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Reach the JBIG2 decoder through the fleet's codec registry #28

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Merged
tannevaled merged 1 commit into from
Aug 28, 2026
Merged

Reach the JBIG2 decoder through the fleet's codec registry #28

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7 changes: 5 additions & 2 deletions go.mod
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Original file line number Diff line number Diff line change
Expand Up @@ -3,7 +3,7 @@ module github.com/go-pdfkit/render
go 1.26.4

require (
github.com/go-gfx/gfx v0.12.0
github.com/go-gfx/gfx v0.14.0
github.com/go-opentype/fonts v0.9.0
github.com/go-opentype/opentype v0.10.0
github.com/go-pdfkit/reader v0.6.0
Expand All @@ -16,6 +16,9 @@ require (

require (
github.com/ajroetker/go-highway v0.0.4 // indirect
github.com/dkrisman/gobig2 v0.0.0-20260513123937-51e39052fde6
github.com/dkrisman/gobig2 v0.0.0-20260513123937-51e39052fde6 // indirect
github.com/sergeymakinen/go-bmp v1.0.0 // indirect
github.com/sergeymakinen/go-ico v1.0.0 // indirect
golang.org/x/image v0.45.0 // indirect
golang.org/x/sys v0.47.0 // indirect
)
10 changes: 8 additions & 2 deletions go.sum
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Original file line number Diff line number Diff line change
Expand Up @@ -4,8 +4,8 @@ github.com/ajroetker/go-jpeg2000 v0.0.2 h1:ni8brffZrci4Kacx3nM5d92ipmTDfak84KgHY
github.com/ajroetker/go-jpeg2000 v0.0.2/go.mod h1:7ld88W47lZy0x8gRQesRGAonDPOpr6ev8rckjCAfbzE=
github.com/dkrisman/gobig2 v0.0.0-20260513123937-51e39052fde6 h1:hHPgbpPdcaSXtpLb9NMEUJPxsZ0cxGtGHwmvKGI36NA=
github.com/dkrisman/gobig2 v0.0.0-20260513123937-51e39052fde6/go.mod h1:2Ij0rpAVy1tZ+PQ9FM1jCpnVo/OOCMCD6rLtSp4JkEI=
github.com/go-gfx/gfx v0.12.0 h1:zBaYHahRwM6yYr86ifRelX132ZjhN5hZNr/uW9dpIzQ=
github.com/go-gfx/gfx v0.12.0/go.mod h1:DpRUcQrlLZH02CSB23J0iEk1F7mQH8w9WMF60xQBxDU=
github.com/go-gfx/gfx v0.14.0 h1:G6A0ZIirv9XjlxVFOl3HLscLRJOdhe9e1HqiCK5CHz0=
github.com/go-gfx/gfx v0.14.0/go.mod h1:8KcjwJmHW2ImXcjeMEIQ1bY+7Q2DNcMYoQCl270Isr8=
github.com/go-opentype/fonts v0.9.0 h1:slB6OB3riLyUPrOxqXe0s6/AzdenF1TDvCN8N87hhQk=
github.com/go-opentype/fonts v0.9.0/go.mod h1:C6yQL2apHItfEZ5hztpsHF0S5mlX/hklLlq/Z5fRG/g=
github.com/go-opentype/opentype v0.10.0 h1:cZVMZ3RVkcijXmxlmpqyVkjlNc33aSB2ugKVWYvoLUg=
Expand All @@ -14,5 +14,11 @@ github.com/go-pdfkit/pdffont v0.3.0 h1:G5DKcAmsZJ0e17QhSrcUaL7PKEXKjUx4P/iGMl7bA
github.com/go-pdfkit/pdffont v0.3.0/go.mod h1:bfmNLna1l1CljNX/Utg55YzFylovfmI7sJnvgA3bzKI=
github.com/go-pdfkit/reader v0.6.0 h1:KAabNOYUcTlZlNBTbG9bEhWP1NiZhjuhzUdavdTdfes=
github.com/go-pdfkit/reader v0.6.0/go.mod h1:fQFOVfCMUui1AdvD4qhimdyvvNr9KvvJ1S7IuKZjyV8=
github.com/sergeymakinen/go-bmp v1.0.0 h1:SdGTzp9WvCV0A1V0mBeaS7kQAwNLdVJbmHlqNWq0R+M=
github.com/sergeymakinen/go-bmp v1.0.0/go.mod h1:/mxlAQZRLxSvJFNIEGGLBE/m40f3ZnUifpgVDlcUIEY=
github.com/sergeymakinen/go-ico v1.0.0 h1:uL3khgvKkY6WfAetA+RqsguClBuu7HpvBB/nq/Jvr80=
github.com/sergeymakinen/go-ico v1.0.0/go.mod h1:wQ47mTczswBO5F0NoDt7O0IXgnV4Xy3ojrroMQzyhUk=
golang.org/x/image v0.45.0 h1:FMb1nTbH5H9vF55SriQHgFw5GnNL9Jg6L25BwXKzhB0=
golang.org/x/image v0.45.0/go.mod h1:n62x/7RqlwXDvGsSU4u6IUTUf6KghUZ9Bt7cG/T9Fx4=
golang.org/x/sys v0.47.0 h1:o7XGOvZQCADBQQ4Y7VNq2dRWQR7JmOUW8Kxx4ZsNgWs=
golang.org/x/sys v0.47.0/go.mod h1:4GL1E5IUh+htKOUEOaiffhrAeqysfVGipDYzABqnCmw=
30 changes: 11 additions & 19 deletions jbig2.go
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Original file line number Diff line number Diff line change
Expand Up @@ -6,10 +6,7 @@
package render

import (
"bytes"
"image"

"github.com/dkrisman/gobig2"
"github.com/go-gfx/gfx/codec"
"github.com/go-pdfkit/reader"
)

Expand All @@ -31,8 +28,7 @@ func (r *renderer) decodeJBIG2(dict reader.Dict, data []byte, w, h int) []byte {
if err != nil || img == nil {
return nil
}
b := img.Bounds()
if b.Dx() != w || b.Dy() != h {
if img.W != w || img.H != h {
// The dictionary's size is the one the page's geometry was computed
// from. A stream that decodes to another size is not this image.
return nil
Expand All @@ -44,8 +40,7 @@ func (r *renderer) decodeJBIG2(dict reader.Dict, data []byte, w, h int) []byte {
}
for y := 0; y < h; y++ {
for x := 0; x < w; x++ {
gr, gg, gb, _ := img.At(b.Min.X+x, b.Min.Y+y).RGBA()
if (gr*299+gg*587+gb*114)/1000 < 0x8000 {
if img.Pix[(y*w+x)*4] < 128 {
out[y*rowBytes+x/8] &^= 0x80 >> uint(x%8)
}
}
Expand Down Expand Up @@ -90,14 +85,11 @@ func (r *renderer) globalsFrom(parms reader.Object) []byte {
// jbig2Decode is a variable so a test can watch what happens when a decoder
// refuses, which is the case that decides whether the image is drawn wrong or
// not drawn.
var jbig2Decode = func(data, globals []byte) (image.Image, error) {
d, err := gobig2.NewDecoderEmbedded(bytes.NewReader(data), globals)
if err != nil {
return nil, err
}
img, err := d.Decode()
if err != nil {
return nil, err
}
return img, nil
}
//
// The decoder is reached through go-gfx/gfx/codec, which is where the fleet
// keeps its image decoders, rather than named here. It matters more than usual
// for this one: its resource limits are process-global rather than per-decode,
// so a library cannot raise them without changing them for everything else in
// the binary, and it publishes no tagged version. The day it is swapped should
// be a change in one place.
var jbig2Decode = codec.DecodeEmbeddedJBIG2
8 changes: 4 additions & 4 deletions jbig2_test.go
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Expand Up @@ -2,9 +2,9 @@ package render

import (
"errors"
"image"
"testing"

"github.com/go-gfx/gfx/raster"
"github.com/go-pdfkit/reader"
)

Expand Down Expand Up @@ -160,7 +160,7 @@ func TestAJBIG2DecoderThatRefusesTakesTheImageWithIt(t *testing.T) {
// answer; drawing the rectangle anyway is not.
restore := jbig2Decode
defer func() { jbig2Decode = restore }()
jbig2Decode = func(data, globals []byte) (image.Image, error) {
jbig2Decode = func(data, globals []byte) (*raster.Image, error) {
return nil, errors.New("resource budget exceeded")
}
d := jbig2Page(t, jbig2Ink, 16, 8, nil)
Expand All @@ -176,7 +176,7 @@ func TestAJBIG2DecoderThatRefusesTakesTheImageWithIt(t *testing.T) {
func TestAJBIG2DecoderThatReturnsNothingTakesTheImageWithIt(t *testing.T) {
restore := jbig2Decode
defer func() { jbig2Decode = restore }()
jbig2Decode = func(data, globals []byte) (image.Image, error) { return nil, nil }
jbig2Decode = func(data, globals []byte) (*raster.Image, error) { return nil, nil }
d := jbig2Page(t, jbig2Ink, 16, 8, nil)
img, err := Page(d, 1, Options{Scale: 1})
if err != nil {
Expand All @@ -195,7 +195,7 @@ func seenGlobals(t *testing.T, parms reader.Object) []byte {
defer func() { jbig2Decode = restore }()
var got []byte
var called bool
jbig2Decode = func(data, globals []byte) (image.Image, error) {
jbig2Decode = func(data, globals []byte) (*raster.Image, error) {
got, called = globals, true
return restore(data, globals)
}
Expand Down
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