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path: root/libgo/go/image/png/reader.go
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Diffstat (limited to 'libgo/go/image/png/reader.go')
-rw-r--r--libgo/go/image/png/reader.go174
1 files changed, 147 insertions, 27 deletions
diff --git a/libgo/go/image/png/reader.go b/libgo/go/image/png/reader.go
index e2d679bb425..eee4eac2e15 100644
--- a/libgo/go/image/png/reader.go
+++ b/libgo/go/image/png/reader.go
@@ -29,11 +29,19 @@ const (
// A cb is a combination of color type and bit depth.
const (
cbInvalid = iota
+ cbG1
+ cbG2
+ cbG4
cbG8
+ cbGA8
cbTC8
+ cbP1
+ cbP2
+ cbP4
cbP8
cbTCA8
cbG16
+ cbGA16
cbTC16
cbTCA16
)
@@ -70,6 +78,7 @@ type imgOrErr struct {
type decoder struct {
width, height int
+ depth int
palette image.PalettedColorModel
cb int
stage int
@@ -138,7 +147,29 @@ func (d *decoder) parseIHDR(r io.Reader, crc hash.Hash32, length uint32) os.Erro
return UnsupportedError("dimension overflow")
}
d.cb = cbInvalid
- switch d.tmp[8] {
+ d.depth = int(d.tmp[8])
+ switch d.depth {
+ case 1:
+ switch d.tmp[9] {
+ case ctGrayscale:
+ d.cb = cbG1
+ case ctPaletted:
+ d.cb = cbP1
+ }
+ case 2:
+ switch d.tmp[9] {
+ case ctGrayscale:
+ d.cb = cbG2
+ case ctPaletted:
+ d.cb = cbP2
+ }
+ case 4:
+ switch d.tmp[9] {
+ case ctGrayscale:
+ d.cb = cbG4
+ case ctPaletted:
+ d.cb = cbP4
+ }
case 8:
switch d.tmp[9] {
case ctGrayscale:
@@ -147,6 +178,8 @@ func (d *decoder) parseIHDR(r io.Reader, crc hash.Hash32, length uint32) os.Erro
d.cb = cbTC8
case ctPaletted:
d.cb = cbP8
+ case ctGrayscaleAlpha:
+ d.cb = cbGA8
case ctTrueColorAlpha:
d.cb = cbTCA8
}
@@ -156,6 +189,8 @@ func (d *decoder) parseIHDR(r io.Reader, crc hash.Hash32, length uint32) os.Erro
d.cb = cbG16
case ctTrueColor:
d.cb = cbTC16
+ case ctGrayscaleAlpha:
+ d.cb = cbGA16
case ctTrueColorAlpha:
d.cb = cbTCA16
}
@@ -169,7 +204,7 @@ func (d *decoder) parseIHDR(r io.Reader, crc hash.Hash32, length uint32) os.Erro
func (d *decoder) parsePLTE(r io.Reader, crc hash.Hash32, length uint32) os.Error {
np := int(length / 3) // The number of palette entries.
- if length%3 != 0 || np <= 0 || np > 256 {
+ if length%3 != 0 || np <= 0 || np > 256 || np > 1<<uint(d.depth) {
return FormatError("bad PLTE length")
}
n, err := io.ReadFull(r, d.tmp[0:3*np])
@@ -178,7 +213,7 @@ func (d *decoder) parsePLTE(r io.Reader, crc hash.Hash32, length uint32) os.Erro
}
crc.Write(d.tmp[0:n])
switch d.cb {
- case cbP8:
+ case cbP1, cbP2, cbP4, cbP8:
d.palette = image.PalettedColorModel(make([]image.Color, np))
for i := 0; i < np; i++ {
d.palette[i] = image.RGBAColor{d.tmp[3*i+0], d.tmp[3*i+1], d.tmp[3*i+2], 0xff}
@@ -206,7 +241,7 @@ func (d *decoder) parsetRNS(r io.Reader, crc hash.Hash32, length uint32) os.Erro
return UnsupportedError("grayscale transparency")
case cbTC8, cbTC16:
return UnsupportedError("truecolor transparency")
- case cbP8:
+ case cbP1, cbP2, cbP4, cbP8:
if n > len(d.palette) {
return FormatError("bad tRNS length")
}
@@ -214,7 +249,7 @@ func (d *decoder) parsetRNS(r io.Reader, crc hash.Hash32, length uint32) os.Erro
rgba := d.palette[i].(image.RGBAColor)
d.palette[i] = image.RGBAColor{rgba.R, rgba.G, rgba.B, d.tmp[i]}
}
- case cbTCA8, cbTCA16:
+ case cbGA8, cbGA16, cbTCA8, cbTCA16:
return FormatError("tRNS, color type mismatch")
}
return nil
@@ -240,7 +275,7 @@ func (d *decoder) idatReader(idat io.Reader) (image.Image, os.Error) {
return nil, err
}
defer r.Close()
- bpp := 0 // Bytes per pixel.
+ bitsPerPixel := 0
maxPalette := uint8(0)
var (
gray *image.Gray
@@ -253,40 +288,50 @@ func (d *decoder) idatReader(idat io.Reader) (image.Image, os.Error) {
img image.Image
)
switch d.cb {
- case cbG8:
- bpp = 1
+ case cbG1, cbG2, cbG4, cbG8:
+ bitsPerPixel = d.depth
gray = image.NewGray(d.width, d.height)
img = gray
+ case cbGA8:
+ bitsPerPixel = 16
+ nrgba = image.NewNRGBA(d.width, d.height)
+ img = nrgba
case cbTC8:
- bpp = 3
+ bitsPerPixel = 24
rgba = image.NewRGBA(d.width, d.height)
img = rgba
- case cbP8:
- bpp = 1
+ case cbP1, cbP2, cbP4, cbP8:
+ bitsPerPixel = d.depth
paletted = image.NewPaletted(d.width, d.height, d.palette)
img = paletted
maxPalette = uint8(len(d.palette) - 1)
case cbTCA8:
- bpp = 4
+ bitsPerPixel = 32
nrgba = image.NewNRGBA(d.width, d.height)
img = nrgba
case cbG16:
- bpp = 2
+ bitsPerPixel = 16
gray16 = image.NewGray16(d.width, d.height)
img = gray16
+ case cbGA16:
+ bitsPerPixel = 32
+ nrgba64 = image.NewNRGBA64(d.width, d.height)
+ img = nrgba64
case cbTC16:
- bpp = 6
+ bitsPerPixel = 48
rgba64 = image.NewRGBA64(d.width, d.height)
img = rgba64
case cbTCA16:
- bpp = 8
+ bitsPerPixel = 64
nrgba64 = image.NewNRGBA64(d.width, d.height)
img = nrgba64
}
+ bytesPerPixel := (bitsPerPixel + 7) / 8
+
// cr and pr are the bytes for the current and previous row.
// The +1 is for the per-row filter type, which is at cr[0].
- cr := make([]uint8, 1+bpp*d.width)
- pr := make([]uint8, 1+bpp*d.width)
+ cr := make([]uint8, 1+(bitsPerPixel*d.width+7)/8)
+ pr := make([]uint8, 1+(bitsPerPixel*d.width+7)/8)
for y := 0; y < d.height; y++ {
// Read the decompressed bytes.
@@ -302,26 +347,26 @@ func (d *decoder) idatReader(idat io.Reader) (image.Image, os.Error) {
case ftNone:
// No-op.
case ftSub:
- for i := bpp; i < len(cdat); i++ {
- cdat[i] += cdat[i-bpp]
+ for i := bytesPerPixel; i < len(cdat); i++ {
+ cdat[i] += cdat[i-bytesPerPixel]
}
case ftUp:
for i := 0; i < len(cdat); i++ {
cdat[i] += pdat[i]
}
case ftAverage:
- for i := 0; i < bpp; i++ {
+ for i := 0; i < bytesPerPixel; i++ {
cdat[i] += pdat[i] / 2
}
- for i := bpp; i < len(cdat); i++ {
- cdat[i] += uint8((int(cdat[i-bpp]) + int(pdat[i])) / 2)
+ for i := bytesPerPixel; i < len(cdat); i++ {
+ cdat[i] += uint8((int(cdat[i-bytesPerPixel]) + int(pdat[i])) / 2)
}
case ftPaeth:
- for i := 0; i < bpp; i++ {
+ for i := 0; i < bytesPerPixel; i++ {
cdat[i] += paeth(0, pdat[i], 0)
}
- for i := bpp; i < len(cdat); i++ {
- cdat[i] += paeth(cdat[i-bpp], pdat[i], pdat[i-bpp])
+ for i := bytesPerPixel; i < len(cdat); i++ {
+ cdat[i] += paeth(cdat[i-bytesPerPixel], pdat[i], pdat[i-bytesPerPixel])
}
default:
return nil, FormatError("bad filter type")
@@ -329,14 +374,79 @@ func (d *decoder) idatReader(idat io.Reader) (image.Image, os.Error) {
// Convert from bytes to colors.
switch d.cb {
+ case cbG1:
+ for x := 0; x < d.width; x += 8 {
+ b := cdat[x/8]
+ for x2 := 0; x2 < 8 && x+x2 < d.width; x2++ {
+ gray.Set(x+x2, y, image.GrayColor{(b >> 7) * 0xff})
+ b <<= 1
+ }
+ }
+ case cbG2:
+ for x := 0; x < d.width; x += 4 {
+ b := cdat[x/4]
+ for x2 := 0; x2 < 4 && x+x2 < d.width; x2++ {
+ gray.Set(x+x2, y, image.GrayColor{(b >> 6) * 0x55})
+ b <<= 2
+ }
+ }
+ case cbG4:
+ for x := 0; x < d.width; x += 2 {
+ b := cdat[x/2]
+ for x2 := 0; x2 < 2 && x+x2 < d.width; x2++ {
+ gray.Set(x+x2, y, image.GrayColor{(b >> 4) * 0x11})
+ b <<= 4
+ }
+ }
case cbG8:
for x := 0; x < d.width; x++ {
gray.Set(x, y, image.GrayColor{cdat[x]})
}
+ case cbGA8:
+ for x := 0; x < d.width; x++ {
+ ycol := cdat[2*x+0]
+ nrgba.Set(x, y, image.NRGBAColor{ycol, ycol, ycol, cdat[2*x+1]})
+ }
case cbTC8:
for x := 0; x < d.width; x++ {
rgba.Set(x, y, image.RGBAColor{cdat[3*x+0], cdat[3*x+1], cdat[3*x+2], 0xff})
}
+ case cbP1:
+ for x := 0; x < d.width; x += 8 {
+ b := cdat[x/8]
+ for x2 := 0; x2 < 8 && x+x2 < d.width; x2++ {
+ idx := b >> 7
+ if idx > maxPalette {
+ return nil, FormatError("palette index out of range")
+ }
+ paletted.SetColorIndex(x+x2, y, idx)
+ b <<= 1
+ }
+ }
+ case cbP2:
+ for x := 0; x < d.width; x += 4 {
+ b := cdat[x/4]
+ for x2 := 0; x2 < 4 && x+x2 < d.width; x2++ {
+ idx := b >> 6
+ if idx > maxPalette {
+ return nil, FormatError("palette index out of range")
+ }
+ paletted.SetColorIndex(x+x2, y, idx)
+ b <<= 2
+ }
+ }
+ case cbP4:
+ for x := 0; x < d.width; x += 2 {
+ b := cdat[x/2]
+ for x2 := 0; x2 < 2 && x+x2 < d.width; x2++ {
+ idx := b >> 4
+ if idx > maxPalette {
+ return nil, FormatError("palette index out of range")
+ }
+ paletted.SetColorIndex(x+x2, y, idx)
+ b <<= 4
+ }
+ }
case cbP8:
for x := 0; x < d.width; x++ {
if cdat[x] > maxPalette {
@@ -353,6 +463,12 @@ func (d *decoder) idatReader(idat io.Reader) (image.Image, os.Error) {
ycol := uint16(cdat[2*x+0])<<8 | uint16(cdat[2*x+1])
gray16.Set(x, y, image.Gray16Color{ycol})
}
+ case cbGA16:
+ for x := 0; x < d.width; x++ {
+ ycol := uint16(cdat[4*x+0])<<8 | uint16(cdat[4*x+1])
+ acol := uint16(cdat[4*x+2])<<8 | uint16(cdat[4*x+3])
+ nrgba64.Set(x, y, image.NRGBA64Color{ycol, ycol, ycol, acol})
+ }
case cbTC16:
for x := 0; x < d.width; x++ {
rcol := uint16(cdat[6*x+0])<<8 | uint16(cdat[6*x+1])
@@ -565,16 +681,20 @@ func DecodeConfig(r io.Reader) (image.Config, os.Error) {
}
var cm image.ColorModel
switch d.cb {
- case cbG8:
+ case cbG1, cbG2, cbG4, cbG8:
cm = image.GrayColorModel
+ case cbGA8:
+ cm = image.NRGBAColorModel
case cbTC8:
cm = image.RGBAColorModel
- case cbP8:
+ case cbP1, cbP2, cbP4, cbP8:
cm = d.palette
case cbTCA8:
cm = image.NRGBAColorModel
case cbG16:
cm = image.Gray16ColorModel
+ case cbGA16:
+ cm = image.NRGBA64ColorModel
case cbTC16:
cm = image.RGBA64ColorModel
case cbTCA16:
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