write_info, or png_write_end function.
+Any chunks previously read into the info structure's unknown-chunk
+list will also be written out in a sequence that satisfies the PNG
+specification's ordering rules.
+
+.SS The high-level write interface
+
+At this point there are two ways to proceed; through the high-level
+write interface, or through a sequence of low-level write operations.
+You can use the high-level interface if your image data is present
+in the info structure.  All defined output
+transformations are permitted, enabled by the following masks.
+
+    PNG_TRANSFORM_IDENTITY      No transformation
+    PNG_TRANSFORM_PACKING       Pack 1, 2 and 4-bit samples
+    PNG_TRANSFORM_PACKSWAP      Change order of packed
+                                pixels to LSB first
+    PNG_TRANSFORM_INVERT_MONO   Invert monochrome images
+    PNG_TRANSFORM_SHIFT         Normalize pixels to the
+                                sBIT depth
+    PNG_TRANSFORM_BGR           Flip RGB to BGR, RGBA
+                                to BGRA
+    PNG_TRANSFORM_SWAP_ALPHA    Flip RGBA to ARGB or GA
+                                to AG
+    PNG_TRANSFORM_INVERT_ALPHA  Change alpha from opacity
+                                to transparency
+    PNG_TRANSFORM_SWAP_ENDIAN   Byte-swap 16-bit samples
+    PNG_TRANSFORM_STRIP_FILLER  Strip out filler bytes.
+
+If you have valid image data in the info structure (you can use
+png_set_rows() to put image data in the info structure), simply do this:
+
+    png_write_png(png_ptr, info_ptr, png_transforms, NULL)
+
+where png_transforms is an integer containing the logical OR of some set of
+transformation flags.  This call is equivalent to png_write_info(),
+followed the set of transformations indicated by the transform mask,
+then png_write_image(), and finally png_write_end().
+
+(The final parameter of this call is not yet used.  Someday it might point
+to transformation parameters required by some future output transform.)
+
+You must use png_transforms and not call any png_set_transform() functions
+when you use png_write_png().
+
+.SS The low-level write interface
+
+If you are going the low-level route instead, you are now ready to
+write all the file information up to the actual image data.  You do
+this with a call to png_write_info().
+
+    png_write_info(png_ptr, info_ptr);
+
+Note that there is one transformation you may need to do before
+png_write_info().  In PNG files, the alpha channel in an image is the
+level of opacity.  If your data is supplied as a level of
+transparency, you can invert the alpha channel before you write it, so
+that 0 is fully transparent and 255 (in 8-bit or paletted images) or
+65535 (in 16-bit images) is fully opaque, with
+
+    png_set_invert_alpha(png_ptr);
+
+This must appear before png_write_info() instead of later with the
+other transformations because in the case of paletted images the tRNS
+chunk data has to be inverted before the tRNS chunk is written.  If
+your image is not a paletted image, the tRNS data (which in such cases
+represents a single color to be rendered as transparent) won't need to
+be changed, and you can safely do this transformation after your
+png_write_info() call.
+
+If you need to write a private chunk that you want to appear before
+the PLTE chunk when PLTE is present, you can write the PNG info in
+two steps, and insert code to write your own chunk between them:
+
+    png_write_info_before_PLTE(png_ptr, info_ptr);
+    png_set_unknown_chunks(png_ptr, info_ptr, ...);
+    png_write_info(png_ptr, info_ptr);
+
+After you've written the file information, you can set up the library
+to handle any special transformations of the image data.  The various
+ways to transform the data will be described in the order that they
+should occur.  This is important, as some of these change the color
+type and/or bit depth of the data, and some others only work on
+certain color types and bit depths.  Even though each transformation
+checks to see if it has data that it can do something with, you should
+make sure to only enable a transformation if it will be valid for the
+data.  For example, don't swap red and blue on grayscale data.
+
+PNG files store RGB pixels packed into 3 or 6 bytes.  This code tells
+the library to strip input data that has 4 or 8 bytes per pixel down
+to 3 or 6 bytes (or strip 2 or 4-byte grayscale+filler data to 1 or 2
+bytes per pixel).
+
+    png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE);
+
+where the 0 is unused, and the location is either PNG_FILLER_BEFORE or
+PNG_FILLER_AFTER, depending upon whether the filler byte in the pixel
+is stored XRGB or RGBX.
+
+PNG files pack pixels of bit depths 1, 2, and 4 into bytes as small as
+they can, resulting in, for example, 8 pixels per byte for 1 bit files.
+If the data is supplied at 1 pixel per byte, use this code, which will
+correctly pack the pixels into a single byte:
+
+    png_set_packing(png_ptr);
+
+PNG files reduce possible bit depths to 1, 2, 4, 8, and 16.  If your
+data is of another bit depth, you can write an sBIT chunk into the
+file so that decoders can recover the original data if desired.
+
+    /* Set the true bit depth of the image data */
+    if (color_type & PNG_COLOR_MASK_COLOR)
+    {
+        sig_bit.red = true_bit_depth;
+        sig_bit.green = true_bit_depth;
+        sig_bit.blue = true_bit_depth;
+    }
+    else
+    {
+        sig_bit.gray = true_bit_depth;
+    }
+    if (color_type & PNG_COLOR_MASK_ALPHA)
+    {
+        sig_bit.alpha = true_bit_depth;
+    }
+
+    png_set_sBIT(png_ptr, info_ptr, &sig_bit);
+
+If the data is stored in the row buffer in a bit depth other than
+one supported by PNG (e.g. 3 bit data in the range 0-7 for a 4-bit PNG),
+this will scale the values to appear to be the correct bit depth as
+is required by PNG.
+
+    png_set_shift(png_ptr, &sig_bit);
+
+PNG files store 16 bit pixels in network byte order (big-endian,
+ie. most significant bits first).  This code would be used if they are
+supplied the other way (little-endian, i.e. least significant bits
+first, the way PCs store them):
+
+    if (bit_depth > 8)
+       png_set_swap(png_ptr);
+
+If you are using packed-pixel images (1, 2, or 4 bits/pixel), and you
+need to change the order the pixels are packed into bytes, you can use:
+
+    if (bit_depth < 8)
+       png_set_packswap(png_ptr);
+
+PNG files store 3 color pixels in red, green, blue order.  This code
+would be used if they are supplied as blue, green, red:
+
+    png_set_bgr(png_ptr);
+
+PNG files describe monochrome as black being zero and white being
+one. This code would be used if the pixels are supplied with this reversed
+(black being one and white being zero):
+
+    png_set_invert_mono(png_ptr);
+
+Finally, you can write your own transformation function if none of
+the existing ones meets your needs.  This is done by setting a callback
+with
+
+    png_set_write_user_transform_fn(png_ptr,
+       write_transform_fn);
+
+You must supply the function
+
+    void write_transform_fn(png_ptr ptr, row_info_ptr
+       row_info, png_bytep data)
+
+See pngtest.c for a working example.  Your function will be called
+before any of the other transformations are processed.
+
+You can also set up a pointer to a user structure for use by your
+callback function.
+
+    png_set_user_transform_info(png_ptr, user_ptr, 0, 0);
+
+The user_channels and user_depth parameters of this function are ignored
+when writing; you can set them to zero as shown.
+
+You can retrieve the pointer via the function png_get_user_transform_ptr().
+For example:
+
+    voidp write_user_transform_ptr =
+       png_get_user_transform_ptr(png_ptr);
+
+It is possible to have libpng flush any pending output, either manually,
+or automatically after a certain number of lines have been written.  To
+flush the output stream a single time call:
+
+    png_write_flush(png_ptr);
+
+and to have libpng flush the output stream periodically after a certain
+number of scanlines have been written, call:
+
+    png_set_flush(png_ptr, nrows);
+
+Note that the distance between rows is from the last time png_write_flush()
+was called, or the first row of the image if it has never been called.
+So if you write 50 lines, and then png_set_flush 25, it will flush the
+output on the next scanline, and every 25 lines thereafter, unless
+png_write_flush() is called before 25 more lines have been written.
+If nrows is too small (less than about 10 lines for a 640 pixel wide
+RGB image) the image compression may decrease noticeably (although this
+may be acceptable for real-time applications).  Infrequent flushing will
+only degrade the compression performance by a few percent over images
+that do not use flushing.
+
+.SS Writing the image data
+
+That's it for the transformations.  Now you can write the image data.
+The simplest way to do this is in one function call.  If you have the
+whole image in memory, you can just call png_write_image() and libpng
+will write the image.  You will need to pass in an array of pointers to
+each row.  This function automatically handles interlacing, so you don't
+need to call png_set_interlace_handling() or call this function multiple
+times, or any of that other stuff necessary with png_write_rows().
+
+    png_write_image(png_ptr, row_pointers);
+
+where row_pointers is:
+
+    png_byte *row_pointers[height];
+
+You can point to void or char or whatever you use for pixels.
+
+If you don't want to write the whole image at once, you can
+use png_write_rows() instead.  If the file is not interlaced,
+this is simple:
+
+    png_write_rows(png_ptr, row_pointers,
+       number_of_rows);
+
+row_pointers is the same as in the png_write_image() call.
+
+If you are just writing one row at a time, you can do this with
+a single row_pointer instead of an array of row_pointers:
+
+    png_bytep row_pointer = row;
+
+    png_write_row(png_ptr, row_pointer);
+
+When the file is interlaced, things can get a good deal more
+complicated.  The only currently (as of the PNG Specification
+version 1.2, dated July 1999) defined interlacing scheme for PNG files
+is the "Adam7" interlace scheme, that breaks down an
+image into seven smaller images of varying size.  libpng will build
+these images for you, or you can do them yourself.  If you want to
+build them yourself, see the PNG specification for details of which
+pixels to write when.
+
+If you don't want libpng to handle the interlacing details, just
+use png_set_interlace_handling() and call png_write_rows() the
+correct number of times to write all seven sub-images.
+
+If you want libpng to build the sub-images, call this before you start
+writing any rows:
+
+    number_of_passes =
+       png_set_interlace_handling(png_ptr);
+
+This will return the number of passes needed.  Currently, this
+is seven, but may change if another interlace type is added.
+
+Then write the complete image number_of_passes times.
+
+    png_write_rows(png_ptr, row_pointers,
+       number_of_rows);
+
+As some of these rows are not used, and thus return immediately,
+you may want to read about interlacing in the PNG specification,
+and only update the rows that are actually used.
+
+.SS Finishing a sequential write
+
+After you are finished writing the image, you should finish writing
+the file.  If you are interested in writing comments or time, you should
+pass an appropriately filled png_info pointer.  If you are not interested,
+you can pass NULL.
+
+    png_write_end(png_ptr, info_ptr);
+
+When you are done, you can free all memory used by libpng like this:
+
+    png_destroy_write_struct(&png_ptr, &info_ptr);
+
+It is also possible to individually free the info_ptr members that
+point to libpng-allocated storage with the following function:
+
+    png_free_data(png_ptr, info_ptr, mask, seq)
+    mask  - identifies data to be freed, a mask
+            containing the logical OR of one or
+            more of
+              PNG_FREE_PLTE, PNG_FREE_TRNS,
+              PNG_FREE_HIST, PNG_FREE_ICCP,
+              PNG_FREE_PCAL, PNG_FREE_ROWS,
+              PNG_FREE_SCAL, PNG_FREE_SPLT,
+              PNG_FREE_TEXT, PNG_FREE_UNKN,
+            or simply PNG_FREE_ALL
+    seq   - sequence number of item to be freed
+            (-1 for all items)
+
+This function may be safely called when the relevant storage has
+already been freed, or has not yet been allocated, or was allocated
+by the user  and not by libpng,  and will in those
+cases do nothing.  The "seq" parameter is ignored if only one item
+of the selected data type, such as PLTE, is allowed.  If "seq" is not
+-1, and multiple items are allowed for the data type identified in
+the mask, such as text or sPLT, only the n'th item in the structure
+is freed, where n is "seq".
+
+If you allocated data such as a palette that you passed
+in to libpng with png_set_*, you must not free it until just before the call to
+png_destroy_write_struct().
+
+The default behavior is only to free data that was allocated internally
+by libpng.  This can be changed, so that libpng will not free the data,
+or so that it will free data that was allocated by the user with png_malloc()
+or png_zalloc() and passed in via a png_set_*() function, with
+
+    png_data_freer(png_ptr, info_ptr, freer, mask)
+    mask   - which data elements are affected
+             same choices as in png_free_data()
+    freer  - one of
+               PNG_DESTROY_WILL_FREE_DATA
+               PNG_SET_WILL_FREE_DATA
+               PNG_USER_WILL_FREE_DATA
+
+For example, to transfer responsibility for some data from a read structure
+to a write structure, you could use
+
+    png_data_freer(read_ptr, read_info_ptr,
+       PNG_USER_WILL_FREE_DATA,
+       PNG_FREE_PLTE|PNG_FREE_tRNS|PNG_FREE_hIST)
+    png_data_freer(write_ptr, write_info_ptr,
+       PNG_DESTROY_WILL_FREE_DATA,
+       PNG_FREE_PLTE|PNG_FREE_tRNS|PNG_FREE_hIST)
+
+thereby briefly reassigning responsibility for freeing to the user but
+immediately afterwards reassigning it once more to the write_destroy
+function.  Having done this, it would then be safe to destroy the read
+structure and continue to use the PLTE, tRNS, and hIST data in the write
+structure.
+
+This function only affects data that has already been allocated.
+You can call this function before calling after the png_set_*() functions
+to control whether the user or png_destroy_*() is supposed to free the data.
+When the user assumes responsibility for libpng-allocated data, the
+application must use
+png_free() to free it, and when the user transfers responsibility to libpng
+for data that the user has allocated, the user must have used png_malloc()
+or png_zalloc() to allocate it.
+
+If you allocated text_ptr.text, text_ptr.lang, and text_ptr.translated_keyword
+separately, do not transfer responsibility for freeing text_ptr to libpng,
+because when libpng fills a png_text structure it combines these members with
+the key member, and png_free_data() will free only text_ptr.key.  Similarly,
+if you transfer responsibility for free'ing text_ptr from libpng to your
+application, your application must not separately free those members.
+For a more compact example of writing a PNG image, see the file example.c.
+
+.SH V. Modifying/Customizing libpng:
+
+There are three issues here.  The first is changing how libpng does
+standard things like memory allocation, input/output, and error handling.
+The second deals with more complicated things like adding new chunks,
+adding new transformations, and generally changing how libpng works.
+Both of those are compile-time issues; that is, they are generally
+determined at the time the code is written, and there is rarely a need
+to provide the user with a means of changing them.  The third is a
+run-time issue:  choosing between and/or tuning one or more alternate
+versions of computationally intensive routines; specifically, optimized
+assembly-language (and therefore compiler- and platform-dependent)
+versions.
+
+Memory allocation, input/output, and error handling
+
+All of the memory allocation, input/output, and error handling in libpng
+goes through callbacks that are user-settable.  The default routines are
+in pngmem.c, pngrio.c, pngwio.c, and pngerror.c, respectively.  To change
+these functions, call the appropriate png_set_*_fn() function.
+
+Memory allocation is done through the functions png_malloc()
+and png_free().  These currently just call the standard C functions.  If
+your pointers can't access more then 64K at a time, you will want to set
+MAXSEG_64K in zlib.h.  Since it is unlikely that the method of handling
+memory allocation on a platform will change between applications, these
+functions must be modified in the library at compile time.  If you prefer
+to use a different method of allocating and freeing data, you can use
+png_create_read_struct_2() or png_create_write_struct_2() to register
+your own functions as described above.
+These functions also provide a void pointer that can be retrieved via
+
+    mem_ptr=png_get_mem_ptr(png_ptr);
+
+Your replacement memory functions must have prototypes as follows:
+
+    png_voidp malloc_fn(png_structp png_ptr,
+       png_size_t size);
+    void free_fn(png_structp png_ptr, png_voidp ptr);
+
+Your malloc_fn() must return NULL in case of failure.  The png_malloc()
+function will normally call png_error() if it receives a NULL from the
+system memory allocator or from your replacement malloc_fn().
+
+Input/Output in libpng is done through png_read() and png_write(),
+which currently just call fread() and fwrite().  The FILE * is stored in
+png_struct and is initialized via png_init_io().  If you wish to change
+the method of I/O, the library supplies callbacks that you can set
+through the function png_set_read_fn() and png_set_write_fn() at run
+time, instead of calling the png_init_io() function.  These functions
+also provide a void pointer that can be retrieved via the function
+png_get_io_ptr().  For example:
+
+    png_set_read_fn(png_structp read_ptr,
+        voidp read_io_ptr, png_rw_ptr read_data_fn)
+
+    png_set_write_fn(png_structp write_ptr,
+        voidp write_io_ptr, png_rw_ptr write_data_fn,
+        png_flush_ptr output_flush_fn);
+
+    voidp read_io_ptr = png_get_io_ptr(read_ptr);
+    voidp write_io_ptr = png_get_io_ptr(write_ptr);
+
+The replacement I/O functions must have prototypes as follows:
+
+    void user_read_data(png_structp png_ptr,
+        png_bytep data, png_size_t length);
+    void user_write_data(png_structp png_ptr,
+        png_bytep data, png_size_t length);
+    void user_flush_data(png_structp png_ptr);
+
+Supplying NULL for the read, write, or flush functions sets them back
+to using the default C stream functions.  It is an error to read from
+a write stream, and vice versa.
+
+Error handling in libpng is done through png_error() and png_warning().
+Errors handled through png_error() are fatal, meaning that png_error()
+should never return to its caller.  Currently, this is handled via
+setjmp() and longjmp() (unless you have compiled libpng with
+PNG_SETJMP_NOT_SUPPORTED, in which case it is handled via PNG_ABORT()),
+but you could change this to do things like exit() if you should wish.
+
+On non-fatal errors, png_warning() is called
+to print a warning message, and then control returns to the calling code.
+By default png_error() and png_warning() print a message on stderr via
+fprintf() unless the library is compiled with PNG_NO_CONSOLE_IO defined
+(because you don't want the messages) or PNG_NO_STDIO defined (because
+fprintf() isn't available).  If you wish to change the behavior of the error
+functions, you will need to set up your own message callbacks.  These
+functions are normally supplied at the time that the png_struct is created.
+It is also possible to redirect errors and warnings to your own replacement
+functions after png_create_*_struct() has been called by calling:
+
+    png_set_error_fn(png_structp png_ptr,
+        png_voidp error_ptr, png_error_ptr error_fn,
+        png_error_ptr warning_fn);
+
+    png_voidp error_ptr = png_get_error_ptr(png_ptr);
+
+If NULL is supplied for either error_fn or warning_fn, then the libpng
+default function will be used, calling fprintf() and/or longjmp() if a
+problem is encountered.  The replacement error functions should have
+parameters as follows:
+
+    void user_error_fn(png_structp png_ptr,
+        png_const_charp error_msg);
+    void user_warning_fn(png_structp png_ptr,
+        png_const_charp warning_msg);
+
+The motivation behind using setjmp() and longjmp() is the C++ throw and
+catch exception handling methods.  This makes the code much easier to write,
+as there is no need to check every return code of every function call.
+However, there are some uncertainties about the status of local variables
+after a longjmp, so the user may want to be careful about doing anything after
+setjmp returns non-zero besides returning itself.  Consult your compiler
+documentation for more details.  For an alternative approach, you may wish
+to use the "cexcept" facility (see http://cexcept.sourceforge.net).
+
+.SS Custom chunks
+
+If you need to read or write custom chunks, you may need to get deeper
+into the libpng code.  The library now has mechanisms for storing
+and writing chunks of unknown type; you can even declare callbacks
+for custom chunks.  Hoewver, this may not be good enough if the
+library code itself needs to know about interactions between your
+chunk and existing `intrinsic' chunks.
+
+If you need to write a new intrinsic chunk, first read the PNG
+specification. Acquire a first level of
+understanding of how it works.  Pay particular attention to the
+sections that describe chunk names, and look at how other chunks were
+designed, so you can do things similarly.  Second, check out the
+sections of libpng that read and write chunks.  Try to find a chunk
+that is similar to yours and use it as a template.  More details can
+be found in the comments inside the code.  It is best to handle unknown
+chunks in a generic method, via callback functions, instead of by
+modifying libpng functions.
+
+If you wish to write your own transformation for the data, look through
+the part of the code that does the transformations, and check out some of
+the simpler ones to get an idea of how they work.  Try to find a similar
+transformation to the one you want to add and copy off of it.  More details
+can be found in the comments inside the code itself.
+
+.SS Configuring for 16 bit platforms
+
+You will want to look into zconf.h to tell zlib (and thus libpng) that
+it cannot allocate more then 64K at a time.  Even if you can, the memory
+won't be accessible.  So limit zlib and libpng to 64K by defining MAXSEG_64K.
+
+.SS Configuring for DOS
+
+For DOS users who only have access to the lower 640K, you will
+have to limit zlib's memory usage via a png_set_compression_mem_level()
+call.  See zlib.h or zconf.h in the zlib library for more information.
+
+.SS Configuring for Medium Model
+
+Libpng's support for medium model has been tested on most of the popular
+compilers.  Make sure MAXSEG_64K gets defined, USE_FAR_KEYWORD gets
+defined, and FAR gets defined to far in pngconf.h, and you should be
+all set.  Everything in the library (except for zlib's structure) is
+expecting far data.  You must use the typedefs with the p or pp on
+the end for pointers (or at least look at them and be careful).  Make
+note that the rows of data are defined as png_bytepp, which is an
+unsigned char far * far *.
+
+.SS Configuring for gui/windowing platforms:
+
+You will need to write new error and warning functions that use the GUI
+interface, as described previously, and set them to be the error and
+warning functions at the time that png_create_*_struct() is called,
+in order to have them available during the structure initialization.
+They can be changed later via png_set_error_fn().  On some compilers,
+you may also have to change the memory allocators (png_malloc, etc.).
+
+.SS Configuring for compiler xxx:
+
+All includes for libpng are in pngconf.h.  If you need to add/change/delete
+an include, this is the place to do it.  The includes that are not
+needed outside libpng are protected by the PNG_INTERNAL definition,
+which is only defined for those routines inside libpng itself.  The
+files in libpng proper only include png.h, which includes pngconf.h.
+
+.SS Configuring zlib:
+
+There are special functions to configure the compression.  Perhaps the
+most useful one changes the compression level, which currently uses
+input compression values in the range 0 - 9.  The library normally
+uses the default compression level (Z_DEFAULT_COMPRESSION = 6).  Tests
+have shown that for a large majority of images, compression values in
+the range 3-6 compress nearly as well as higher levels, and do so much
+faster.  For online applications it may be desirable to have maximum speed
+(Z_BEST_SPEED = 1).  With versions of zlib after v0.99, you can also
+specify no compression (Z_NO_COMPRESSION = 0), but this would create
+files larger than just storing the raw bitmap.  You can specify the
+compression level by calling:
+
+    png_set_compression_level(png_ptr, level);
+
+Another useful one is to reduce the memory level used by the library.
+The memory level defaults to 8, but it can be lowered if you are
+short on memory (running DOS, for example, where you only have 640K).
+Note that the memory level does have an effect on compression; among
+other things, lower levels will result in sections of incompressible
+data being emitted in smaller stored blocks, with a correspondingly
+larger relative overhead of up to 15% in the worst case.
+
+    png_set_compression_mem_level(png_ptr, level);
+
+The other functions are for configuring zlib.  They are not recommended
+for normal use and may result in writing an invalid PNG file.  See
+zlib.h for more information on what these mean.
+
+    png_set_compression_strategy(png_ptr,
+        strategy);
+    png_set_compression_window_bits(png_ptr,
+        window_bits);
+    png_set_compression_method(png_ptr, method);
+    png_set_compression_buffer_size(png_ptr, size);
+
+.SS Controlling row filtering
+
+If you want to control whether libpng uses filtering or not, which
+filters are used, and how it goes about picking row filters, you
+can call one of these functions.  The selection and configuration
+of row filters can have a significant impact on the size and
+encoding speed and a somewhat lesser impact on the decoding speed
+of an image.  Filtering is enabled by default for RGB and grayscale
+images (with and without alpha), but not for paletted images nor
+for any images with bit depths less than 8 bits/pixel.
+
+The 'method' parameter sets the main filtering method, which is
+currently only '0' in the PNG 1.2 specification.  The 'filters'
+parameter sets which filter(s), if any, should be used for each
+scanline.  Possible values are PNG_ALL_FILTERS and PNG_NO_FILTERS
+to turn filtering on and off, respectively.
+
+Individual filter types are PNG_FILTER_NONE, PNG_FILTER_SUB,
+PNG_FILTER_UP, PNG_FILTER_AVG, PNG_FILTER_PAETH, which can be bitwise
+ORed together with '|' to specify one or more filters to use.
+These filters are described in more detail in the PNG specification.
+If you intend to change the filter type during the course of writing
+the image, you should start with flags set for all of the filters
+you intend to use so that libpng can initialize its internal
+structures appropriately for all of the filter types.  (Note that this
+means the first row must always be adaptively filtered, because libpng
+currently does not allocate the filter buffers until png_write_row()
+is called for the first time.)
+
+    filters = PNG_FILTER_NONE | PNG_FILTER_SUB
+              PNG_FILTER_UP | PNG_FILTER_AVE |
+              PNG_FILTER_PAETH | PNG_ALL_FILTERS;
+
+    png_set_filter(png_ptr, PNG_FILTER_TYPE_BASE,
+       filters);
+              The second parameter can also be
+              PNG_INTRAPIXEL_DIFFERENCING if you are
+              writing a PNG to be embedded in a MNG
+              datastream.  This parameter must be the
+              same as the value of filter_method used
+              in png_set_IHDR().
+
+It is also possible to influence how libpng chooses from among the
+available filters.  This is done in one or both of two ways - by
+telling it how important it is to keep the same filter for successive
+rows, and by telling it the relative computational costs of the filters.
+
+    double weights[3] = {1.5, 1.3, 1.1},
+       costs[PNG_FILTER_VALUE_LAST] =
+       {1.0, 1.3, 1.3, 1.5, 1.7};
+
+    png_set_filter_heuristics(png_ptr,
+       PNG_FILTER_HEURISTIC_WEIGHTED, 3,
+       weights, costs);
+
+The weights are multiplying factors that indicate to libpng that the
+row filter should be the same for successive rows unless another row filter
+is that many times better than the previous filter.  In the above example,
+if the previous 3 filters were SUB, SUB, NONE, the SUB filter could have a
+"sum of absolute differences" 1.5 x 1.3 times higher than other filters
+and still be chosen, while the NONE filter could have a sum 1.1 times
+higher than other filters and still be chosen.  Unspecified weights are
+taken to be 1.0, and the specified weights should probably be declining
+like those above in order to emphasize recent filters over older filters.
+
+The filter costs specify for each filter type a relative decoding cost
+to be considered when selecting row filters.  This means that filters
+with higher costs are less likely to be chosen over filters with lower
+costs, unless their "sum of absolute differences" is that much smaller.
+The costs do not necessarily reflect the exact computational speeds of
+the various filters, since this would unduly influence the final image
+size.
+
+Note that the numbers above were invented purely for this example and
+are given only to help explain the function usage.  Little testing has
+been done to find optimum values for either the costs or the weights.
+
+.SS Removing unwanted object code
+
+There are a bunch of #define's in pngconf.h that control what parts of
+libpng are compiled.  All the defines end in _SUPPORTED.  If you are
+never going to use a capability, you can change the #define to #undef
+before recompiling libpng and save yourself code and data space, or
+you can turn off individual capabilities with defines that begin with
+PNG_NO_.
+
+You can also turn all of the transforms and ancillary chunk capabilities
+off en masse with compiler directives that define
+PNG_NO_READ[or WRITE]_TRANSFORMS, or PNG_NO_READ[or WRITE]_ANCILLARY_CHUNKS,
+or all four,
+along with directives to turn on any of the capabilities that you do
+want.  The PNG_NO_READ[or WRITE]_TRANSFORMS directives disable
+the extra transformations but still leave the library fully capable of reading
+and writing PNG files with all known public chunks
+Use of the PNG_NO_READ[or WRITE]_ANCILLARY_CHUNKS directive
+produces a library that is incapable of reading or writing ancillary chunks.
+If you are not using the progressive reading capability, you can
+turn that off with PNG_NO_PROGRESSIVE_READ (don't confuse
+this with the INTERLACING capability, which you'll still have).
+
+All the reading and writing specific code are in separate files, so the
+linker should only grab the files it needs.  However, if you want to
+make sure, or if you are building a stand alone library, all the
+reading files start with pngr and all the writing files start with
+pngw.  The files that don't match either (like png.c, pngtrans.c, etc.)
+are used for both reading and writing, and always need to be included.
+The progressive reader is in pngpread.c
+
+If you are creating or distributing a dynamically linked library (a .so
+or DLL file), you should not remove or disable any parts of the library,
+as this will cause applications linked with different versions of the
+library to fail if they call functions not available in your library.
+The size of the library itself should not be an issue, because only
+those sections that are actually used will be loaded into memory.
+
+.SS Requesting debug printout
+
+The macro definition PNG_DEBUG can be used to request debugging
+printout.  Set it to an integer value in the range 0 to 3.  Higher
+numbers result in increasing amounts of debugging information.  The
+information is printed to the "stderr" file, unless another file
+name is specified in the PNG_DEBUG_FILE macro definition.
+
+When PNG_DEBUG > 0, the following functions (macros) become available:
+
+   png_debug(level, message)
+   png_debug1(level, message, p1)
+   png_debug2(level, message, p1, p2)
+
+in which "level" is compared to PNG_DEBUG to decide whether to print
+the message, "message" is the formatted string to be printed,
+and p1 and p2 are parameters that are to be embedded in the string
+according to printf-style formatting directives.  For example,
+
+   png_debug1(2, "foo=%d\n", foo);
+
+is expanded to
+
+   if(PNG_DEBUG > 2)
+     fprintf(PNG_DEBUG_FILE, "foo=%d\n", foo);
+
+When PNG_DEBUG is defined but is zero, the macros aren't defined, but you
+can still use PNG_DEBUG to control your own debugging:
+
+   #ifdef PNG_DEBUG
+       fprintf(stderr, ...
+   #endif
+
+When PNG_DEBUG = 1, the macros are defined, but only png_debug statements
+having level = 0 will be printed.  There aren't any such statements in
+this version of libpng, but if you insert some they will be printed.
+
+.SH VI.  Runtime optimization
+
+A new feature in libpng 1.2.0 is the ability to dynamically switch between
+standard and optimized versions of some routines.  Currently these are
+limited to three computationally intensive tasks when reading PNG files:
+decoding row filters, expanding interlacing, and combining interlaced or
+transparent row data with previous row data.  Currently the optimized
+versions are available only for x86 (Intel, AMD, etc.) platforms with
+MMX support, though this may change in future versions.  (For example,
+the non-MMX assembler optimizations for zlib might become similarly
+runtime-selectable in future releases, in which case libpng could be
+extended to support them.  Alternatively, the compile-time choice of
+floating-point versus integer routines for gamma correction might become
+runtime-selectable.)
+
+Because such optimizations tend to be very platform- and compiler-dependent,
+both in how they are written and in how they perform, the new runtime code
+in libpng has been written to allow programs to query, enable, and disable
+either specific optimizations or all such optimizations.  For example, to
+enable all possible optimizations (bearing in mind that some "optimizations"
+may actually run more slowly in rare cases):
+
+    #if defined(PNG_LIBPNG_VER) && (PNG_LIBPNG_VER >= 10200)
+       png_uint_32 mask, flags;
+
+       flags = png_get_asm_flags(png_ptr);
+       mask = png_get_asm_flagmask(PNG_SELECT_READ | PNG_SELECT_WRITE);
+       png_set_asm_flags(png_ptr, flags | mask);
+    #endif
+
+To enable only optimizations relevant to reading PNGs, use PNG_SELECT_READ
+by itself when calling png_get_asm_flagmask(); similarly for optimizing
+only writing.  To disable all optimizations:
+
+    #if defined(PNG_LIBPNG_VER) && (PNG_LIBPNG_VER >= 10200)
+       flags = png_get_asm_flags(png_ptr);
+       mask = png_get_asm_flagmask(PNG_SELECT_READ | PNG_SELECT_WRITE);
+       png_set_asm_flags(png_ptr, flags & ~mask);
+    #endif
+
+To enable or disable only MMX-related features, use png_get_mmx_flagmask()
+in place of png_get_asm_flagmask().  The mmx version takes one additional
+parameter:
+
+    #if defined(PNG_LIBPNG_VER) && (PNG_LIBPNG_VER >= 10200)
+       int selection = PNG_SELECT_READ | PNG_SELECT_WRITE;
+       int compilerID;
+
+       mask = png_get_mmx_flagmask(selection, &compilerID);
+    #endif
+
+On return, compilerID will indicate which version of the MMX assembler
+optimizations was compiled.  Currently two flavors exist:  Microsoft
+Visual C++ (compilerID == 1) and GNU C (a.k.a. gcc/gas, compilerID == 2).
+On non-x86 platforms or on systems compiled without MMX optimizations, a
+value of -1 is used.
+
+Note that both png_get_asm_flagmask() and png_get_mmx_flagmask() return
+all valid, settable optimization bits for the version of the library that's
+currently in use.  In the case of shared (dynamically linked) libraries,
+this may include optimizations that did not exist at the time the code was
+written and compiled.  It is also possible, of course, to enable only known,
+specific optimizations; for example:
+
+    #if defined(PNG_LIBPNG_VER) && (PNG_LIBPNG_VER >= 10200)
+       flags = PNG_ASM_FLAG_MMX_READ_COMBINE_ROW  \
+             | PNG_ASM_FLAG_MMX_READ_INTERLACE    \
+             | PNG_ASM_FLAG_MMX_READ_FILTER_SUB   \
+             | PNG_ASM_FLAG_MMX_READ_FILTER_UP    \
+             | PNG_ASM_FLAG_MMX_READ_FILTER_AVG   \
+             | PNG_ASM_FLAG_MMX_READ_FILTER_PAETH ;
+       png_set_asm_flags(png_ptr, flags);
+    #endif
+
+This method would enable only the MMX read-optimizations available at the
+time of libpng 1.2.0's release, regardless of whether a later version of
+the DLL were actually being used.  (Also note that these functions did not
+exist in versions older than 1.2.0, so any attempt to run a dynamically
+linked app on such an older version would fail.)
+
+To determine whether the processor supports MMX instructions at all, use
+the png_mmx_support() function:
+
+    #if defined(PNG_LIBPNG_VER) && (PNG_LIBPNG_VER >= 10200)
+       mmxsupport = png_mmx_support();
+    #endif
+
+It returns -1 if MMX support is not compiled into libpng, 0 if MMX code
+is compiled but MMX is not supported by the processor, or 1 if MMX support
+is fully available.  Note that png_mmx_support(), png_get_mmx_flagmask(),
+and png_get_asm_flagmask() all may be called without allocating and ini-
+tializing any PNG structures (for example, as part of a usage screen or
+"about" box).
+
+The following code can be used to prevent an application from using the
+thread_unsafe features, even if libpng was built with PNG_THREAD_UNSAFE_OK
+defined:
+
+#if defined(PNG_USE_PNGGCCRD) && defined(PNG_ASSEMBLER_CODE_SUPPORTED) \
+  && defined(PNG_THREAD_UNSAFE_OK)
+    /* Disable thread-unsafe features of pnggccrd */
+    if (png_access_version() >= 10200)
+    {
+      png_uint_32 mmx_disable_mask = 0;
+      png_uint_32 asm_flags;
+
+      mmx_disable_mask |= ( PNG_ASM_FLAG_MMX_READ_COMBINE_ROW  \
+                          | PNG_ASM_FLAG_MMX_READ_FILTER_SUB   \
+                          | PNG_ASM_FLAG_MMX_READ_FILTER_AVG   \
+                          | PNG_ASM_FLAG_MMX_READ_FILTER_PAETH );
+      asm_flags = png_get_asm_flags(png_ptr);
+      png_set_asm_flags(png_ptr, asm_flags & ~mmx_disable_mask);
+    }
+#endif
+
+For more extensive examples of runtime querying, enabling and disabling
+of optimized features, see contrib/gregbook/readpng2.c in the libpng
+source-code distribution.
+
+.SH VII.  MNG support
+
+The MNG specification (available at http://www.libpng.org/pub/mng) allows
+certain extensions to PNG for PNG images that are embedded in MNG datastreams.
+Libpng can support some of these extensions.  To enable them, use the
+png_permit_mng_features() function:
+
+   feature_set = png_permit_mng_features(png_ptr, mask)
+   mask is a png_uint_32 containing the logical OR of the
+        features you want to enable.  These include
+        PNG_FLAG_MNG_EMPTY_PLTE
+        PNG_FLAG_MNG_FILTER_64
+        PNG_ALL_MNG_FEATURES
+   feature_set is a png_uint_32 that is the logical AND of
+      your mask with the set of MNG features that is
+      supported by the version of libpng that you are using.
+
+It is an error to use this function when reading or writing a standalone
+PNG file with the PNG 8-byte signature.  The PNG datastream must be wrapped
+in a MNG datastream.  As a minimum, it must have the MNG 8-byte signature
+and the MHDR and MEND chunks.  Libpng does not provide support for these
+or any other MNG chunks; your application must provide its own support for
+them.  You may wish to consider using libmng (available at
+http://www.libmng.com) instead.
+
+.SH VIII.  Changes to Libpng from version 0.88
+
+It should be noted that versions of libpng later than 0.96 are not
+distributed by the original libpng author, Guy Schalnat, nor by
+Andreas Dilger, who had taken over from Guy during 1996 and 1997, and
+distributed versions 0.89 through 0.96, but rather by another member
+of the original PNG Group, Glenn Randers-Pehrson.  Guy and Andreas are
+still alive and well, but they have moved on to other things.
+
+The old libpng functions png_read_init(), png_write_init(),
+png_info_init(), png_read_destroy(), and png_write_destroy() have been
+moved to PNG_INTERNAL in version 0.95 to discourage their use.  These
+functions will be removed from libpng version 2.0.0.
+
+The preferred method of creating and initializing the libpng structures is
+via the png_create_read_struct(), png_create_write_struct(), and
+png_create_info_struct() because they isolate the size of the structures
+from the application, allow version error checking, and also allow the
+use of custom error handling routines during the initialization, which
+the old functions do not.  The functions png_read_destroy() and
+png_write_destroy() do not actually free the memory that libpng
+allocated for these structs, but just reset the data structures, so they
+can be used instead of png_destroy_read_struct() and
+png_destroy_write_struct() if you feel there is too much system overhead
+allocating and freeing the png_struct for each image read.
+
+Setting the error callbacks via png_set_message_fn() before
+png_read_init() as was suggested in libpng-0.88 is no longer supported
+because this caused applications that do not use custom error functions
+to fail if the png_ptr was not initialized to zero.  It is still possible
+to set the error callbacks AFTER png_read_init(), or to change them with
+png_set_error_fn(), which is essentially the same function, but with a new
+name to force compilation errors with applications that try to use the old
+method.
+
+Starting with version 1.0.7, you can find out which version of the library
+you are using at run-time:
+
+   png_uint_32 libpng_vn = png_access_version_number();
+
+The number libpng_vn is constructed from the major version, minor
+version with leading zero, and release number with leading zero,
+(e.g., libpng_vn for version 1.0.7 is 10007).
+
+You can also check which version of png.h you used when compiling your
+application:
+
+   png_uint_32 application_vn = PNG_LIBPNG_VER;
+
+.SH IX. Y2K Compliance in libpng
+
+December 3, 2004
+
+Since the PNG Development group is an ad-hoc body, we can't make
+an official declaration.
+
+This is your unofficial assurance that libpng from version 0.71 and
+upward through 1.2.8 are Y2K compliant.  It is my belief that earlier
+versions were also Y2K compliant.
+
+Libpng only has three year fields.  One is a 2-byte unsigned integer that
+will hold years up to 65535.  The other two hold the date in text
+format, and will hold years up to 9999.
+
+The integer is
+    "png_uint_16 year" in png_time_struct.
+
+The strings are
+    "png_charp time_buffer" in png_struct and
+    "near_time_buffer", which is a local character string in png.c.
+
+There are seven time-related functions:
+
+    png_convert_to_rfc_1123() in png.c
+      (formerly png_convert_to_rfc_1152() in error)
+    png_convert_from_struct_tm() in pngwrite.c, called
+      in pngwrite.c
+    png_convert_from_time_t() in pngwrite.c
+    png_get_tIME() in pngget.c
+    png_handle_tIME() in pngrutil.c, called in pngread.c
+    png_set_tIME() in pngset.c
+    png_write_tIME() in pngwutil.c, called in pngwrite.c
+
+All appear to handle dates properly in a Y2K environment.  The
+png_convert_from_time_t() function calls gmtime() to convert from system
+clock time, which returns (year - 1900), which we properly convert to
+the full 4-digit year.  There is a possibility that applications using
+libpng are not passing 4-digit years into the png_convert_to_rfc_1123()
+function, or that they are incorrectly passing only a 2-digit year
+instead of "year - 1900" into the png_convert_from_struct_tm() function,
+but this is not under our control.  The libpng documentation has always
+stated that it works with 4-digit years, and the APIs have been
+documented as such.
+
+The tIME chunk itself is also Y2K compliant.  It uses a 2-byte unsigned
+integer to hold the year, and can hold years as large as 65535.
+
+zlib, upon which libpng depends, is also Y2K compliant.  It contains
+no date-related code.
+
+
+   Glenn Randers-Pehrson
+   libpng maintainer
+   PNG Development Group
+
+.SH NOTE
+
+Note about libpng version numbers:
+
+Due to various miscommunications, unforeseen code incompatibilities
+and occasional factors outside the authors' control, version numbering
+on the library has not always been consistent and straightforward.
+The following table summarizes matters since version 0.89c, which was
+the first widely used release:
+
+ source             png.h  png.h  shared-lib
+ version            string   int  version
+ -------            ------  ----- ----------
+ 0.89c ("beta 3")  0.89       89  1.0.89
+ 0.90  ("beta 4")  0.90       90  0.90
+ 0.95  ("beta 5")  0.95       95  0.95
+ 0.96  ("beta 6")  0.96       96  0.96
+ 0.97b ("beta 7")  1.00.97    97  1.0.1
+ 0.97c             0.97       97  2.0.97
+ 0.98              0.98       98  2.0.98
+ 0.99              0.99       98  2.0.99
+ 0.99a-m           0.99       99  2.0.99
+ 1.00              1.00      100  2.1.0
+ 1.0.0             1.0.0     100  2.1.0
+ 1.0.0   (from here on, the  100  2.1.0
+ 1.0.1    png.h string is  10001  2.1.0
+ 1.0.1a-e identical to the 10002  from here on, the
+ 1.0.2    source version)  10002  shared library is 2.V
+ 1.0.2a-b                  10003  where V is the source
+ 1.0.1                     10001  code version except as
+ 1.0.1a-e                  10002  2.1.0.1a-e   noted.
+ 1.0.2                     10002  2.1.0.2
+ 1.0.2a-b                  10003  2.1.0.2a-b
+ 1.0.3                     10003  2.1.0.3
+ 1.0.3a-d                  10004  2.1.0.3a-d
+ 1.0.4                     10004  2.1.0.4
+ 1.0.4a-f                  10005  2.1.0.4a-f
+ 1.0.5 (+ 2 patches)       10005  2.1.0.5
+ 1.0.5a-d                  10006  2.1.0.5a-d
+ 1.0.5e-r                  10100  2.1.0.5e-r
+ 1.0.5s-v                  10006  2.1.0.5s-v
+ 1.0.6 (+ 3 patches)       10006  2.1.0.6
+ 1.0.6d-g                  10007  2.1.0.6d-g
+ 1.0.6h                    10007  10.6h
+ 1.0.6i                    10007  10.6i
+ 1.0.6j                    10007  2.1.0.6j
+ 1.0.7beta11-14    DLLNUM  10007  2.1.0.7beta11-14
+ 1.0.7beta15-18       1    10007  2.1.0.7beta15-18
+ 1.0.7rc1-2           1    10007  2.1.0.7rc1-2
+ 1.0.7                1    10007  2.1.0.7
+ 1.0.8beta1-4         1    10008  2.1.0.8beta1-4
+ 1.0.8rc1             1    10008  2.1.0.8rc1
+ 1.0.8                1    10008  2.1.0.8
+ 1.0.9beta1-6         1    10009  2.1.0.9beta1-6
+ 1.0.9rc1             1    10009  2.1.0.9rc1
+ 1.0.9beta7-10        1    10009  2.1.0.9beta7-10
+ 1.0.9rc2             1    10009  2.1.0.9rc2
+ 1.0.9                1    10009  2.1.0.9
+ 1.0.10beta1          1    10010  2.1.0.10beta1
+ 1.0.10rc1            1    10010  2.1.0.10rc1
+ 1.0.10               1    10010  2.1.0.10
+ 1.0.11beta1-3        1    10011  2.1.0.11beta1-3
+ 1.0.11rc1            1    10011  2.1.0.11rc1
+ 1.0.11               1    10011  2.1.0.11
+ 1.0.12beta1-2        2    10012  2.1.0.12beta1-2
+ 1.0.12rc1            2    10012  2.1.0.12rc1
+ 1.0.12               2    10012  2.1.0.12
+ 1.1.0a-f             -    10100  2.1.1.0a-f abandoned
+ 1.2.0beta1-2         2    10200  2.1.2.0beta1-2
+ 1.2.0beta3-5         3    10200  3.1.2.0beta3-5
+ 1.2.0rc1             3    10200  3.1.2.0rc1
+ 1.2.0                3    10200  3.1.2.0
+ 1.2.1beta-4          3    10201  3.1.2.1beta1-4
+ 1.2.1rc1-2           3    10201  3.1.2.1rc1-2
+ 1.2.1                3    10201  3.1.2.1
+ 1.2.2beta1-6        12    10202  12.so.0.1.2.2beta1-6
+ 1.0.13beta1         10    10013  10.so.0.1.0.13beta1
+ 1.0.13rc1           10    10013  10.so.0.1.0.13rc1
+ 1.2.2rc1            12    10202  12.so.0.1.2.2rc1
+ 1.0.13              10    10013  10.so.0.1.0.13
+ 1.2.2               12    10202  12.so.0.1.2.2
+ 1.2.3rc1-6          12    10203  12.so.0.1.2.3rc1-6
+ 1.2.3               12    10203  12.so.0.1.2.3
+ 1.2.4beta1-3        13    10204  12.so.0.1.2.4beta1-3
+ 1.2.4rc1            13    10204  12.so.0.1.2.4rc1
+ 1.0.14              10    10014  10.so.0.1.0.14
+ 1.2.4               13    10204  12.so.0.1.2.4
+ 1.2.5beta1-2        13    10205  12.so.0.1.2.5beta1-2
+ 1.0.15rc1           10    10015  10.so.0.1.0.15rc1
+ 1.0.15              10    10015  10.so.0.1.0.15
+ 1.2.5               13    10205  12.so.0.1.2.5
+ 1.2.6beta1-4        13    10206  12.so.0.1.2.6beta1-4
+ 1.2.6rc1-5          13    10206  12.so.0.1.2.6rc1-5
+ 1.0.16              10    10016  10.so.0.1.0.16
+ 1.2.6               13    10206  12.so.0.1.2.6
+ 1.2.7beta1-2        13    10207  12.so.0.1.2.7beta1-2
+ 1.0.17rc1           10    10017  12.so.0.1.0.17rc1
+ 1.2.7rc1            13    10207  12.so.0.1.2.7rc1
+ 1.0.17              10    10017  12.so.0.1.0.17
+ 1.2.7               13    10207  12.so.0.1.2.7
+ 1.2.8beta1-5        13    10208  12.so.0.1.2.8beta1-5
+ 1.0.18rc1-5         10    10018  12.so.0.1.0.18rc1-5
+ 1.2.8rc1-5          13    10208  12.so.0.1.2.8rc1-5
+ 1.0.18              10    10018  12.so.0.1.0.18
+ 1.2.8               13    10208  12.so.0.1.2.8
+
+Henceforth the source version will match the shared-library minor
+and patch numbers; the shared-library major version number will be
+used for changes in backward compatibility, as it is intended.  The
+PNG_PNGLIB_VER macro, which is not used within libpng but is available
+for applications, is an unsigned integer of the form xyyzz corresponding
+to the source version x.y.z (leading zeros in y and z).  Beta versions
+were given the previous public release number plus a letter, until
+version 1.0.6j; from then on they were given the upcoming public
+release number plus "betaNN" or "rcN".
+
+.SH "SEE ALSO"
+libpngpf(3), png(5)
+.LP
+.IR libpng :
+.IP
+http://libpng.sourceforge.net (follow the [DOWNLOAD] link)
+http://www.libpng.org/pub/png
+
+.LP
+.IR zlib :
+.IP
+(generally) at the same location as
+.I libpng
+or at
+.br
+ftp://ftp.info-zip.org/pub/infozip/zlib
+
+.LP
+.IR PNG specification: RFC 2083
+.IP
+(generally) at the same location as
+.I libpng
+or at
+.br
+ftp://ds.internic.net/rfc/rfc2083.txt
+.br
+or (as a W3C Recommendation) at
+.br
+http://www.w3.org/TR/REC-png.html
+
+.LP
+In the case of any inconsistency between the PNG specification
+and this library, the specification takes precedence.
+
+.SH AUTHORS
+This man page: Glenn Randers-Pehrson
+<glennrp at users.sourceforge.net>
+
+The contributing authors would like to thank all those who helped
+with testing, bug fixes, and patience.  This wouldn't have been
+possible without all of you.
+
+Thanks to Frank J. T. Wojcik for helping with the documentation.
+
+Libpng version 1.2.8 - December 3, 2004:
+Initially created in 1995 by Guy Eric Schalnat, then of Group 42, Inc.
+Currently maintained by Glenn Randers-Pehrson (glennrp at users.sourceforge.net).
+
+Supported by the PNG development group
+.br
+png-implement at ccrc.wustl.edu (subscription required; write to
+majordomo at ccrc.wustl.edu with "subscribe png-implement" in the message).
+
+.SH COPYRIGHT NOTICE, DISCLAIMER, and LICENSE:
+
+(This copy of the libpng notices is provided for your convenience.  In case of
+any discrepancy between this copy and the notices in the file png.h that is
+included in the libpng distribution, the latter shall prevail.)
+
+If you modify libpng you may insert additional notices immediately following
+this sentence.
+
+libpng version 1.2.6, December 3, 2004, is
+Copyright (c) 2004 Glenn Randers-Pehrson, and is
+distributed according to the same disclaimer and license as libpng-1.2.5
+with the following individual added to the list of Contributing Authors
+
+   Cosmin Truta
+
+libpng versions 1.0.7, July 1, 2000, through 1.2.5 - October 3, 2002, are
+Copyright (c) 2000-2002 Glenn Randers-Pehrson, and are
+distributed according to the same disclaimer and license as libpng-1.0.6
+with the following individuals added to the list of Contributing Authors
+
+   Simon-Pierre Cadieux
+   Eric S. Raymond
+   Gilles Vollant
+
+and with the following additions to the disclaimer:
+
+   There is no warranty against interference with your
+   enjoyment of the library or against infringement.
+   There is no warranty that our efforts or the library
+   will fulfill any of your particular purposes or needs.
+   This library is provided with all faults, and the entire
+   risk of satisfactory quality, performance, accuracy, and
+   effort is with the user.
+
+libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
+Copyright (c) 1998, 1999 Glenn Randers-Pehrson
+Distributed according to the same disclaimer and license as libpng-0.96,
+with the following individuals added to the list of Contributing Authors:
+
+   Tom Lane
+   Glenn Randers-Pehrson
+   Willem van Schaik
+
+libpng versions 0.89, June 1996, through 0.96, May 1997, are
+Copyright (c) 1996, 1997 Andreas Dilger
+Distributed according to the same disclaimer and license as libpng-0.88,
+with the following individuals added to the list of Contributing Authors:
+
+   John Bowler
+   Kevin Bracey
+   Sam Bushell
+   Magnus Holmgren
+   Greg Roelofs
+   Tom Tanner
+
+libpng versions 0.5, May 1995, through 0.88, January 1996, are
+Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
+
+For the purposes of this copyright and license, "Contributing Authors"
+is defined as the following set of individuals:
+
+   Andreas Dilger
+   Dave Martindale
+   Guy Eric Schalnat
+   Paul Schmidt
+   Tim Wegner
+
+The PNG Reference Library is supplied "AS IS".  The Contributing Authors
+and Group 42, Inc. disclaim all warranties, expressed or implied,
+including, without limitation, the warranties of merchantability and of
+fitness for any purpose.  The Contributing Authors and Group 42, Inc.
+assume no liability for direct, indirect, incidental, special, exemplary,
+or consequential damages, which may result from the use of the PNG
+Reference Library, even if advised of the possibility of such damage.
+
+Permission is hereby granted to use, copy, modify, and distribute this
+source code, or portions hereof, for any purpose, without fee, subject
+to the following restrictions:
+
+1. The origin of this source code must not be misrepresented.
+
+2. Altered versions must be plainly marked as such and
+   must not be misrepresented as being the original source.
+
+3. This Copyright notice may not be removed or altered from
+   any source or altered source distribution.
+
+The Contributing Authors and Group 42, Inc. specifically permit, without
+fee, and encourage the use of this source code as a component to
+supporting the PNG file format in commercial products.  If you use this
+source code in a product, acknowledgment is not required but would be
+appreciated.
+
+
+A "png_get_copyright" function is available, for convenient use in "about"
+boxes and the like:
+
+   printf("%s",png_get_copyright(NULL));
+
+Also, the PNG logo (in PNG format, of course) is supplied in the
+files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
+
+Libpng is OSI Certified Open Source Software.  OSI Certified Open Source is a
+certification mark of the Open Source Initiative.
+
+Glenn Randers-Pehrson
+glennrp at users.sourceforge.net
+December 3, 2004
+
+.\" end of man page
+
diff --git a/com32/lib/libpng/libpngpf.3 b/com32/lib/libpng/libpngpf.3
new file mode 100644
index 00000000..d196d70c
--- /dev/null
+++ b/com32/lib/libpng/libpngpf.3
@@ -0,0 +1,1096 @@
+.TH LIBPNGPF 3 "December 3, 2004"
+.SH NAME
+libpng \- Portable Network Graphics (PNG) Reference Library 1.2.8
+(private functions)
+.SH SYNOPSIS
+\fB\fB#include <png.h>\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_build_gamma_table (png_structp \fI\fIpng_ptr\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_build_grayscale_palette (int \fP\fI\fP\fIbit_depth\fP\fB\fP\fB, png_colorp \fI\fIpalette\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_calculate_crc (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_bytep \fP\fI\fP\fIptr\fP\fB\fP\fB, png_size_t \fI\fIlength\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_check_chunk_name (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_bytep \fI\fIchunk_name\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBpng_size_t png_check_keyword (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_charp \fP\fI\fP\fIkey\fP\fB\fP\fB, png_charpp \fI\fInew_key\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_combine_row (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_bytep \fP\fI\fP\fIrow\fP\fB\fP\fB, int \fI\fImask\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_correct_palette (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_colorp \fP\fI\fP\fIpalette\fP\fB\fP\fB, int \fI\fInum_palette\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBint png_crc_error (png_structp \fI\fIpng_ptr\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBint png_crc_finish (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_uint_32 \fI\fIskip\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_crc_read (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_bytep \fP\fI\fP\fIbuf\fP\fB\fP\fB, png_size_t \fI\fIlength\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBpng_voidp png_create_struct (int \fI\fItype\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBpng_voidp png_create_struct_2 (int \fP\fI\fP\fItype\fP\fB\fP\fB, png_malloc_ptr \fP\fI\fP\fImalloc_fn\fP\fB\fP\fB, png_voidp \fI\fImem_ptr\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBpng_charp png_decompress_chunk (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, int \fP\fI\fP\fIcomp_type\fP\fB\fP\fB, png_charp \fP\fI\fP\fIchunkdata\fP\fB\fP\fB, png_size_t \fP\fI\fP\fIchunklength\fP\fB\fP\fB, png_size_t \fP\fI\fP\fIprefix_length\fP\fB\fP\fB, png_size_t \fI\fI*data_length\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_destroy_struct (png_voidp \fI\fIstruct_ptr\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_destroy_struct_2 (png_voidp \fP\fI\fP\fIstruct_ptr\fP\fB\fP\fB, png_free_ptr \fP\fI\fP\fIfree_fn\fP\fB\fP\fB, png_voidp \fI\fImem_ptr\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_do_background (png_row_infop \fP\fI\fP\fIrow_info\fP\fB\fP\fB, png_bytep \fP\fI\fP\fIrow\fP\fB\fP\fB, png_color_16p \fP\fI\fP\fItrans_values\fP\fB\fP\fB, png_color_16p \fP\fI\fP\fIbackground\fP\fB\fP\fB, png_color_16p \fP\fI\fP\fIbackground_1\fP\fB\fP\fB, png_bytep \fP\fI\fP\fIgamma_table\fP\fB\fP\fB, png_bytep \fP\fI\fP\fIgamma_from_1\fP\fB\fP\fB, png_bytep \fP\fI\fP\fIgamma_to_1\fP\fB\fP\fB, png_uint_16pp \fP\fI\fP\fIgamma_16\fP\fB\fP\fB, png_uint_16pp \fP\fI\fP\fIgamma_16_from_1\fP\fB\fP\fB, png_uint_16pp \fP\fI\fP\fIgamma_16_to_1\fP\fB\fP\fB, int \fI\fIgamma_shift\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_do_bgr (png_row_infop \fP\fI\fP\fIrow_info\fP\fB\fP\fB, png_bytep \fI\fIrow\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_do_chop (png_row_infop \fP\fI\fP\fIrow_info\fP\fB\fP\fB, png_bytep \fI\fIrow\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_do_dither (png_row_infop \fP\fI\fP\fIrow_info\fP\fB\fP\fB, png_bytep \fP\fI\fP\fIrow\fP\fB\fP\fB, png_bytep \fP\fI\fP\fIpalette_lookup\fP\fB\fP\fB, png_bytep \fI\fIdither_lookup\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_do_expand (png_row_infop \fP\fI\fP\fIrow_info\fP\fB\fP\fB, png_bytep \fP\fI\fP\fIrow\fP\fB\fP\fB, png_color_16p \fI\fItrans_value\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_do_expand_palette (png_row_infop \fP\fI\fP\fIrow_info\fP\fB\fP\fB, png_bytep \fP\fI\fP\fIrow\fP\fB\fP\fB, png_colorp \fP\fI\fP\fIpalette\fP\fB\fP\fB, png_bytep \fP\fI\fP\fItrans\fP\fB\fP\fB, int \fI\fInum_trans\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_do_gamma (png_row_infop \fP\fI\fP\fIrow_info\fP\fB\fP\fB, png_bytep \fP\fI\fP\fIrow\fP\fB\fP\fB, png_bytep \fP\fI\fP\fIgamma_table\fP\fB\fP\fB, png_uint_16pp \fP\fI\fP\fIgamma_16_table\fP\fB\fP\fB, int \fI\fIgamma_shift\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_do_gray_to_rgb (png_row_infop \fP\fI\fP\fIrow_info\fP\fB\fP\fB, png_bytep \fI\fIrow\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_do_invert (png_row_infop \fP\fI\fP\fIrow_info\fP\fB\fP\fB, png_bytep \fI\fIrow\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_do_pack (png_row_infop \fP\fI\fP\fIrow_info\fP\fB\fP\fB, png_bytep \fP\fI\fP\fIrow\fP\fB\fP\fB, png_uint_32 \fI\fIbit_depth\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_do_packswap (png_row_infop \fP\fI\fP\fIrow_info\fP\fB\fP\fB, png_bytep \fI\fIrow\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_do_read_filler (png_row_infop \fP\fI\fP\fIrow_info\fP\fB\fP\fB, png_bytep \fP\fI\fP\fIrow\fP\fB\fP\fB, png_uint_32 \fP\fI\fP\fIfiller\fP\fB\fP\fB, png_uint_32 \fI\fIflags\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_do_read_interlace (png_row_infop \fP\fI\fP\fIrow_info\fP\fB\fP\fB, png_bytep \fP\fI\fP\fIrow\fP\fB\fP\fB, int \fP\fI\fP\fIpass\fP\fB\fP\fB, png_uint_32 \fI\fItransformations\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_do_read_invert_alpha (png_row_infop \fP\fI\fP\fIrow_info\fP\fB\fP\fB, png_bytep \fI\fIrow\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_do_read_swap_alpha (png_row_infop \fP\fI\fP\fIrow_info\fP\fB\fP\fB, png_bytep \fI\fIrow\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_do_read_transformations (png_structp \fI\fIpng_ptr\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBint png_do_rgb_to_gray (png_row_infop \fP\fI\fP\fIrow_info\fP\fB\fP\fB, png_bytep \fI\fIrow\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_do_shift (png_row_infop \fP\fI\fP\fIrow_info\fP\fB\fP\fB, png_bytep \fP\fI\fP\fIrow\fP\fB\fP\fB, png_color_8p \fI\fIbit_depth\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_do_strip_filler (png_row_infop \fP\fI\fP\fIrow_info\fP\fB\fP\fB, png_bytep \fP\fI\fP\fIrow\fP\fB\fP\fB, png_uint_32 \fI\fIflags\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_do_swap (png_row_infop \fP\fI\fP\fIrow_info\fP\fB\fP\fB, png_bytep \fI\fIrow\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_do_unpack (png_row_infop \fP\fI\fP\fIrow_info\fP\fB\fP\fB, png_bytep \fI\fIrow\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_do_unshift (png_row_infop \fP\fI\fP\fIrow_info\fP\fB\fP\fB, png_bytep \fP\fI\fP\fIrow\fP\fB\fP\fB, png_color_8p \fI\fIsig_bits\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_do_write_interlace (png_row_infop \fP\fI\fP\fIrow_info\fP\fB\fP\fB, png_bytep \fP\fI\fP\fIrow\fP\fB\fP\fB, int \fI\fIpass\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_do_write_invert_alpha (png_row_infop \fP\fI\fP\fIrow_info\fP\fB\fP\fB, png_bytep \fI\fIrow\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_do_write_swap_alpha (png_row_infop \fP\fI\fP\fIrow_info\fP\fB\fP\fB, png_bytep \fI\fIrow\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_do_write_transformations (png_structp \fI\fIpng_ptr\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid *png_far_to_near (png_structp png_ptr,png_voidp \fP\fI\fP\fIptr\fP\fB\fP\fB, int \fI\fIcheck\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_flush (png_structp \fI\fIpng_ptr\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBpng_int_32 png_get_int_32 (png_bytep \fI\fIbuf\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBpng_uint_16 png_get_uint_16 (png_bytep \fI\fIbuf\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBpng_uint_32 png_get_uint_31 (png_bytep \fI\fIbuf\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBpng_uint_32 png_get_uint_32 (png_bytep \fI\fIbuf\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_handle_bKGD (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_infop \fP\fI\fP\fIinfo_ptr\fP\fB\fP\fB, png_uint_32 \fI\fIlength\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_handle_cHRM (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_infop \fP\fI\fP\fIinfo_ptr\fP\fB\fP\fB, png_uint_32 \fI\fIlength\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_handle_gAMA (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_infop \fP\fI\fP\fIinfo_ptr\fP\fB\fP\fB, png_uint_32 \fI\fIlength\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_handle_hIST (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_infop \fP\fI\fP\fIinfo_ptr\fP\fB\fP\fB, png_uint_32 \fI\fIlength\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_handle_IEND (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_infop \fP\fI\fP\fIinfo_ptr\fP\fB\fP\fB, png_uint_32 \fI\fIlength\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_handle_IHDR (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_infop \fP\fI\fP\fIinfo_ptr\fP\fB\fP\fB, png_uint_32 \fI\fIlength\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_handle_iCCP (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_infop \fP\fI\fP\fIinfo_ptr\fP\fB\fP\fB, png_uint_32 \fI\fIlength\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_handle_iTXt (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_infop \fP\fI\fP\fIinfo_ptr\fP\fB\fP\fB, png_uint_32 \fI\fIlength\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_handle_oFFs (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_infop \fP\fI\fP\fIinfo_ptr\fP\fB\fP\fB, png_uint_32 \fI\fIlength\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_handle_pCAL (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_infop \fP\fI\fP\fIinfo_ptr\fP\fB\fP\fB, png_uint_32 \fI\fIlength\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_handle_pHYs (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_infop \fP\fI\fP\fIinfo_ptr\fP\fB\fP\fB, png_uint_32 \fI\fIlength\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_handle_PLTE (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_infop \fP\fI\fP\fIinfo_ptr\fP\fB\fP\fB, png_uint_32 \fI\fIlength\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_handle_sBIT (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_infop \fP\fI\fP\fIinfo_ptr\fP\fB\fP\fB, png_uint_32 \fI\fIlength\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_handle_sCAL (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_infop \fP\fI\fP\fIinfo_ptr\fP\fB\fP\fB, png_uint_32 \fI\fIlength\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_handle_sPLT (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_infop \fP\fI\fP\fIinfo_ptr\fP\fB\fP\fB, png_uint_32 \fI\fIlength\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_handle_sRGB (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_infop \fP\fI\fP\fIinfo_ptr\fP\fB\fP\fB, png_uint_32 \fI\fIlength\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_handle_tEXt (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_infop \fP\fI\fP\fIinfo_ptr\fP\fB\fP\fB, png_uint_32 \fI\fIlength\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_handle_tIME (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_infop \fP\fI\fP\fIinfo_ptr\fP\fB\fP\fB, png_uint_32 \fI\fIlength\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_handle_tRNS (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_infop \fP\fI\fP\fIinfo_ptr\fP\fB\fP\fB, png_uint_32 \fI\fIlength\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_handle_unknown (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_infop \fP\fI\fP\fIinfo_ptr\fP\fB\fP\fB, png_uint_32 \fI\fIlength\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_handle_zTXt (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_infop \fP\fI\fP\fIinfo_ptr\fP\fB\fP\fB, png_uint_32 \fI\fIlength\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_info_destroy (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_infop \fI\fIinfo_ptr\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_init_mmx_flags (png_structp \fI\fIpng_ptr\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_init_read_transformations (png_structp \fI\fIpng_ptr\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_process_IDAT_data (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_bytep \fP\fI\fP\fIbuffer\fP\fB\fP\fB, png_size_t \fI\fIbuffer_length\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_process_some_data (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_infop \fI\fIinfo_ptr\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_push_check_crc (png_structp \fI\fIpng_ptr\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_push_crc_finish (png_structp \fI\fIpng_ptr\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_push_crc_skip (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_uint_32 \fI\fIlength\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_push_fill_buffer (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_bytep \fP\fI\fP\fIbuffer\fP\fB\fP\fB, png_size_t \fI\fIlength\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_push_handle_tEXt (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_infop \fP\fI\fP\fIinfo_ptr\fP\fB\fP\fB, png_uint_32 \fI\fIlength\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_push_handle_unknown (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_infop \fP\fI\fP\fIinfo_ptr\fP\fB\fP\fB, png_uint_32 \fI\fIlength\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_push_handle_zTXt (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_infop \fP\fI\fP\fIinfo_ptr\fP\fB\fP\fB, png_uint_32 \fI\fIlength\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_push_have_end (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_infop \fI\fIinfo_ptr\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_push_have_info (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_infop \fI\fIinfo_ptr\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_push_have_row (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_bytep \fI\fIrow\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_push_process_row (png_structp \fI\fIpng_ptr\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_push_read_chunk (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_infop \fI\fIinfo_ptr\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_push_read_end (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_infop \fI\fIinfo_ptr\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_push_read_IDAT (png_structp \fI\fIpng_ptr\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_push_read_sig (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_infop \fI\fIinfo_ptr\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_push_read_tEXt (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_infop \fI\fIinfo_ptr\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_push_read_zTXt (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_infop \fI\fIinfo_ptr\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_push_restore_buffer (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_bytep \fP\fI\fP\fIbuffer\fP\fB\fP\fB, png_size_t \fI\fIbuffer_length\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_push_save_buffer (png_structp \fI\fIpng_ptr\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_read_data (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_bytep \fP\fI\fP\fIdata\fP\fB\fP\fB, png_size_t \fI\fIlength\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_read_filter_row (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_row_infop \fP\fI\fP\fIrow_info\fP\fB\fP\fB, png_bytep \fP\fI\fP\fIrow\fP\fB\fP\fB, png_bytep \fP\fI\fP\fIprev_row\fP\fB\fP\fB, int \fI\fIfilter\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_read_finish_row (png_structp \fI\fIpng_ptr\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_read_push_finish_row (png_structp \fI\fIpng_ptr\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_read_start_row (png_structp \fI\fIpng_ptr\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_read_transform_info (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_infop \fI\fIinfo_ptr\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_reset_crc (png_structp \fI\fIpng_ptr\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_save_int_32 (png_bytep \fP\fI\fP\fIbuf\fP\fB\fP\fB, png_int_32 \fI\fIi\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_save_uint_16 (png_bytep \fP\fI\fP\fIbuf\fP\fB\fP\fB, unsigned int \fI\fIi\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_save_uint_32 (png_bytep \fP\fI\fP\fIbuf\fP\fB\fP\fB, png_uint_32 \fI\fIi\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBint png_set_text_2 (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_infop \fP\fI\fP\fIinfo_ptr\fP\fB\fP\fB, png_textp \fP\fI\fP\fItext_ptr\fP\fB\fP\fB, int \fI\fInum_text\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_write_cHRM (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, double \fP\fI\fP\fIwhite_x\fP\fB\fP\fB, double \fP\fI\fP\fIwhite_y\fP\fB\fP\fB, double \fP\fI\fP\fIred_x\fP\fB\fP\fB, double \fP\fI\fP\fIred_y\fP\fB\fP\fB, double \fP\fI\fP\fIgreen_x\fP\fB\fP\fB, double \fP\fI\fP\fIgreen_y\fP\fB\fP\fB, double \fP\fI\fP\fIblue_x\fP\fB\fP\fB, double \fI\fIblue_y\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_write_cHRM_fixed (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_uint_32 \fP\fI\fP\fIwhite_x\fP\fB\fP\fB, png_uint_32 \fP\fI\fP\fIwhite_y\fP\fB\fP\fB, png_uint_32 \fP\fI\fP\fIred_x\fP\fB\fP\fB, png_uint_32 \fP\fI\fP\fIred_y\fP\fB\fP\fB, png_uint_32 \fP\fI\fP\fIgreen_x\fP\fB\fP\fB, png_uint_32 \fP\fI\fP\fIgreen_y\fP\fB\fP\fB, png_uint_32 \fP\fI\fP\fIblue_x\fP\fB\fP\fB, png_uint_32 \fI\fIblue_y\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_write_data (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_bytep \fP\fI\fP\fIdata\fP\fB\fP\fB, png_size_t \fI\fIlength\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_write_filtered_row (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_bytep \fI\fIfiltered_row\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_write_find_filter (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_row_infop \fI\fIrow_info\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_write_finish_row (png_structp \fI\fIpng_ptr\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_write_gAMA (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, double \fI\fIfile_gamma\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_write_gAMA_fixed (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_uint_32 \fI\fIint_file_gamma\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_write_hIST (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_uint_16p \fP\fI\fP\fIhist\fP\fB\fP\fB, int \fI\fInum_hist\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_write_iCCP (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_charp \fP\fI\fP\fIname\fP\fB\fP\fB, int \fP\fI\fP\fIcompression_type\fP\fB\fP\fB, png_charp \fP\fI\fP\fIprofile\fP\fB\fP\fB, int \fI\fIproflen\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_write_IDAT (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_bytep \fP\fI\fP\fIdata\fP\fB\fP\fB, png_size_t \fI\fIlength\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_write_IEND (png_structp \fI\fIpng_ptr\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_write_IHDR (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_uint_32 \fP\fI\fP\fIwidth\fP\fB\fP\fB, png_uint_32 \fP\fI\fP\fIheight\fP\fB\fP\fB, int \fP\fI\fP\fIbit_depth\fP\fB\fP\fB, int \fP\fI\fP\fIcolor_type\fP\fB\fP\fB, int \fP\fI\fP\fIcompression_type\fP\fB\fP\fB, int \fP\fI\fP\fIfilter_type\fP\fB\fP\fB, int \fI\fIinterlace_type\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_write_iTXt (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, int \fP\fI\fP\fIcompression\fP\fB\fP\fB, png_charp \fP\fI\fP\fIkey\fP\fB\fP\fB, png_charp \fP\fI\fP\fIlang\fP\fB\fP\fB, png_charp \fP\fI\fP\fItranslated_key\fP\fB\fP\fB, png_charp \fI\fItext\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_write_oFFs (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_uint_32 \fP\fI\fP\fIx_offset\fP\fB\fP\fB, png_uint_32 \fP\fI\fP\fIy_offset\fP\fB\fP\fB, int \fI\fIunit_type\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_write_pCAL (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_charp \fP\fI\fP\fIpurpose\fP\fB\fP\fB, png_int_32 \fP\fI\fP\fIX0\fP\fB\fP\fB, png_int_32 \fP\fI\fP\fIX1\fP\fB\fP\fB, int \fP\fI\fP\fItype\fP\fB\fP\fB, int \fP\fI\fP\fInparams\fP\fB\fP\fB, png_charp \fP\fI\fP\fIunits\fP\fB\fP\fB, png_charpp \fI\fIparams\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_write_pHYs (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_uint_32 \fP\fI\fP\fIx_pixels_per_unit\fP\fB\fP\fB, png_uint_32 \fP\fI\fP\fIy_pixels_per_unit\fP\fB\fP\fB, int \fI\fIunit_type\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_write_PLTE (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_colorp \fP\fI\fP\fIpalette\fP\fB\fP\fB, png_uint_32 \fI\fInum_pal\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_write_sBIT (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_color_8p \fP\fI\fP\fIsbit\fP\fB\fP\fB, int \fI\fIcolor_type\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_write_sCAL (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_charp \fP\fI\fP\fIunit\fP\fB\fP\fB, double \fP\fI\fP\fIwidth\fP\fB\fP\fB, double \fI\fIheight\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_write_sCAL_s (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_charp \fP\fI\fP\fIunit\fP\fB\fP\fB, png_charp \fP\fI\fP\fIwidth\fP\fB\fP\fB, png_charp \fI\fIheight\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_write_sig (png_structp \fI\fIpng_ptr\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_write_sRGB (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, int \fI\fIintent\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_write_sPLT (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_spalette_p \fI\fIpalette\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_write_start_row (png_structp \fI\fIpng_ptr\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_write_tEXt (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_charp \fP\fI\fP\fIkey\fP\fB\fP\fB, png_charp \fP\fI\fP\fItext\fP\fB\fP\fB, png_size_t \fI\fItext_len\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_write_tIME (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_timep \fI\fImod_time\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_write_tRNS (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_bytep \fP\fI\fP\fItrans\fP\fB\fP\fB, png_color_16p \fP\fI\fP\fIvalues\fP\fB\fP\fB, int \fP\fI\fP\fInumber\fP\fB\fP\fB, int \fI\fIcolor_type\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_write_zTXt (png_structp \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, png_charp \fP\fI\fP\fIkey\fP\fB\fP\fB, png_charp \fP\fI\fP\fItext\fP\fB\fP\fB, png_size_t \fP\fI\fP\fItext_len\fP\fB\fP\fB, int \fI\fIcompression\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoidpf png_zalloc (voidpf \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, uInt \fP\fI\fP\fIitems\fP\fB\fP\fB, uInt \fI\fIsize\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+\fB\fBvoid png_zfree (voidpf \fP\fI\fP\fIpng_ptr\fP\fB\fP\fB, voidpf \fI\fIptr\fP\fB\fP\fB);\fP\fP
+
+\fI\fB
+
+\fI\fB\fI\fB
+
+\fI\fB
+
+.SH DESCRIPTION
+The functions listed above are used privately by libpng
+and are not recommended for use by applications.  They are
+not "exported" to applications using shared libraries.  They
+are listed alphabetically here as an aid to libpng maintainers.
+See png.h for more information on these functions.
+
+.SH SEE ALSO
+libpng(3), png(5)
+.SH AUTHOR
+Glenn Randers-Pehrson
diff --git a/com32/lib/libpng/png.5 b/com32/lib/libpng/png.5
new file mode 100644
index 00000000..db7c8341
--- /dev/null
+++ b/com32/lib/libpng/png.5
@@ -0,0 +1,74 @@
+.TH PNG 5 "December 3, 2004"
+.SH NAME
+png \- Portable Network Graphics (PNG) format
+.SH DESCRIPTION
+PNG (Portable Network Graphics) is an extensible file format for the
+lossless, portable, well-compressed storage of raster images. PNG provides
+a patent-free replacement for GIF and can also replace many
+common uses of TIFF. Indexed-color, grayscale, and truecolor images are
+supported, plus an optional alpha channel. Sample depths range from
+1 to 16 bits.
+.br
+
+PNG is designed to work well in online viewing applications, such as the
+World Wide Web, so it is fully streamable with a progressive display
+option. PNG is robust, providing both full file integrity checking and
+fast, simple detection of common transmission errors. Also, PNG can store
+gamma and chromaticity data for improved color matching on heterogeneous
+platforms.
+
+.SH "SEE ALSO"
+.IR libpng(3), zlib(3), deflate(5), and zlib(5)
+.LP
+PNG specification (second edition), November 2003:
+.IP
+.br
+  <http://www.w3.org/TR/2003/REC-PNG-20031110/
+PNG 1.2 specification, July 1999:
+.IP
+.br
+http://www.libpng.org/pub/png
+.LP
+PNG 1.0 specification, October 1996:
+.IP
+.br
+RFC 2083
+.IP
+.br
+ftp://ds.internic.net/rfc/rfc2083.txt
+.br
+or (as a W3C Recommendation) at
+.br
+http://www.w3.org/TR/REC-png.html
+.SH AUTHORS
+This man page: Glenn Randers-Pehrson
+.LP
+Portable Network Graphics (PNG) Specification (Second Edition)
+Information technology - Computer graphics and image processing -
+Portable Network Graphics (PNG): Functional specification.
+ISO/IEC 15948:2003 (E) (November 10, 2003): David Duce and others.
+.LP
+Portable Network Graphics (PNG) Specification Version 1.2 (July 8, 1999):
+Glenn Randers-Pehrson and others (png-list).
+.LP
+Portable Network Graphics (PNG) Specification Version 1.0 (October 1, 1996):
+Thomas Boutell and others (png-list).
+.LP
+
+
+.SH COPYRIGHT NOTICE
+.LP
+This man page is Copyright (c) 1998-2004 Glenn Randers-Pehrson.  See png.h
+for conditions of use and distribution.
+.LP
+The PNG Specification (Second Edition) is
+Copyright (c) 2003 W3C. (MIT, ERCIM, Keio), All Rights Reserved.
+.LP
+The PNG-1.2 specification is copyright (c) 1999 Glenn Randers-Pehrson.
+See the specification for conditions of use and distribution.
+.LP
+The PNG-1.0 specification is copyright (c) 1996 Massachusetts Institute of
+Technology.  See the specification for conditions of use and distribution.
+.LP
+.\" end of man page
+
diff --git a/com32/lib/libpng/png.h b/com32/lib/libpng/png.h
deleted file mode 100644
index e87a3011..00000000
--- a/com32/lib/libpng/png.h
+++ /dev/null
@@ -1,3419 +0,0 @@
-/* png.h - header file for PNG reference library
- *
- * libpng version 1.2.8 - December 3, 2004
- * Copyright (c) 1998-2004 Glenn Randers-Pehrson
- * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
- * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
- *
- * Authors and maintainers:
- *  libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat
- *  libpng versions 0.89c, June 1996, through 0.96, May 1997: Andreas Dilger
- *  libpng versions 0.97, January 1998, through 1.2.8 - December 3, 2004: Glenn
- *  See also "Contributing Authors", below.
- *
- * Note about libpng version numbers:
- *
- *    Due to various miscommunications, unforeseen code incompatibilities
- *    and occasional factors outside the authors' control, version numbering
- *    on the library has not always been consistent and straightforward.
- *    The following table summarizes matters since version 0.89c, which was
- *    the first widely used release:
- *
- *    source                 png.h  png.h  shared-lib
- *    version                string   int  version
- *    -------                ------ -----  ----------
- *    0.89c "1.0 beta 3"     0.89      89  1.0.89
- *    0.90  "1.0 beta 4"     0.90      90  0.90  [should have been 2.0.90]
- *    0.95  "1.0 beta 5"     0.95      95  0.95  [should have been 2.0.95]
- *    0.96  "1.0 beta 6"     0.96      96  0.96  [should have been 2.0.96]
- *    0.97b "1.00.97 beta 7" 1.00.97   97  1.0.1 [should have been 2.0.97]
- *    0.97c                  0.97      97  2.0.97
- *    0.98                   0.98      98  2.0.98
- *    0.99                   0.99      98  2.0.99
- *    0.99a-m                0.99      99  2.0.99
- *    1.00                   1.00     100  2.1.0 [100 should be 10000]
- *    1.0.0      (from here on, the   100  2.1.0 [100 should be 10000]
- *    1.0.1       png.h string is   10001  2.1.0
- *    1.0.1a-e    identical to the  10002  from here on, the shared library
- *    1.0.2       source version)   10002  is 2.V where V is the source code
- *    1.0.2a-b                      10003  version, except as noted.
- *    1.0.3                         10003
- *    1.0.3a-d                      10004
- *    1.0.4                         10004
- *    1.0.4a-f                      10005
- *    1.0.5 (+ 2 patches)           10005
- *    1.0.5a-d                      10006
- *    1.0.5e-r                      10100 (not source compatible)
- *    1.0.5s-v                      10006 (not binary compatible)
- *    1.0.6 (+ 3 patches)           10006 (still binary incompatible)
- *    1.0.6d-f                      10007 (still binary incompatible)
- *    1.0.6g                        10007
- *    1.0.6h                        10007  10.6h (testing xy.z so-numbering)
- *    1.0.6i                        10007  10.6i
- *    1.0.6j                        10007  2.1.0.6j (incompatible with 1.0.0)
- *    1.0.7beta11-14        DLLNUM  10007  2.1.0.7beta11-14 (binary compatible)
- *    1.0.7beta15-18           1    10007  2.1.0.7beta15-18 (binary compatible)
- *    1.0.7rc1-2               1    10007  2.1.0.7rc1-2 (binary compatible)
- *    1.0.7                    1    10007  (still compatible)
- *    1.0.8beta1-4             1    10008  2.1.0.8beta1-4
- *    1.0.8rc1                 1    10008  2.1.0.8rc1
- *    1.0.8                    1    10008  2.1.0.8
- *    1.0.9beta1-6             1    10009  2.1.0.9beta1-6
- *    1.0.9rc1                 1    10009  2.1.0.9rc1
- *    1.0.9beta7-10            1    10009  2.1.0.9beta7-10
- *    1.0.9rc2                 1    10009  2.1.0.9rc2
- *    1.0.9                    1    10009  2.1.0.9
- *    1.0.10beta1              1    10010  2.1.0.10beta1
- *    1.0.10rc1                1    10010  2.1.0.10rc1
- *    1.0.10                   1    10010  2.1.0.10
- *    1.0.11beta1-3            1    10011  2.1.0.11beta1-3
- *    1.0.11rc1                1    10011  2.1.0.11rc1
- *    1.0.11                   1    10011  2.1.0.11
- *    1.0.12beta1-2            2    10012  2.1.0.12beta1-2
- *    1.0.12rc1                2    10012  2.1.0.12rc1
- *    1.0.12                   2    10012  2.1.0.12
- *    1.1.0a-f                 -    10100  2.1.1.0a-f (branch abandoned)
- *    1.2.0beta1-2             2    10200  2.1.2.0beta1-2
- *    1.2.0beta3-5             3    10200  3.1.2.0beta3-5
- *    1.2.0rc1                 3    10200  3.1.2.0rc1
- *    1.2.0                    3    10200  3.1.2.0
- *    1.2.1beta1-4             3    10201  3.1.2.1beta1-4
- *    1.2.1rc1-2               3    10201  3.1.2.1rc1-2
- *    1.2.1                    3    10201  3.1.2.1
- *    1.2.2beta1-6            12    10202  12.so.0.1.2.2beta1-6
- *    1.0.13beta1             10    10013  10.so.0.1.0.13beta1
- *    1.0.13rc1               10    10013  10.so.0.1.0.13rc1
- *    1.2.2rc1                12    10202  12.so.0.1.2.2rc1
- *    1.0.13                  10    10013  10.so.0.1.0.13
- *    1.2.2                   12    10202  12.so.0.1.2.2
- *    1.2.3rc1-6              12    10203  12.so.0.1.2.3rc1-6
- *    1.2.3                   12    10203  12.so.0.1.2.3
- *    1.2.4beta1-3            13    10204  12.so.0.1.2.4beta1-3
- *    1.0.14rc1               13    10014  10.so.0.1.0.14rc1
- *    1.2.4rc1                13    10204  12.so.0.1.2.4rc1
- *    1.0.14                  10    10014  10.so.0.1.0.14
- *    1.2.4                   13    10204  12.so.0.1.2.4
- *    1.2.5beta1-2            13    10205  12.so.0.1.2.5beta1-2
- *    1.0.15rc1-3             10    10015  10.so.0.1.0.15rc1-3
- *    1.2.5rc1-3              13    10205  12.so.0.1.2.5rc1-3
- *    1.0.15                  10    10015  10.so.0.1.0.15
- *    1.2.5                   13    10205  12.so.0.1.2.5
- *    1.2.6beta1-4            13    10206  12.so.0.1.2.6beta1-4
- *    1.0.16                  10    10016  10.so.0.1.0.16
- *    1.2.6                   13    10206  12.so.0.1.2.6
- *    1.2.7beta1-2            13    10207  12.so.0.1.2.7beta1-2
- *    1.0.17rc1               10    10017  12.so.0.1.0.17rc1
- *    1.2.7rc1                13    10207  12.so.0.1.2.7rc1
- *    1.0.17                  10    10017  12.so.0.1.0.17
- *    1.2.7                   13    10207  12.so.0.1.2.7
- *    1.2.8beta1-5            13    10208  12.so.0.1.2.8beta1-5
- *    1.0.18rc1-5             10    10018  12.so.0.1.0.18rc1-5
- *    1.2.8rc1-5              13    10208  12.so.0.1.2.8rc1-5
- *    1.0.18                  10    10018  12.so.0.1.0.18
- *    1.2.8                   13    10208  12.so.0.1.2.8
- *
- *    Henceforth the source version will match the shared-library major
- *    and minor numbers; the shared-library major version number will be
- *    used for changes in backward compatibility, as it is intended.  The
- *    PNG_LIBPNG_VER macro, which is not used within libpng but is available
- *    for applications, is an unsigned integer of the form xyyzz corresponding
- *    to the source version x.y.z (leading zeros in y and z).  Beta versions
- *    were given the previous public release number plus a letter, until
- *    version 1.0.6j; from then on they were given the upcoming public
- *    release number plus "betaNN" or "rcN".
- *
- *    Binary incompatibility exists only when applications make direct access
- *    to the info_ptr or png_ptr members through png.h, and the compiled
- *    application is loaded with a different version of the library.
- *
- *    DLLNUM will change each time there are forward or backward changes
- *    in binary compatibility (e.g., when a new feature is added).
- *
- * See libpng.txt or libpng.3 for more information.  The PNG specification
- * is available as a W3C Recommendation and as an ISO Specification,
- * <http://www.w3.org/TR/2003/REC-PNG-20031110/
- */
-
-/*
- * COPYRIGHT NOTICE, DISCLAIMER, and LICENSE:
- *
- * If you modify libpng you may insert additional notices immediately following
- * this sentence.
- *
- * libpng versions 1.2.6, August 15, 2004, through 1.2.8, December 3, 2004, are
- * Copyright (c) 2004 Glenn Randers-Pehrson, and are
- * distributed according to the same disclaimer and license as libpng-1.2.5
- * with the following individual added to the list of Contributing Authors:
- *
- *    Cosmin Truta
- *
- * libpng versions 1.0.7, July 1, 2000, through 1.2.5, October 3, 2002, are
- * Copyright (c) 2000-2002 Glenn Randers-Pehrson, and are
- * distributed according to the same disclaimer and license as libpng-1.0.6
- * with the following individuals added to the list of Contributing Authors:
- *
- *    Simon-Pierre Cadieux
- *    Eric S. Raymond
- *    Gilles Vollant
- *
- * and with the following additions to the disclaimer:
- *
- *    There is no warranty against interference with your enjoyment of the
- *    library or against infringement.  There is no warranty that our
- *    efforts or the library will fulfill any of your particular purposes
- *    or needs.  This library is provided with all faults, and the entire
- *    risk of satisfactory quality, performance, accuracy, and effort is with
- *    the user.
- *
- * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
- * Copyright (c) 1998, 1999, 2000 Glenn Randers-Pehrson, and are
- * distributed according to the same disclaimer and license as libpng-0.96,
- * with the following individuals added to the list of Contributing Authors:
- *
- *    Tom Lane
- *    Glenn Randers-Pehrson
- *    Willem van Schaik
- *
- * libpng versions 0.89, June 1996, through 0.96, May 1997, are
- * Copyright (c) 1996, 1997 Andreas Dilger
- * Distributed according to the same disclaimer and license as libpng-0.88,
- * with the following individuals added to the list of Contributing Authors:
- *
- *    John Bowler
- *    Kevin Bracey
- *    Sam Bushell
- *    Magnus Holmgren
- *    Greg Roelofs
- *    Tom Tanner
- *
- * libpng versions 0.5, May 1995, through 0.88, January 1996, are
- * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
- *
- * For the purposes of this copyright and license, "Contributing Authors"
- * is defined as the following set of individuals:
- *
- *    Andreas Dilger
- *    Dave Martindale
- *    Guy Eric Schalnat
- *    Paul Schmidt
- *    Tim Wegner
- *
- * The PNG Reference Library is supplied "AS IS".  The Contributing Authors
- * and Group 42, Inc. disclaim all warranties, expressed or implied,
- * including, without limitation, the warranties of merchantability and of
- * fitness for any purpose.  The Contributing Authors and Group 42, Inc.
- * assume no liability for direct, indirect, incidental, special, exemplary,
- * or consequential damages, which may result from the use of the PNG
- * Reference Library, even if advised of the possibility of such damage.
- *
- * Permission is hereby granted to use, copy, modify, and distribute this
- * source code, or portions hereof, for any purpose, without fee, subject
- * to the following restrictions:
- *
- * 1. The origin of this source code must not be misrepresented.
- *
- * 2. Altered versions must be plainly marked as such and
- * must not be misrepresented as being the original source.
- *
- * 3. This Copyright notice may not be removed or altered from
- *    any source or altered source distribution.
- *
- * The Contributing Authors and Group 42, Inc. specifically permit, without
- * fee, and encourage the use of this source code as a component to
- * supporting the PNG file format in commercial products.  If you use this
- * source code in a product, acknowledgment is not required but would be
- * appreciated.
- */
-
-/*
- * A "png_get_copyright" function is available, for convenient use in "about"
- * boxes and the like:
- *
- * printf("%s",png_get_copyright(NULL));
- *
- * Also, the PNG logo (in PNG format, of course) is supplied in the
- * files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
- */
-
-/*
- * Libpng is OSI Certified Open Source Software.  OSI Certified is a
- * certification mark of the Open Source Initiative.
- */
-
-/*
- * The contributing authors would like to thank all those who helped
- * with testing, bug fixes, and patience.  This wouldn't have been
- * possible without all of you.
- *
- * Thanks to Frank J. T. Wojcik for helping with the documentation.
- */
-
-/*
- * Y2K compliance in libpng:
- * =========================
- *
- *    December 3, 2004
- *
- *    Since the PNG Development group is an ad-hoc body, we can't make
- *    an official declaration.
- *
- *    This is your unofficial assurance that libpng from version 0.71 and
- *    upward through 1.2.8 are Y2K compliant.  It is my belief that earlier
- *    versions were also Y2K compliant.
- *
- *    Libpng only has three year fields.  One is a 2-byte unsigned integer
- *    that will hold years up to 65535.  The other two hold the date in text
- *    format, and will hold years up to 9999.
- *
- *    The integer is
- *        "png_uint_16 year" in png_time_struct.
- *
- *    The strings are
- *        "png_charp time_buffer" in png_struct and
- *        "near_time_buffer", which is a local character string in png.c.
- *
- *    There are seven time-related functions:
- *        png.c: png_convert_to_rfc_1123() in png.c
- *          (formerly png_convert_to_rfc_1152() in error)
- *        png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c
- *        png_convert_from_time_t() in pngwrite.c
- *        png_get_tIME() in pngget.c
- *        png_handle_tIME() in pngrutil.c, called in pngread.c
- *        png_set_tIME() in pngset.c
- *        png_write_tIME() in pngwutil.c, called in pngwrite.c
- *
- *    All handle dates properly in a Y2K environment.  The
- *    png_convert_from_time_t() function calls gmtime() to convert from system
- *    clock time, which returns (year - 1900), which we properly convert to
- *    the full 4-digit year.  There is a possibility that applications using
- *    libpng are not passing 4-digit years into the png_convert_to_rfc_1123()
- *    function, or that they are incorrectly passing only a 2-digit year
- *    instead of "year - 1900" into the png_convert_from_struct_tm() function,
- *    but this is not under our control.  The libpng documentation has always
- *    stated that it works with 4-digit years, and the APIs have been
- *    documented as such.
- *
- *    The tIME chunk itself is also Y2K compliant.  It uses a 2-byte unsigned
- *    integer to hold the year, and can hold years as large as 65535.
- *
- *    zlib, upon which libpng depends, is also Y2K compliant.  It contains
- *    no date-related code.
- *
- *       Glenn Randers-Pehrson
- *       libpng maintainer
- *       PNG Development Group
- */
-
-#ifndef PNG_H
-#define PNG_H
-
-/* This is not the place to learn how to use libpng.  The file libpng.txt
- * describes how to use libpng, and the file example.c summarizes it
- * with some code on which to build.  This file is useful for looking
- * at the actual function definitions and structure components.
- */
-
-/* Version information for png.h - this should match the version in png.c */
-#define PNG_LIBPNG_VER_STRING "1.2.8"
-#define PNG_HEADER_VERSION_STRING \
-   " libpng version 1.2.8 - December 3, 2004 (header)\n"
-
-#define PNG_LIBPNG_VER_SONUM   0
-#define PNG_LIBPNG_VER_DLLNUM  13
-
-/* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
-#define PNG_LIBPNG_VER_MAJOR   1
-#define PNG_LIBPNG_VER_MINOR   2
-#define PNG_LIBPNG_VER_RELEASE 8
-/* This should match the numeric part of the final component of
- * PNG_LIBPNG_VER_STRING, omitting any leading zero: */
-
-#define PNG_LIBPNG_VER_BUILD  0
-
-/* Release Status */
-#define PNG_LIBPNG_BUILD_ALPHA    1
-#define PNG_LIBPNG_BUILD_BETA     2
-#define PNG_LIBPNG_BUILD_RC       3
-#define PNG_LIBPNG_BUILD_STABLE   4
-#define PNG_LIBPNG_BUILD_RELEASE_STATUS_MASK 7
-  
-/* Release-Specific Flags */
-#define PNG_LIBPNG_BUILD_PATCH    8 /* Can be OR'ed with
-                                       PNG_LIBPNG_BUILD_STABLE only */
-#define PNG_LIBPNG_BUILD_PRIVATE 16 /* Cannot be OR'ed with
-                                       PNG_LIBPNG_BUILD_SPECIAL */
-#define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with
-                                       PNG_LIBPNG_BUILD_PRIVATE */
-
-#define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_STABLE
-
-/* Careful here.  At one time, Guy wanted to use 082, but that would be octal.
- * We must not include leading zeros.
- * Versions 0.7 through 1.0.0 were in the range 0 to 100 here (only
- * version 1.0.0 was mis-numbered 100 instead of 10000).  From
- * version 1.0.1 it's    xxyyzz, where x=major, y=minor, z=release */
-#define PNG_LIBPNG_VER 10208 /* 1.2.8 */
-
-#ifndef PNG_VERSION_INFO_ONLY
-/* include the compression library's header */
-#include "zlib.h"
-#endif
-
-/* include all user configurable info, including optional assembler routines */
-#include "pngconf.h"
-
-/*
- * Added at libpng-1.2.8 */
-/* Ref MSDN: Private as priority over Special
- * VS_FF_PRIVATEBUILD File *was not* built using standard release
- * procedures. If this value is given, the StringFileInfo block must
- * contain a PrivateBuild string. 
- *
- * VS_FF_SPECIALBUILD File *was* built by the original company using
- * standard release procedures but is a variation of the standard
- * file of the same version number. If this value is given, the
- * StringFileInfo block must contain a SpecialBuild string. 
- */
-
-#if defined(PNG_USER_PRIVATEBUILD)
-#  define PNG_LIBPNG_BUILD_TYPE PNG_LIBPNG_BUILD_BASE_TYPE | \
-          PNG_LIBPNG_BUILD_PRIVATE
-#else
-#  if defined(PNG_LIBPNG_SPECIALBUILD)
-#    define PNG_LIBPNG_BUILD_TYPE PNG_LIBPNG_BUILD_BASE_TYPE | \
-            PNG_LIBPNG_BUILD_SPECIAL
-#  else
-#    define PNG_LIBPNG_BUILD_TYPE PNG_LIBPNG_BUILD_BASE_TYPE
-#  endif
-#endif
-
-#ifndef PNG_VERSION_INFO_ONLY
-
-/* Inhibit C++ name-mangling for libpng functions but not for system calls. */
-#ifdef __cplusplus
-extern "C" {
-#endif /* __cplusplus */
-
-/* This file is arranged in several sections.  The first section contains
- * structure and type definitions.  The second section contains the external
- * library functions, while the third has the internal library functions,
- * which applications aren't expected to use directly.
- */
-
-#ifndef PNG_NO_TYPECAST_NULL
-#define int_p_NULL                (int *)NULL
-#define png_bytep_NULL            (png_bytep)NULL
-#define png_bytepp_NULL           (png_bytepp)NULL
-#define png_doublep_NULL          (png_doublep)NULL
-#define png_error_ptr_NULL        (png_error_ptr)NULL
-#define png_flush_ptr_NULL        (png_flush_ptr)NULL
-#define png_free_ptr_NULL         (png_free_ptr)NULL
-#define png_infopp_NULL           (png_infopp)NULL
-#define png_malloc_ptr_NULL       (png_malloc_ptr)NULL
-#define png_read_status_ptr_NULL  (png_read_status_ptr)NULL
-#define png_rw_ptr_NULL           (png_rw_ptr)NULL
-#define png_structp_NULL          (png_structp)NULL
-#define png_uint_16p_NULL         (png_uint_16p)NULL
-#define png_voidp_NULL            (png_voidp)NULL
-#define png_write_status_ptr_NULL (png_write_status_ptr)NULL
-#else
-#define int_p_NULL                NULL
-#define png_bytep_NULL            NULL
-#define png_bytepp_NULL           NULL
-#define png_doublep_NULL          NULL
-#define png_error_ptr_NULL        NULL
-#define png_flush_ptr_NULL        NULL
-#define png_free_ptr_NULL         NULL
-#define png_infopp_NULL           NULL
-#define png_malloc_ptr_NULL       NULL
-#define png_read_status_ptr_NULL  NULL
-#define png_rw_ptr_NULL           NULL
-#define png_structp_NULL          NULL
-#define png_uint_16p_NULL         NULL
-#define png_voidp_NULL            NULL
-#define png_write_status_ptr_NULL NULL
-#endif
-
-/* variables declared in png.c - only it needs to define PNG_NO_EXTERN */
-#if !defined(PNG_NO_EXTERN) || defined(PNG_ALWAYS_EXTERN)
-/* Version information for C files, stored in png.c.  This had better match
- * the version above.
- */
-#ifdef PNG_USE_GLOBAL_ARRAYS
-PNG_EXPORT_VAR (const char) png_libpng_ver[18];
-  /* need room for 99.99.99beta99z */
-#else
-#define png_libpng_ver png_get_header_ver(NULL)
-#endif
-
-#ifdef PNG_USE_GLOBAL_ARRAYS
-/* This was removed in version 1.0.5c */
-/* Structures to facilitate easy interlacing.  See png.c for more details */
-PNG_EXPORT_VAR (const int FARDATA) png_pass_start[7];
-PNG_EXPORT_VAR (const int FARDATA) png_pass_inc[7];
-PNG_EXPORT_VAR (const int FARDATA) png_pass_ystart[7];
-PNG_EXPORT_VAR (const int FARDATA) png_pass_yinc[7];
-PNG_EXPORT_VAR (const int FARDATA) png_pass_mask[7];
-PNG_EXPORT_VAR (const int FARDATA) png_pass_dsp_mask[7];
-#ifdef PNG_HAVE_ASSEMBLER_COMBINE_ROW
-PNG_EXPORT_VAR (const int FARDATA) png_pass_width[7];
-#endif
-/* This isn't currently used.  If you need it, see png.c for more details.
-PNG_EXPORT_VAR (const int FARDATA) png_pass_height[7];
-*/
-#endif
-
-#endif /* PNG_NO_EXTERN */
-
-/* Three color definitions.  The order of the red, green, and blue, (and the
- * exact size) is not important, although the size of the fields need to
- * be png_byte or png_uint_16 (as defined below).
- */
-typedef struct png_color_struct
-{
-   png_byte red;
-   png_byte green;
-   png_byte blue;
-} png_color;
-typedef png_color FAR * png_colorp;
-typedef png_color FAR * FAR * png_colorpp;
-
-typedef struct png_color_16_struct
-{
-   png_byte index;    /* used for palette files */
-   png_uint_16 red;   /* for use in red green blue files */
-   png_uint_16 green;
-   png_uint_16 blue;
-   png_uint_16 gray;  /* for use in grayscale files */
-} png_color_16;
-typedef png_color_16 FAR * png_color_16p;
-typedef png_color_16 FAR * FAR * png_color_16pp;
-
-typedef struct png_color_8_struct
-{
-   png_byte red;   /* for use in red green blue files */
-   png_byte green;
-   png_byte blue;
-   png_byte gray;  /* for use in grayscale files */
-   png_byte alpha; /* for alpha channel files */
-} png_color_8;
-typedef png_color_8 FAR * png_color_8p;
-typedef png_color_8 FAR * FAR * png_color_8pp;
-
-/*
- * The following two structures are used for the in-core representation
- * of sPLT chunks.
- */
-typedef struct png_sPLT_entry_struct
-{
-   png_uint_16 red;
-   png_uint_16 green;
-   png_uint_16 blue;
-   png_uint_16 alpha;
-   png_uint_16 frequency;
-} png_sPLT_entry;
-typedef png_sPLT_entry FAR * png_sPLT_entryp;
-typedef png_sPLT_entry FAR * FAR * png_sPLT_entrypp;
-
-/*  When the depth of the sPLT palette is 8 bits, the color and alpha samples
- *  occupy the LSB of their respective members, and the MSB of each member
- *  is zero-filled.  The frequency member always occupies the full 16 bits.
- */
-
-typedef struct png_sPLT_struct
-{
-   png_charp name;           /* palette name */
-   png_byte depth;           /* depth of palette samples */
-   png_sPLT_entryp entries;  /* palette entries */
-   png_int_32 nentries;      /* number of palette entries */
-} png_sPLT_t;
-typedef png_sPLT_t FAR * png_sPLT_tp;
-typedef png_sPLT_t FAR * FAR * png_sPLT_tpp;
-
-#ifdef PNG_TEXT_SUPPORTED
-/* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file,
- * and whether that contents is compressed or not.  The "key" field
- * points to a regular zero-terminated C string.  The "text", "lang", and
- * "lang_key" fields can be regular C strings, empty strings, or NULL pointers.
- * However, the * structure returned by png_get_text() will always contain
- * regular zero-terminated C strings (possibly empty), never NULL pointers,
- * so they can be safely used in printf() and other string-handling functions.
- */
-typedef struct png_text_struct
-{
-   int  compression;       /* compression value:
-                             -1: tEXt, none
-                              0: zTXt, deflate
-                              1: iTXt, none
-                              2: iTXt, deflate  */
-   png_charp key;          /* keyword, 1-79 character description of "text" */
-   png_charp text;         /* comment, may be an empty string (ie "")
-                              or a NULL pointer */
-   png_size_t text_length; /* length of the text string */
-#ifdef PNG_iTXt_SUPPORTED
-   png_size_t itxt_length; /* length of the itxt string */
-   png_charp lang;         /* language code, 0-79 characters
-                              or a NULL pointer */
-   png_charp lang_key;     /* keyword translated UTF-8 string, 0 or more
-                              chars or a NULL pointer */
-#endif
-} png_text;
-typedef png_text FAR * png_textp;
-typedef png_text FAR * FAR * png_textpp;
-#endif
-
-/* Supported compression types for text in PNG files (tEXt, and zTXt).
- * The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed. */
-#define PNG_TEXT_COMPRESSION_NONE_WR -3
-#define PNG_TEXT_COMPRESSION_zTXt_WR -2
-#define PNG_TEXT_COMPRESSION_NONE    -1
-#define PNG_TEXT_COMPRESSION_zTXt     0
-#define PNG_ITXT_COMPRESSION_NONE     1
-#define PNG_ITXT_COMPRESSION_zTXt     2
-#define PNG_TEXT_COMPRESSION_LAST     3  /* Not a valid value */
-
-/* png_time is a way to hold the time in an machine independent way.
- * Two conversions are provided, both from time_t and struct tm.  There
- * is no portable way to convert to either of these structures, as far
- * as I know.  If you know of a portable way, send it to me.  As a side
- * note - PNG has always been Year 2000 compliant!
- */
-typedef struct png_time_struct
-{
-   png_uint_16 year; /* full year, as in, 1995 */
-   png_byte month;   /* month of year, 1 - 12 */
-   png_byte day;     /* day of month, 1 - 31 */
-   png_byte hour;    /* hour of day, 0 - 23 */
-   png_byte minute;  /* minute of hour, 0 - 59 */
-   png_byte second;  /* second of minute, 0 - 60 (for leap seconds) */
-} png_time;
-typedef png_time FAR * png_timep;
-typedef png_time FAR * FAR * png_timepp;
-
-#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
-/* png_unknown_chunk is a structure to hold queued chunks for which there is
- * no specific support.  The idea is that we can use this to queue
- * up private chunks for output even though the library doesn't actually
- * know about their semantics.
- */
-typedef struct png_unknown_chunk_t
-{
-    png_byte name[5];
-    png_byte *data;
-    png_size_t size;
-
-    /* libpng-using applications should NOT directly modify this byte. */
-    png_byte location; /* mode of operation at read time */
-}
-png_unknown_chunk;
-typedef png_unknown_chunk FAR * png_unknown_chunkp;
-typedef png_unknown_chunk FAR * FAR * png_unknown_chunkpp;
-#endif
-
-/* png_info is a structure that holds the information in a PNG file so
- * that the application can find out the characteristics of the image.
- * If you are reading the file, this structure will tell you what is
- * in the PNG file.  If you are writing the file, fill in the information
- * you want to put into the PNG file, then call png_write_info().
- * The names chosen should be very close to the PNG specification, so
- * consult that document for information about the meaning of each field.
- *
- * With libpng < 0.95, it was only possible to directly set and read the
- * the values in the png_info_struct, which meant that the contents and
- * order of the values had to remain fixed.  With libpng 0.95 and later,
- * however, there are now functions that abstract the contents of
- * png_info_struct from the application, so this makes it easier to use
- * libpng with dynamic libraries, and even makes it possible to use
- * libraries that don't have all of the libpng ancillary chunk-handing
- * functionality.
- *
- * In any case, the order of the parameters in png_info_struct should NOT
- * be changed for as long as possible to keep compatibility with applications
- * that use the old direct-access method with png_info_struct.
- *
- * The following members may have allocated storage attached that should be
- * cleaned up before the structure is discarded: palette, trans, text,
- * pcal_purpose, pcal_units, pcal_params, hist, iccp_name, iccp_profile,
- * splt_palettes, scal_unit, row_pointers, and unknowns.   By default, these
- * are automatically freed when the info structure is deallocated, if they were
- * allocated internally by libpng.  This behavior can be changed by means
- * of the png_data_freer() function.
- *
- * More allocation details: all the chunk-reading functions that
- * change these members go through the corresponding png_set_*
- * functions.  A function to clear these members is available: see
- * png_free_data().  The png_set_* functions do not depend on being
- * able to point info structure members to any of the storage they are
- * passed (they make their own copies), EXCEPT that the png_set_text
- * functions use the same storage passed to them in the text_ptr or
- * itxt_ptr structure argument, and the png_set_rows and png_set_unknowns
- * functions do not make their own copies.
- */
-typedef struct png_info_struct
-{
-   /* the following are necessary for every PNG file */
-   png_uint_32 width;       /* width of image in pixels (from IHDR) */
-   png_uint_32 height;      /* height of image in pixels (from IHDR) */
-   png_uint_32 valid;       /* valid chunk data (see PNG_INFO_ below) */
-   png_uint_32 rowbytes;    /* bytes needed to hold an untransformed row */
-   png_colorp palette;      /* array of color values (valid & PNG_INFO_PLTE) */
-   png_uint_16 num_palette; /* number of color entries in "palette" (PLTE) */
-   png_uint_16 num_trans;   /* number of transparent palette color (tRNS) */
-   png_byte bit_depth;      /* 1, 2, 4, 8, or 16 bits/channel (from IHDR) */
-   png_byte color_type;     /* see PNG_COLOR_TYPE_ below (from IHDR) */
-   /* The following three should have been named *_method not *_type */
-   png_byte compression_type; /* must be PNG_COMPRESSION_TYPE_BASE (IHDR) */
-   png_byte filter_type;    /* must be PNG_FILTER_TYPE_BASE (from IHDR) */
-   png_byte interlace_type; /* One of PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
-
-   /* The following is informational only on read, and not used on writes. */
-   png_byte channels;       /* number of data channels per pixel (1, 2, 3, 4) */
-   png_byte pixel_depth;    /* number of bits per pixel */
-   png_byte spare_byte;     /* to align the data, and for future use */
-   png_byte signature[8];   /* magic bytes read by libpng from start of file */
-
-   /* The rest of the data is optional.  If you are reading, check the
-    * valid field to see if the information in these are valid.  If you
-    * are writing, set the valid field to those chunks you want written,
-    * and initialize the appropriate fields below.
-    */
-
-#if defined(PNG_gAMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED)
-   /* The gAMA chunk describes the gamma characteristics of the system
-    * on which the image was created, normally in the range [1.0, 2.5].
-    * Data is valid if (valid & PNG_INFO_gAMA) is non-zero.
-    */
-   float gamma; /* gamma value of image, if (valid & PNG_INFO_gAMA) */
-#endif
-
-#if defined(PNG_sRGB_SUPPORTED)
-    /* GR-P, 0.96a */
-    /* Data valid if (valid & PNG_INFO_sRGB) non-zero. */
-   png_byte srgb_intent; /* sRGB rendering intent [0, 1, 2, or 3] */
-#endif
-
-#if defined(PNG_TEXT_SUPPORTED)
-   /* The tEXt, and zTXt chunks contain human-readable textual data in
-    * uncompressed, compressed, and optionally compressed forms, respectively.
-    * The data in "text" is an array of pointers to uncompressed,
-    * null-terminated C strings. Each chunk has a keyword that describes the
-    * textual data contained in that chunk.  Keywords are not required to be
-    * unique, and the text string may be empty.  Any number of text chunks may
-    * be in an image.
-    */
-   int num_text; /* number of comments read/to write */
-   int max_text; /* current size of text array */
-   png_textp text; /* array of comments read/to write */
-#endif /* PNG_TEXT_SUPPORTED */
-
-#if defined(PNG_tIME_SUPPORTED)
-   /* The tIME chunk holds the last time the displayed image data was
-    * modified.  See the png_time struct for the contents of this struct.
-    */
-   png_time mod_time;
-#endif
-
-#if defined(PNG_sBIT_SUPPORTED)
-   /* The sBIT chunk specifies the number of significant high-order bits
-    * in the pixel data.  Values are in the range [1, bit_depth], and are
-    * only specified for the channels in the pixel data.  The contents of
-    * the low-order bits is not specified.  Data is valid if
-    * (valid & PNG_INFO_sBIT) is non-zero.
-    */
-   png_color_8 sig_bit; /* significant bits in color channels */
-#endif
-
-#if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_EXPAND_SUPPORTED) || \
-defined(PNG_READ_BACKGROUND_SUPPORTED)
-   /* The tRNS chunk supplies transparency data for paletted images and
-    * other image types that don't need a full alpha channel.  There are
-    * "num_trans" transparency values for a paletted image, stored in the
-    * same order as the palette colors, starting from index 0.  Values
-    * for the data are in the range [0, 255], ranging from fully transparent
-    * to fully opaque, respectively.  For non-paletted images, there is a
-    * single color specified that should be treated as fully transparent.
-    * Data is valid if (valid & PNG_INFO_tRNS) is non-zero.
-    */
-   png_bytep trans; /* transparent values for paletted image */
-   png_color_16 trans_values; /* transparent color for non-palette image */
-#endif
-
-#if defined(PNG_bKGD_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
-   /* The bKGD chunk gives the suggested image background color if the
-    * display program does not have its own background color and the image
-    * is needs to composited onto a background before display.  The colors
-    * in "background" are normally in the same color space/depth as the
-    * pixel data.  Data is valid if (valid & PNG_INFO_bKGD) is non-zero.
-    */
-   png_color_16 background;
-#endif
-
-#if defined(PNG_oFFs_SUPPORTED)
-   /* The oFFs chunk gives the offset in "offset_unit_type" units rightwards
-    * and downwards from the top-left corner of the display, page, or other
-    * application-specific co-ordinate space.  See the PNG_OFFSET_ defines
-    * below for the unit types.  Valid if (valid & PNG_INFO_oFFs) non-zero.
-    */
-   png_int_32 x_offset; /* x offset on page */
-   png_int_32 y_offset; /* y offset on page */
-   png_byte offset_unit_type; /* offset units type */
-#endif
-
-#if defined(PNG_pHYs_SUPPORTED)
-   /* The pHYs chunk gives the physical pixel density of the image for
-    * display or printing in "phys_unit_type" units (see PNG_RESOLUTION_
-    * defines below).  Data is valid if (valid & PNG_INFO_pHYs) is non-zero.
-    */
-   png_uint_32 x_pixels_per_unit; /* horizontal pixel density */
-   png_uint_32 y_pixels_per_unit; /* vertical pixel density */
-   png_byte phys_unit_type; /* resolution type (see PNG_RESOLUTION_ below) */
-#endif
-
-#if defined(PNG_hIST_SUPPORTED)
-   /* The hIST chunk contains the relative frequency or importance of the
-    * various palette entries, so that a viewer can intelligently select a
-    * reduced-color palette, if required.  Data is an array of "num_palette"
-    * values in the range [0,65535]. Data valid if (valid & PNG_INFO_hIST)
-    * is non-zero.
-    */
-   png_uint_16p hist;
-#endif
-
-#ifdef PNG_cHRM_SUPPORTED
-   /* The cHRM chunk describes the CIE color characteristics of the monitor
-    * on which the PNG was created.  This data allows the viewer to do gamut
-    * mapping of the input image to ensure that the viewer sees the same
-    * colors in the image as the creator.  Values are in the range
-    * [0.0, 0.8].  Data valid if (valid & PNG_INFO_cHRM) non-zero.
-    */
-#ifdef PNG_FLOATING_POINT_SUPPORTED
-   float x_white;
-   float y_white;
-   float x_red;
-   float y_red;
-   float x_green;
-   float y_green;
-   float x_blue;
-   float y_blue;
-#endif
-#endif
-
-#if defined(PNG_pCAL_SUPPORTED)
-   /* The pCAL chunk describes a transformation between the stored pixel
-    * values and original physical data values used to create the image.
-    * The integer range [0, 2^bit_depth - 1] maps to the floating-point
-    * range given by [pcal_X0, pcal_X1], and are further transformed by a
-    * (possibly non-linear) transformation function given by "pcal_type"
-    * and "pcal_params" into "pcal_units".  Please see the PNG_EQUATION_
-    * defines below, and the PNG-Group's PNG extensions document for a
-    * complete description of the transformations and how they should be
-    * implemented, and for a description of the ASCII parameter strings.
-    * Data values are valid if (valid & PNG_INFO_pCAL) non-zero.
-    */
-   png_charp pcal_purpose;  /* pCAL chunk description string */
-   png_int_32 pcal_X0;      /* minimum value */
-   png_int_32 pcal_X1;      /* maximum value */
-   png_charp pcal_units;    /* Latin-1 string giving physical units */
-   png_charpp pcal_params;  /* ASCII strings containing parameter values */
-   png_byte pcal_type;      /* equation type (see PNG_EQUATION_ below) */
-   png_byte pcal_nparams;   /* number of parameters given in pcal_params */
-#endif
-
-/* New members added in libpng-1.0.6 */
-#ifdef PNG_FREE_ME_SUPPORTED
-   png_uint_32 free_me;     /* flags items libpng is responsible for freeing */
-#endif
-
-#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
-   /* storage for unknown chunks that the library doesn't recognize. */
-   png_unknown_chunkp unknown_chunks;
-   png_size_t unknown_chunks_num;
-#endif
-
-#if defined(PNG_iCCP_SUPPORTED)
-   /* iCCP chunk data. */
-   png_charp iccp_name;     /* profile name */
-   png_charp iccp_profile;  /* International Color Consortium profile data */
-                            /* Note to maintainer: should be png_bytep */
-   png_uint_32 iccp_proflen;  /* ICC profile data length */
-   png_byte iccp_compression; /* Always zero */
-#endif
-
-#if defined(PNG_sPLT_SUPPORTED)
-   /* data on sPLT chunks (there may be more than one). */
-   png_sPLT_tp splt_palettes;
-   png_uint_32 splt_palettes_num;
-#endif
-
-#if defined(PNG_sCAL_SUPPORTED)
-   /* The sCAL chunk describes the actual physical dimensions of the
-    * subject matter of the graphic.  The chunk contains a unit specification
-    * a byte value, and two ASCII strings representing floating-point
-    * values.  The values are width and height corresponsing to one pixel
-    * in the image.  This external representation is converted to double
-    * here.  Data values are valid if (valid & PNG_INFO_sCAL) is non-zero.
-    */
-   png_byte scal_unit;         /* unit of physical scale */
-#ifdef PNG_FLOATING_POINT_SUPPORTED
-   double scal_pixel_width;    /* width of one pixel */
-   double scal_pixel_height;   /* height of one pixel */
-#endif
-#ifdef PNG_FIXED_POINT_SUPPORTED
-   png_charp scal_s_width;     /* string containing height */
-   png_charp scal_s_height;    /* string containing width */
-#endif
-#endif
-
-#if defined(PNG_INFO_IMAGE_SUPPORTED)
-   /* Memory has been allocated if (valid & PNG_ALLOCATED_INFO_ROWS) non-zero */
-   /* Data valid if (valid & PNG_INFO_IDAT) non-zero */
-   png_bytepp row_pointers;        /* the image bits */
-#endif
-
-#if defined(PNG_FIXED_POINT_SUPPORTED) && defined(PNG_gAMA_SUPPORTED)
-   png_fixed_point int_gamma; /* gamma of image, if (valid & PNG_INFO_gAMA) */
-#endif
-
-#if defined(PNG_cHRM_SUPPORTED) && defined(PNG_FIXED_POINT_SUPPORTED)
-   png_fixed_point int_x_white;
-   png_fixed_point int_y_white;
-   png_fixed_point int_x_red;
-   png_fixed_point int_y_red;
-   png_fixed_point int_x_green;
-   png_fixed_point int_y_green;
-   png_fixed_point int_x_blue;
-   png_fixed_point int_y_blue;
-#endif
-
-} png_info;
-
-typedef png_info FAR * png_infop;
-typedef png_info FAR * FAR * png_infopp;
-
-/* Maximum positive integer used in PNG is (2^31)-1 */
-#define PNG_UINT_31_MAX ((png_uint_32)0x7fffffffL)
-#define PNG_UINT_32_MAX ((png_uint_32)(-1))
-#define PNG_SIZE_MAX ((png_size_t)(-1))
-/* PNG_MAX_UINT is deprecated; use PNG_UINT_31_MAX instead. */
-#define PNG_MAX_UINT PNG_UINT_31_MAX
-
-/* These describe the color_type field in png_info. */
-/* color type masks */
-#define PNG_COLOR_MASK_PALETTE    1
-#define PNG_COLOR_MASK_COLOR      2
-#define PNG_COLOR_MASK_ALPHA      4
-
-/* color types.  Note that not all combinations are legal */
-#define PNG_COLOR_TYPE_GRAY 0
-#define PNG_COLOR_TYPE_PALETTE  (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE)
-#define PNG_COLOR_TYPE_RGB        (PNG_COLOR_MASK_COLOR)
-#define PNG_COLOR_TYPE_RGB_ALPHA  (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA)
-#define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA)
-/* aliases */
-#define PNG_COLOR_TYPE_RGBA  PNG_COLOR_TYPE_RGB_ALPHA
-#define PNG_COLOR_TYPE_GA  PNG_COLOR_TYPE_GRAY_ALPHA
-
-/* This is for compression type. PNG 1.0-1.2 only define the single type. */
-#define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */
-#define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE
-
-/* This is for filter type. PNG 1.0-1.2 only define the single type. */
-#define PNG_FILTER_TYPE_BASE      0 /* Single row per-byte filtering */
-#define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */
-#define PNG_FILTER_TYPE_DEFAULT   PNG_FILTER_TYPE_BASE
-
-/* These are for the interlacing type.  These values should NOT be changed. */
-#define PNG_INTERLACE_NONE        0 /* Non-interlaced image */
-#define PNG_INTERLACE_ADAM7       1 /* Adam7 interlacing */
-#define PNG_INTERLACE_LAST        2 /* Not a valid value */
-
-/* These are for the oFFs chunk.  These values should NOT be changed. */
-#define PNG_OFFSET_PIXEL          0 /* Offset in pixels */
-#define PNG_OFFSET_MICROMETER     1 /* Offset in micrometers (1/10^6 meter) */
-#define PNG_OFFSET_LAST           2 /* Not a valid value */
-
-/* These are for the pCAL chunk.  These values should NOT be changed. */
-#define PNG_EQUATION_LINEAR       0 /* Linear transformation */
-#define PNG_EQUATION_BASE_E       1 /* Exponential base e transform */
-#define PNG_EQUATION_ARBITRARY    2 /* Arbitrary base exponential transform */
-#define PNG_EQUATION_HYPERBOLIC   3 /* Hyperbolic sine transformation */
-#define PNG_EQUATION_LAST         4 /* Not a valid value */
-
-/* These are for the sCAL chunk.  These values should NOT be changed. */
-#define PNG_SCALE_UNKNOWN         0 /* unknown unit (image scale) */
-#define PNG_SCALE_METER           1 /* meters per pixel */
-#define PNG_SCALE_RADIAN          2 /* radians per pixel */
-#define PNG_SCALE_LAST            3 /* Not a valid value */
-
-/* These are for the pHYs chunk.  These values should NOT be changed. */
-#define PNG_RESOLUTION_UNKNOWN    0 /* pixels/unknown unit (aspect ratio) */
-#define PNG_RESOLUTION_METER      1 /* pixels/meter */
-#define PNG_RESOLUTION_LAST       2 /* Not a valid value */
-
-/* These are for the sRGB chunk.  These values should NOT be changed. */
-#define PNG_sRGB_INTENT_PERCEPTUAL 0
-#define PNG_sRGB_INTENT_RELATIVE   1
-#define PNG_sRGB_INTENT_SATURATION 2
-#define PNG_sRGB_INTENT_ABSOLUTE   3
-#define PNG_sRGB_INTENT_LAST       4 /* Not a valid value */
-
-/* This is for text chunks */
-#define PNG_KEYWORD_MAX_LENGTH     79
-
-/* Maximum number of entries in PLTE/sPLT/tRNS arrays */
-#define PNG_MAX_PALETTE_LENGTH    256
-
-/* These determine if an ancillary chunk's data has been successfully read
- * from the PNG header, or if the application has filled in the corresponding
- * data in the info_struct to be written into the output file.  The values
- * of the PNG_INFO_<chunk> defines should NOT be changed.
- */
-#define PNG_INFO_gAMA 0x0001
-#define PNG_INFO_sBIT 0x0002
-#define PNG_INFO_cHRM 0x0004
-#define PNG_INFO_PLTE 0x0008
-#define PNG_INFO_tRNS 0x0010
-#define PNG_INFO_bKGD 0x0020
-#define PNG_INFO_hIST 0x0040
-#define PNG_INFO_pHYs 0x0080
-#define PNG_INFO_oFFs 0x0100
-#define PNG_INFO_tIME 0x0200
-#define PNG_INFO_pCAL 0x0400
-#define PNG_INFO_sRGB 0x0800   /* GR-P, 0.96a */
-#define PNG_INFO_iCCP 0x1000   /* ESR, 1.0.6 */
-#define PNG_INFO_sPLT 0x2000   /* ESR, 1.0.6 */
-#define PNG_INFO_sCAL 0x4000   /* ESR, 1.0.6 */
-#define PNG_INFO_IDAT 0x8000L  /* ESR, 1.0.6 */
-
-/* This is used for the transformation routines, as some of them
- * change these values for the row.  It also should enable using
- * the routines for other purposes.
- */
-typedef struct png_row_info_struct
-{
-   png_uint_32 width; /* width of row */
-   png_uint_32 rowbytes; /* number of bytes in row */
-   png_byte color_type; /* color type of row */
-   png_byte bit_depth; /* bit depth of row */
-   png_byte channels; /* number of channels (1, 2, 3, or 4) */
-   png_byte pixel_depth; /* bits per pixel (depth * channels) */
-} png_row_info;
-
-typedef png_row_info FAR * png_row_infop;
-typedef png_row_info FAR * FAR * png_row_infopp;
-
-/* These are the function types for the I/O functions and for the functions
- * that allow the user to override the default I/O functions with his or her
- * own.  The png_error_ptr type should match that of user-supplied warning
- * and error functions, while the png_rw_ptr type should match that of the
- * user read/write data functions.
- */
-typedef struct png_struct_def png_struct;
-typedef png_struct FAR * png_structp;
-
-typedef void (PNGAPI *png_error_ptr) PNGARG((png_structp, png_const_charp));
-typedef void (PNGAPI *png_rw_ptr) PNGARG((png_structp, png_bytep, png_size_t));
-typedef void (PNGAPI *png_flush_ptr) PNGARG((png_structp));
-typedef void (PNGAPI *png_read_status_ptr) PNGARG((png_structp, png_uint_32,
-   int));
-typedef void (PNGAPI *png_write_status_ptr) PNGARG((png_structp, png_uint_32,
-   int));
-
-#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
-typedef void (PNGAPI *png_progressive_info_ptr) PNGARG((png_structp, png_infop));
-typedef void (PNGAPI *png_progressive_end_ptr) PNGARG((png_structp, png_infop));
-typedef void (PNGAPI *png_progressive_row_ptr) PNGARG((png_structp, png_bytep,
-   png_uint_32, int));
-#endif
-
-#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
-    defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) || \
-    defined(PNG_LEGACY_SUPPORTED)
-typedef void (PNGAPI *png_user_transform_ptr) PNGARG((png_structp,
-    png_row_infop, png_bytep));
-#endif
-
-#if defined(PNG_USER_CHUNKS_SUPPORTED)
-typedef int (PNGAPI *png_user_chunk_ptr) PNGARG((png_structp, png_unknown_chunkp));
-#endif
-#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
-typedef void (PNGAPI *png_unknown_chunk_ptr) PNGARG((png_structp));
-#endif
-
-/* Transform masks for the high-level interface */
-#define PNG_TRANSFORM_IDENTITY       0x0000    /* read and write */
-#define PNG_TRANSFORM_STRIP_16       0x0001    /* read only */
-#define PNG_TRANSFORM_STRIP_ALPHA    0x0002    /* read only */
-#define PNG_TRANSFORM_PACKING        0x0004    /* read and write */
-#define PNG_TRANSFORM_PACKSWAP       0x0008    /* read and write */
-#define PNG_TRANSFORM_EXPAND         0x0010    /* read only */
-#define PNG_TRANSFORM_INVERT_MONO    0x0020    /* read and write */
-#define PNG_TRANSFORM_SHIFT          0x0040    /* read and write */
-#define PNG_TRANSFORM_BGR            0x0080    /* read and write */
-#define PNG_TRANSFORM_SWAP_ALPHA     0x0100    /* read and write */
-#define PNG_TRANSFORM_SWAP_ENDIAN    0x0200    /* read and write */
-#define PNG_TRANSFORM_INVERT_ALPHA   0x0400    /* read and write */
-#define PNG_TRANSFORM_STRIP_FILLER   0x0800    /* WRITE only */
-
-/* Flags for MNG supported features */
-#define PNG_FLAG_MNG_EMPTY_PLTE     0x01
-#define PNG_FLAG_MNG_FILTER_64      0x04
-#define PNG_ALL_MNG_FEATURES        0x05
-
-typedef png_voidp (*png_malloc_ptr) PNGARG((png_structp, png_size_t));
-typedef void (*png_free_ptr) PNGARG((png_structp, png_voidp));
-
-/* The structure that holds the information to read and write PNG files.
- * The only people who need to care about what is inside of this are the
- * people who will be modifying the library for their own special needs.
- * It should NOT be accessed directly by an application, except to store
- * the jmp_buf.
- */
-
-struct png_struct_def
-{
-#ifdef PNG_SETJMP_SUPPORTED
-   jmp_buf jmpbuf;            /* used in png_error */
-#endif
-   png_error_ptr error_fn;    /* function for printing errors and aborting */
-   png_error_ptr warning_fn;  /* function for printing warnings */
-   png_voidp error_ptr;       /* user supplied struct for error functions */
-   png_rw_ptr write_data_fn;  /* function for writing output data */
-   png_rw_ptr read_data_fn;   /* function for reading input data */
-   png_voidp io_ptr;          /* ptr to application struct for I/O functions */
-
-#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED)
-   png_user_transform_ptr read_user_transform_fn; /* user read transform */
-#endif
-
-#if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
-   png_user_transform_ptr write_user_transform_fn; /* user write transform */
-#endif
-
-/* These were added in libpng-1.0.2 */
-#if defined(PNG_USER_TRANSFORM_PTR_SUPPORTED)
-#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
-    defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
-   png_voidp user_transform_ptr; /* user supplied struct for user transform */
-   png_byte user_transform_depth;    /* bit depth of user transformed pixels */
-   png_byte user_transform_channels; /* channels in user transformed pixels */
-#endif
-#endif
-
-   png_uint_32 mode;          /* tells us where we are in the PNG file */
-   png_uint_32 flags;         /* flags indicating various things to libpng */
-   png_uint_32 transformations; /* which transformations to perform */
-
-   z_stream zstream;          /* pointer to decompression structure (below) */
-   png_bytep zbuf;            /* buffer for zlib */
-   png_size_t zbuf_size;      /* size of zbuf */
-   int zlib_level;            /* holds zlib compression level */
-   int zlib_method;           /* holds zlib compression method */
-   int zlib_window_bits;      /* holds zlib compression window bits */
-   int zlib_mem_level;        /* holds zlib compression memory level */
-   int zlib_strategy;         /* holds zlib compression strategy */
-
-   png_uint_32 width;         /* width of image in pixels */
-   png_uint_32 height;        /* height of image in pixels */
-   png_uint_32 num_rows;      /* number of rows in current pass */
-   png_uint_32 usr_width;     /* width of row at start of write */
-   png_uint_32 rowbytes;      /* size of row in bytes */
-   png_uint_32 irowbytes;     /* size of current interlaced row in bytes */
-   png_uint_32 iwidth;        /* width of current interlaced row in pixels */
-   png_uint_32 row_number;    /* current row in interlace pass */
-   png_bytep prev_row;        /* buffer to save previous (unfiltered) row */
-   png_bytep row_buf;         /* buffer to save current (unfiltered) row */
-   png_bytep sub_row;         /* buffer to save "sub" row when filtering */
-   png_bytep up_row;          /* buffer to save "up" row when filtering */
-   png_bytep avg_row;         /* buffer to save "avg" row when filtering */
-   png_bytep paeth_row;       /* buffer to save "Paeth" row when filtering */
-   png_row_info row_info;     /* used for transformation routines */
-
-   png_uint_32 idat_size;     /* current IDAT size for read */
-   png_uint_32 crc;           /* current chunk CRC value */
-   png_colorp palette;        /* palette from the input file */
-   png_uint_16 num_palette;   /* number of color entries in palette */
-   png_uint_16 num_trans;     /* number of transparency values */
-   png_byte chunk_name[5];    /* null-terminated name of current chunk */
-   png_byte compression;      /* file compression type (always 0) */
-   png_byte filter;           /* file filter type (always 0) */
-   png_byte interlaced;       /* PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
-   png_byte pass;             /* current interlace pass (0 - 6) */
-   png_byte do_filter;        /* row filter flags (see PNG_FILTER_ below ) */
-   png_byte color_type;       /* color type of file */
-   png_byte bit_depth;        /* bit depth of file */
-   png_byte usr_bit_depth;    /* bit depth of users row */
-   png_byte pixel_depth;      /* number of bits per pixel */
-   png_byte channels;         /* number of channels in file */
-   png_byte usr_channels;     /* channels at start of write */
-   png_byte sig_bytes;        /* magic bytes read/written from start of file */
-
-#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
-#ifdef PNG_LEGACY_SUPPORTED
-   png_byte filler;           /* filler byte for pixel expansion */
-#else
-   png_uint_16 filler;           /* filler bytes for pixel expansion */
-#endif
-#endif
-
-#if defined(PNG_bKGD_SUPPORTED)
-   png_byte background_gamma_type;
-#  ifdef PNG_FLOATING_POINT_SUPPORTED
-   float background_gamma;
-#  endif
-   png_color_16 background;   /* background color in screen gamma space */
-#if defined(PNG_READ_GAMMA_SUPPORTED)
-   png_color_16 background_1; /* background normalized to gamma 1.0 */
-#endif
-#endif /* PNG_bKGD_SUPPORTED */
-
-#if defined(PNG_WRITE_FLUSH_SUPPORTED)
-   png_flush_ptr output_flush_fn;/* Function for flushing output */
-   png_uint_32 flush_dist;    /* how many rows apart to flush, 0 - no flush */
-   png_uint_32 flush_rows;    /* number of rows written since last flush */
-#endif
-
-#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
-   int gamma_shift;      /* number of "insignificant" bits 16-bit gamma */
-#ifdef PNG_FLOATING_POINT_SUPPORTED
-   float gamma;          /* file gamma value */
-   float screen_gamma;   /* screen gamma value (display_exponent) */
-#endif
-#endif
-
-#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
-   png_bytep gamma_table;     /* gamma table for 8-bit depth files */
-   png_bytep gamma_from_1;    /* converts from 1.0 to screen */
-   png_bytep gamma_to_1;      /* converts from file to 1.0 */
-   png_uint_16pp gamma_16_table; /* gamma table for 16-bit depth files */
-   png_uint_16pp gamma_16_from_1; /* converts from 1.0 to screen */
-   png_uint_16pp gamma_16_to_1; /* converts from file to 1.0 */
-#endif
-
-#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_sBIT_SUPPORTED)
-   png_color_8 sig_bit;       /* significant bits in each available channel */
-#endif
-
-#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
-   png_color_8 shift;         /* shift for significant bit tranformation */
-#endif
-
-#if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) \
- || defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
-   png_bytep trans;           /* transparency values for paletted files */
-   png_color_16 trans_values; /* transparency values for non-paletted files */
-#endif
-
-   png_read_status_ptr read_row_fn;   /* called after each row is decoded */
-   png_write_status_ptr write_row_fn; /* called after each row is encoded */
-#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
-   png_progressive_info_ptr info_fn; /* called after header data fully read */
-   png_progressive_row_ptr row_fn;   /* called after each prog. row is decoded */
-   png_progressive_end_ptr end_fn;   /* called after image is complete */
-   png_bytep save_buffer_ptr;        /* current location in save_buffer */
-   png_bytep save_buffer;            /* buffer for previously read data */
-   png_bytep current_buffer_ptr;     /* current location in current_buffer */
-   png_bytep current_buffer;         /* buffer for recently used data */
-   png_uint_32 push_length;          /* size of current input chunk */
-   png_uint_32 skip_length;          /* bytes to skip in input data */
-   png_size_t save_buffer_size;      /* amount of data now in save_buffer */
-   png_size_t save_buffer_max;       /* total size of save_buffer */
-   png_size_t buffer_size;           /* total amount of available input data */
-   png_size_t current_buffer_size;   /* amount of data now in current_buffer */
-   int process_mode;                 /* what push library is currently doing */
-   int cur_palette;                  /* current push library palette index */
-
-#  if defined(PNG_TEXT_SUPPORTED)
-     png_size_t current_text_size;   /* current size of text input data */
-     png_size_t current_text_left;   /* how much text left to read in input */
-     png_charp current_text;         /* current text chunk buffer */
-     png_charp current_text_ptr;     /* current location in current_text */
-#  endif /* PNG_PROGRESSIVE_READ_SUPPORTED && PNG_TEXT_SUPPORTED */
-
-#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
-
-#if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__)
-/* for the Borland special 64K segment handler */
-   png_bytepp offset_table_ptr;
-   png_bytep offset_table;
-   png_uint_16 offset_table_number;
-   png_uint_16 offset_table_count;
-   png_uint_16 offset_table_count_free;
-#endif
-
-#if defined(PNG_READ_DITHER_SUPPORTED)
-   png_bytep palette_lookup;         /* lookup table for dithering */
-   png_bytep dither_index;           /* index translation for palette files */
-#endif
-
-#if defined(PNG_READ_DITHER_SUPPORTED) || defined(PNG_hIST_SUPPORTED)
-   png_uint_16p hist;                /* histogram */
-#endif
-
-#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
-   png_byte heuristic_method;        /* heuristic for row filter selection */
-   png_byte num_prev_filters;        /* number of weights for previous rows */
-   png_bytep prev_filters;           /* filter type(s) of previous row(s) */
-   png_uint_16p filter_weights;      /* weight(s) for previous line(s) */
-   png_uint_16p inv_filter_weights;  /* 1/weight(s) for previous line(s) */
-   png_uint_16p filter_costs;        /* relative filter calculation cost */
-   png_uint_16p inv_filter_costs;    /* 1/relative filter calculation cost */
-#endif
-
-#if defined(PNG_TIME_RFC1123_SUPPORTED)
-   png_charp time_buffer;            /* String to hold RFC 1123 time text */
-#endif
-
-/* New members added in libpng-1.0.6 */
-
-#ifdef PNG_FREE_ME_SUPPORTED
-   png_uint_32 free_me;       /* flags items libpng is responsible for freeing */
-#endif
-
-#if defined(PNG_USER_CHUNKS_SUPPORTED)
-   png_voidp user_chunk_ptr;
-   png_user_chunk_ptr read_user_chunk_fn; /* user read chunk handler */
-#endif
-
-#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
-   int num_chunk_list;
-   png_bytep chunk_list;
-#endif
-
-/* New members added in libpng-1.0.3 */
-#if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
-   png_byte rgb_to_gray_status;
-   /* These were changed from png_byte in libpng-1.0.6 */
-   png_uint_16 rgb_to_gray_red_coeff;
-   png_uint_16 rgb_to_gray_green_coeff;
-   png_uint_16 rgb_to_gray_blue_coeff;
-#endif
-
-/* New member added in libpng-1.0.4 (renamed in 1.0.9) */
-#if defined(PNG_MNG_FEATURES_SUPPORTED) || \
-    defined(PNG_READ_EMPTY_PLTE_SUPPORTED) || \
-    defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED)
-/* changed from png_byte to png_uint_32 at version 1.2.0 */
-#ifdef PNG_1_0_X
-   png_byte mng_features_permitted;
-#else
-   png_uint_32 mng_features_permitted;
-#endif /* PNG_1_0_X */
-#endif
-
-/* New member added in libpng-1.0.7 */
-#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
-   png_fixed_point int_gamma;
-#endif
-
-/* New member added in libpng-1.0.9, ifdef'ed out in 1.0.12, enabled in 1.2.0 */
-#if defined(PNG_MNG_FEATURES_SUPPORTED)
-   png_byte filter_type;
-#endif
-
-#if defined(PNG_1_0_X) || (defined(PNG_DEBUG) && defined(PNG_USE_PNGGCCRD))
-/* New member added in libpng-1.0.10, ifdef'ed out in 1.2.0 */
-   png_uint_32 row_buf_size;
-#endif
-
-/* New members added in libpng-1.2.0 */
-#if !defined(PNG_1_0_X) && defined(PNG_ASSEMBLER_CODE_SUPPORTED)
-   png_byte     mmx_bitdepth_threshold;
-   png_uint_32  mmx_rowbytes_threshold;
-   png_uint_32  asm_flags;
-#endif
-
-/* New members added in libpng-1.0.2 but first enabled by default in 1.2.0 */
-#ifdef PNG_USER_MEM_SUPPORTED
-   png_voidp mem_ptr;                /* user supplied struct for mem functions */
-   png_malloc_ptr malloc_fn;         /* function for allocating memory */
-   png_free_ptr free_fn;             /* function for freeing memory */
-#endif
-
-/* New member added in libpng-1.0.13 and 1.2.0 */
-   png_bytep big_row_buf;         /* buffer to save current (unfiltered) row */
-
-#if defined(PNG_READ_DITHER_SUPPORTED)
-/* The following three members were added at version 1.0.14 and 1.2.4 */
-   png_bytep dither_sort;            /* working sort array */
-   png_bytep index_to_palette;       /* where the original index currently is */
-                                     /* in the palette */
-   png_bytep palette_to_index;       /* which original index points to this */
-                                     /* palette color */
-#endif
-
-/* New members added in libpng-1.0.16 and 1.2.6 */
-   png_byte compression_type;
-
-#ifdef PNG_SET_USER_LIMITS_SUPPORTED
-   png_uint_32 user_width_max;
-   png_uint_32 user_height_max;
-#endif
-
-};
-
-
-/* This triggers a compiler error in png.c, if png.c and png.h
- * do not agree upon the version number.
- */
-typedef png_structp version_1_2_8;
-
-typedef png_struct FAR * FAR * png_structpp;
-
-/* Here are the function definitions most commonly used.  This is not
- * the place to find out how to use libpng.  See libpng.txt for the
- * full explanation, see example.c for the summary.  This just provides
- * a simple one line description of the use of each function.
- */
-
-/* Returns the version number of the library */
-extern PNG_EXPORT(png_uint_32,png_access_version_number) PNGARG((void));
-
-/* Tell lib we have already handled the first <num_bytes> magic bytes.
- * Handling more than 8 bytes from the beginning of the file is an error.
- */
-extern PNG_EXPORT(void,png_set_sig_bytes) PNGARG((png_structp png_ptr,
-   int num_bytes));
-
-/* Check sig[start] through sig[start + num_to_check - 1] to see if it's a
- * PNG file.  Returns zero if the supplied bytes match the 8-byte PNG
- * signature, and non-zero otherwise.  Having num_to_check == 0 or
- * start > 7 will always fail (ie return non-zero).
- */
-extern PNG_EXPORT(int,png_sig_cmp) PNGARG((png_bytep sig, png_size_t start,
-   png_size_t num_to_check));
-
-/* Simple signature checking function.  This is the same as calling
- * png_check_sig(sig, n) := !png_sig_cmp(sig, 0, n).
- */
-extern PNG_EXPORT(int,png_check_sig) PNGARG((png_bytep sig, int num));
-
-/* Allocate and initialize png_ptr struct for reading, and any other memory. */
-extern PNG_EXPORT(png_structp,png_create_read_struct)
-   PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
-   png_error_ptr error_fn, png_error_ptr warn_fn));
-
-/* Allocate and initialize png_ptr struct for writing, and any other memory */
-extern PNG_EXPORT(png_structp,png_create_write_struct)
-   PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
-   png_error_ptr error_fn, png_error_ptr warn_fn));
-
-#ifdef PNG_WRITE_SUPPORTED
-extern PNG_EXPORT(png_uint_32,png_get_compression_buffer_size)
-   PNGARG((png_structp png_ptr));
-#endif
-
-#ifdef PNG_WRITE_SUPPORTED
-extern PNG_EXPORT(void,png_set_compression_buffer_size)
-   PNGARG((png_structp png_ptr, png_uint_32 size));
-#endif
-
-/* Reset the compression stream */
-extern PNG_EXPORT(int,png_reset_zstream) PNGARG((png_structp png_ptr));
-
-/* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */
-#ifdef PNG_USER_MEM_SUPPORTED
-extern PNG_EXPORT(png_structp,png_create_read_struct_2)
-   PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
-   png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
-   png_malloc_ptr malloc_fn, png_free_ptr free_fn));
-extern PNG_EXPORT(png_structp,png_create_write_struct_2)
-   PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
-   png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
-   png_malloc_ptr malloc_fn, png_free_ptr free_fn));
-#endif
-
-/* Write a PNG chunk - size, type, (optional) data, CRC. */
-extern PNG_EXPORT(void,png_write_chunk) PNGARG((png_structp png_ptr,
-   png_bytep chunk_name, png_bytep data, png_size_t length));
-
-/* Write the start of a PNG chunk - length and chunk name. */
-extern PNG_EXPORT(void,png_write_chunk_start) PNGARG((png_structp png_ptr,
-   png_bytep chunk_name, png_uint_32 length));
-
-/* Write the data of a PNG chunk started with png_write_chunk_start(). */
-extern PNG_EXPORT(void,png_write_chunk_data) PNGARG((png_structp png_ptr,
-   png_bytep data, png_size_t length));
-
-/* Finish a chunk started with png_write_chunk_start() (includes CRC). */
-extern PNG_EXPORT(void,png_write_chunk_end) PNGARG((png_structp png_ptr));
-
-/* Allocate and initialize the info structure */
-extern PNG_EXPORT(png_infop,png_create_info_struct)
-   PNGARG((png_structp png_ptr));
-
-/* Initialize the info structure (old interface - DEPRECATED) */
-extern PNG_EXPORT(void,png_info_init) PNGARG((png_infop info_ptr));
-#undef png_info_init
-#define png_info_init(info_ptr) png_info_init_3(&info_ptr,\
-    png_sizeof(png_info));
-extern PNG_EXPORT(void,png_info_init_3) PNGARG((png_infopp info_ptr,
-    png_size_t png_info_struct_size));
-
-/* Writes all the PNG information before the image. */
-extern PNG_EXPORT(void,png_write_info_before_PLTE) PNGARG((png_structp png_ptr,
-   png_infop info_ptr));
-extern PNG_EXPORT(void,png_write_info) PNGARG((png_structp png_ptr,
-   png_infop info_ptr));
-
-#ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
-/* read the information before the actual image data. */
-extern PNG_EXPORT(void,png_read_info) PNGARG((png_structp png_ptr,
-   png_infop info_ptr));
-#endif
-
-#if defined(PNG_TIME_RFC1123_SUPPORTED)
-extern PNG_EXPORT(png_charp,png_convert_to_rfc1123)
-   PNGARG((png_structp png_ptr, png_timep ptime));
-#endif
-
-#if !defined(_WIN32_WCE)
-/* "time.h" functions are not supported on WindowsCE */
-#if defined(PNG_WRITE_tIME_SUPPORTED)
-/* convert from a struct tm to png_time */
-extern PNG_EXPORT(void,png_convert_from_struct_tm) PNGARG((png_timep ptime,
-   struct tm FAR * ttime));
-
-/* convert from time_t to png_time.  Uses gmtime() */
-extern PNG_EXPORT(void,png_convert_from_time_t) PNGARG((png_timep ptime,
-   time_t ttime));
-#endif /* PNG_WRITE_tIME_SUPPORTED */
-#endif /* _WIN32_WCE */
-
-#if defined(PNG_READ_EXPAND_SUPPORTED)
-/* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */
-extern PNG_EXPORT(void,png_set_expand) PNGARG((png_structp png_ptr));
-extern PNG_EXPORT(void,png_set_gray_1_2_4_to_8) PNGARG((png_structp png_ptr));
-extern PNG_EXPORT(void,png_set_palette_to_rgb) PNGARG((png_structp png_ptr));
-extern PNG_EXPORT(void,png_set_tRNS_to_alpha) PNGARG((png_structp png_ptr));
-#endif
-
-#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
-/* Use blue, green, red order for pixels. */
-extern PNG_EXPORT(void,png_set_bgr) PNGARG((png_structp png_ptr));
-#endif
-
-#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
-/* Expand the grayscale to 24-bit RGB if necessary. */
-extern PNG_EXPORT(void,png_set_gray_to_rgb) PNGARG((png_structp png_ptr));
-#endif
-
-#if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
-/* Reduce RGB to grayscale. */
-#ifdef PNG_FLOATING_POINT_SUPPORTED
-extern PNG_EXPORT(void,png_set_rgb_to_gray) PNGARG((png_structp png_ptr,
-   int error_action, double red, double green ));
-#endif
-extern PNG_EXPORT(void,png_set_rgb_to_gray_fixed) PNGARG((png_structp png_ptr,
-   int error_action, png_fixed_point red, png_fixed_point green ));
-extern PNG_EXPORT(png_byte,png_get_rgb_to_gray_status) PNGARG((png_structp
-   png_ptr));
-#endif
-
-extern PNG_EXPORT(void,png_build_grayscale_palette) PNGARG((int bit_depth,
-   png_colorp palette));
-
-#if defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
-extern PNG_EXPORT(void,png_set_strip_alpha) PNGARG((png_structp png_ptr));
-#endif
-
-#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \
-    defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
-extern PNG_EXPORT(void,png_set_swap_alpha) PNGARG((png_structp png_ptr));
-#endif
-
-#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \
-    defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
-extern PNG_EXPORT(void,png_set_invert_alpha) PNGARG((png_structp png_ptr));
-#endif
-
-#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
-/* Add a filler byte to 8-bit Gray or 24-bit RGB images. */
-extern PNG_EXPORT(void,png_set_filler) PNGARG((png_structp png_ptr,
-   png_uint_32 filler, int flags));
-/* The values of the PNG_FILLER_ defines should NOT be changed */
-#define PNG_FILLER_BEFORE 0
-#define PNG_FILLER_AFTER 1
-/* Add an alpha byte to 8-bit Gray or 24-bit RGB images. */
-#if !defined(PNG_1_0_X)
-extern PNG_EXPORT(void,png_set_add_alpha) PNGARG((png_structp png_ptr,
-   png_uint_32 filler, int flags));
-#endif
-#endif /* PNG_READ_FILLER_SUPPORTED || PNG_WRITE_FILLER_SUPPORTED */
-
-#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
-/* Swap bytes in 16-bit depth files. */
-extern PNG_EXPORT(void,png_set_swap) PNGARG((png_structp png_ptr));
-#endif
-
-#if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
-/* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */
-extern PNG_EXPORT(void,png_set_packing) PNGARG((png_structp png_ptr));
-#endif
-
-#if defined(PNG_READ_PACKSWAP_SUPPORTED) || defined(PNG_WRITE_PACKSWAP_SUPPORTED)
-/* Swap packing order of pixels in bytes. */
-extern PNG_EXPORT(void,png_set_packswap) PNGARG((png_structp png_ptr));
-#endif
-
-#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
-/* Converts files to legal bit depths. */
-extern PNG_EXPORT(void,png_set_shift) PNGARG((png_structp png_ptr,
-   png_color_8p true_bits));
-#endif
-
-#if defined(PNG_READ_INTERLACING_SUPPORTED) || \
-    defined(PNG_WRITE_INTERLACING_SUPPORTED)
-/* Have the code handle the interlacing.  Returns the number of passes. */
-extern PNG_EXPORT(int,png_set_interlace_handling) PNGARG((png_structp png_ptr));
-#endif
-
-#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
-/* Invert monochrome files */
-extern PNG_EXPORT(void,png_set_invert_mono) PNGARG((png_structp png_ptr));
-#endif
-
-#if defined(PNG_READ_BACKGROUND_SUPPORTED)
-/* Handle alpha and tRNS by replacing with a background color. */
-#ifdef PNG_FLOATING_POINT_SUPPORTED
-extern PNG_EXPORT(void,png_set_background) PNGARG((png_structp png_ptr,
-   png_color_16p background_color, int background_gamma_code,
-   int need_expand, double background_gamma));
-#endif
-#define PNG_BACKGROUND_GAMMA_UNKNOWN 0
-#define PNG_BACKGROUND_GAMMA_SCREEN  1
-#define PNG_BACKGROUND_GAMMA_FILE    2
-#define PNG_BACKGROUND_GAMMA_UNIQUE  3
-#endif
-
-#if defined(PNG_READ_16_TO_8_SUPPORTED)
-/* strip the second byte of information from a 16-bit depth file. */
-extern PNG_EXPORT(void,png_set_strip_16) PNGARG((png_structp png_ptr));
-#endif
-
-#if defined(PNG_READ_DITHER_SUPPORTED)
-/* Turn on dithering, and reduce the palette to the number of colors available. */
-extern PNG_EXPORT(void,png_set_dither) PNGARG((png_structp png_ptr,
-   png_colorp palette, int num_palette, int maximum_colors,
-   png_uint_16p histogram, int full_dither));
-#endif
-
-#if defined(PNG_READ_GAMMA_SUPPORTED)
-/* Handle gamma correction. Screen_gamma=(display_exponent) */
-#ifdef PNG_FLOATING_POINT_SUPPORTED
-extern PNG_EXPORT(void,png_set_gamma) PNGARG((png_structp png_ptr,
-   double screen_gamma, double default_file_gamma));
-#endif
-#endif
-
-#if defined(PNG_READ_EMPTY_PLTE_SUPPORTED) || \
-    defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED)
-/* Permit or disallow empty PLTE (0: not permitted, 1: permitted) */
-/* Deprecated and will be removed.  Use png_permit_mng_features() instead. */
-extern PNG_EXPORT(void,png_permit_empty_plte) PNGARG((png_structp png_ptr,
-   int empty_plte_permitted));
-#endif
-
-#if defined(PNG_WRITE_FLUSH_SUPPORTED)
-/* Set how many lines between output flushes - 0 for no flushing */
-extern PNG_EXPORT(void,png_set_flush) PNGARG((png_structp png_ptr, int nrows));
-/* Flush the current PNG output buffer */
-extern PNG_EXPORT(void,png_write_flush) PNGARG((png_structp png_ptr));
-#endif
-
-/* optional update palette with requested transformations */
-extern PNG_EXPORT(void,png_start_read_image) PNGARG((png_structp png_ptr));
-
-/* optional call to update the users info structure */
-extern PNG_EXPORT(void,png_read_update_info) PNGARG((png_structp png_ptr,
-   png_infop info_ptr));
-
-#ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
-/* read one or more rows of image data. */
-extern PNG_EXPORT(void,png_read_rows) PNGARG((png_structp png_ptr,
-   png_bytepp row, png_bytepp display_row, png_uint_32 num_rows));
-#endif
-
-#ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
-/* read a row of data. */
-extern PNG_EXPORT(void,png_read_row) PNGARG((png_structp png_ptr,
-   png_bytep row,
-   png_bytep display_row));
-#endif
-
-#ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
-/* read the whole image into memory at once. */
-extern PNG_EXPORT(void,png_read_image) PNGARG((png_structp png_ptr,
-   png_bytepp image));
-#endif
-
-/* write a row of image data */
-extern PNG_EXPORT(void,png_write_row) PNGARG((png_structp png_ptr,
-   png_bytep row));
-
-/* write a few rows of image data */
-extern PNG_EXPORT(void,png_write_rows) PNGARG((png_structp png_ptr,
-   png_bytepp row, png_uint_32 num_rows));
-
-/* write the image data */
-extern PNG_EXPORT(void,png_write_image) PNGARG((png_structp png_ptr,
-   png_bytepp image));
-
-/* writes the end of the PNG file. */
-extern PNG_EXPORT(void,png_write_end) PNGARG((png_structp png_ptr,
-   png_infop info_ptr));
-
-#ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
-/* read the end of the PNG file. */
-extern PNG_EXPORT(void,png_read_end) PNGARG((png_structp png_ptr,
-   png_infop info_ptr));
-#endif
-
-/* free any memory associated with the png_info_struct */
-extern PNG_EXPORT(void,png_destroy_info_struct) PNGARG((png_structp png_ptr,
-   png_infopp info_ptr_ptr));
-
-/* free any memory associated with the png_struct and the png_info_structs */
-extern PNG_EXPORT(void,png_destroy_read_struct) PNGARG((png_structpp
-   png_ptr_ptr, png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr));
-
-/* free all memory used by the read (old method - NOT DLL EXPORTED) */
-extern void png_read_destroy PNGARG((png_structp png_ptr, png_infop info_ptr,
-   png_infop end_info_ptr));
-
-/* free any memory associated with the png_struct and the png_info_structs */
-extern PNG_EXPORT(void,png_destroy_write_struct)
-   PNGARG((png_structpp png_ptr_ptr, png_infopp info_ptr_ptr));
-
-/* free any memory used in png_ptr struct (old method - NOT DLL EXPORTED) */
-extern void png_write_destroy PNGARG((png_structp png_ptr));
-
-/* set the libpng method of handling chunk CRC errors */
-extern PNG_EXPORT(void,png_set_crc_action) PNGARG((png_structp png_ptr,
-   int crit_action, int ancil_action));
-
-/* Values for png_set_crc_action() to say how to handle CRC errors in
- * ancillary and critical chunks, and whether to use the data contained
- * therein.  Note that it is impossible to "discard" data in a critical
- * chunk.  For versions prior to 0.90, the action was always error/quit,
- * whereas in version 0.90 and later, the action for CRC errors in ancillary
- * chunks is warn/discard.  These values should NOT be changed.
- *
- *      value                       action:critical     action:ancillary
- */
-#define PNG_CRC_DEFAULT       0  /* error/quit          warn/discard data */
-#define PNG_CRC_ERROR_QUIT    1  /* error/quit          error/quit        */
-#define PNG_CRC_WARN_DISCARD  2  /* (INVALID)           warn/discard data */
-#define PNG_CRC_WARN_USE      3  /* warn/use data       warn/use data     */
-#define PNG_CRC_QUIET_USE     4  /* quiet/use data      quiet/use data    */
-#define PNG_CRC_NO_CHANGE     5  /* use current value   use current value */
-
-/* These functions give the user control over the scan-line filtering in
- * libpng and the compression methods used by zlib.  These functions are
- * mainly useful for testing, as the defaults should work with most users.
- * Those users who are tight on memory or want faster performance at the
- * expense of compression can modify them.  See the compression library
- * header file (zlib.h) for an explination of the compression functions.
- */
-
-/* set the filtering method(s) used by libpng.  Currently, the only valid
- * value for "method" is 0.
- */
-extern PNG_EXPORT(void,png_set_filter) PNGARG((png_structp png_ptr, int method,
-   int filters));
-
-/* Flags for png_set_filter() to say which filters to use.  The flags
- * are chosen so that they don't conflict with real filter types
- * below, in case they are supplied instead of the #defined constants.
- * These values should NOT be changed.
- */
-#define PNG_NO_FILTERS     0x00
-#define PNG_FILTER_NONE    0x08
-#define PNG_FILTER_SUB     0x10
-#define PNG_FILTER_UP      0x20
-#define PNG_FILTER_AVG     0x40
-#define PNG_FILTER_PAETH   0x80
-#define PNG_ALL_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP | \
-                         PNG_FILTER_AVG | PNG_FILTER_PAETH)
-
-/* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now.
- * These defines should NOT be changed.
- */
-#define PNG_FILTER_VALUE_NONE  0
-#define PNG_FILTER_VALUE_SUB   1
-#define PNG_FILTER_VALUE_UP    2
-#define PNG_FILTER_VALUE_AVG   3
-#define PNG_FILTER_VALUE_PAETH 4
-#define PNG_FILTER_VALUE_LAST  5
-
-#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED) /* EXPERIMENTAL */
-/* The "heuristic_method" is given by one of the PNG_FILTER_HEURISTIC_
- * defines, either the default (minimum-sum-of-absolute-differences), or
- * the experimental method (weighted-minimum-sum-of-absolute-differences).
- *
- * Weights are factors >= 1.0, indicating how important it is to keep the
- * filter type consistent between rows.  Larger numbers mean the current
- * filter is that many times as likely to be the same as the "num_weights"
- * previous filters.  This is cumulative for each previous row with a weight.
- * There needs to be "num_weights" values in "filter_weights", or it can be
- * NULL if the weights aren't being specified.  Weights have no influence on
- * the selection of the first row filter.  Well chosen weights can (in theory)
- * improve the compression for a given image.
- *
- * Costs are factors >= 1.0 indicating the relative decoding costs of a
- * filter type.  Higher costs indicate more decoding expense, and are
- * therefore less likely to be selected over a filter with lower computational
- * costs.  There needs to be a value in "filter_costs" for each valid filter
- * type (given by PNG_FILTER_VALUE_LAST), or it can be NULL if you aren't
- * setting the costs.  Costs try to improve the speed of decompression without
- * unduly increasing the compressed image size.
- *
- * A negative weight or cost indicates the default value is to be used, and
- * values in the range [0.0, 1.0) indicate the value is to remain unchanged.
- * The default values for both weights and costs are currently 1.0, but may
- * change if good general weighting/cost heuristics can be found.  If both
- * the weights and costs are set to 1.0, this degenerates the WEIGHTED method
- * to the UNWEIGHTED method, but with added encoding time/computation.
- */
-#ifdef PNG_FLOATING_POINT_SUPPORTED
-extern PNG_EXPORT(void,png_set_filter_heuristics) PNGARG((png_structp png_ptr,
-   int heuristic_method, int num_weights, png_doublep filter_weights,
-   png_doublep filter_costs));
-#endif
-#endif /*  PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */
-
-/* Heuristic used for row filter selection.  These defines should NOT be
- * changed.
- */
-#define PNG_FILTER_HEURISTIC_DEFAULT    0  /* Currently "UNWEIGHTED" */
-#define PNG_FILTER_HEURISTIC_UNWEIGHTED 1  /* Used by libpng < 0.95 */
-#define PNG_FILTER_HEURISTIC_WEIGHTED   2  /* Experimental feature */
-#define PNG_FILTER_HEURISTIC_LAST       3  /* Not a valid value */
-
-/* Set the library compression level.  Currently, valid values range from
- * 0 - 9, corresponding directly to the zlib compression levels 0 - 9
- * (0 - no compression, 9 - "maximal" compression).  Note that tests have
- * shown that zlib compression levels 3-6 usually perform as well as level 9
- * for PNG images, and do considerably fewer caclulations.  In the future,
- * these values may not correspond directly to the zlib compression levels.
- */
-extern PNG_EXPORT(void,png_set_compression_level) PNGARG((png_structp png_ptr,
-   int level));
-
-extern PNG_EXPORT(void,png_set_compression_mem_level)
-   PNGARG((png_structp png_ptr, int mem_level));
-
-extern PNG_EXPORT(void,png_set_compression_strategy)
-   PNGARG((png_structp png_ptr, int strategy));
-
-extern PNG_EXPORT(void,png_set_compression_window_bits)
-   PNGARG((png_structp png_ptr, int window_bits));
-
-extern PNG_EXPORT(void,png_set_compression_method) PNGARG((png_structp png_ptr,
-   int method));
-
-/* These next functions are called for input/output, memory, and error
- * handling.  They are in the file pngrio.c, pngwio.c, and pngerror.c,
- * and call standard C I/O routines such as fread(), fwrite(), and
- * fprintf().  These functions can be made to use other I/O routines
- * at run time for those applications that need to handle I/O in a
- * different manner by calling png_set_???_fn().  See libpng.txt for
- * more information.
- */
-
-#if !defined(PNG_NO_STDIO)
-/* Initialize the input/output for the PNG file to the default functions. */
-extern PNG_EXPORT(void,png_init_io) PNGARG((png_structp png_ptr, png_FILE_p fp));
-#endif
-
-/* Replace the (error and abort), and warning functions with user
- * supplied functions.  If no messages are to be printed you must still
- * write and use replacement functions. The replacement error_fn should
- * still do a longjmp to the last setjmp location if you are using this
- * method of error handling.  If error_fn or warning_fn is NULL, the
- * default function will be used.
- */
-
-extern PNG_EXPORT(void,png_set_error_fn) PNGARG((png_structp png_ptr,
-   png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn));
-
-/* Return the user pointer associated with the error functions */
-extern PNG_EXPORT(png_voidp,png_get_error_ptr) PNGARG((png_structp png_ptr));
-
-/* Replace the default data output functions with a user supplied one(s).
- * If buffered output is not used, then output_flush_fn can be set to NULL.
- * If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time
- * output_flush_fn will be ignored (and thus can be NULL).
- */
-extern PNG_EXPORT(void,png_set_write_fn) PNGARG((png_structp png_ptr,
-   png_voidp io_ptr, png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn));
-
-/* Replace the default data input function with a user supplied one. */
-extern PNG_EXPORT(void,png_set_read_fn) PNGARG((png_structp png_ptr,
-   png_voidp io_ptr, png_rw_ptr read_data_fn));
-
-/* Return the user pointer associated with the I/O functions */
-extern PNG_EXPORT(png_voidp,png_get_io_ptr) PNGARG((png_structp png_ptr));
-
-extern PNG_EXPORT(void,png_set_read_status_fn) PNGARG((png_structp png_ptr,
-   png_read_status_ptr read_row_fn));
-
-extern PNG_EXPORT(void,png_set_write_status_fn) PNGARG((png_structp png_ptr,
-   png_write_status_ptr write_row_fn));
-
-#ifdef PNG_USER_MEM_SUPPORTED
-/* Replace the default memory allocation functions with user supplied one(s). */
-extern PNG_EXPORT(void,png_set_mem_fn) PNGARG((png_structp png_ptr,
-   png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn));
-/* Return the user pointer associated with the memory functions */
-extern PNG_EXPORT(png_voidp,png_get_mem_ptr) PNGARG((png_structp png_ptr));
-#endif
-
-#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
-    defined(PNG_LEGACY_SUPPORTED)
-extern PNG_EXPORT(void,png_set_read_user_transform_fn) PNGARG((png_structp
-   png_ptr, png_user_transform_ptr read_user_transform_fn));
-#endif
-
-#if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) || \
-    defined(PNG_LEGACY_SUPPORTED)
-extern PNG_EXPORT(void,png_set_write_user_transform_fn) PNGARG((png_structp
-   png_ptr, png_user_transform_ptr write_user_transform_fn));
-#endif
-
-#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
-    defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) || \
-    defined(PNG_LEGACY_SUPPORTED)
-extern PNG_EXPORT(void,png_set_user_transform_info) PNGARG((png_structp
-   png_ptr, png_voidp user_transform_ptr, int user_transform_depth,
-   int user_transform_channels));
-/* Return the user pointer associated with the user transform functions */
-extern PNG_EXPORT(png_voidp,png_get_user_transform_ptr)
-   PNGARG((png_structp png_ptr));
-#endif
-
-#ifdef PNG_USER_CHUNKS_SUPPORTED
-extern PNG_EXPORT(void,png_set_read_user_chunk_fn) PNGARG((png_structp png_ptr,
-   png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn));
-extern PNG_EXPORT(png_voidp,png_get_user_chunk_ptr) PNGARG((png_structp
-   png_ptr));
-#endif
-
-#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
-/* Sets the function callbacks for the push reader, and a pointer to a
- * user-defined structure available to the callback functions.
- */
-extern PNG_EXPORT(void,png_set_progressive_read_fn) PNGARG((png_structp png_ptr,
-   png_voidp progressive_ptr,
-   png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn,
-   png_progressive_end_ptr end_fn));
-
-/* returns the user pointer associated with the push read functions */
-extern PNG_EXPORT(png_voidp,png_get_progressive_ptr)
-   PNGARG((png_structp png_ptr));
-
-/* function to be called when data becomes available */
-extern PNG_EXPORT(void,png_process_data) PNGARG((png_structp png_ptr,
-   png_infop info_ptr, png_bytep buffer, png_size_t buffer_size));
-
-/* function that combines rows.  Not very much different than the
- * png_combine_row() call.  Is this even used?????
- */
-extern PNG_EXPORT(void,png_progressive_combine_row) PNGARG((png_structp png_ptr,
-   png_bytep old_row, png_bytep new_row));
-#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
-
-extern PNG_EXPORT(png_voidp,png_malloc) PNGARG((png_structp png_ptr,
-   png_uint_32 size));
-
-#if defined(PNG_1_0_X)
-#  define png_malloc_warn png_malloc
-#else
-/* Added at libpng version 1.2.4 */
-extern PNG_EXPORT(png_voidp,png_malloc_warn) PNGARG((png_structp png_ptr,
-   png_uint_32 size));
-#endif
-
-/* frees a pointer allocated by png_malloc() */
-extern PNG_EXPORT(void,png_free) PNGARG((png_structp png_ptr, png_voidp ptr));
-
-#if defined(PNG_1_0_X)
-/* Function to allocate memory for zlib. */
-extern PNG_EXPORT(voidpf,png_zalloc) PNGARG((voidpf png_ptr, uInt items,
-   uInt size));
-
-/* Function to free memory for zlib */
-extern PNG_EXPORT(void,png_zfree) PNGARG((voidpf png_ptr, voidpf ptr));
-#endif
-
-/* Free data that was allocated internally */
-extern PNG_EXPORT(void,png_free_data) PNGARG((png_structp png_ptr,
-   png_infop info_ptr, png_uint_32 free_me, int num));
-#ifdef PNG_FREE_ME_SUPPORTED
-/* Reassign responsibility for freeing existing data, whether allocated
- * by libpng or by the application */
-extern PNG_EXPORT(void,png_data_freer) PNGARG((png_structp png_ptr,
-   png_infop info_ptr, int freer, png_uint_32 mask));
-#endif
-/* assignments for png_data_freer */
-#define PNG_DESTROY_WILL_FREE_DATA 1
-#define PNG_SET_WILL_FREE_DATA 1
-#define PNG_USER_WILL_FREE_DATA 2
-/* Flags for png_ptr->free_me and info_ptr->free_me */
-#define PNG_FREE_HIST 0x0008
-#define PNG_FREE_ICCP 0x0010
-#define PNG_FREE_SPLT 0x0020
-#define PNG_FREE_ROWS 0x0040
-#define PNG_FREE_PCAL 0x0080
-#define PNG_FREE_SCAL 0x0100
-#define PNG_FREE_UNKN 0x0200
-#define PNG_FREE_LIST 0x0400
-#define PNG_FREE_PLTE 0x1000
-#define PNG_FREE_TRNS 0x2000
-#define PNG_FREE_TEXT 0x4000
-#define PNG_FREE_ALL  0x7fff
-#define PNG_FREE_MUL  0x4220 /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */
-
-#ifdef PNG_USER_MEM_SUPPORTED
-extern PNG_EXPORT(png_voidp,png_malloc_default) PNGARG((png_structp png_ptr,
-   png_uint_32 size));
-extern PNG_EXPORT(void,png_free_default) PNGARG((png_structp png_ptr,
-   png_voidp ptr));
-#endif
-
-extern PNG_EXPORT(png_voidp,png_memcpy_check) PNGARG((png_structp png_ptr,
-   png_voidp s1, png_voidp s2, png_uint_32 size));
-
-extern PNG_EXPORT(png_voidp,png_memset_check) PNGARG((png_structp png_ptr,
-   png_voidp s1, int value, png_uint_32 size));
-
-#if defined(USE_FAR_KEYWORD)  /* memory model conversion function */
-extern void *png_far_to_near PNGARG((png_structp png_ptr,png_voidp ptr,
-   int check));
-#endif /* USE_FAR_KEYWORD */
-
-/* Fatal error in PNG image of libpng - can't continue */
-extern PNG_EXPORT(void,png_error) PNGARG((png_structp png_ptr,
-   png_const_charp error_message));
-
-/* The same, but the chunk name is prepended to the error string. */
-extern PNG_EXPORT(void,png_chunk_error) PNGARG((png_structp png_ptr,
-   png_const_charp error_message));
-
-/* Non-fatal error in libpng.  Can continue, but may have a problem. */
-extern PNG_EXPORT(void,png_warning) PNGARG((png_structp png_ptr,
-   png_const_charp warning_message));
-
-/* Non-fatal error in libpng, chunk name is prepended to message. */
-extern PNG_EXPORT(void,png_chunk_warning) PNGARG((png_structp png_ptr,
-   png_const_charp warning_message));
-
-/* The png_set_<chunk> functions are for storing values in the png_info_struct.
- * Similarly, the png_get_<chunk> calls are used to read values from the
- * png_info_struct, either storing the parameters in the passed variables, or
- * setting pointers into the png_info_struct where the data is stored.  The
- * png_get_<chunk> functions return a non-zero value if the data was available
- * in info_ptr, or return zero and do not change any of the parameters if the
- * data was not available.
- *
- * These functions should be used instead of directly accessing png_info
- * to avoid problems with future changes in the size and internal layout of
- * png_info_struct.
- */
-/* Returns "flag" if chunk data is valid in info_ptr. */
-extern PNG_EXPORT(png_uint_32,png_get_valid) PNGARG((png_structp png_ptr,
-png_infop info_ptr, png_uint_32 flag));
-
-/* Returns number of bytes needed to hold a transformed row. */
-extern PNG_EXPORT(png_uint_32,png_get_rowbytes) PNGARG((png_structp png_ptr,
-png_infop info_ptr));
-
-#if defined(PNG_INFO_IMAGE_SUPPORTED)
-/* Returns row_pointers, which is an array of pointers to scanlines that was
-returned from png_read_png(). */
-extern PNG_EXPORT(png_bytepp,png_get_rows) PNGARG((png_structp png_ptr,
-png_infop info_ptr));
-/* Set row_pointers, which is an array of pointers to scanlines for use
-by png_write_png(). */
-extern PNG_EXPORT(void,png_set_rows) PNGARG((png_structp png_ptr,
-   png_infop info_ptr, png_bytepp row_pointers));
-#endif
-
-/* Returns number of color channels in image. */
-extern PNG_EXPORT(png_byte,png_get_channels) PNGARG((png_structp png_ptr,
-png_infop info_ptr));
-
-#ifdef PNG_EASY_ACCESS_SUPPORTED
-/* Returns image width in pixels. */
-extern PNG_EXPORT(png_uint_32, png_get_image_width) PNGARG((png_structp
-png_ptr, png_infop info_ptr));
-
-/* Returns image height in pixels. */
-extern PNG_EXPORT(png_uint_32, png_get_image_height) PNGARG((png_structp
-png_ptr, png_infop info_ptr));
-
-/* Returns image bit_depth. */
-extern PNG_EXPORT(png_byte, png_get_bit_depth) PNGARG((png_structp
-png_ptr, png_infop info_ptr));
-
-/* Returns image color_type. */
-extern PNG_EXPORT(png_byte, png_get_color_type) PNGARG((png_structp
-png_ptr, png_infop info_ptr));
-
-/* Returns image filter_type. */
-extern PNG_EXPORT(png_byte, png_get_filter_type) PNGARG((png_structp
-png_ptr, png_infop info_ptr));
-
-/* Returns image interlace_type. */
-extern PNG_EXPORT(png_byte, png_get_interlace_type) PNGARG((png_structp
-png_ptr, png_infop info_ptr));
-
-/* Returns image compression_type. */
-extern PNG_EXPORT(png_byte, png_get_compression_type) PNGARG((png_structp
-png_ptr, png_infop info_ptr));
-
-/* Returns image resolution in pixels per meter, from pHYs chunk data. */
-extern PNG_EXPORT(png_uint_32, png_get_pixels_per_meter) PNGARG((png_structp
-png_ptr, png_infop info_ptr));
-extern PNG_EXPORT(png_uint_32, png_get_x_pixels_per_meter) PNGARG((png_structp
-png_ptr, png_infop info_ptr));
-extern PNG_EXPORT(png_uint_32, png_get_y_pixels_per_meter) PNGARG((png_structp
-png_ptr, png_infop info_ptr));
-
-/* Returns pixel aspect ratio, computed from pHYs chunk data.  */
-#ifdef PNG_FLOATING_POINT_SUPPORTED
-extern PNG_EXPORT(float, png_get_pixel_aspect_ratio) PNGARG((png_structp
-png_ptr, png_infop info_ptr));
-#endif
-
-/* Returns image x, y offset in pixels or microns, from oFFs chunk data. */
-extern PNG_EXPORT(png_int_32, png_get_x_offset_pixels) PNGARG((png_structp
-png_ptr, png_infop info_ptr));
-extern PNG_EXPORT(png_int_32, png_get_y_offset_pixels) PNGARG((png_structp
-png_ptr, png_infop info_ptr));
-extern PNG_EXPORT(png_int_32, png_get_x_offset_microns) PNGARG((png_structp
-png_ptr, png_infop info_ptr));
-extern PNG_EXPORT(png_int_32, png_get_y_offset_microns) PNGARG((png_structp
-png_ptr, png_infop info_ptr));
-
-#endif /* PNG_EASY_ACCESS_SUPPORTED */
-
-/* Returns pointer to signature string read from PNG header */
-extern PNG_EXPORT(png_bytep,png_get_signature) PNGARG((png_structp png_ptr,
-png_infop info_ptr));
-
-#if defined(PNG_bKGD_SUPPORTED)
-extern PNG_EXPORT(png_uint_32,png_get_bKGD) PNGARG((png_structp png_ptr,
-   png_infop info_ptr, png_color_16p *background));
-#endif
-
-#if defined(PNG_bKGD_SUPPORTED)
-extern PNG_EXPORT(void,png_set_bKGD) PNGARG((png_structp png_ptr,
-   png_infop info_ptr, png_color_16p background));
-#endif
-
-#if defined(PNG_cHRM_SUPPORTED)
-#ifdef PNG_FLOATING_POINT_SUPPORTED
-extern PNG_EXPORT(png_uint_32,png_get_cHRM) PNGARG((png_structp png_ptr,
-   png_infop info_ptr, double *white_x, double *white_y, double *red_x,
-   double *red_y, double *green_x, double *green_y, double *blue_x,
-   double *blue_y));
-#endif
-#ifdef PNG_FIXED_POINT_SUPPORTED
-extern PNG_EXPORT(png_uint_32,png_get_cHRM_fixed) PNGARG((png_structp png_ptr,
-   png_infop info_ptr, png_fixed_point *int_white_x, png_fixed_point
-   *int_white_y, png_fixed_point *int_red_x, png_fixed_point *int_red_y,
-   png_fixed_point *int_green_x, png_fixed_point *int_green_y, png_fixed_point
-   *int_blue_x, png_fixed_point *int_blue_y));
-#endif
-#endif
-
-#if defined(PNG_cHRM_SUPPORTED)
-#ifdef PNG_FLOATING_POINT_SUPPORTED
-extern PNG_EXPORT(void,png_set_cHRM) PNGARG((png_structp png_ptr,
-   png_infop info_ptr, double white_x, double white_y, double red_x,
-   double red_y, double green_x, double green_y, double blue_x, double blue_y));
-#endif
-#ifdef PNG_FIXED_POINT_SUPPORTED
-extern PNG_EXPORT(void,png_set_cHRM_fixed) PNGARG((png_structp png_ptr,
-   png_infop info_ptr, png_fixed_point int_white_x, png_fixed_point int_white_y,
-   png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
-   int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
-   png_fixed_point int_blue_y));
-#endif
-#endif
-
-#if defined(PNG_gAMA_SUPPORTED)
-#ifdef PNG_FLOATING_POINT_SUPPORTED
-extern PNG_EXPORT(png_uint_32,png_get_gAMA) PNGARG((png_structp png_ptr,
-   png_infop info_ptr, double *file_gamma));
-#endif
-extern PNG_EXPORT(png_uint_32,png_get_gAMA_fixed) PNGARG((png_structp png_ptr,
-   png_infop info_ptr, png_fixed_point *int_file_gamma));
-#endif
-
-#if defined(PNG_gAMA_SUPPORTED)
-#ifdef PNG_FLOATING_POINT_SUPPORTED
-extern PNG_EXPORT(void,png_set_gAMA) PNGARG((png_structp png_ptr,
-   png_infop info_ptr, double file_gamma));
-#endif
-extern PNG_EXPORT(void,png_set_gAMA_fixed) PNGARG((png_structp png_ptr,
-   png_infop info_ptr, png_fixed_point int_file_gamma));
-#endif
-
-#if defined(PNG_hIST_SUPPORTED)
-extern PNG_EXPORT(png_uint_32,png_get_hIST) PNGARG((png_structp png_ptr,
-   png_infop info_ptr, png_uint_16p *hist));
-#endif
-
-#if defined(PNG_hIST_SUPPORTED)
-extern PNG_EXPORT(void,png_set_hIST) PNGARG((png_structp png_ptr,
-   png_infop info_ptr, png_uint_16p hist));
-#endif
-
-extern PNG_EXPORT(png_uint_32,png_get_IHDR) PNGARG((png_structp png_ptr,
-   png_infop info_ptr, png_uint_32 *width, png_uint_32 *height,
-   int *bit_depth, int *color_type, int *interlace_method,
-   int *compression_method, int *filter_method));
-
-extern PNG_EXPORT(void,png_set_IHDR) PNGARG((png_structp png_ptr,
-   png_infop info_ptr, png_uint_32 width, png_uint_32 height, int bit_depth,
-   int color_type, int interlace_method, int compression_method,
-   int filter_method));
-
-#if defined(PNG_oFFs_SUPPORTED)
-extern PNG_EXPORT(png_uint_32,png_get_oFFs) PNGARG((png_structp png_ptr,
-   png_infop info_ptr, png_int_32 *offset_x, png_int_32 *offset_y,
-   int *unit_type));
-#endif
-
-#if defined(PNG_oFFs_SUPPORTED)
-extern PNG_EXPORT(void,png_set_oFFs) PNGARG((png_structp png_ptr,
-   png_infop info_ptr, png_int_32 offset_x, png_int_32 offset_y,
-   int unit_type));
-#endif
-
-#if defined(PNG_pCAL_SUPPORTED)
-extern PNG_EXPORT(png_uint_32,png_get_pCAL) PNGARG((png_structp png_ptr,
-   png_infop info_ptr, png_charp *purpose, png_int_32 *X0, png_int_32 *X1,
-   int *type, int *nparams, png_charp *units, png_charpp *params));
-#endif
-
-#if defined(PNG_pCAL_SUPPORTED)
-extern PNG_EXPORT(void,png_set_pCAL) PNGARG((png_structp png_ptr,
-   png_infop info_ptr, png_charp purpose, png_int_32 X0, png_int_32 X1,
-   int type, int nparams, png_charp units, png_charpp params));
-#endif
-
-#if defined(PNG_pHYs_SUPPORTED)
-extern PNG_EXPORT(png_uint_32,png_get_pHYs) PNGARG((png_structp png_ptr,
-   png_infop info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type));
-#endif
-
-#if defined(PNG_pHYs_SUPPORTED)
-extern PNG_EXPORT(void,png_set_pHYs) PNGARG((png_structp png_ptr,
-   png_infop info_ptr, png_uint_32 res_x, png_uint_32 res_y, int unit_type));
-#endif
-
-extern PNG_EXPORT(png_uint_32,png_get_PLTE) PNGARG((png_structp png_ptr,
-   png_infop info_ptr, png_colorp *palette, int *num_palette));
-
-extern PNG_EXPORT(void,png_set_PLTE) PNGARG((png_structp png_ptr,
-   png_infop info_ptr, png_colorp palette, int num_palette));
-
-#if defined(PNG_sBIT_SUPPORTED)
-extern PNG_EXPORT(png_uint_32,png_get_sBIT) PNGARG((png_structp png_ptr,
-   png_infop info_ptr, png_color_8p *sig_bit));
-#endif
-
-#if defined(PNG_sBIT_SUPPORTED)
-extern PNG_EXPORT(void,png_set_sBIT) PNGARG((png_structp png_ptr,
-   png_infop info_ptr, png_color_8p sig_bit));
-#endif
-
-#if defined(PNG_sRGB_SUPPORTED)
-extern PNG_EXPORT(png_uint_32,png_get_sRGB) PNGARG((png_structp png_ptr,
-   png_infop info_ptr, int *intent));
-#endif
-
-#if defined(PNG_sRGB_SUPPORTED)
-extern PNG_EXPORT(void,png_set_sRGB) PNGARG((png_structp png_ptr,
-   png_infop info_ptr, int intent));
-extern PNG_EXPORT(void,png_set_sRGB_gAMA_and_cHRM) PNGARG((png_structp png_ptr,
-   png_infop info_ptr, int intent));
-#endif
-
-#if defined(PNG_iCCP_SUPPORTED)
-extern PNG_EXPORT(png_uint_32,png_get_iCCP) PNGARG((png_structp png_ptr,
-   png_infop info_ptr, png_charpp name, int *compression_type,
-   png_charpp profile, png_uint_32 *proflen));
-   /* Note to maintainer: profile should be png_bytepp */
-#endif
-
-#if defined(PNG_iCCP_SUPPORTED)
-extern PNG_EXPORT(void,png_set_iCCP) PNGARG((png_structp png_ptr,
-   png_infop info_ptr, png_charp name, int compression_type,
-   png_charp profile, png_uint_32 proflen));
-   /* Note to maintainer: profile should be png_bytep */
-#endif
-
-#if defined(PNG_sPLT_SUPPORTED)
-extern PNG_EXPORT(png_uint_32,png_get_sPLT) PNGARG((png_structp png_ptr,
-   png_infop info_ptr, png_sPLT_tpp entries));
-#endif
-
-#if defined(PNG_sPLT_SUPPORTED)
-extern PNG_EXPORT(void,png_set_sPLT) PNGARG((png_structp png_ptr,
-   png_infop info_ptr, png_sPLT_tp entries, int nentries));
-#endif
-
-#if defined(PNG_TEXT_SUPPORTED)
-/* png_get_text also returns the number of text chunks in *num_text */
-extern PNG_EXPORT(png_uint_32,png_get_text) PNGARG((png_structp png_ptr,
-   png_infop info_ptr, png_textp *text_ptr, int *num_text));
-#endif
-
-/*
- *  Note while png_set_text() will accept a structure whose text,
- *  language, and  translated keywords are NULL pointers, the structure
- *  returned by png_get_text will always contain regular
- *  zero-terminated C strings.  They might be empty strings but
- *  they will never be NULL pointers.
- */
-
-#if defined(PNG_TEXT_SUPPORTED)
-extern PNG_EXPORT(void,png_set_text) PNGARG((png_structp png_ptr,
-   png_infop info_ptr, png_textp text_ptr, int num_text));
-#endif
-
-#if defined(PNG_tIME_SUPPORTED)
-extern PNG_EXPORT(png_uint_32,png_get_tIME) PNGARG((png_structp png_ptr,
-   png_infop info_ptr, png_timep *mod_time));
-#endif
-
-#if defined(PNG_tIME_SUPPORTED)
-extern PNG_EXPORT(void,png_set_tIME) PNGARG((png_structp png_ptr,
-   png_infop info_ptr, png_timep mod_time));
-#endif
-
-#if defined(PNG_tRNS_SUPPORTED)
-extern PNG_EXPORT(png_uint_32,png_get_tRNS) PNGARG((png_structp png_ptr,
-   png_infop info_ptr, png_bytep *trans, int *num_trans,
-   png_color_16p *trans_values));
-#endif
-
-#if defined(PNG_tRNS_SUPPORTED)
-extern PNG_EXPORT(void,png_set_tRNS) PNGARG((png_structp png_ptr,
-   png_infop info_ptr, png_bytep trans, int num_trans,
-   png_color_16p trans_values));
-#endif
-
-#if defined(PNG_tRNS_SUPPORTED)
-#endif
-
-#if defined(PNG_sCAL_SUPPORTED)
-#ifdef PNG_FLOATING_POINT_SUPPORTED
-extern PNG_EXPORT(png_uint_32,png_get_sCAL) PNGARG((png_structp png_ptr,
-   png_infop info_ptr, int *unit, double *width, double *height));
-#else
-#ifdef PNG_FIXED_POINT_SUPPORTED
-extern PNG_EXPORT(png_uint_32,png_get_sCAL_s) PNGARG((png_structp png_ptr,
-   png_infop info_ptr, int *unit, png_charpp swidth, png_charpp sheight));
-#endif
-#endif
-#endif /* PNG_sCAL_SUPPORTED */
-
-#if defined(PNG_sCAL_SUPPORTED)
-#ifdef PNG_FLOATING_POINT_SUPPORTED
-extern PNG_EXPORT(void,png_set_sCAL) PNGARG((png_structp png_ptr,
-   png_infop info_ptr, int unit, double width, double height));
-#endif
-#ifdef PNG_FIXED_POINT_SUPPORTED
-extern PNG_EXPORT(void,png_set_sCAL_s) PNGARG((png_structp png_ptr,
-   png_infop info_ptr, int unit, png_charp swidth, png_charp sheight));
-#endif
-#endif /* PNG_sCAL_SUPPORTED || PNG_WRITE_sCAL_SUPPORTED */
-
-#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
-/* provide a list of chunks and how they are to be handled, if the built-in
-   handling or default unknown chunk handling is not desired.  Any chunks not
-   listed will be handled in the default manner.  The IHDR and IEND chunks
-   must not be listed.
-      keep = 0: follow default behavour
-           = 1: do not keep
-           = 2: keep only if safe-to-copy
-           = 3: keep even if unsafe-to-copy
-*/
-extern PNG_EXPORT(void, png_set_keep_unknown_chunks) PNGARG((png_structp
-   png_ptr, int keep, png_bytep chunk_list, int num_chunks));
-extern PNG_EXPORT(void, png_set_unknown_chunks) PNGARG((png_structp png_ptr,
-   png_infop info_ptr, png_unknown_chunkp unknowns, int num_unknowns));
-extern PNG_EXPORT(void, png_set_unknown_chunk_location)
-   PNGARG((png_structp png_ptr, png_infop info_ptr, int chunk, int location));
-extern PNG_EXPORT(png_uint_32,png_get_unknown_chunks) PNGARG((png_structp
-   png_ptr, png_infop info_ptr, png_unknown_chunkpp entries));
-#endif
-#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
-PNG_EXPORT(int,png_handle_as_unknown) PNGARG((png_structp png_ptr, png_bytep
-   chunk_name));
-#endif
-
-/* Png_free_data() will turn off the "valid" flag for anything it frees.
-   If you need to turn it off for a chunk that your application has freed,
-   you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK); */
-extern PNG_EXPORT(void, png_set_invalid) PNGARG((png_structp png_ptr,
-   png_infop info_ptr, int mask));
-
-#if defined(PNG_INFO_IMAGE_SUPPORTED)
-/* The "params" pointer is currently not used and is for future expansion. */
-extern PNG_EXPORT(void, png_read_png) PNGARG((png_structp png_ptr,
-                        png_infop info_ptr,
-                        int transforms,
-                        png_voidp params));
-extern PNG_EXPORT(void, png_write_png) PNGARG((png_structp png_ptr,
-                        png_infop info_ptr,
-                        int transforms,
-                        png_voidp params));
-#endif
-
-/* Define PNG_DEBUG at compile time for debugging information.  Higher
- * numbers for PNG_DEBUG mean more debugging information.  This has
- * only been added since version 0.95 so it is not implemented throughout
- * libpng yet, but more support will be added as needed.
- */
-#ifdef PNG_DEBUG
-#if (PNG_DEBUG > 0)
-#if !defined(PNG_DEBUG_FILE) && defined(_MSC_VER)
-#include <crtdbg.h>
-#if (PNG_DEBUG > 1)
-#define png_debug(l,m)  _RPT0(_CRT_WARN,m)
-#define png_debug1(l,m,p1)  _RPT1(_CRT_WARN,m,p1)
-#define png_debug2(l,m,p1,p2) _RPT2(_CRT_WARN,m,p1,p2)
-#endif
-#else /* PNG_DEBUG_FILE || !_MSC_VER */
-#ifndef PNG_DEBUG_FILE
-#define PNG_DEBUG_FILE stderr
-#endif /* PNG_DEBUG_FILE */
-#if (PNG_DEBUG > 1)
-#define png_debug(l,m) \
-{ \
-     int num_tabs=l; \
-     fprintf(PNG_DEBUG_FILE,"%s"m,(num_tabs==1 ? "\t" : \
-       (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":"")))); \
-}
-#define png_debug1(l,m,p1) \
-{ \
-     int num_tabs=l; \
-     fprintf(PNG_DEBUG_FILE,"%s"m,(num_tabs==1 ? "\t" : \
-       (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))),p1); \
-}
-#define png_debug2(l,m,p1,p2) \
-{ \
-     int num_tabs=l; \
-     fprintf(PNG_DEBUG_FILE,"%s"m,(num_tabs==1 ? "\t" : \
-       (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))),p1,p2); \
-}
-#endif /* (PNG_DEBUG > 1) */
-#endif /* _MSC_VER */
-#endif /* (PNG_DEBUG > 0) */
-#endif /* PNG_DEBUG */
-#ifndef png_debug
-#define png_debug(l, m)
-#endif
-#ifndef png_debug1
-#define png_debug1(l, m, p1)
-#endif
-#ifndef png_debug2
-#define png_debug2(l, m, p1, p2)
-#endif
-
-extern PNG_EXPORT(png_bytep,png_sig_bytes) PNGARG((void));
-
-extern PNG_EXPORT(png_charp,png_get_copyright) PNGARG((png_structp png_ptr));
-extern PNG_EXPORT(png_charp,png_get_header_ver) PNGARG((png_structp png_ptr));
-extern PNG_EXPORT(png_charp,png_get_header_version) PNGARG((png_structp png_ptr));
-extern PNG_EXPORT(png_charp,png_get_libpng_ver) PNGARG((png_structp png_ptr));
-
-#ifdef PNG_MNG_FEATURES_SUPPORTED
-extern PNG_EXPORT(png_uint_32,png_permit_mng_features) PNGARG((png_structp
-   png_ptr, png_uint_32 mng_features_permitted));
-#endif
-
-/* For use in png_set_keep_unknown, added to version 1.2.6 */
-#define PNG_HANDLE_CHUNK_AS_DEFAULT   0
-#define PNG_HANDLE_CHUNK_NEVER        1
-#define PNG_HANDLE_CHUNK_IF_SAFE      2
-#define PNG_HANDLE_CHUNK_ALWAYS       3
-
-/* Added to version 1.2.0 */
-#if defined(PNG_ASSEMBLER_CODE_SUPPORTED)
-#define PNG_ASM_FLAG_MMX_SUPPORT_COMPILED  0x01  /* not user-settable */
-#define PNG_ASM_FLAG_MMX_SUPPORT_IN_CPU    0x02  /* not user-settable */
-#define PNG_ASM_FLAG_MMX_READ_COMBINE_ROW  0x04
-#define PNG_ASM_FLAG_MMX_READ_INTERLACE    0x08
-#define PNG_ASM_FLAG_MMX_READ_FILTER_SUB   0x10
-#define PNG_ASM_FLAG_MMX_READ_FILTER_UP    0x20
-#define PNG_ASM_FLAG_MMX_READ_FILTER_AVG   0x40
-#define PNG_ASM_FLAG_MMX_READ_FILTER_PAETH 0x80
-#define PNG_ASM_FLAGS_INITIALIZED          0x80000000  /* not user-settable */
-
-#define PNG_MMX_READ_FLAGS ( PNG_ASM_FLAG_MMX_READ_COMBINE_ROW  \
-                           | PNG_ASM_FLAG_MMX_READ_INTERLACE    \
-                           | PNG_ASM_FLAG_MMX_READ_FILTER_SUB   \
-                           | PNG_ASM_FLAG_MMX_READ_FILTER_UP    \
-                           | PNG_ASM_FLAG_MMX_READ_FILTER_AVG   \
-                           | PNG_ASM_FLAG_MMX_READ_FILTER_PAETH )
-#define PNG_MMX_WRITE_FLAGS ( 0 )
-
-#define PNG_MMX_FLAGS ( PNG_ASM_FLAG_MMX_SUPPORT_COMPILED \
-                      | PNG_ASM_FLAG_MMX_SUPPORT_IN_CPU   \
-                      | PNG_MMX_READ_FLAGS                \
-                      | PNG_MMX_WRITE_FLAGS )
-
-#define PNG_SELECT_READ   1
-#define PNG_SELECT_WRITE  2
-
-#if !defined(PNG_1_0_X)
-/* pngget.c */
-extern PNG_EXPORT(png_uint_32,png_get_mmx_flagmask)
-   PNGARG((int flag_select, int *compilerID));
-
-/* pngget.c */
-extern PNG_EXPORT(png_uint_32,png_get_asm_flagmask)
-   PNGARG((int flag_select));
-
-/* pngget.c */
-extern PNG_EXPORT(png_uint_32,png_get_asm_flags)
-   PNGARG((png_structp png_ptr));
-
-/* pngget.c */
-extern PNG_EXPORT(png_byte,png_get_mmx_bitdepth_threshold)
-   PNGARG((png_structp png_ptr));
-
-/* pngget.c */
-extern PNG_EXPORT(png_uint_32,png_get_mmx_rowbytes_threshold)
-   PNGARG((png_structp png_ptr));
-
-/* pngset.c */
-extern PNG_EXPORT(void,png_set_asm_flags)
-   PNGARG((png_structp png_ptr, png_uint_32 asm_flags));
-
-/* pngset.c */
-extern PNG_EXPORT(void,png_set_mmx_thresholds)
-   PNGARG((png_structp png_ptr, png_byte mmx_bitdepth_threshold,
-   png_uint_32 mmx_rowbytes_threshold));
-
-#endif /* PNG_1_0_X */
-#endif /* PNG_ASSEMBLER_CODE_SUPPORTED */
-
-#if !defined(PNG_1_0_X)
-/* png.c, pnggccrd.c, or pngvcrd.c */
-extern PNG_EXPORT(int,png_mmx_support) PNGARG((void));
-
-/* Strip the prepended error numbers ("#nnn ") from error and warning
- * messages before passing them to the error or warning handler. */
-#ifdef PNG_ERROR_NUMBERS_SUPPORTED
-extern PNG_EXPORT(void,png_set_strip_error_numbers) PNGARG((png_structp
-   png_ptr, png_uint_32 strip_mode));
-#endif
-
-#endif /* PNG_1_0_X */
-
-/* Added at libpng-1.2.6 */
-#ifdef PNG_SET_USER_LIMITS_SUPPORTED
-extern PNG_EXPORT(void,png_set_user_limits) PNGARG((png_structp
-   png_ptr, png_uint_32 user_width_max, png_uint_32 user_height_max));
-extern PNG_EXPORT(png_uint_32,png_get_user_width_max) PNGARG((png_structp
-   png_ptr));
-extern PNG_EXPORT(png_uint_32,png_get_user_height_max) PNGARG((png_structp
-   png_ptr));
-#endif
-
-/* Maintainer: Put new public prototypes here ^, in libpng.3, and project defs */
-
-#ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED
-/* With these routines we avoid an integer divide, which will be slower on
- * most machines.  However, it does take more operations than the corresponding
- * divide method, so it may be slower on a few RISC systems.  There are two
- * shifts (by 8 or 16 bits) and an addition, versus a single integer divide.
- *
- * Note that the rounding factors are NOT supposed to be the same!  128 and
- * 32768 are correct for the NODIV code; 127 and 32767 are correct for the
- * standard method.
- *
- * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ]
- */
-
- /* fg and bg should be in `gamma 1.0' space; alpha is the opacity          */
-
-#  define png_composite(composite, fg, alpha, bg)                            \
-     { png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) * (png_uint_16)(alpha) \
-                        +        (png_uint_16)(bg)*(png_uint_16)(255 -       \
-                        (png_uint_16)(alpha)) + (png_uint_16)128);           \
-       (composite) = (png_byte)((temp + (temp >> 8)) >> 8); }
-
-#  define png_composite_16(composite, fg, alpha, bg)                         \
-     { png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) * (png_uint_32)(alpha) \
-                        + (png_uint_32)(bg)*(png_uint_32)(65535L -           \
-                        (png_uint_32)(alpha)) + (png_uint_32)32768L);        \
-       (composite) = (png_uint_16)((temp + (temp >> 16)) >> 16); }
-
-#else  /* standard method using integer division */
-
-#  define png_composite(composite, fg, alpha, bg)                            \
-     (composite) = (png_byte)(((png_uint_16)(fg) * (png_uint_16)(alpha) +    \
-       (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) +       \
-       (png_uint_16)127) / 255)
-
-#  define png_composite_16(composite, fg, alpha, bg)                         \
-     (composite) = (png_uint_16)(((png_uint_32)(fg) * (png_uint_32)(alpha) + \
-       (png_uint_32)(bg)*(png_uint_32)(65535L - (png_uint_32)(alpha)) +      \
-       (png_uint_32)32767) / (png_uint_32)65535L)
-
-#endif /* PNG_READ_COMPOSITE_NODIV_SUPPORTED */
-
-/* These next functions are used internally in the code.  They generally
- * shouldn't be used unless you are writing code to add or replace some
- * functionality in libpng.  More information about most functions can
- * be found in the files where the functions are located.
- */
-
-#if defined(PNG_INTERNAL)
-
-/* Various modes of operation.  Note that after an init, mode is set to
- * zero automatically when the structure is created.
- */
-#define PNG_HAVE_IHDR               0x01
-#define PNG_HAVE_PLTE               0x02
-#define PNG_HAVE_IDAT               0x04
-#define PNG_AFTER_IDAT              0x08
-#define PNG_HAVE_IEND               0x10
-#define PNG_HAVE_gAMA               0x20
-#define PNG_HAVE_cHRM               0x40
-#define PNG_HAVE_sRGB               0x80
-#define PNG_HAVE_CHUNK_HEADER      0x100
-#define PNG_WROTE_tIME             0x200
-#define PNG_WROTE_INFO_BEFORE_PLTE 0x400
-#define PNG_BACKGROUND_IS_GRAY     0x800
-#define PNG_HAVE_PNG_SIGNATURE    0x1000
-
-/* flags for the transformations the PNG library does on the image data */
-#define PNG_BGR                0x0001
-#define PNG_INTERLACE          0x0002
-#define PNG_PACK               0x0004
-#define PNG_SHIFT              0x0008
-#define PNG_SWAP_BYTES         0x0010
-#define PNG_INVERT_MONO        0x0020
-#define PNG_DITHER             0x0040
-#define PNG_BACKGROUND         0x0080
-#define PNG_BACKGROUND_EXPAND  0x0100
-                          /*   0x0200 unused */
-#define PNG_16_TO_8            0x0400
-#define PNG_RGBA               0x0800
-#define PNG_EXPAND             0x1000
-#define PNG_GAMMA              0x2000
-#define PNG_GRAY_TO_RGB        0x4000
-#define PNG_FILLER             0x8000L
-#define PNG_PACKSWAP          0x10000L
-#define PNG_SWAP_ALPHA        0x20000L
-#define PNG_STRIP_ALPHA       0x40000L
-#define PNG_INVERT_ALPHA      0x80000L
-#define PNG_USER_TRANSFORM   0x100000L
-#define PNG_RGB_TO_GRAY_ERR  0x200000L
-#define PNG_RGB_TO_GRAY_WARN 0x400000L
-#define PNG_RGB_TO_GRAY      0x600000L  /* two bits, RGB_TO_GRAY_ERR|WARN */
-                       /*    0x800000L     Unused */
-#define PNG_ADD_ALPHA       0x1000000L  /* Added to libpng-1.2.7 */
-                       /*   0x2000000L  unused */
-                       /*   0x4000000L  unused */
-                       /*   0x8000000L  unused */
-                       /*  0x10000000L  unused */
-                       /*  0x20000000L  unused */
-                       /*  0x40000000L  unused */
-
-/* flags for png_create_struct */
-#define PNG_STRUCT_PNG   0x0001
-#define PNG_STRUCT_INFO  0x0002
-
-/* Scaling factor for filter heuristic weighting calculations */
-#define PNG_WEIGHT_SHIFT 8
-#define PNG_WEIGHT_FACTOR (1<<(PNG_WEIGHT_SHIFT))
-#define PNG_COST_SHIFT 3
-#define PNG_COST_FACTOR (1<<(PNG_COST_SHIFT))
-
-/* flags for the png_ptr->flags rather than declaring a byte for each one */
-#define PNG_FLAG_ZLIB_CUSTOM_STRATEGY     0x0001
-#define PNG_FLAG_ZLIB_CUSTOM_LEVEL        0x0002
-#define PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL    0x0004
-#define PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS  0x0008
-#define PNG_FLAG_ZLIB_CUSTOM_METHOD       0x0010
-#define PNG_FLAG_ZLIB_FINISHED            0x0020
-#define PNG_FLAG_ROW_INIT                 0x0040
-#define PNG_FLAG_FILLER_AFTER             0x0080
-#define PNG_FLAG_CRC_ANCILLARY_USE        0x0100
-#define PNG_FLAG_CRC_ANCILLARY_NOWARN     0x0200
-#define PNG_FLAG_CRC_CRITICAL_USE         0x0400
-#define PNG_FLAG_CRC_CRITICAL_IGNORE      0x0800
-#define PNG_FLAG_FREE_PLTE                0x1000
-#define PNG_FLAG_FREE_TRNS                0x2000
-#define PNG_FLAG_FREE_HIST                0x4000
-#define PNG_FLAG_KEEP_UNKNOWN_CHUNKS      0x8000L
-#define PNG_FLAG_KEEP_UNSAFE_CHUNKS       0x10000L
-#define PNG_FLAG_LIBRARY_MISMATCH         0x20000L
-#define PNG_FLAG_STRIP_ERROR_NUMBERS      0x40000L
-#define PNG_FLAG_STRIP_ERROR_TEXT         0x80000L
-#define PNG_FLAG_MALLOC_NULL_MEM_OK       0x100000L
-#define PNG_FLAG_ADD_ALPHA                0x200000L  /* Added to libpng-1.2.8 */
-#define PNG_FLAG_STRIP_ALPHA              0x400000L  /* Added to libpng-1.2.8 */
-                                  /*      0x800000L  unused */
-                                  /*     0x1000000L  unused */
-                                  /*     0x2000000L  unused */
-                                  /*     0x4000000L  unused */
-                                  /*     0x8000000L  unused */
-                                  /*    0x10000000L  unused */
-                                  /*    0x20000000L  unused */
-                                  /*    0x40000000L  unused */
-
-#define PNG_FLAG_CRC_ANCILLARY_MASK (PNG_FLAG_CRC_ANCILLARY_USE | \
-                                     PNG_FLAG_CRC_ANCILLARY_NOWARN)
-
-#define PNG_FLAG_CRC_CRITICAL_MASK  (PNG_FLAG_CRC_CRITICAL_USE | \
-                                     PNG_FLAG_CRC_CRITICAL_IGNORE)
-
-#define PNG_FLAG_CRC_MASK           (PNG_FLAG_CRC_ANCILLARY_MASK | \
-                                     PNG_FLAG_CRC_CRITICAL_MASK)
-
-/* save typing and make code easier to understand */
-
-#define PNG_COLOR_DIST(c1, c2) (abs((int)((c1).red) - (int)((c2).red)) + \
-   abs((int)((c1).green) - (int)((c2).green)) + \
-   abs((int)((c1).blue) - (int)((c2).blue)))
-
-/* Added to libpng-1.2.6 JB */
-#define PNG_ROWBYTES(pixel_bits, width) \
-    ((pixel_bits) >= 8 ? \
-    ((width) * (((png_uint_32)(pixel_bits)) >> 3)) : \
-    (( ((width) * ((png_uint_32)(pixel_bits))) + 7) >> 3) )
-
-/* PNG_OUT_OF_RANGE returns true if value is outside the range
-   ideal-delta..ideal+delta.  Each argument is evaluated twice.
-   "ideal" and "delta" should be constants, normally simple
-   integers, "value" a variable. Added to libpng-1.2.6 JB */
-#define PNG_OUT_OF_RANGE(value, ideal, delta) \
-        ( (value) < (ideal)-(delta) || (value) > (ideal)+(delta) )
-
-/* variables declared in png.c - only it needs to define PNG_NO_EXTERN */
-#if !defined(PNG_NO_EXTERN) || defined(PNG_ALWAYS_EXTERN)
-/* place to hold the signature string for a PNG file. */
-#ifdef PNG_USE_GLOBAL_ARRAYS
-   PNG_EXPORT_VAR (const png_byte FARDATA) png_sig[8];
-#else
-#define png_sig png_sig_bytes(NULL)
-#endif
-#endif /* PNG_NO_EXTERN */
-
-/* Constant strings for known chunk types.  If you need to add a chunk,
- * define the name here, and add an invocation of the macro in png.c and
- * wherever it's needed.
- */
-#define PNG_IHDR const png_byte png_IHDR[5] = { 73,  72,  68,  82, '\0'}
-#define PNG_IDAT const png_byte png_IDAT[5] = { 73,  68,  65,  84, '\0'}
-#define PNG_IEND const png_byte png_IEND[5] = { 73,  69,  78,  68, '\0'}
-#define PNG_PLTE const png_byte png_PLTE[5] = { 80,  76,  84,  69, '\0'}
-#define PNG_bKGD const png_byte png_bKGD[5] = { 98,  75,  71,  68, '\0'}
-#define PNG_cHRM const png_byte png_cHRM[5] = { 99,  72,  82,  77, '\0'}
-#define PNG_gAMA const png_byte png_gAMA[5] = {103,  65,  77,  65, '\0'}
-#define PNG_hIST const png_byte png_hIST[5] = {104,  73,  83,  84, '\0'}
-#define PNG_iCCP const png_byte png_iCCP[5] = {105,  67,  67,  80, '\0'}
-#define PNG_iTXt const png_byte png_iTXt[5] = {105,  84,  88, 116, '\0'}
-#define PNG_oFFs const png_byte png_oFFs[5] = {111,  70,  70, 115, '\0'}
-#define PNG_pCAL const png_byte png_pCAL[5] = {112,  67,  65,  76, '\0'}
-#define PNG_sCAL const png_byte png_sCAL[5] = {115,  67,  65,  76, '\0'}
-#define PNG_pHYs const png_byte png_pHYs[5] = {112,  72,  89, 115, '\0'}
-#define PNG_sBIT const png_byte png_sBIT[5] = {115,  66,  73,  84, '\0'}
-#define PNG_sPLT const png_byte png_sPLT[5] = {115,  80,  76,  84, '\0'}
-#define PNG_sRGB const png_byte png_sRGB[5] = {115,  82,  71,  66, '\0'}
-#define PNG_tEXt const png_byte png_tEXt[5] = {116,  69,  88, 116, '\0'}
-#define PNG_tIME const png_byte png_tIME[5] = {116,  73,  77,  69, '\0'}
-#define PNG_tRNS const png_byte png_tRNS[5] = {116,  82,  78,  83, '\0'}
-#define PNG_zTXt const png_byte png_zTXt[5] = {122,  84,  88, 116, '\0'}
-
-#ifdef PNG_USE_GLOBAL_ARRAYS
-PNG_EXPORT_VAR (const png_byte FARDATA) png_IHDR[5];
-PNG_EXPORT_VAR (const png_byte FARDATA) png_IDAT[5];
-PNG_EXPORT_VAR (const png_byte FARDATA) png_IEND[5];
-PNG_EXPORT_VAR (const png_byte FARDATA) png_PLTE[5];
-PNG_EXPORT_VAR (const png_byte FARDATA) png_bKGD[5];
-PNG_EXPORT_VAR (const png_byte FARDATA) png_cHRM[5];
-PNG_EXPORT_VAR (const png_byte FARDATA) png_gAMA[5];
-PNG_EXPORT_VAR (const png_byte FARDATA) png_hIST[5];
-PNG_EXPORT_VAR (const png_byte FARDATA) png_iCCP[5];
-PNG_EXPORT_VAR (const png_byte FARDATA) png_iTXt[5];
-PNG_EXPORT_VAR (const png_byte FARDATA) png_oFFs[5];
-PNG_EXPORT_VAR (const png_byte FARDATA) png_pCAL[5];
-PNG_EXPORT_VAR (const png_byte FARDATA) png_sCAL[5];
-PNG_EXPORT_VAR (const png_byte FARDATA) png_pHYs[5];
-PNG_EXPORT_VAR (const png_byte FARDATA) png_sBIT[5];
-PNG_EXPORT_VAR (const png_byte FARDATA) png_sPLT[5];
-PNG_EXPORT_VAR (const png_byte FARDATA) png_sRGB[5];
-PNG_EXPORT_VAR (const png_byte FARDATA) png_tEXt[5];
-PNG_EXPORT_VAR (const png_byte FARDATA) png_tIME[5];
-PNG_EXPORT_VAR (const png_byte FARDATA) png_tRNS[5];
-PNG_EXPORT_VAR (const png_byte FARDATA) png_zTXt[5];
-#endif /* PNG_USE_GLOBAL_ARRAYS */
-
-
-/* Inline macros to do direct reads of bytes from the input buffer.  These
- * require that you are using an architecture that uses PNG byte ordering
- * (MSB first) and supports unaligned data storage.  I think that PowerPC
- * in big-endian mode and 680x0 are the only ones that will support this.
- * The x86 line of processors definitely do not.  The png_get_int_32()
- * routine also assumes we are using two's complement format for negative
- * values, which is almost certainly true.
- */
-#if defined(PNG_READ_BIG_ENDIAN_SUPPORTED)
-#  if defined(PNG_pCAL_SUPPORTED) || defined(PNG_oFFs_SUPPORTED)
-#    define png_get_int_32(buf) ( *((png_int_32p) (buf)))
-#  endif
-#  define png_get_uint_32(buf) ( *((png_uint_32p) (buf)))
-#  define png_get_uint_16(buf) ( *((png_uint_16p) (buf)))
-#else
-#  if defined(PNG_pCAL_SUPPORTED) || defined(PNG_oFFs_SUPPORTED)
-PNG_EXTERN png_int_32 png_get_int_32 PNGARG((png_bytep buf));
-#  endif
-PNG_EXTERN png_uint_32 png_get_uint_32 PNGARG((png_bytep buf));
-PNG_EXTERN png_uint_16 png_get_uint_16 PNGARG((png_bytep buf));
-#endif /* !PNG_READ_BIG_ENDIAN_SUPPORTED */
-PNG_EXTERN png_uint_32 png_get_uint_31 PNGARG((png_structp png_ptr,
-  png_bytep buf));
-
-/* Initialize png_ptr struct for reading, and allocate any other memory.
- * (old interface - DEPRECATED - use png_create_read_struct instead).
- */
-extern PNG_EXPORT(void,png_read_init) PNGARG((png_structp png_ptr));
-#undef png_read_init
-#define png_read_init(png_ptr) png_read_init_3(&png_ptr, \
-    PNG_LIBPNG_VER_STRING,  png_sizeof(png_struct));
-extern PNG_EXPORT(void,png_read_init_3) PNGARG((png_structpp ptr_ptr,
-    png_const_charp user_png_ver, png_size_t png_struct_size));
-extern PNG_EXPORT(void,png_read_init_2) PNGARG((png_structp png_ptr,
-    png_const_charp user_png_ver, png_size_t png_struct_size, png_size_t
-    png_info_size));
-
-/* Initialize png_ptr struct for writing, and allocate any other memory.
- * (old interface - DEPRECATED - use png_create_write_struct instead).
- */
-extern PNG_EXPORT(void,png_write_init) PNGARG((png_structp png_ptr));
-#undef png_write_init
-#define png_write_init(png_ptr) png_write_init_3(&png_ptr, \
-    PNG_LIBPNG_VER_STRING, png_sizeof(png_struct));
-extern PNG_EXPORT(void,png_write_init_3) PNGARG((png_structpp ptr_ptr,
-    png_const_charp user_png_ver, png_size_t png_struct_size));
-extern PNG_EXPORT(void,png_write_init_2) PNGARG((png_structp png_ptr,
-    png_const_charp user_png_ver, png_size_t png_struct_size, png_size_t
-    png_info_size));
-
-/* Allocate memory for an internal libpng struct */
-PNG_EXTERN png_voidp png_create_struct PNGARG((int type));
-
-/* Free memory from internal libpng struct */
-PNG_EXTERN void png_destroy_struct PNGARG((png_voidp struct_ptr));
-
-PNG_EXTERN png_voidp png_create_struct_2 PNGARG((int type, png_malloc_ptr
-  malloc_fn, png_voidp mem_ptr));
-PNG_EXTERN void png_destroy_struct_2 PNGARG((png_voidp struct_ptr,
-   png_free_ptr free_fn, png_voidp mem_ptr));
-
-/* Free any memory that info_ptr points to and reset struct. */
-PNG_EXTERN void png_info_destroy PNGARG((png_structp png_ptr,
-   png_infop info_ptr));
-
-#ifndef PNG_1_0_X
-/* Function to allocate memory for zlib. */
-PNG_EXTERN voidpf png_zalloc PNGARG((voidpf png_ptr, uInt items, uInt size));
-
-/* Function to free memory for zlib */
-PNG_EXTERN void png_zfree PNGARG((voidpf png_ptr, voidpf ptr));
-
-#ifdef PNG_SIZE_T
-/* Function to convert a sizeof an item to png_sizeof item */
-   PNG_EXTERN png_size_t PNGAPI png_convert_size PNGARG((size_t size));
-#endif
-
-/* Next four functions are used internally as callbacks.  PNGAPI is required
- * but not PNG_EXPORT.  PNGAPI added at libpng version 1.2.3. */
-
-PNG_EXTERN void PNGAPI png_default_read_data PNGARG((png_structp png_ptr,
-   png_bytep data, png_size_t length));
-
-#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
-PNG_EXTERN void PNGAPI png_push_fill_buffer PNGARG((png_structp png_ptr,
-   png_bytep buffer, png_size_t length));
-#endif
-
-PNG_EXTERN void PNGAPI png_default_write_data PNGARG((png_structp png_ptr,
-   png_bytep data, png_size_t length));
-
-#if defined(PNG_WRITE_FLUSH_SUPPORTED)
-#if !defined(PNG_NO_STDIO)
-PNG_EXTERN void PNGAPI png_default_flush PNGARG((png_structp png_ptr));
-#endif
-#endif
-#else /* PNG_1_0_X */
-#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
-PNG_EXTERN void png_push_fill_buffer PNGARG((png_structp png_ptr,
-   png_bytep buffer, png_size_t length));
-#endif
-#endif /* PNG_1_0_X */
-
-/* Reset the CRC variable */
-PNG_EXTERN void png_reset_crc PNGARG((png_structp png_ptr));
-
-/* Write the "data" buffer to whatever output you are using. */
-PNG_EXTERN void png_write_data PNGARG((png_structp png_ptr, png_bytep data,
-   png_size_t length));
-
-/* Read data from whatever input you are using into the "data" buffer */
-PNG_EXTERN void png_read_data PNGARG((png_structp png_ptr, png_bytep data,
-   png_size_t length));
-
-/* Read bytes into buf, and update png_ptr->crc */
-PNG_EXTERN void png_crc_read PNGARG((png_structp png_ptr, png_bytep buf,
-   png_size_t length));
-
-/* Decompress data in a chunk that uses compression */
-#if defined(PNG_zTXt_SUPPORTED) || defined(PNG_iTXt_SUPPORTED) || \
-    defined(PNG_iCCP_SUPPORTED) || defined(PNG_sPLT_SUPPORTED)
-PNG_EXTERN png_charp png_decompress_chunk PNGARG((png_structp png_ptr,
-   int comp_type, png_charp chunkdata, png_size_t chunklength,
-   png_size_t prefix_length, png_size_t *data_length));
-#endif
-
-/* Read "skip" bytes, read the file crc, and (optionally) verify png_ptr->crc */
-PNG_EXTERN int png_crc_finish PNGARG((png_structp png_ptr, png_uint_32 skip));
-
-/* Read the CRC from the file and compare it to the libpng calculated CRC */
-PNG_EXTERN int png_crc_error PNGARG((png_structp png_ptr));
-
-/* Calculate the CRC over a section of data.  Note that we are only
- * passing a maximum of 64K on systems that have this as a memory limit,
- * since this is the maximum buffer size we can specify.
- */
-PNG_EXTERN void png_calculate_crc PNGARG((png_structp png_ptr, png_bytep ptr,
-   png_size_t length));
-
-#if defined(PNG_WRITE_FLUSH_SUPPORTED)
-PNG_EXTERN void png_flush PNGARG((png_structp png_ptr));
-#endif
-
-
-/* Place a 32-bit number into a buffer in PNG byte order (big-endian).
- * The only currently known PNG chunks that use signed numbers are
- * the ancillary extension chunks, oFFs and pCAL.
- */
-PNG_EXTERN void png_save_uint_32 PNGARG((png_bytep buf, png_uint_32 i));
-
-#if defined(PNG_WRITE_pCAL_SUPPORTED) || defined(PNG_WRITE_oFFs_SUPPORTED)
-PNG_EXTERN void png_save_int_32 PNGARG((png_bytep buf, png_int_32 i));
-#endif
-
-/* Place a 16-bit number into a buffer in PNG byte order.
- * The parameter is declared unsigned int, not png_uint_16,
- * just to avoid potential problems on pre-ANSI C compilers.
- */
-PNG_EXTERN void png_save_uint_16 PNGARG((png_bytep buf, unsigned int i));
-
-/* simple function to write the signature */
-PNG_EXTERN void png_write_sig PNGARG((png_structp png_ptr));
-
-/* write various chunks */
-
-/* Write the IHDR chunk, and update the png_struct with the necessary
- * information.
- */
-PNG_EXTERN void png_write_IHDR PNGARG((png_structp png_ptr, png_uint_32 width,
-   png_uint_32 height,
-   int bit_depth, int color_type, int compression_method, int filter_method,
-   int interlace_method));
-
-PNG_EXTERN void png_write_PLTE PNGARG((png_structp png_ptr, png_colorp palette,
-   png_uint_32 num_pal));
-
-PNG_EXTERN void png_write_IDAT PNGARG((png_structp png_ptr, png_bytep data,
-   png_size_t length));
-
-PNG_EXTERN void png_write_IEND PNGARG((png_structp png_ptr));
-
-#if defined(PNG_WRITE_gAMA_SUPPORTED)
-#ifdef PNG_FLOATING_POINT_SUPPORTED
-PNG_EXTERN void png_write_gAMA PNGARG((png_structp png_ptr, double file_gamma));
-#endif
-#ifdef PNG_FIXED_POINT_SUPPORTED
-PNG_EXTERN void png_write_gAMA_fixed PNGARG((png_structp png_ptr, png_fixed_point
-    file_gamma));
-#endif
-#endif
-
-#if defined(PNG_WRITE_sBIT_SUPPORTED)
-PNG_EXTERN void png_write_sBIT PNGARG((png_structp png_ptr, png_color_8p sbit,
-   int color_type));
-#endif
-
-#if defined(PNG_WRITE_cHRM_SUPPORTED)
-#ifdef PNG_FLOATING_POINT_SUPPORTED
-PNG_EXTERN void png_write_cHRM PNGARG((png_structp png_ptr,
-   double white_x, double white_y,
-   double red_x, double red_y, double green_x, double green_y,
-   double blue_x, double blue_y));
-#endif
-#ifdef PNG_FIXED_POINT_SUPPORTED
-PNG_EXTERN void png_write_cHRM_fixed PNGARG((png_structp png_ptr,
-   png_fixed_point int_white_x, png_fixed_point int_white_y,
-   png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
-   int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
-   png_fixed_point int_blue_y));
-#endif
-#endif
-
-#if defined(PNG_WRITE_sRGB_SUPPORTED)
-PNG_EXTERN void png_write_sRGB PNGARG((png_structp png_ptr,
-   int intent));
-#endif
-
-#if defined(PNG_WRITE_iCCP_SUPPORTED)
-PNG_EXTERN void png_write_iCCP PNGARG((png_structp png_ptr,
-   png_charp name, int compression_type,
-   png_charp profile, int proflen));
-   /* Note to maintainer: profile should be png_bytep */
-#endif
-
-#if defined(PNG_WRITE_sPLT_SUPPORTED)
-PNG_EXTERN void png_write_sPLT PNGARG((png_structp png_ptr,
-   png_sPLT_tp palette));
-#endif
-
-#if defined(PNG_WRITE_tRNS_SUPPORTED)
-PNG_EXTERN void png_write_tRNS PNGARG((png_structp png_ptr, png_bytep trans,
-   png_color_16p values, int number, int color_type));
-#endif
-
-#if defined(PNG_WRITE_bKGD_SUPPORTED)
-PNG_EXTERN void png_write_bKGD PNGARG((png_structp png_ptr,
-   png_color_16p values, int color_type));
-#endif
-
-#if defined(PNG_WRITE_hIST_SUPPORTED)
-PNG_EXTERN void png_write_hIST PNGARG((png_structp png_ptr, png_uint_16p hist,
-   int num_hist));
-#endif
-
-#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED) || \
-    defined(PNG_WRITE_iCCP_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
-PNG_EXTERN png_size_t png_check_keyword PNGARG((png_structp png_ptr,
-   png_charp key, png_charpp new_key));
-#endif
-
-#if defined(PNG_WRITE_tEXt_SUPPORTED)
-PNG_EXTERN void png_write_tEXt PNGARG((png_structp png_ptr, png_charp key,
-   png_charp text, png_size_t text_len));
-#endif
-
-#if defined(PNG_WRITE_zTXt_SUPPORTED)
-PNG_EXTERN void png_write_zTXt PNGARG((png_structp png_ptr, png_charp key,
-   png_charp text, png_size_t text_len, int compression));
-#endif
-
-#if defined(PNG_WRITE_iTXt_SUPPORTED)
-PNG_EXTERN void png_write_iTXt PNGARG((png_structp png_ptr,
-   int compression, png_charp key, png_charp lang, png_charp lang_key,
-   png_charp text));
-#endif
-
-#if defined(PNG_TEXT_SUPPORTED)  /* Added at version 1.0.14 and 1.2.4 */
-PNG_EXTERN int png_set_text_2 PNGARG((png_structp png_ptr,
-   png_infop info_ptr, png_textp text_ptr, int num_text));
-#endif
-
-#if defined(PNG_WRITE_oFFs_SUPPORTED)
-PNG_EXTERN void png_write_oFFs PNGARG((png_structp png_ptr,
-   png_int_32 x_offset, png_int_32 y_offset, int unit_type));
-#endif
-
-#if defined(PNG_WRITE_pCAL_SUPPORTED)
-PNG_EXTERN void png_write_pCAL PNGARG((png_structp png_ptr, png_charp purpose,
-   png_int_32 X0, png_int_32 X1, int type, int nparams,
-   png_charp units, png_charpp params));
-#endif
-
-#if defined(PNG_WRITE_pHYs_SUPPORTED)
-PNG_EXTERN void png_write_pHYs PNGARG((png_structp png_ptr,
-   png_uint_32 x_pixels_per_unit, png_uint_32 y_pixels_per_unit,
-   int unit_type));
-#endif
-
-#if defined(PNG_WRITE_tIME_SUPPORTED)
-PNG_EXTERN void png_write_tIME PNGARG((png_structp png_ptr,
-   png_timep mod_time));
-#endif
-
-#if defined(PNG_WRITE_sCAL_SUPPORTED)
-#if defined(PNG_FLOATING_POINT_SUPPORTED) && !defined(PNG_NO_STDIO)
-PNG_EXTERN void png_write_sCAL PNGARG((png_structp png_ptr,
-   int unit, double width, double height));
-#else
-#ifdef PNG_FIXED_POINT_SUPPORTED
-PNG_EXTERN void png_write_sCAL_s PNGARG((png_structp png_ptr,
-   int unit, png_charp width, png_charp height));
-#endif
-#endif
-#endif
-
-/* Called when finished processing a row of data */
-PNG_EXTERN void png_write_finish_row PNGARG((png_structp png_ptr));
-
-/* Internal use only.   Called before first row of data */
-PNG_EXTERN void png_write_start_row PNGARG((png_structp png_ptr));
-
-#if defined(PNG_READ_GAMMA_SUPPORTED)
-PNG_EXTERN void png_build_gamma_table PNGARG((png_structp png_ptr));
-#endif
-
-/* combine a row of data, dealing with alpha, etc. if requested */
-PNG_EXTERN void png_combine_row PNGARG((png_structp png_ptr, png_bytep row,
-   int mask));
-
-#if defined(PNG_READ_INTERLACING_SUPPORTED)
-/* expand an interlaced row */
-/* OLD pre-1.0.9 interface:
-PNG_EXTERN void png_do_read_interlace PNGARG((png_row_infop row_info,
-   png_bytep row, int pass, png_uint_32 transformations));
- */
-PNG_EXTERN void png_do_read_interlace PNGARG((png_structp png_ptr));
-#endif
-
-/* GRR TO DO (2.0 or whenever):  simplify other internal calling interfaces */
-
-#if defined(PNG_WRITE_INTERLACING_SUPPORTED)
-/* grab pixels out of a row for an interlaced pass */
-PNG_EXTERN void png_do_write_interlace PNGARG((png_row_infop row_info,
-   png_bytep row, int pass));
-#endif
-
-/* unfilter a row */
-PNG_EXTERN void png_read_filter_row PNGARG((png_structp png_ptr,
-   png_row_infop row_info, png_bytep row, png_bytep prev_row, int filter));
-
-/* Choose the best filter to use and filter the row data */
-PNG_EXTERN void png_write_find_filter PNGARG((png_structp png_ptr,
-   png_row_infop row_info));
-
-/* Write out the filtered row. */
-PNG_EXTERN void png_write_filtered_row PNGARG((png_structp png_ptr,
-   png_bytep filtered_row));
-/* finish a row while reading, dealing with interlacing passes, etc. */
-PNG_EXTERN void png_read_finish_row PNGARG((png_structp png_ptr));
-
-/* initialize the row buffers, etc. */
-PNG_EXTERN void png_read_start_row PNGARG((png_structp png_ptr));
-/* optional call to update the users info structure */
-PNG_EXTERN void png_read_transform_info PNGARG((png_structp png_ptr,
-   png_infop info_ptr));
-
-/* these are the functions that do the transformations */
-#if defined(PNG_READ_FILLER_SUPPORTED)
-PNG_EXTERN void png_do_read_filler PNGARG((png_row_infop row_info,
-   png_bytep row, png_uint_32 filler, png_uint_32 flags));
-#endif
-
-#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED)
-PNG_EXTERN void png_do_read_swap_alpha PNGARG((png_row_infop row_info,
-   png_bytep row));
-#endif
-
-#if defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
-PNG_EXTERN void png_do_write_swap_alpha PNGARG((png_row_infop row_info,
-   png_bytep row));
-#endif
-
-#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED)
-PNG_EXTERN void png_do_read_invert_alpha PNGARG((png_row_infop row_info,
-   png_bytep row));
-#endif
-
-#if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
-PNG_EXTERN void png_do_write_invert_alpha PNGARG((png_row_infop row_info,
-   png_bytep row));
-#endif
-
-#if defined(PNG_WRITE_FILLER_SUPPORTED) || \
-    defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
-PNG_EXTERN void png_do_strip_filler PNGARG((png_row_infop row_info,
-   png_bytep row, png_uint_32 flags));
-#endif
-
-#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
-PNG_EXTERN void png_do_swap PNGARG((png_row_infop row_info, png_bytep row));
-#endif
-
-#if defined(PNG_READ_PACKSWAP_SUPPORTED) || defined(PNG_WRITE_PACKSWAP_SUPPORTED)
-PNG_EXTERN void png_do_packswap PNGARG((png_row_infop row_info, png_bytep row));
-#endif
-
-#if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
-PNG_EXTERN int png_do_rgb_to_gray PNGARG((png_structp png_ptr, png_row_infop
-   row_info, png_bytep row));
-#endif
-
-#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
-PNG_EXTERN void png_do_gray_to_rgb PNGARG((png_row_infop row_info,
-   png_bytep row));
-#endif
-
-#if defined(PNG_READ_PACK_SUPPORTED)
-PNG_EXTERN void png_do_unpack PNGARG((png_row_infop row_info, png_bytep row));
-#endif
-
-#if defined(PNG_READ_SHIFT_SUPPORTED)
-PNG_EXTERN void png_do_unshift PNGARG((png_row_infop row_info, png_bytep row,
-   png_color_8p sig_bits));
-#endif
-
-#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
-PNG_EXTERN void png_do_invert PNGARG((png_row_infop row_info, png_bytep row));
-#endif
-
-#if defined(PNG_READ_16_TO_8_SUPPORTED)
-PNG_EXTERN void png_do_chop PNGARG((png_row_infop row_info, png_bytep row));
-#endif
-
-#if defined(PNG_READ_DITHER_SUPPORTED)
-PNG_EXTERN void png_do_dither PNGARG((png_row_infop row_info,
-   png_bytep row, png_bytep palette_lookup, png_bytep dither_lookup));
-
-#  if defined(PNG_CORRECT_PALETTE_SUPPORTED)
-PNG_EXTERN void png_correct_palette PNGARG((png_structp png_ptr,
-   png_colorp palette, int num_palette));
-#  endif
-#endif
-
-#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
-PNG_EXTERN void png_do_bgr PNGARG((png_row_infop row_info, png_bytep row));
-#endif
-
-#if defined(PNG_WRITE_PACK_SUPPORTED)
-PNG_EXTERN void png_do_pack PNGARG((png_row_infop row_info,
-   png_bytep row, png_uint_32 bit_depth));
-#endif
-
-#if defined(PNG_WRITE_SHIFT_SUPPORTED)
-PNG_EXTERN void png_do_shift PNGARG((png_row_infop row_info, png_bytep row,
-   png_color_8p bit_depth));
-#endif
-
-#if defined(PNG_READ_BACKGROUND_SUPPORTED)
-#if defined(PNG_READ_GAMMA_SUPPORTED)
-PNG_EXTERN void png_do_background PNGARG((png_row_infop row_info, png_bytep row,
-   png_color_16p trans_values, png_color_16p background,
-   png_color_16p background_1,
-   png_bytep gamma_table, png_bytep gamma_from_1, png_bytep gamma_to_1,
-   png_uint_16pp gamma_16, png_uint_16pp gamma_16_from_1,
-   png_uint_16pp gamma_16_to_1, int gamma_shift));
-#else
-PNG_EXTERN void png_do_background PNGARG((png_row_infop row_info, png_bytep row,
-   png_color_16p trans_values, png_color_16p background));
-#endif
-#endif
-
-#if defined(PNG_READ_GAMMA_SUPPORTED)
-PNG_EXTERN void png_do_gamma PNGARG((png_row_infop row_info, png_bytep row,
-   png_bytep gamma_table, png_uint_16pp gamma_16_table,
-   int gamma_shift));
-#endif
-
-#if defined(PNG_READ_EXPAND_SUPPORTED)
-PNG_EXTERN void png_do_expand_palette PNGARG((png_row_infop row_info,
-   png_bytep row, png_colorp palette, png_bytep trans, int num_trans));
-PNG_EXTERN void png_do_expand PNGARG((png_row_infop row_info,
-   png_bytep row, png_color_16p trans_value));
-#endif
-
-/* The following decodes the appropriate chunks, and does error correction,
- * then calls the appropriate callback for the chunk if it is valid.
- */
-
-/* decode the IHDR chunk */
-PNG_EXTERN void png_handle_IHDR PNGARG((png_structp png_ptr, png_infop info_ptr,
-   png_uint_32 length));
-PNG_EXTERN void png_handle_PLTE PNGARG((png_structp png_ptr, png_infop info_ptr,
-   png_uint_32 length));
-PNG_EXTERN void png_handle_IEND PNGARG((png_structp png_ptr, png_infop info_ptr,
-   png_uint_32 length));
-
-#if defined(PNG_READ_bKGD_SUPPORTED)
-PNG_EXTERN void png_handle_bKGD PNGARG((png_structp png_ptr, png_infop info_ptr,
-   png_uint_32 length));
-#endif
-
-#if defined(PNG_READ_cHRM_SUPPORTED)
-PNG_EXTERN void png_handle_cHRM PNGARG((png_structp png_ptr, png_infop info_ptr,
-   png_uint_32 length));
-#endif
-
-#if defined(PNG_READ_gAMA_SUPPORTED)
-PNG_EXTERN void png_handle_gAMA PNGARG((png_structp png_ptr, png_infop info_ptr,
-   png_uint_32 length));
-#endif
-
-#if defined(PNG_READ_hIST_SUPPORTED)
-PNG_EXTERN void png_handle_hIST PNGARG((png_structp png_ptr, png_infop info_ptr,
-   png_uint_32 length));
-#endif
-
-#if defined(PNG_READ_iCCP_SUPPORTED)
-extern void png_handle_iCCP PNGARG((png_structp png_ptr, png_infop info_ptr,
-   png_uint_32 length));
-#endif /* PNG_READ_iCCP_SUPPORTED */
-
-#if defined(PNG_READ_iTXt_SUPPORTED)
-PNG_EXTERN void png_handle_iTXt PNGARG((png_structp png_ptr, png_infop info_ptr,
-   png_uint_32 length));
-#endif
-
-#if defined(PNG_READ_oFFs_SUPPORTED)
-PNG_EXTERN void png_handle_oFFs PNGARG((png_structp png_ptr, png_infop info_ptr,
-   png_uint_32 length));
-#endif
-
-#if defined(PNG_READ_pCAL_SUPPORTED)
-PNG_EXTERN void png_handle_pCAL PNGARG((png_structp png_ptr, png_infop info_ptr,
-   png_uint_32 length));
-#endif
-
-#if defined(PNG_READ_pHYs_SUPPORTED)
-PNG_EXTERN void png_handle_pHYs PNGARG((png_structp png_ptr, png_infop info_ptr,
-   png_uint_32 length));
-#endif
-
-#if defined(PNG_READ_sBIT_SUPPORTED)
-PNG_EXTERN void png_handle_sBIT PNGARG((png_structp png_ptr, png_infop info_ptr,
-   png_uint_32 length));
-#endif
-
-#if defined(PNG_READ_sCAL_SUPPORTED)
-PNG_EXTERN void png_handle_sCAL PNGARG((png_structp png_ptr, png_infop info_ptr,
-   png_uint_32 length));
-#endif
-
-#if defined(PNG_READ_sPLT_SUPPORTED)
-extern void png_handle_sPLT PNGARG((png_structp png_ptr, png_infop info_ptr,
-   png_uint_32 length));
-#endif /* PNG_READ_sPLT_SUPPORTED */
-
-#if defined(PNG_READ_sRGB_SUPPORTED)
-PNG_EXTERN void png_handle_sRGB PNGARG((png_structp png_ptr, png_infop info_ptr,
-   png_uint_32 length));
-#endif
-
-#if defined(PNG_READ_tEXt_SUPPORTED)
-PNG_EXTERN void png_handle_tEXt PNGARG((png_structp png_ptr, png_infop info_ptr,
-   png_uint_32 length));
-#endif
-
-#if defined(PNG_READ_tIME_SUPPORTED)
-PNG_EXTERN void png_handle_tIME PNGARG((png_structp png_ptr, png_infop info_ptr,
-   png_uint_32 length));
-#endif
-
-#if defined(PNG_READ_tRNS_SUPPORTED)
-PNG_EXTERN void png_handle_tRNS PNGARG((png_structp png_ptr, png_infop info_ptr,
-   png_uint_32 length));
-#endif
-
-#if defined(PNG_READ_zTXt_SUPPORTED)
-PNG_EXTERN void png_handle_zTXt PNGARG((png_structp png_ptr, png_infop info_ptr,
-   png_uint_32 length));
-#endif
-
-PNG_EXTERN void png_handle_unknown PNGARG((png_structp png_ptr,
-   png_infop info_ptr, png_uint_32 length));
-
-PNG_EXTERN void png_check_chunk_name PNGARG((png_structp png_ptr,
-   png_bytep chunk_name));
-
-/* handle the transformations for reading and writing */
-PNG_EXTERN void png_do_read_transformations PNGARG((png_structp png_ptr));
-PNG_EXTERN void png_do_write_transformations PNGARG((png_structp png_ptr));
-
-PNG_EXTERN void png_init_read_transformations PNGARG((png_structp png_ptr));
-
-#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
-PNG_EXTERN void png_push_read_chunk PNGARG((png_structp png_ptr,
-   png_infop info_ptr));
-PNG_EXTERN void png_push_read_sig PNGARG((png_structp png_ptr,
-   png_infop info_ptr));
-PNG_EXTERN void png_push_check_crc PNGARG((png_structp png_ptr));
-PNG_EXTERN void png_push_crc_skip PNGARG((png_structp png_ptr,
-   png_uint_32 length));
-PNG_EXTERN void png_push_crc_finish PNGARG((png_structp png_ptr));
-PNG_EXTERN void png_push_save_buffer PNGARG((png_structp png_ptr));
-PNG_EXTERN void png_push_restore_buffer PNGARG((png_structp png_ptr,
-   png_bytep buffer, png_size_t buffer_length));
-PNG_EXTERN void png_push_read_IDAT PNGARG((png_structp png_ptr));
-PNG_EXTERN void png_process_IDAT_data PNGARG((png_structp png_ptr,
-   png_bytep buffer, png_size_t buffer_length));
-PNG_EXTERN void png_push_process_row PNGARG((png_structp png_ptr));
-PNG_EXTERN void png_push_handle_unknown PNGARG((png_structp png_ptr,
-   png_infop info_ptr, png_uint_32 length));
-PNG_EXTERN void png_push_have_info PNGARG((png_structp png_ptr,
-   png_infop info_ptr));
-PNG_EXTERN void png_push_have_end PNGARG((png_structp png_ptr,
-   png_infop info_ptr));
-PNG_EXTERN void png_push_have_row PNGARG((png_structp png_ptr, png_bytep row));
-PNG_EXTERN void png_push_read_end PNGARG((png_structp png_ptr,
-   png_infop info_ptr));
-PNG_EXTERN void png_process_some_data PNGARG((png_structp png_ptr,
-   png_infop info_ptr));
-PNG_EXTERN void png_read_push_finish_row PNGARG((png_structp png_ptr));
-#if defined(PNG_READ_tEXt_SUPPORTED)
-PNG_EXTERN void png_push_handle_tEXt PNGARG((png_structp png_ptr,
-   png_infop info_ptr, png_uint_32 length));
-PNG_EXTERN void png_push_read_tEXt PNGARG((png_structp png_ptr,
-   png_infop info_ptr));
-#endif
-#if defined(PNG_READ_zTXt_SUPPORTED)
-PNG_EXTERN void png_push_handle_zTXt PNGARG((png_structp png_ptr,
-   png_infop info_ptr, png_uint_32 length));
-PNG_EXTERN void png_push_read_zTXt PNGARG((png_structp png_ptr,
-   png_infop info_ptr));
-#endif
-#if defined(PNG_READ_iTXt_SUPPORTED)
-PNG_EXTERN void png_push_handle_iTXt PNGARG((png_structp png_ptr,
-   png_infop info_ptr, png_uint_32 length));
-PNG_EXTERN void png_push_read_iTXt PNGARG((png_structp png_ptr,
-   png_infop info_ptr));
-#endif
-
-#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
-
-#ifdef PNG_MNG_FEATURES_SUPPORTED
-PNG_EXTERN void png_do_read_intrapixel PNGARG((png_row_infop row_info,
-   png_bytep row));
-PNG_EXTERN void png_do_write_intrapixel PNGARG((png_row_infop row_info,
-   png_bytep row));
-#endif
-
-#if defined(PNG_ASSEMBLER_CODE_SUPPORTED)
-/* png.c */ /* PRIVATE */
-PNG_EXTERN void png_init_mmx_flags PNGARG((png_structp png_ptr));
-#endif
-/* Maintainer: Put new private prototypes here ^ and in libpngpf.3 */
-
-#endif /* PNG_INTERNAL */
-
-#ifdef __cplusplus
-}
-#endif
-
-#endif /* PNG_VERSION_INFO_ONLY */
-/* do not put anything past this line */
-#endif /* PNG_H */
diff --git a/com32/lib/libpng/pngconf.h b/com32/lib/libpng/pngconf.h
deleted file mode 100644
index 7f4cbede..00000000
--- a/com32/lib/libpng/pngconf.h
+++ /dev/null
@@ -1,1437 +0,0 @@
-
-/* pngconf.h - machine configurable file for libpng
- *
- * libpng version 1.2.8 - December 3, 2004
- * For conditions of distribution and use, see copyright notice in png.h
- * Copyright (c) 1998-2004 Glenn Randers-Pehrson
- * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
- * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
- */
-
-/* Any machine specific code is near the front of this file, so if you
- * are configuring libpng for a machine, you may want to read the section
- * starting here down to where it starts to typedef png_color, png_text,
- * and png_info.
- */
-
-#ifndef PNGCONF_H
-#define PNGCONF_H
-
-#define PNG_1_2_X
-
-/* 
- * PNG_USER_CONFIG has to be defined on the compiler command line. This
- * includes the resource compiler for Windows DLL configurations.
- */
-#ifdef PNG_USER_CONFIG
-#include "pngusr.h"
-#endif
-
-/*
- * Added at libpng-1.2.8
- *  
- * If you create a private DLL you need to define in "pngusr.h" the followings:
- * #define PNG_USER_PRIVATEBUILD <Describes by whom and why this version of
- *        the DLL was built>
- *  e.g. #define PNG_USER_PRIVATEBUILD "Build by MyCompany for xyz reasons."
- * #define PNG_USER_DLLFNAME_POSTFIX <two-letter postfix that serve to
- *        distinguish your DLL from those of the official release. These
- *        correspond to the trailing letters that come after the version
- *        number and must match your private DLL name>
- *  e.g. // private DLL "libpng13gx.dll"
- *       #define PNG_USER_DLLFNAME_POSTFIX "gx"
- * 
- * The following macros are also at your disposal if you want to complete the 
- * DLL VERSIONINFO structure.
- * - PNG_USER_VERSIONINFO_COMMENTS
- * - PNG_USER_VERSIONINFO_COMPANYNAME
- * - PNG_USER_VERSIONINFO_LEGALTRADEMARKS
- */
-
-#ifdef __STDC__
-#ifdef SPECIALBUILD
-#  pragma message("PNG_LIBPNG_SPECIALBUILD (and deprecated SPECIALBUILD)\
- are now LIBPNG reserved macros. Use PNG_USER_PRIVATEBUILD instead.")
-#endif
-
-#ifdef PRIVATEBUILD
-# pragma message("PRIVATEBUILD is deprecated. Use\
- PNG_USER_PRIVATEBUILD instead.")
-# define PNG_USER_PRIVATEBUILD PRIVATEBUILD
-#endif
-#endif /* __STDC__ */
-
-#ifndef PNG_VERSION_INFO_ONLY
-
-/* End of material added to libpng-1.2.8 */
-
-/* This is the size of the compression buffer, and thus the size of
- * an IDAT chunk.  Make this whatever size you feel is best for your
- * machine.  One of these will be allocated per png_struct.  When this
- * is full, it writes the data to the disk, and does some other
- * calculations.  Making this an extremely small size will slow
- * the library down, but you may want to experiment to determine
- * where it becomes significant, if you are concerned with memory
- * usage.  Note that zlib allocates at least 32Kb also.  For readers,
- * this describes the size of the buffer available to read the data in.
- * Unless this gets smaller than the size of a row (compressed),
- * it should not make much difference how big this is.
- */
-
-#ifndef PNG_ZBUF_SIZE
-#  define PNG_ZBUF_SIZE 8192
-#endif
-
-/* Enable if you want a write-only libpng */
-
-#ifndef PNG_NO_READ_SUPPORTED
-#  define PNG_READ_SUPPORTED
-#endif
-
-/* Enable if you want a read-only libpng */
-
-#ifndef PNG_NO_WRITE_SUPPORTED
-#  define PNG_WRITE_SUPPORTED
-#endif
-
-/* Enabled by default in 1.2.0.  You can disable this if you don't need to
-   support PNGs that are embedded in MNG datastreams */
-#if !defined(PNG_1_0_X) && !defined(PNG_NO_MNG_FEATURES)
-#  ifndef PNG_MNG_FEATURES_SUPPORTED
-#    define PNG_MNG_FEATURES_SUPPORTED
-#  endif
-#endif
-
-#ifndef PNG_NO_FLOATING_POINT_SUPPORTED
-#  ifndef PNG_FLOATING_POINT_SUPPORTED
-#    define PNG_FLOATING_POINT_SUPPORTED
-#  endif
-#endif
-
-/* If you are running on a machine where you cannot allocate more
- * than 64K of memory at once, uncomment this.  While libpng will not
- * normally need that much memory in a chunk (unless you load up a very
- * large file), zlib needs to know how big of a chunk it can use, and
- * libpng thus makes sure to check any memory allocation to verify it
- * will fit into memory.
-#define PNG_MAX_MALLOC_64K
- */
-#if defined(MAXSEG_64K) && !defined(PNG_MAX_MALLOC_64K)
-#  define PNG_MAX_MALLOC_64K
-#endif
-
-/* Special munging to support doing things the 'cygwin' way:
- * 'Normal' png-on-win32 defines/defaults:
- *   PNG_BUILD_DLL -- building dll
- *   PNG_USE_DLL   -- building an application, linking to dll
- *   (no define)   -- building static library, or building an
- *                    application and linking to the static lib
- * 'Cygwin' defines/defaults:
- *   PNG_BUILD_DLL -- (ignored) building the dll
- *   (no define)   -- (ignored) building an application, linking to the dll
- *   PNG_STATIC    -- (ignored) building the static lib, or building an 
- *                    application that links to the static lib.
- *   ALL_STATIC    -- (ignored) building various static libs, or building an 
- *                    application that links to the static libs.
- * Thus,
- * a cygwin user should define either PNG_BUILD_DLL or PNG_STATIC, and
- * this bit of #ifdefs will define the 'correct' config variables based on
- * that. If a cygwin user *wants* to define 'PNG_USE_DLL' that's okay, but
- * unnecessary.
- *
- * Also, the precedence order is:
- *   ALL_STATIC (since we can't #undef something outside our namespace)
- *   PNG_BUILD_DLL
- *   PNG_STATIC
- *   (nothing) == PNG_USE_DLL
- * 
- * CYGWIN (2002-01-20): The preceding is now obsolete. With the advent
- *   of auto-import in binutils, we no longer need to worry about 
- *   __declspec(dllexport) / __declspec(dllimport) and friends.  Therefore,
- *   we don't need to worry about PNG_STATIC or ALL_STATIC when it comes
- *   to __declspec() stuff.  However, we DO need to worry about 
- *   PNG_BUILD_DLL and PNG_STATIC because those change some defaults
- *   such as CONSOLE_IO and whether GLOBAL_ARRAYS are allowed.
- */
-#if defined(__CYGWIN__)
-#  if defined(ALL_STATIC)
-#    if defined(PNG_BUILD_DLL)
-#      undef PNG_BUILD_DLL
-#    endif
-#    if defined(PNG_USE_DLL)
-#      undef PNG_USE_DLL
-#    endif
-#    if defined(PNG_DLL)
-#      undef PNG_DLL
-#    endif
-#    if !defined(PNG_STATIC)
-#      define PNG_STATIC
-#    endif
-#  else
-#    if defined (PNG_BUILD_DLL)
-#      if defined(PNG_STATIC)
-#        undef PNG_STATIC
-#      endif
-#      if defined(PNG_USE_DLL)
-#        undef PNG_USE_DLL
-#      endif
-#      if !defined(PNG_DLL)
-#        define PNG_DLL
-#      endif
-#    else
-#      if defined(PNG_STATIC)
-#        if defined(PNG_USE_DLL)
-#          undef PNG_USE_DLL
-#        endif
-#        if defined(PNG_DLL)
-#          undef PNG_DLL
-#        endif
-#      else
-#        if !defined(PNG_USE_DLL)
-#          define PNG_USE_DLL
-#        endif
-#        if !defined(PNG_DLL)
-#          define PNG_DLL
-#        endif
-#      endif  
-#    endif  
-#  endif
-#endif
-
-/* This protects us against compilers that run on a windowing system
- * and thus don't have or would rather us not use the stdio types:
- * stdin, stdout, and stderr.  The only one currently used is stderr
- * in png_error() and png_warning().  #defining PNG_NO_CONSOLE_IO will
- * prevent these from being compiled and used. #defining PNG_NO_STDIO
- * will also prevent these, plus will prevent the entire set of stdio
- * macros and functions (FILE *, printf, etc.) from being compiled and used,
- * unless (PNG_DEBUG > 0) has been #defined.
- *
- * #define PNG_NO_CONSOLE_IO
- * #define PNG_NO_STDIO
- */
-
-#if defined(_WIN32_WCE)
-#  include <windows.h>
-   /* Console I/O functions are not supported on WindowsCE */
-#  define PNG_NO_CONSOLE_IO
-#  ifdef PNG_DEBUG
-#    undef PNG_DEBUG
-#  endif
-#endif
-
-#ifdef PNG_BUILD_DLL
-#  ifndef PNG_CONSOLE_IO_SUPPORTED
-#    ifndef PNG_NO_CONSOLE_IO
-#      define PNG_NO_CONSOLE_IO
-#    endif
-#  endif
-#endif
-
-#  ifdef PNG_NO_STDIO
-#    ifndef PNG_NO_CONSOLE_IO
-#      define PNG_NO_CONSOLE_IO
-#    endif
-#    ifdef PNG_DEBUG
-#      if (PNG_DEBUG > 0)
-#        include <stdio.h>
-#      endif
-#    endif
-#  else
-#    if !defined(_WIN32_WCE)
-/* "stdio.h" functions are not supported on WindowsCE */
-#      include <stdio.h>
-#    endif
-#  endif
-
-/* This macro protects us against machines that don't have function
- * prototypes (ie K&R style headers).  If your compiler does not handle
- * function prototypes, define this macro and use the included ansi2knr.
- * I've always been able to use _NO_PROTO as the indicator, but you may
- * need to drag the empty declaration out in front of here, or change the
- * ifdef to suit your own needs.
- */
-#ifndef PNGARG
-
-#ifdef OF /* zlib prototype munger */
-#  define PNGARG(arglist) OF(arglist)
-#else
-
-#ifdef _NO_PROTO
-#  define PNGARG(arglist) ()
-#  ifndef PNG_TYPECAST_NULL
-#     define PNG_TYPECAST_NULL
-#  endif
-#else
-#  define PNGARG(arglist) arglist
-#endif /* _NO_PROTO */
-
-#endif /* OF */
-
-#endif /* PNGARG */
-
-/* Try to determine if we are compiling on a Mac.  Note that testing for
- * just __MWERKS__ is not good enough, because the Codewarrior is now used
- * on non-Mac platforms.
- */
-#ifndef MACOS
-#  if (defined(__MWERKS__) && defined(macintosh)) || defined(applec) || \
-      defined(THINK_C) || defined(__SC__) || defined(TARGET_OS_MAC)
-#    define MACOS
-#  endif
-#endif
-
-/* enough people need this for various reasons to include it here */
-#if !defined(MACOS) && !defined(RISCOS) && !defined(_WIN32_WCE)
-#  include <sys/types.h>
-#endif
-
-#if !defined(PNG_SETJMP_NOT_SUPPORTED) && !defined(PNG_NO_SETJMP_SUPPORTED)
-#  define PNG_SETJMP_SUPPORTED
-#endif
-
-#ifdef PNG_SETJMP_SUPPORTED
-/* This is an attempt to force a single setjmp behaviour on Linux.  If
- * the X config stuff didn't define _BSD_SOURCE we wouldn't need this.
- */
-
-#  ifdef __linux__
-#    ifdef _BSD_SOURCE
-#      define PNG_SAVE_BSD_SOURCE
-#      undef _BSD_SOURCE
-#    endif
-#    ifdef _SETJMP_H
-     /* If you encounter a compiler error here, see the explanation
-      * near the end of INSTALL.
-      */
-         __png.h__ already includes setjmp.h;
-         __dont__ include it again.;
-#    endif
-#  endif /* __linux__ */
-
-   /* include setjmp.h for error handling */
-#  include <setjmp.h>
-
-#  ifdef __linux__
-#    ifdef PNG_SAVE_BSD_SOURCE
-#      define _BSD_SOURCE
-#      undef PNG_SAVE_BSD_SOURCE
-#    endif
-#  endif /* __linux__ */
-#endif /* PNG_SETJMP_SUPPORTED */
-
-#ifdef BSD
-#  include <strings.h>
-#else
-#  include <string.h>
-#endif
-
-/* Other defines for things like memory and the like can go here.  */
-#ifdef PNG_INTERNAL
-
-#include <stdlib.h>
-
-/* The functions exported by PNG_EXTERN are PNG_INTERNAL functions, which
- * aren't usually used outside the library (as far as I know), so it is
- * debatable if they should be exported at all.  In the future, when it is
- * possible to have run-time registry of chunk-handling functions, some of
- * these will be made available again.
-#define PNG_EXTERN extern
- */
-#define PNG_EXTERN
-
-/* Other defines specific to compilers can go here.  Try to keep
- * them inside an appropriate ifdef/endif pair for portability.
- */
-
-#if defined(PNG_FLOATING_POINT_SUPPORTED)
-#  if defined(MACOS)
-     /* We need to check that <math.h> hasn't already been included earlier
-      * as it seems it doesn't agree with <fp.h>, yet we should really use
-      * <fp.h> if possible.
-      */
-#    if !defined(__MATH_H__) && !defined(__MATH_H) && !defined(__cmath__)
-#      include <fp.h>
-#    endif
-#  else
-#    include <math.h>
-#  endif
-#  if defined(_AMIGA) && defined(__SASC) && defined(_M68881)
-     /* Amiga SAS/C: We must include builtin FPU functions when compiling using
-      * MATH=68881
-      */
-#    include <m68881.h>
-#  endif
-#endif
-
-/* Codewarrior on NT has linking problems without this. */
-#if (defined(__MWERKS__) && defined(WIN32)) || defined(__STDC__)
-#  define PNG_ALWAYS_EXTERN
-#endif
-
-/* This provides the non-ANSI (far) memory allocation routines. */
-#if defined(__TURBOC__) && defined(__MSDOS__)
-#  include <mem.h>
-#  include <alloc.h>
-#endif
-
-/* I have no idea why is this necessary... */
-#if defined(_MSC_VER) && (defined(WIN32) || defined(_Windows) || \
-    defined(_WINDOWS) || defined(_WIN32) || defined(__WIN32__))
-#  include <malloc.h>
-#endif
-
-/* This controls how fine the dithering gets.  As this allocates
- * a largish chunk of memory (32K), those who are not as concerned
- * with dithering quality can decrease some or all of these.
- */
-#ifndef PNG_DITHER_RED_BITS
-#  define PNG_DITHER_RED_BITS 5
-#endif
-#ifndef PNG_DITHER_GREEN_BITS
-#  define PNG_DITHER_GREEN_BITS 5
-#endif
-#ifndef PNG_DITHER_BLUE_BITS
-#  define PNG_DITHER_BLUE_BITS 5
-#endif
-
-/* This controls how fine the gamma correction becomes when you
- * are only interested in 8 bits anyway.  Increasing this value
- * results in more memory being used, and more pow() functions
- * being called to fill in the gamma tables.  Don't set this value
- * less then 8, and even that may not work (I haven't tested it).
- */
-
-#ifndef PNG_MAX_GAMMA_8
-#  define PNG_MAX_GAMMA_8 11
-#endif
-
-/* This controls how much a difference in gamma we can tolerate before
- * we actually start doing gamma conversion.
- */
-#ifndef PNG_GAMMA_THRESHOLD
-#  define PNG_GAMMA_THRESHOLD 0.05
-#endif
-
-#endif /* PNG_INTERNAL */
-
-/* The following uses const char * instead of char * for error
- * and warning message functions, so some compilers won't complain.
- * If you do not want to use const, define PNG_NO_CONST here.
- */
-
-#ifndef PNG_NO_CONST
-#  define PNG_CONST const
-#else
-#  define PNG_CONST
-#endif
-
-/* The following defines give you the ability to remove code from the
- * library that you will not be using.  I wish I could figure out how to
- * automate this, but I can't do that without making it seriously hard
- * on the users.  So if you are not using an ability, change the #define
- * to and #undef, and that part of the library will not be compiled.  If
- * your linker can't find a function, you may want to make sure the
- * ability is defined here.  Some of these depend upon some others being
- * defined.  I haven't figured out all the interactions here, so you may
- * have to experiment awhile to get everything to compile.  If you are
- * creating or using a shared library, you probably shouldn't touch this,
- * as it will affect the size of the structures, and this will cause bad
- * things to happen if the library and/or application ever change.
- */
-
-/* Any features you will not be using can be undef'ed here */
-
-/* GR-P, 0.96a: Set "*TRANSFORMS_SUPPORTED as default but allow user
- * to turn it off with "*TRANSFORMS_NOT_SUPPORTED" or *PNG_NO_*_TRANSFORMS
- * on the compile line, then pick and choose which ones to define without
- * having to edit this file. It is safe to use the *TRANSFORMS_NOT_SUPPORTED
- * if you only want to have a png-compliant reader/writer but don't need
- * any of the extra transformations.  This saves about 80 kbytes in a
- * typical installation of the library. (PNG_NO_* form added in version
- * 1.0.1c, for consistency)
- */
-
-/* The size of the png_text structure changed in libpng-1.0.6 when
- * iTXt is supported.  It is turned off by default, to support old apps
- * that malloc the png_text structure instead of calling png_set_text()
- * and letting libpng malloc it.  It will be turned on by default in
- * libpng-1.3.0.
- */
-
-#ifndef PNG_iTXt_SUPPORTED
-#  if !defined(PNG_READ_iTXt_SUPPORTED) && !defined(PNG_NO_READ_iTXt)
-#    define PNG_NO_READ_iTXt
-#  endif
-#  if !defined(PNG_WRITE_iTXt_SUPPORTED) && !defined(PNG_NO_WRITE_iTXt)
-#    define PNG_NO_WRITE_iTXt
-#  endif
-#endif
-
-/* The following support, added after version 1.0.0, can be turned off here en
- * masse by defining PNG_LEGACY_SUPPORTED in case you need binary compatibility
- * with old applications that require the length of png_struct and png_info
- * to remain unchanged.
- */
-
-#ifdef PNG_LEGACY_SUPPORTED
-#  define PNG_NO_FREE_ME
-#  define PNG_NO_READ_UNKNOWN_CHUNKS
-#  define PNG_NO_WRITE_UNKNOWN_CHUNKS
-#  define PNG_NO_READ_USER_CHUNKS
-#  define PNG_NO_READ_iCCP
-#  define PNG_NO_WRITE_iCCP
-#  define PNG_NO_READ_iTXt
-#  define PNG_NO_WRITE_iTXt
-#  define PNG_NO_READ_sCAL
-#  define PNG_NO_WRITE_sCAL
-#  define PNG_NO_READ_sPLT
-#  define PNG_NO_WRITE_sPLT
-#  define PNG_NO_INFO_IMAGE
-#  define PNG_NO_READ_RGB_TO_GRAY
-#  define PNG_NO_READ_USER_TRANSFORM
-#  define PNG_NO_WRITE_USER_TRANSFORM
-#  define PNG_NO_USER_MEM
-#  define PNG_NO_READ_EMPTY_PLTE
-#  define PNG_NO_MNG_FEATURES
-#  define PNG_NO_FIXED_POINT_SUPPORTED
-#endif
-
-/* Ignore attempt to turn off both floating and fixed point support */
-#if !defined(PNG_FLOATING_POINT_SUPPORTED) || \
-    !defined(PNG_NO_FIXED_POINT_SUPPORTED)
-#  define PNG_FIXED_POINT_SUPPORTED
-#endif
-
-#ifndef PNG_NO_FREE_ME
-#  define PNG_FREE_ME_SUPPORTED
-#endif
-
-#if defined(PNG_READ_SUPPORTED)
-
-#if !defined(PNG_READ_TRANSFORMS_NOT_SUPPORTED) && \
-      !defined(PNG_NO_READ_TRANSFORMS)
-#  define PNG_READ_TRANSFORMS_SUPPORTED
-#endif
-
-#ifdef PNG_READ_TRANSFORMS_SUPPORTED
-#  ifndef PNG_NO_READ_EXPAND
-#    define PNG_READ_EXPAND_SUPPORTED
-#  endif
-#  ifndef PNG_NO_READ_SHIFT
-#    define PNG_READ_SHIFT_SUPPORTED
-#  endif
-#  ifndef PNG_NO_READ_PACK
-#    define PNG_READ_PACK_SUPPORTED
-#  endif
-#  ifndef PNG_NO_READ_BGR
-#    define PNG_READ_BGR_SUPPORTED
-#  endif
-#  ifndef PNG_NO_READ_SWAP
-#    define PNG_READ_SWAP_SUPPORTED
-#  endif
-#  ifndef PNG_NO_READ_PACKSWAP
-#    define PNG_READ_PACKSWAP_SUPPORTED
-#  endif
-#  ifndef PNG_NO_READ_INVERT
-#    define PNG_READ_INVERT_SUPPORTED
-#  endif
-#  ifndef PNG_NO_READ_DITHER
-#    define PNG_READ_DITHER_SUPPORTED
-#  endif
-#  ifndef PNG_NO_READ_BACKGROUND
-#    define PNG_READ_BACKGROUND_SUPPORTED
-#  endif
-#  ifndef PNG_NO_READ_16_TO_8
-#    define PNG_READ_16_TO_8_SUPPORTED
-#  endif
-#  ifndef PNG_NO_READ_FILLER
-#    define PNG_READ_FILLER_SUPPORTED
-#  endif
-#  ifndef PNG_NO_READ_GAMMA
-#    define PNG_READ_GAMMA_SUPPORTED
-#  endif
-#  ifndef PNG_NO_READ_GRAY_TO_RGB
-#    define PNG_READ_GRAY_TO_RGB_SUPPORTED
-#  endif
-#  ifndef PNG_NO_READ_SWAP_ALPHA
-#    define PNG_READ_SWAP_ALPHA_SUPPORTED
-#  endif
-#  ifndef PNG_NO_READ_INVERT_ALPHA
-#    define PNG_READ_INVERT_ALPHA_SUPPORTED
-#  endif
-#  ifndef PNG_NO_READ_STRIP_ALPHA
-#    define PNG_READ_STRIP_ALPHA_SUPPORTED
-#  endif
-#  ifndef PNG_NO_READ_USER_TRANSFORM
-#    define PNG_READ_USER_TRANSFORM_SUPPORTED
-#  endif
-#  ifndef PNG_NO_READ_RGB_TO_GRAY
-#    define PNG_READ_RGB_TO_GRAY_SUPPORTED
-#  endif
-#endif /* PNG_READ_TRANSFORMS_SUPPORTED */
-
-#if !defined(PNG_NO_PROGRESSIVE_READ) && \
- !defined(PNG_PROGRESSIVE_READ_NOT_SUPPORTED)  /* if you don't do progressive */
-#  define PNG_PROGRESSIVE_READ_SUPPORTED     /* reading.  This is not talking */
-#endif                               /* about interlacing capability!  You'll */
-              /* still have interlacing unless you change the following line: */
-
-#define PNG_READ_INTERLACING_SUPPORTED /* required for PNG-compliant decoders */
-
-#ifndef PNG_NO_READ_COMPOSITE_NODIV
-#  ifndef PNG_NO_READ_COMPOSITED_NODIV  /* libpng-1.0.x misspelling */
-#    define PNG_READ_COMPOSITE_NODIV_SUPPORTED   /* well tested on Intel, SGI */
-#  endif
-#endif
-
-/* Deprecated, will be removed from version 2.0.0.
-   Use PNG_MNG_FEATURES_SUPPORTED instead. */
-#ifndef PNG_NO_READ_EMPTY_PLTE
-#  define PNG_READ_EMPTY_PLTE_SUPPORTED
-#endif
-
-#endif /* PNG_READ_SUPPORTED */
-
-#if defined(PNG_WRITE_SUPPORTED)
-
-# if !defined(PNG_WRITE_TRANSFORMS_NOT_SUPPORTED) && \
-    !defined(PNG_NO_WRITE_TRANSFORMS)
-#  define PNG_WRITE_TRANSFORMS_SUPPORTED
-#endif
-
-#ifdef PNG_WRITE_TRANSFORMS_SUPPORTED
-#  ifndef PNG_NO_WRITE_SHIFT
-#    define PNG_WRITE_SHIFT_SUPPORTED
-#  endif
-#  ifndef PNG_NO_WRITE_PACK
-#    define PNG_WRITE_PACK_SUPPORTED
-#  endif
-#  ifndef PNG_NO_WRITE_BGR
-#    define PNG_WRITE_BGR_SUPPORTED
-#  endif
-#  ifndef PNG_NO_WRITE_SWAP
-#    define PNG_WRITE_SWAP_SUPPORTED
-#  endif
-#  ifndef PNG_NO_WRITE_PACKSWAP
-#    define PNG_WRITE_PACKSWAP_SUPPORTED
-#  endif
-#  ifndef PNG_NO_WRITE_INVERT
-#    define PNG_WRITE_INVERT_SUPPORTED
-#  endif
-#  ifndef PNG_NO_WRITE_FILLER
-#    define PNG_WRITE_FILLER_SUPPORTED   /* same as WRITE_STRIP_ALPHA */
-#  endif
-#  ifndef PNG_NO_WRITE_SWAP_ALPHA
-#    define PNG_WRITE_SWAP_ALPHA_SUPPORTED
-#  endif
-#  ifndef PNG_NO_WRITE_INVERT_ALPHA
-#    define PNG_WRITE_INVERT_ALPHA_SUPPORTED
-#  endif
-#  ifndef PNG_NO_WRITE_USER_TRANSFORM
-#    define PNG_WRITE_USER_TRANSFORM_SUPPORTED
-#  endif
-#endif /* PNG_WRITE_TRANSFORMS_SUPPORTED */
-
-#define PNG_WRITE_INTERLACING_SUPPORTED  /* not required for PNG-compliant
-                                            encoders, but can cause trouble
-                                            if left undefined */
-
-#if !defined(PNG_NO_WRITE_WEIGHTED_FILTER) && \
-     defined(PNG_FLOATING_POINT_SUPPORTED)
-#  define PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
-#endif
-
-#ifndef PNG_NO_WRITE_FLUSH
-#  define PNG_WRITE_FLUSH_SUPPORTED
-#endif
-
-/* Deprecated, see PNG_MNG_FEATURES_SUPPORTED, above */
-#ifndef PNG_NO_WRITE_EMPTY_PLTE
-#  define PNG_WRITE_EMPTY_PLTE_SUPPORTED
-#endif
-
-#endif /* PNG_WRITE_SUPPORTED */
-
-#ifndef PNG_1_0_X
-#  ifndef PNG_NO_ERROR_NUMBERS
-#    define PNG_ERROR_NUMBERS_SUPPORTED
-#  endif
-#endif /* PNG_1_0_X */
-
-#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
-    defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
-#  ifndef PNG_NO_USER_TRANSFORM_PTR
-#    define PNG_USER_TRANSFORM_PTR_SUPPORTED
-#  endif
-#endif
-
-#ifndef PNG_NO_STDIO
-#  define PNG_TIME_RFC1123_SUPPORTED
-#endif
-
-/* This adds extra functions in pngget.c for accessing data from the
- * info pointer (added in version 0.99)
- * png_get_image_width()
- * png_get_image_height()
- * png_get_bit_depth()
- * png_get_color_type()
- * png_get_compression_type()
- * png_get_filter_type()
- * png_get_interlace_type()
- * png_get_pixel_aspect_ratio()
- * png_get_pixels_per_meter()
- * png_get_x_offset_pixels()
- * png_get_y_offset_pixels()
- * png_get_x_offset_microns()
- * png_get_y_offset_microns()
- */
-#if !defined(PNG_NO_EASY_ACCESS) && !defined(PNG_EASY_ACCESS_SUPPORTED)
-#  define PNG_EASY_ACCESS_SUPPORTED
-#endif
-
-/* PNG_ASSEMBLER_CODE was enabled by default in version 1.2.0 
-   even when PNG_USE_PNGVCRD or PNG_USE_PNGGCCRD is not defined */
-#if defined(PNG_READ_SUPPORTED) && !defined(PNG_NO_ASSEMBLER_CODE)
-#  ifndef PNG_ASSEMBLER_CODE_SUPPORTED
-#    define PNG_ASSEMBLER_CODE_SUPPORTED
-#  endif
-#  if !defined(PNG_MMX_CODE_SUPPORTED) && !defined(PNG_NO_MMX_CODE)
-#    define PNG_MMX_CODE_SUPPORTED
-#  endif
-#endif
-
-/* If you are sure that you don't need thread safety and you are compiling
-   with PNG_USE_PNGCCRD for an MMX application, you can define this for
-   faster execution.  See pnggccrd.c.
-#define PNG_THREAD_UNSAFE_OK
-*/
-
-#if !defined(PNG_1_0_X)
-#if !defined(PNG_NO_USER_MEM) && !defined(PNG_USER_MEM_SUPPORTED)
-#  define PNG_USER_MEM_SUPPORTED
-#endif
-#endif /* PNG_1_0_X */
-
-/* Added at libpng-1.2.6 */
-#if !defined(PNG_1_0_X)
-#ifndef PNG_SET_USER_LIMITS_SUPPORTED
-#if !defined(PNG_NO_SET_USER_LIMITS) && !defined(PNG_SET_USER_LIMITS_SUPPORTED)
-#  define PNG_SET_USER_LIMITS_SUPPORTED
-#endif
-#endif
-#endif /* PNG_1_0_X */
-
-/* Added at libpng-1.0.16 and 1.2.6.  To accept all valid PNGS no matter
- * how large, set these limits to 0x7fffffffL
- */
-#ifndef PNG_USER_WIDTH_MAX
-#  define PNG_USER_WIDTH_MAX 1000000L
-#endif
-#ifndef PNG_USER_HEIGHT_MAX
-#  define PNG_USER_HEIGHT_MAX 1000000L
-#endif
-
-/* These are currently experimental features, define them if you want */
-
-/* very little testing */
-/*
-#ifdef PNG_READ_SUPPORTED
-#  ifndef PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED
-#    define PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED
-#  endif
-#endif
-*/
-
-/* This is only for PowerPC big-endian and 680x0 systems */
-/* some testing */
-/*
-#ifndef PNG_READ_BIG_ENDIAN_SUPPORTED
-#  define PNG_READ_BIG_ENDIAN_SUPPORTED
-#endif
-*/
-
-/* Buggy compilers (e.g., gcc 2.7.2.2) need this */
-/*
-#define PNG_NO_POINTER_INDEXING
-*/
-
-/* These functions are turned off by default, as they will be phased out. */
-/*
-#define  PNG_USELESS_TESTS_SUPPORTED
-#define  PNG_CORRECT_PALETTE_SUPPORTED
-*/
-
-/* Any chunks you are not interested in, you can undef here.  The
- * ones that allocate memory may be expecially important (hIST,
- * tEXt, zTXt, tRNS, pCAL).  Others will just save time and make png_info
- * a bit smaller.
- */
-
-#if defined(PNG_READ_SUPPORTED) && \
-    !defined(PNG_READ_ANCILLARY_CHUNKS_NOT_SUPPORTED) && \
-    !defined(PNG_NO_READ_ANCILLARY_CHUNKS)
-#  define PNG_READ_ANCILLARY_CHUNKS_SUPPORTED
-#endif
-
-#if defined(PNG_WRITE_SUPPORTED) && \
-    !defined(PNG_WRITE_ANCILLARY_CHUNKS_NOT_SUPPORTED) && \
-    !defined(PNG_NO_WRITE_ANCILLARY_CHUNKS)
-#  define PNG_WRITE_ANCILLARY_CHUNKS_SUPPORTED
-#endif
-
-#ifdef PNG_READ_ANCILLARY_CHUNKS_SUPPORTED
-
-#ifdef PNG_NO_READ_TEXT
-#  define PNG_NO_READ_iTXt
-#  define PNG_NO_READ_tEXt
-#  define PNG_NO_READ_zTXt
-#endif
-#ifndef PNG_NO_READ_bKGD
-#  define PNG_READ_bKGD_SUPPORTED
-#  define PNG_bKGD_SUPPORTED
-#endif
-#ifndef PNG_NO_READ_cHRM
-#  define PNG_READ_cHRM_SUPPORTED
-#  define PNG_cHRM_SUPPORTED
-#endif
-#ifndef PNG_NO_READ_gAMA
-#  define PNG_READ_gAMA_SUPPORTED
-#  define PNG_gAMA_SUPPORTED
-#endif
-#ifndef PNG_NO_READ_hIST
-#  define PNG_READ_hIST_SUPPORTED
-#  define PNG_hIST_SUPPORTED
-#endif
-#ifndef PNG_NO_READ_iCCP
-#  define PNG_READ_iCCP_SUPPORTED
-#  define PNG_iCCP_SUPPORTED
-#endif
-#ifndef PNG_NO_READ_iTXt
-#  ifndef PNG_READ_iTXt_SUPPORTED
-#    define PNG_READ_iTXt_SUPPORTED
-#  endif
-#  ifndef PNG_iTXt_SUPPORTED
-#    define PNG_iTXt_SUPPORTED
-#  endif
-#endif
-#ifndef PNG_NO_READ_oFFs
-#  define PNG_READ_oFFs_SUPPORTED
-#  define PNG_oFFs_SUPPORTED
-#endif
-#ifndef PNG_NO_READ_pCAL
-#  define PNG_READ_pCAL_SUPPORTED
-#  define PNG_pCAL_SUPPORTED
-#endif
-#ifndef PNG_NO_READ_sCAL
-#  define PNG_READ_sCAL_SUPPORTED
-#  define PNG_sCAL_SUPPORTED
-#endif
-#ifndef PNG_NO_READ_pHYs
-#  define PNG_READ_pHYs_SUPPORTED
-#  define PNG_pHYs_SUPPORTED
-#endif
-#ifndef PNG_NO_READ_sBIT
-#  define PNG_READ_sBIT_SUPPORTED
-#  define PNG_sBIT_SUPPORTED
-#endif
-#ifndef PNG_NO_READ_sPLT
-#  define PNG_READ_sPLT_SUPPORTED
-#  define PNG_sPLT_SUPPORTED
-#endif
-#ifndef PNG_NO_READ_sRGB
-#  define PNG_READ_sRGB_SUPPORTED
-#  define PNG_sRGB_SUPPORTED
-#endif
-#ifndef PNG_NO_READ_tEXt
-#  define PNG_READ_tEXt_SUPPORTED
-#  define PNG_tEXt_SUPPORTED
-#endif
-#ifndef PNG_NO_READ_tIME
-#  define PNG_READ_tIME_SUPPORTED
-#  define PNG_tIME_SUPPORTED
-#endif
-#ifndef PNG_NO_READ_tRNS
-#  define PNG_READ_tRNS_SUPPORTED
-#  define PNG_tRNS_SUPPORTED
-#endif
-#ifndef PNG_NO_READ_zTXt
-#  define PNG_READ_zTXt_SUPPORTED
-#  define PNG_zTXt_SUPPORTED
-#endif
-#ifndef PNG_NO_READ_UNKNOWN_CHUNKS
-#  define PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
-#  ifndef PNG_UNKNOWN_CHUNKS_SUPPORTED
-#    define PNG_UNKNOWN_CHUNKS_SUPPORTED
-#  endif
-#  ifndef PNG_NO_HANDLE_AS_UNKNOWN
-#    define PNG_HANDLE_AS_UNKNOWN_SUPPORTED
-#  endif
-#endif
-#if !defined(PNG_NO_READ_USER_CHUNKS) && \
-     defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
-#  define PNG_READ_USER_CHUNKS_SUPPORTED
-#  define PNG_USER_CHUNKS_SUPPORTED
-#  ifdef PNG_NO_READ_UNKNOWN_CHUNKS
-#    undef PNG_NO_READ_UNKNOWN_CHUNKS
-#  endif
-#  ifdef PNG_NO_HANDLE_AS_UNKNOWN
-#    undef PNG_NO_HANDLE_AS_UNKNOWN
-#  endif
-#endif
-#ifndef PNG_NO_READ_OPT_PLTE
-#  define PNG_READ_OPT_PLTE_SUPPORTED /* only affects support of the */
-#endif                      /* optional PLTE chunk in RGB and RGBA images */
-#if defined(PNG_READ_iTXt_SUPPORTED) || defined(PNG_READ_tEXt_SUPPORTED) || \
-    defined(PNG_READ_zTXt_SUPPORTED)
-#  define PNG_READ_TEXT_SUPPORTED
-#  define PNG_TEXT_SUPPORTED
-#endif
-
-#endif /* PNG_READ_ANCILLARY_CHUNKS_SUPPORTED */
-
-#ifdef PNG_WRITE_ANCILLARY_CHUNKS_SUPPORTED
-
-#ifdef PNG_NO_WRITE_TEXT
-#  define PNG_NO_WRITE_iTXt
-#  define PNG_NO_WRITE_tEXt
-#  define PNG_NO_WRITE_zTXt
-#endif
-#ifndef PNG_NO_WRITE_bKGD
-#  define PNG_WRITE_bKGD_SUPPORTED
-#  ifndef PNG_bKGD_SUPPORTED
-#    define PNG_bKGD_SUPPORTED
-#  endif
-#endif
-#ifndef PNG_NO_WRITE_cHRM
-#  define PNG_WRITE_cHRM_SUPPORTED
-#  ifndef PNG_cHRM_SUPPORTED
-#    define PNG_cHRM_SUPPORTED
-#  endif
-#endif
-#ifndef PNG_NO_WRITE_gAMA
-#  define PNG_WRITE_gAMA_SUPPORTED
-#  ifndef PNG_gAMA_SUPPORTED
-#    define PNG_gAMA_SUPPORTED
-#  endif
-#endif
-#ifndef PNG_NO_WRITE_hIST
-#  define PNG_WRITE_hIST_SUPPORTED
-#  ifndef PNG_hIST_SUPPORTED
-#    define PNG_hIST_SUPPORTED
-#  endif
-#endif
-#ifndef PNG_NO_WRITE_iCCP
-#  define PNG_WRITE_iCCP_SUPPORTED
-#  ifndef PNG_iCCP_SUPPORTED
-#    define PNG_iCCP_SUPPORTED
-#  endif
-#endif
-#ifndef PNG_NO_WRITE_iTXt
-#  ifndef PNG_WRITE_iTXt_SUPPORTED
-#    define PNG_WRITE_iTXt_SUPPORTED
-#  endif
-#  ifndef PNG_iTXt_SUPPORTED
-#    define PNG_iTXt_SUPPORTED
-#  endif
-#endif
-#ifndef PNG_NO_WRITE_oFFs
-#  define PNG_WRITE_oFFs_SUPPORTED
-#  ifndef PNG_oFFs_SUPPORTED
-#    define PNG_oFFs_SUPPORTED
-#  endif
-#endif
-#ifndef PNG_NO_WRITE_pCAL
-#  define PNG_WRITE_pCAL_SUPPORTED
-#  ifndef PNG_pCAL_SUPPORTED
-#    define PNG_pCAL_SUPPORTED
-#  endif
-#endif
-#ifndef PNG_NO_WRITE_sCAL
-#  define PNG_WRITE_sCAL_SUPPORTED
-#  ifndef PNG_sCAL_SUPPORTED
-#    define PNG_sCAL_SUPPORTED
-#  endif
-#endif
-#ifndef PNG_NO_WRITE_pHYs
-#  define PNG_WRITE_pHYs_SUPPORTED
-#  ifndef PNG_pHYs_SUPPORTED
-#    define PNG_pHYs_SUPPORTED
-#  endif
-#endif
-#ifndef PNG_NO_WRITE_sBIT
-#  define PNG_WRITE_sBIT_SUPPORTED
-#  ifndef PNG_sBIT_SUPPORTED
-#    define PNG_sBIT_SUPPORTED
-#  endif
-#endif
-#ifndef PNG_NO_WRITE_sPLT
-#  define PNG_WRITE_sPLT_SUPPORTED
-#  ifndef PNG_sPLT_SUPPORTED
-#    define PNG_sPLT_SUPPORTED
-#  endif
-#endif
-#ifndef PNG_NO_WRITE_sRGB
-#  define PNG_WRITE_sRGB_SUPPORTED
-#  ifndef PNG_sRGB_SUPPORTED
-#    define PNG_sRGB_SUPPORTED
-#  endif
-#endif
-#ifndef PNG_NO_WRITE_tEXt
-#  define PNG_WRITE_tEXt_SUPPORTED
-#  ifndef PNG_tEXt_SUPPORTED
-#    define PNG_tEXt_SUPPORTED
-#  endif
-#endif
-#ifndef PNG_NO_WRITE_tIME
-#  define PNG_WRITE_tIME_SUPPORTED
-#  ifndef PNG_tIME_SUPPORTED
-#    define PNG_tIME_SUPPORTED
-#  endif
-#endif
-#ifndef PNG_NO_WRITE_tRNS
-#  define PNG_WRITE_tRNS_SUPPORTED
-#  ifndef PNG_tRNS_SUPPORTED
-#    define PNG_tRNS_SUPPORTED
-#  endif
-#endif
-#ifndef PNG_NO_WRITE_zTXt
-#  define PNG_WRITE_zTXt_SUPPORTED
-#  ifndef PNG_zTXt_SUPPORTED
-#    define PNG_zTXt_SUPPORTED
-#  endif
-#endif
-#ifndef PNG_NO_WRITE_UNKNOWN_CHUNKS
-#  define PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
-#  ifndef PNG_UNKNOWN_CHUNKS_SUPPORTED
-#    define PNG_UNKNOWN_CHUNKS_SUPPORTED
-#  endif
-#  ifndef PNG_NO_HANDLE_AS_UNKNOWN
-#     ifndef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
-#       define PNG_HANDLE_AS_UNKNOWN_SUPPORTED
-#     endif
-#  endif
-#endif
-#if defined(PNG_WRITE_iTXt_SUPPORTED) || defined(PNG_WRITE_tEXt_SUPPORTED) || \
-    defined(PNG_WRITE_zTXt_SUPPORTED)
-#  define PNG_WRITE_TEXT_SUPPORTED
-#  ifndef PNG_TEXT_SUPPORTED
-#    define PNG_TEXT_SUPPORTED
-#  endif
-#endif
-
-#endif /* PNG_WRITE_ANCILLARY_CHUNKS_SUPPORTED */
-
-/* Turn this off to disable png_read_png() and
- * png_write_png() and leave the row_pointers member
- * out of the info structure.
- */
-#ifndef PNG_NO_INFO_IMAGE
-#  define PNG_INFO_IMAGE_SUPPORTED
-#endif
-
-/* need the time information for reading tIME chunks */
-#if defined(PNG_tIME_SUPPORTED)
-#  if !defined(_WIN32_WCE) && !defined(__COM32__)
-     /* "time.h" functions are not supported on WindowsCE */
-#    include <time.h>
-#  endif
-#endif
-
-/* Some typedefs to get us started.  These should be safe on most of the
- * common platforms.  The typedefs should be at least as large as the
- * numbers suggest (a png_uint_32 must be at least 32 bits long), but they
- * don't have to be exactly that size.  Some compilers dislike passing
- * unsigned shorts as function parameters, so you may be better off using
- * unsigned int for png_uint_16.  Likewise, for 64-bit systems, you may
- * want to have unsigned int for png_uint_32 instead of unsigned long.
- */
-
-typedef unsigned long png_uint_32;
-typedef long png_int_32;
-typedef unsigned short png_uint_16;
-typedef short png_int_16;
-typedef unsigned char png_byte;
-
-/* This is usually size_t.  It is typedef'ed just in case you need it to
-   change (I'm not sure if you will or not, so I thought I'd be safe) */
-#ifdef PNG_SIZE_T
-   typedef PNG_SIZE_T png_size_t;
-#  define png_sizeof(x) png_convert_size(sizeof (x))
-#else
-   typedef size_t png_size_t;
-#  define png_sizeof(x) sizeof (x)
-#endif
-
-/* The following is needed for medium model support.  It cannot be in the
- * PNG_INTERNAL section.  Needs modification for other compilers besides
- * MSC.  Model independent support declares all arrays and pointers to be
- * large using the far keyword.  The zlib version used must also support
- * model independent data.  As of version zlib 1.0.4, the necessary changes
- * have been made in zlib.  The USE_FAR_KEYWORD define triggers other
- * changes that are needed. (Tim Wegner)
- */
-
-/* Separate compiler dependencies (problem here is that zlib.h always
-   defines FAR. (SJT) */
-#ifdef __BORLANDC__
-#  if defined(__LARGE__) || defined(__HUGE__) || defined(__COMPACT__)
-#    define LDATA 1
-#  else
-#    define LDATA 0
-#  endif
-   /* GRR:  why is Cygwin in here?  Cygwin is not Borland C... */
-#  if !defined(__WIN32__) && !defined(__FLAT__) && !defined(__CYGWIN__)
-#    define PNG_MAX_MALLOC_64K
-#    if (LDATA != 1)
-#      ifndef FAR
-#        define FAR __far
-#      endif
-#      define USE_FAR_KEYWORD
-#    endif   /* LDATA != 1 */
-     /* Possibly useful for moving data out of default segment.
-      * Uncomment it if you want. Could also define FARDATA as
-      * const if your compiler supports it. (SJT)
-#    define FARDATA FAR
-      */
-#  endif  /* __WIN32__, __FLAT__, __CYGWIN__ */
-#endif   /* __BORLANDC__ */
-
-
-/* Suggest testing for specific compiler first before testing for
- * FAR.  The Watcom compiler defines both __MEDIUM__ and M_I86MM,
- * making reliance oncertain keywords suspect. (SJT)
- */
-
-/* MSC Medium model */
-#if defined(FAR)
-#  if defined(M_I86MM)
-#    define USE_FAR_KEYWORD
-#    define FARDATA FAR
-#    include <dos.h>
-#  endif
-#endif
-
-/* SJT: default case */
-#ifndef FAR
-#  define FAR
-#endif
-
-/* At this point FAR is always defined */
-#ifndef FARDATA
-#  define FARDATA
-#endif
-
-/* Typedef for floating-point numbers that are converted
-   to fixed-point with a multiple of 100,000, e.g., int_gamma */
-typedef png_int_32 png_fixed_point;
-
-/* Add typedefs for pointers */
-typedef void            FAR * png_voidp;
-typedef png_byte        FAR * png_bytep;
-typedef png_uint_32     FAR * png_uint_32p;
-typedef png_int_32      FAR * png_int_32p;
-typedef png_uint_16     FAR * png_uint_16p;
-typedef png_int_16      FAR * png_int_16p;
-typedef PNG_CONST char  FAR * png_const_charp;
-typedef char            FAR * png_charp;
-typedef png_fixed_point FAR * png_fixed_point_p;
-
-#ifndef PNG_NO_STDIO
-#if defined(_WIN32_WCE)
-typedef HANDLE                png_FILE_p;
-#else
-typedef FILE                * png_FILE_p;
-#endif
-#endif
-
-#ifdef PNG_FLOATING_POINT_SUPPORTED
-typedef double          FAR * png_doublep;
-#endif
-
-/* Pointers to pointers; i.e. arrays */
-typedef png_byte        FAR * FAR * png_bytepp;
-typedef png_uint_32     FAR * FAR * png_uint_32pp;
-typedef png_int_32      FAR * FAR * png_int_32pp;
-typedef png_uint_16     FAR * FAR * png_uint_16pp;
-typedef png_int_16      FAR * FAR * png_int_16pp;
-typedef PNG_CONST char  FAR * FAR * png_const_charpp;
-typedef char            FAR * FAR * png_charpp;
-typedef png_fixed_point FAR * FAR * png_fixed_point_pp;
-#ifdef PNG_FLOATING_POINT_SUPPORTED
-typedef double          FAR * FAR * png_doublepp;
-#endif
-
-/* Pointers to pointers to pointers; i.e., pointer to array */
-typedef char            FAR * FAR * FAR * png_charppp;
-
-#if defined(PNG_1_0_X) || defined(PNG_1_2_X)
-/* SPC -  Is this stuff deprecated? */
-/* It'll be removed as of libpng-1.3.0 - GR-P */
-/* libpng typedefs for types in zlib. If zlib changes
- * or another compression library is used, then change these.
- * Eliminates need to change all the source files.
- */
-typedef charf *         png_zcharp;
-typedef charf * FAR *   png_zcharpp;
-typedef z_stream FAR *  png_zstreamp;
-#endif /* (PNG_1_0_X) || defined(PNG_1_2_X) */
-
-/*
- * Define PNG_BUILD_DLL if the module being built is a Windows
- * LIBPNG DLL.
- *
- * Define PNG_USE_DLL if you want to *link* to the Windows LIBPNG DLL.
- * It is equivalent to Microsoft predefined macro _DLL that is
- * automatically defined when you compile using the share
- * version of the CRT (C Run-Time library)
- *
- * The cygwin mods make this behavior a little different:
- * Define PNG_BUILD_DLL if you are building a dll for use with cygwin
- * Define PNG_STATIC if you are building a static library for use with cygwin,
- *   -or- if you are building an application that you want to link to the
- *   static library.
- * PNG_USE_DLL is defined by default (no user action needed) unless one of
- *   the other flags is defined.
- */
-
-#if !defined(PNG_DLL) && (defined(PNG_BUILD_DLL) || defined(PNG_USE_DLL))
-#  define PNG_DLL
-#endif
-/* If CYGWIN, then disallow GLOBAL ARRAYS unless building a static lib.
- * When building a static lib, default to no GLOBAL ARRAYS, but allow
- * command-line override
- */
-#if defined(__CYGWIN__)
-#  if !defined(PNG_STATIC)
-#    if defined(PNG_USE_GLOBAL_ARRAYS)
-#      undef PNG_USE_GLOBAL_ARRAYS
-#    endif
-#    if !defined(PNG_USE_LOCAL_ARRAYS)
-#      define PNG_USE_LOCAL_ARRAYS
-#    endif
-#  else
-#    if defined(PNG_USE_LOCAL_ARRAYS) || defined(PNG_NO_GLOBAL_ARRAYS)
-#      if defined(PNG_USE_GLOBAL_ARRAYS)
-#        undef PNG_USE_GLOBAL_ARRAYS
-#      endif
-#    endif
-#  endif
-#  if !defined(PNG_USE_LOCAL_ARRAYS) && !defined(PNG_USE_GLOBAL_ARRAYS)
-#    define PNG_USE_LOCAL_ARRAYS
-#  endif
-#endif
-
-/* Do not use global arrays (helps with building DLL's)
- * They are no longer used in libpng itself, since version 1.0.5c,
- * but might be required for some pre-1.0.5c applications.
- */
-#if !defined(PNG_USE_LOCAL_ARRAYS) && !defined(PNG_USE_GLOBAL_ARRAYS)
-#  if defined(PNG_NO_GLOBAL_ARRAYS) || (defined(__GNUC__) && defined(PNG_DLL))
-#    define PNG_USE_LOCAL_ARRAYS
-#  else
-#    define PNG_USE_GLOBAL_ARRAYS
-#  endif
-#endif
-
-#if defined(__CYGWIN__)
-#  undef PNGAPI
-#  define PNGAPI __cdecl
-#  undef PNG_IMPEXP
-#  define PNG_IMPEXP
-#endif  
-
-/* If you define PNGAPI, e.g., with compiler option "-DPNGAPI=__stdcall",
- * you may get warnings regarding the linkage of png_zalloc and png_zfree.
- * Don't ignore those warnings; you must also reset the default calling
- * convention in your compiler to match your PNGAPI, and you must build
- * zlib and your applications the same way you build libpng.
- */
-
-#if defined(__MINGW32__) && !defined(PNG_MODULEDEF)
-#  ifndef PNG_NO_MODULEDEF
-#    define PNG_NO_MODULEDEF
-#  endif
-#endif
-
-#if !defined(PNG_IMPEXP) && defined(PNG_BUILD_DLL) && !defined(PNG_NO_MODULEDEF)
-#  define PNG_IMPEXP
-#endif
-
-#if defined(PNG_DLL) || defined(_DLL) || defined(__DLL__ ) || \
-    (( defined(_Windows) || defined(_WINDOWS) || \
-       defined(WIN32) || defined(_WIN32) || defined(__WIN32__) ))
-
-#  ifndef PNGAPI
-#     if defined(__GNUC__) || (defined (_MSC_VER) && (_MSC_VER >= 800))
-#        define PNGAPI __cdecl
-#     else
-#        define PNGAPI _cdecl
-#     endif
-#  endif
-
-#  if !defined(PNG_IMPEXP) && (!defined(PNG_DLL) || \
-       0 /* WINCOMPILER_WITH_NO_SUPPORT_FOR_DECLIMPEXP */)
-#     define PNG_IMPEXP
-#  endif
-
-#  if !defined(PNG_IMPEXP)
-
-#     define PNG_EXPORT_TYPE1(type,symbol)  PNG_IMPEXP type PNGAPI symbol
-#     define PNG_EXPORT_TYPE2(type,symbol)  type PNG_IMPEXP PNGAPI symbol
-
-      /* Borland/Microsoft */
-#     if defined(_MSC_VER) || defined(__BORLANDC__)
-#        if (_MSC_VER >= 800) || (__BORLANDC__ >= 0x500)
-#           define PNG_EXPORT PNG_EXPORT_TYPE1
-#        else
-#           define PNG_EXPORT PNG_EXPORT_TYPE2
-#           if defined(PNG_BUILD_DLL)
-#              define PNG_IMPEXP __export
-#           else
-#              define PNG_IMPEXP /*__import */ /* doesn't exist AFAIK in
-                                                 VC++ */
-#           endif                             /* Exists in Borland C++ for
-                                                 C++ classes (== huge) */
-#        endif
-#     endif
-
-#     if !defined(PNG_IMPEXP)
-#        if defined(PNG_BUILD_DLL)
-#           define PNG_IMPEXP __declspec(dllexport)
-#        else
-#           define PNG_IMPEXP __declspec(dllimport)
-#        endif
-#     endif
-#  endif  /* PNG_IMPEXP */
-#else /* !(DLL || non-cygwin WINDOWS) */
-#   if (defined(__IBMC__) || defined(__IBMCPP__)) && defined(__OS2__)
-#      ifndef PNGAPI
-#         define PNGAPI _System
-#      endif
-#   else
-#      if 0 /* ... other platforms, with other meanings */
-#      endif
-#   endif
-#endif
-
-#ifndef PNGAPI
-#  define PNGAPI
-#endif
-#ifndef PNG_IMPEXP
-#  define PNG_IMPEXP
-#endif
-
-#ifdef PNG_BUILDSYMS
-#  ifndef PNG_EXPORT
-#    define PNG_EXPORT(type,symbol) PNG_FUNCTION_EXPORT symbol END
-#  endif
-#  ifdef PNG_USE_GLOBAL_ARRAYS
-#    ifndef PNG_EXPORT_VAR
-#      define PNG_EXPORT_VAR(type) PNG_DATA_EXPORT
-#    endif
-#  endif
-#endif
-
-#ifndef PNG_EXPORT
-#  define PNG_EXPORT(type,symbol) PNG_IMPEXP type PNGAPI symbol
-#endif
-
-#ifdef PNG_USE_GLOBAL_ARRAYS
-#  ifndef PNG_EXPORT_VAR
-#    define PNG_EXPORT_VAR(type) extern PNG_IMPEXP type
-#  endif
-#endif
-
-/* User may want to use these so they are not in PNG_INTERNAL. Any library
- * functions that are passed far data must be model independent.
- */
-
-#ifndef PNG_ABORT
-#  define PNG_ABORT() abort()
-#endif
-
-#ifdef PNG_SETJMP_SUPPORTED
-#  define png_jmpbuf(png_ptr) ((png_ptr)->jmpbuf)
-#else
-#  define png_jmpbuf(png_ptr) \
-   (LIBPNG_WAS_COMPILED_WITH__PNG_SETJMP_NOT_SUPPORTED)
-#endif
-
-#if defined(USE_FAR_KEYWORD)  /* memory model independent fns */
-/* use this to make far-to-near assignments */
-#  define CHECK   1
-#  define NOCHECK 0
-#  define CVT_PTR(ptr) (png_far_to_near(png_ptr,ptr,CHECK))
-#  define CVT_PTR_NOCHECK(ptr) (png_far_to_near(png_ptr,ptr,NOCHECK))
-#  define png_strcpy  _fstrcpy
-#  define png_strncpy _fstrncpy   /* Added to v 1.2.6 */
-#  define png_strlen  _fstrlen
-#  define png_memcmp  _fmemcmp    /* SJT: added */
-#  define png_memcpy  _fmemcpy
-#  define png_memset  _fmemset
-#else /* use the usual functions */
-#  define CVT_PTR(ptr)         (ptr)
-#  define CVT_PTR_NOCHECK(ptr) (ptr)
-#  define png_strcpy  strcpy
-#  define png_strncpy strncpy     /* Added to v 1.2.6 */
-#  define png_strlen  strlen
-#  define png_memcmp  memcmp      /* SJT: added */
-#  define png_memcpy  memcpy
-#  define png_memset  memset
-#endif
-/* End of memory model independent support */
-
-/* Just a little check that someone hasn't tried to define something
- * contradictory.
- */
-#if (PNG_ZBUF_SIZE > 65536L) && defined(PNG_MAX_MALLOC_64K)
-#  undef PNG_ZBUF_SIZE
-#  define PNG_ZBUF_SIZE 65536L
-#endif
-
-#ifdef PNG_READ_SUPPORTED
-/* Prior to libpng-1.0.9, this block was in pngasmrd.h */
-#if defined(PNG_INTERNAL)
-
-/* These are the default thresholds before the MMX code kicks in; if either
- * rowbytes or bitdepth is below the threshold, plain C code is used.  These
- * can be overridden at runtime via the png_set_mmx_thresholds() call in
- * libpng 1.2.0 and later.  The values below were chosen by Intel.
- */
-
-#ifndef PNG_MMX_ROWBYTES_THRESHOLD_DEFAULT
-#  define PNG_MMX_ROWBYTES_THRESHOLD_DEFAULT  128  /*  >=  */
-#endif
-#ifndef PNG_MMX_BITDEPTH_THRESHOLD_DEFAULT
-#  define PNG_MMX_BITDEPTH_THRESHOLD_DEFAULT  9    /*  >=  */   
-#endif
-
-/* Set this in the makefile for VC++ on Pentium, not here. */
-/* Platform must be Pentium.  Makefile must assemble and load pngvcrd.c .
- * MMX will be detected at run time and used if present.
- */
-#ifdef PNG_USE_PNGVCRD
-#  define PNG_HAVE_ASSEMBLER_COMBINE_ROW
-#  define PNG_HAVE_ASSEMBLER_READ_INTERLACE
-#  define PNG_HAVE_ASSEMBLER_READ_FILTER_ROW
-#endif
-
-/* Set this in the makefile for gcc/as on Pentium, not here. */
-/* Platform must be Pentium.  Makefile must assemble and load pnggccrd.c .
- * MMX will be detected at run time and used if present.
- */
-#ifdef PNG_USE_PNGGCCRD
-#  define PNG_HAVE_ASSEMBLER_COMBINE_ROW
-#  define PNG_HAVE_ASSEMBLER_READ_INTERLACE
-#  define PNG_HAVE_ASSEMBLER_READ_FILTER_ROW
-#endif
-/* - see pnggccrd.c for info about what is currently enabled */
-
-#endif /* PNG_INTERNAL */
-#endif /* PNG_READ_SUPPORTED */
-
-/* Added at libpng-1.2.8 */
-#endif /* PNG_VERSION_INFO_ONLY */
-
-#endif /* PNGCONF_H */