Guessing mechanics now documented in manual page.

1 files changed, 26 insertions, 5 deletions

diff --git a/man/raw2tiff.1 b/man/raw2tiff.1
index 69945cb5..8d9c2750 100644
--- a/man/raw2tiff.1
+++ b/man/raw2tiff.1
@@ -1,4 +1,4 @@
-.\"	$Header: /cvs/maptools/cvsroot/libtiff/man/raw2tiff.1,v 1.2 2003-07-10 20:07:27 dron Exp $
+.\"	$Header: /cvs/maptools/cvsroot/libtiff/man/raw2tiff.1,v 1.3 2003-11-12 09:20:10 dron Exp $
 .\"
 .\" Copyright (c) 1990-1997 Sam Leffler
 .\" Copyright (c) 1991-1997 Silicon Graphics, Inc.
@@ -30,7 +30,6 @@ raw2tiff \- create a
 file from a raw data
 .SH SYNOPSIS
 .B raw2tiff
-.I -w <number>
 [
 .I options
 ]
@@ -56,11 +55,16 @@ size of input image file header in bytes (0 by default). This amount of data
 just will be skipped from the start of file while reading.
 .TP
 .B \-w <number>
-width of input image in pixels. You must set this parameter.
+width of input image in pixels (can be guessed, see
+.SM
+.B "GUESSING THE IMAGE GEOMETRY"
+below).
 .TP
 .B \-l <number>
-length of input image in lines. Will be calculated from the size of input file
-if not specified.
+length of input image in lines(can be guessed, see
+.SM
+.B "GUESSING THE IMAGE GEOMETRY"
+below).
 .TP
 .B \-b <number>
 number of bands in input image (1 by default).
@@ -161,6 +165,23 @@ for Lempel-Ziv & Welch.
 Write data with a specified number of rows per strip;
 by default the number of rows/strip is selected so that each strip
 is approximately 8 kilobytes.
+.SH GUESSING THE IMAGE GEOMETRY
+.I raw2tiff
+can guess image width and height in case one or both of these parameters are
+not specified. If you omit one of those parameters, the complementary one will
+be calculated based on the file size (taking into account header size, number
+of bands and data type). If you omit both parameters, the statistical approach
+will be used. Utility will compute correlation coefficient between two lines
+at the image center using several appropriate line sizes and the highest
+absolute value of the coefficient will indicate the right line size. That is
+why you should be cautious with the very large images, because guessing
+process may take a while (depending on your system perfomance). Of course, the
+utility can't guess the header size, number of bands and data type, so it
+should be specified manually. If you don't know anything about your image,
+just try with the several combinations of those options.
+.P
+There is no magic, it is just a mathematical statistics, so it can be wrong
+in some cases. But for most ordinary images guessing method will work fine.
 .SH "SEE ALSO"
 .IR pal2rgb (1),
 .IR tiffinfo (1),