summaryrefslogtreecommitdiffstats
path: root/src/image/png/reader_test.go
diff options
context:
space:
mode:
Diffstat (limited to 'src/image/png/reader_test.go')
-rw-r--r--src/image/png/reader_test.go878
1 files changed, 878 insertions, 0 deletions
diff --git a/src/image/png/reader_test.go b/src/image/png/reader_test.go
new file mode 100644
index 0000000..ccf30b2
--- /dev/null
+++ b/src/image/png/reader_test.go
@@ -0,0 +1,878 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package png
+
+import (
+ "bufio"
+ "bytes"
+ "fmt"
+ "image"
+ "image/color"
+ "io"
+ "os"
+ "reflect"
+ "strings"
+ "testing"
+)
+
+var filenames = []string{
+ "basn0g01",
+ "basn0g01-30",
+ "basn0g02",
+ "basn0g02-29",
+ "basn0g04",
+ "basn0g04-31",
+ "basn0g08",
+ "basn0g16",
+ "basn2c08",
+ "basn2c16",
+ "basn3p01",
+ "basn3p02",
+ "basn3p04",
+ "basn3p04-31i",
+ "basn3p08",
+ "basn3p08-trns",
+ "basn4a08",
+ "basn4a16",
+ "basn6a08",
+ "basn6a16",
+ "ftbbn0g01",
+ "ftbbn0g02",
+ "ftbbn0g04",
+ "ftbbn2c16",
+ "ftbbn3p08",
+ "ftbgn2c16",
+ "ftbgn3p08",
+ "ftbrn2c08",
+ "ftbwn0g16",
+ "ftbwn3p08",
+ "ftbyn3p08",
+ "ftp0n0g08",
+ "ftp0n2c08",
+ "ftp0n3p08",
+ "ftp1n3p08",
+}
+
+var filenamesPaletted = []string{
+ "basn3p01",
+ "basn3p02",
+ "basn3p04",
+ "basn3p08",
+ "basn3p08-trns",
+}
+
+var filenamesShort = []string{
+ "basn0g01",
+ "basn0g04-31",
+ "basn6a16",
+}
+
+func readPNG(filename string) (image.Image, error) {
+ f, err := os.Open(filename)
+ if err != nil {
+ return nil, err
+ }
+ defer f.Close()
+ return Decode(f)
+}
+
+// fakebKGDs maps from filenames to fake bKGD chunks for our approximation to
+// the sng command-line tool. Package png doesn't keep that metadata when
+// png.Decode returns an image.Image.
+var fakebKGDs = map[string]string{
+ "ftbbn0g01": "bKGD {gray: 0;}\n",
+ "ftbbn0g02": "bKGD {gray: 0;}\n",
+ "ftbbn0g04": "bKGD {gray: 0;}\n",
+ "ftbbn2c16": "bKGD {red: 0; green: 0; blue: 65535;}\n",
+ "ftbbn3p08": "bKGD {index: 245}\n",
+ "ftbgn2c16": "bKGD {red: 0; green: 65535; blue: 0;}\n",
+ "ftbgn3p08": "bKGD {index: 245}\n",
+ "ftbrn2c08": "bKGD {red: 255; green: 0; blue: 0;}\n",
+ "ftbwn0g16": "bKGD {gray: 65535;}\n",
+ "ftbwn3p08": "bKGD {index: 0}\n",
+ "ftbyn3p08": "bKGD {index: 245}\n",
+}
+
+// fakegAMAs maps from filenames to fake gAMA chunks for our approximation to
+// the sng command-line tool. Package png doesn't keep that metadata when
+// png.Decode returns an image.Image.
+var fakegAMAs = map[string]string{
+ "ftbbn0g01": "",
+ "ftbbn0g02": "gAMA {0.45455}\n",
+}
+
+// fakeIHDRUsings maps from filenames to fake IHDR "using" lines for our
+// approximation to the sng command-line tool. The PNG model is that
+// transparency (in the tRNS chunk) is separate to the color/grayscale/palette
+// color model (in the IHDR chunk). The Go model is that the concrete
+// image.Image type returned by png.Decode, such as image.RGBA (with all pixels
+// having 100% alpha) or image.NRGBA, encapsulates whether or not the image has
+// transparency. This map is a hack to work around the fact that the Go model
+// can't otherwise discriminate PNG's "IHDR says color (with no alpha) but tRNS
+// says alpha" and "IHDR says color with alpha".
+var fakeIHDRUsings = map[string]string{
+ "ftbbn0g01": " using grayscale;\n",
+ "ftbbn0g02": " using grayscale;\n",
+ "ftbbn0g04": " using grayscale;\n",
+ "ftbbn2c16": " using color;\n",
+ "ftbgn2c16": " using color;\n",
+ "ftbrn2c08": " using color;\n",
+ "ftbwn0g16": " using grayscale;\n",
+}
+
+// An approximation of the sng command-line tool.
+func sng(w io.WriteCloser, filename string, png image.Image) {
+ defer w.Close()
+ bounds := png.Bounds()
+ cm := png.ColorModel()
+ var bitdepth int
+ switch cm {
+ case color.RGBAModel, color.NRGBAModel, color.AlphaModel, color.GrayModel:
+ bitdepth = 8
+ default:
+ bitdepth = 16
+ }
+ cpm, _ := cm.(color.Palette)
+ var paletted *image.Paletted
+ if cpm != nil {
+ switch {
+ case len(cpm) <= 2:
+ bitdepth = 1
+ case len(cpm) <= 4:
+ bitdepth = 2
+ case len(cpm) <= 16:
+ bitdepth = 4
+ default:
+ bitdepth = 8
+ }
+ paletted = png.(*image.Paletted)
+ }
+
+ // Write the filename and IHDR.
+ io.WriteString(w, "#SNG: from "+filename+".png\nIHDR {\n")
+ fmt.Fprintf(w, " width: %d; height: %d; bitdepth: %d;\n", bounds.Dx(), bounds.Dy(), bitdepth)
+ if s, ok := fakeIHDRUsings[filename]; ok {
+ io.WriteString(w, s)
+ } else {
+ switch {
+ case cm == color.RGBAModel, cm == color.RGBA64Model:
+ io.WriteString(w, " using color;\n")
+ case cm == color.NRGBAModel, cm == color.NRGBA64Model:
+ io.WriteString(w, " using color alpha;\n")
+ case cm == color.GrayModel, cm == color.Gray16Model:
+ io.WriteString(w, " using grayscale;\n")
+ case cpm != nil:
+ io.WriteString(w, " using color palette;\n")
+ default:
+ io.WriteString(w, "unknown PNG decoder color model\n")
+ }
+ }
+ io.WriteString(w, "}\n")
+
+ // We fake a gAMA chunk. The test files have a gAMA chunk but the go PNG
+ // parser ignores it (the PNG spec section 11.3 says "Ancillary chunks may
+ // be ignored by a decoder").
+ if s, ok := fakegAMAs[filename]; ok {
+ io.WriteString(w, s)
+ } else {
+ io.WriteString(w, "gAMA {1.0000}\n")
+ }
+
+ // Write the PLTE and tRNS (if applicable).
+ useTransparent := false
+ if cpm != nil {
+ lastAlpha := -1
+ io.WriteString(w, "PLTE {\n")
+ for i, c := range cpm {
+ var r, g, b, a uint8
+ switch c := c.(type) {
+ case color.RGBA:
+ r, g, b, a = c.R, c.G, c.B, 0xff
+ case color.NRGBA:
+ r, g, b, a = c.R, c.G, c.B, c.A
+ default:
+ panic("unknown palette color type")
+ }
+ if a != 0xff {
+ lastAlpha = i
+ }
+ fmt.Fprintf(w, " (%3d,%3d,%3d) # rgb = (0x%02x,0x%02x,0x%02x)\n", r, g, b, r, g, b)
+ }
+ io.WriteString(w, "}\n")
+ if s, ok := fakebKGDs[filename]; ok {
+ io.WriteString(w, s)
+ }
+ if lastAlpha != -1 {
+ io.WriteString(w, "tRNS {\n")
+ for i := 0; i <= lastAlpha; i++ {
+ _, _, _, a := cpm[i].RGBA()
+ a >>= 8
+ fmt.Fprintf(w, " %d", a)
+ }
+ io.WriteString(w, "}\n")
+ }
+ } else if strings.HasPrefix(filename, "ft") {
+ if s, ok := fakebKGDs[filename]; ok {
+ io.WriteString(w, s)
+ }
+ // We fake a tRNS chunk. The test files' grayscale and truecolor
+ // transparent images all have their top left corner transparent.
+ switch c := png.At(0, 0).(type) {
+ case color.NRGBA:
+ if c.A == 0 {
+ useTransparent = true
+ io.WriteString(w, "tRNS {\n")
+ switch filename {
+ case "ftbbn0g01", "ftbbn0g02", "ftbbn0g04":
+ // The standard image package doesn't have a "gray with
+ // alpha" type. Instead, we use an image.NRGBA.
+ fmt.Fprintf(w, " gray: %d;\n", c.R)
+ default:
+ fmt.Fprintf(w, " red: %d; green: %d; blue: %d;\n", c.R, c.G, c.B)
+ }
+ io.WriteString(w, "}\n")
+ }
+ case color.NRGBA64:
+ if c.A == 0 {
+ useTransparent = true
+ io.WriteString(w, "tRNS {\n")
+ switch filename {
+ case "ftbwn0g16":
+ // The standard image package doesn't have a "gray16 with
+ // alpha" type. Instead, we use an image.NRGBA64.
+ fmt.Fprintf(w, " gray: %d;\n", c.R)
+ default:
+ fmt.Fprintf(w, " red: %d; green: %d; blue: %d;\n", c.R, c.G, c.B)
+ }
+ io.WriteString(w, "}\n")
+ }
+ }
+ }
+
+ // Write the IMAGE.
+ io.WriteString(w, "IMAGE {\n pixels hex\n")
+ for y := bounds.Min.Y; y < bounds.Max.Y; y++ {
+ switch {
+ case cm == color.GrayModel:
+ for x := bounds.Min.X; x < bounds.Max.X; x++ {
+ gray := png.At(x, y).(color.Gray)
+ fmt.Fprintf(w, "%02x", gray.Y)
+ }
+ case cm == color.Gray16Model:
+ for x := bounds.Min.X; x < bounds.Max.X; x++ {
+ gray16 := png.At(x, y).(color.Gray16)
+ fmt.Fprintf(w, "%04x ", gray16.Y)
+ }
+ case cm == color.RGBAModel:
+ for x := bounds.Min.X; x < bounds.Max.X; x++ {
+ rgba := png.At(x, y).(color.RGBA)
+ fmt.Fprintf(w, "%02x%02x%02x ", rgba.R, rgba.G, rgba.B)
+ }
+ case cm == color.RGBA64Model:
+ for x := bounds.Min.X; x < bounds.Max.X; x++ {
+ rgba64 := png.At(x, y).(color.RGBA64)
+ fmt.Fprintf(w, "%04x%04x%04x ", rgba64.R, rgba64.G, rgba64.B)
+ }
+ case cm == color.NRGBAModel:
+ for x := bounds.Min.X; x < bounds.Max.X; x++ {
+ nrgba := png.At(x, y).(color.NRGBA)
+ switch filename {
+ case "ftbbn0g01", "ftbbn0g02", "ftbbn0g04":
+ fmt.Fprintf(w, "%02x", nrgba.R)
+ default:
+ if useTransparent {
+ fmt.Fprintf(w, "%02x%02x%02x ", nrgba.R, nrgba.G, nrgba.B)
+ } else {
+ fmt.Fprintf(w, "%02x%02x%02x%02x ", nrgba.R, nrgba.G, nrgba.B, nrgba.A)
+ }
+ }
+ }
+ case cm == color.NRGBA64Model:
+ for x := bounds.Min.X; x < bounds.Max.X; x++ {
+ nrgba64 := png.At(x, y).(color.NRGBA64)
+ switch filename {
+ case "ftbwn0g16":
+ fmt.Fprintf(w, "%04x ", nrgba64.R)
+ default:
+ if useTransparent {
+ fmt.Fprintf(w, "%04x%04x%04x ", nrgba64.R, nrgba64.G, nrgba64.B)
+ } else {
+ fmt.Fprintf(w, "%04x%04x%04x%04x ", nrgba64.R, nrgba64.G, nrgba64.B, nrgba64.A)
+ }
+ }
+ }
+ case cpm != nil:
+ var b, c int
+ for x := bounds.Min.X; x < bounds.Max.X; x++ {
+ b = b<<uint(bitdepth) | int(paletted.ColorIndexAt(x, y))
+ c++
+ if c == 8/bitdepth {
+ fmt.Fprintf(w, "%02x", b)
+ b = 0
+ c = 0
+ }
+ }
+ if c != 0 {
+ for c != 8/bitdepth {
+ b = b << uint(bitdepth)
+ c++
+ }
+ fmt.Fprintf(w, "%02x", b)
+ }
+ }
+ io.WriteString(w, "\n")
+ }
+ io.WriteString(w, "}\n")
+}
+
+func TestReader(t *testing.T) {
+ names := filenames
+ if testing.Short() {
+ names = filenamesShort
+ }
+ for _, fn := range names {
+ // Read the .png file.
+ img, err := readPNG("testdata/pngsuite/" + fn + ".png")
+ if err != nil {
+ t.Error(fn, err)
+ continue
+ }
+
+ if fn == "basn4a16" {
+ // basn4a16.sng is gray + alpha but sng() will produce true color + alpha
+ // so we just check a single random pixel.
+ c := img.At(2, 1).(color.NRGBA64)
+ if c.R != 0x11a7 || c.G != 0x11a7 || c.B != 0x11a7 || c.A != 0x1085 {
+ t.Error(fn, fmt.Errorf("wrong pixel value at (2, 1): %x", c))
+ }
+ continue
+ }
+
+ piper, pipew := io.Pipe()
+ pb := bufio.NewScanner(piper)
+ go sng(pipew, fn, img)
+ defer piper.Close()
+
+ // Read the .sng file.
+ sf, err := os.Open("testdata/pngsuite/" + fn + ".sng")
+ if err != nil {
+ t.Error(fn, err)
+ continue
+ }
+ defer sf.Close()
+ sb := bufio.NewScanner(sf)
+
+ // Compare the two, in SNG format, line by line.
+ for {
+ pdone := !pb.Scan()
+ sdone := !sb.Scan()
+ if pdone && sdone {
+ break
+ }
+ if pdone || sdone {
+ t.Errorf("%s: Different sizes", fn)
+ break
+ }
+ ps := pb.Text()
+ ss := sb.Text()
+
+ // Newer versions of the sng command line tool append an optional
+ // color name to the RGB tuple. For example:
+ // # rgb = (0xff,0xff,0xff) grey100
+ // # rgb = (0x00,0x00,0xff) blue1
+ // instead of the older version's plainer:
+ // # rgb = (0xff,0xff,0xff)
+ // # rgb = (0x00,0x00,0xff)
+ // We strip any such name.
+ if strings.Contains(ss, "# rgb = (") && !strings.HasSuffix(ss, ")") {
+ if i := strings.LastIndex(ss, ") "); i >= 0 {
+ ss = ss[:i+1]
+ }
+ }
+
+ if ps != ss {
+ t.Errorf("%s: Mismatch\n%s\nversus\n%s\n", fn, ps, ss)
+ break
+ }
+ }
+ if pb.Err() != nil {
+ t.Error(fn, pb.Err())
+ }
+ if sb.Err() != nil {
+ t.Error(fn, sb.Err())
+ }
+ }
+}
+
+var readerErrors = []struct {
+ file string
+ err string
+}{
+ {"invalid-zlib.png", "zlib: invalid checksum"},
+ {"invalid-crc32.png", "invalid checksum"},
+ {"invalid-noend.png", "unexpected EOF"},
+ {"invalid-trunc.png", "unexpected EOF"},
+}
+
+func TestReaderError(t *testing.T) {
+ for _, tt := range readerErrors {
+ img, err := readPNG("testdata/" + tt.file)
+ if err == nil {
+ t.Errorf("decoding %s: missing error", tt.file)
+ continue
+ }
+ if !strings.Contains(err.Error(), tt.err) {
+ t.Errorf("decoding %s: %s, want %s", tt.file, err, tt.err)
+ }
+ if img != nil {
+ t.Errorf("decoding %s: have image + error", tt.file)
+ }
+ }
+}
+
+func TestPalettedDecodeConfig(t *testing.T) {
+ for _, fn := range filenamesPaletted {
+ f, err := os.Open("testdata/pngsuite/" + fn + ".png")
+ if err != nil {
+ t.Errorf("%s: open failed: %v", fn, err)
+ continue
+ }
+ defer f.Close()
+ cfg, err := DecodeConfig(f)
+ if err != nil {
+ t.Errorf("%s: %v", fn, err)
+ continue
+ }
+ pal, ok := cfg.ColorModel.(color.Palette)
+ if !ok {
+ t.Errorf("%s: expected paletted color model", fn)
+ continue
+ }
+ if pal == nil {
+ t.Errorf("%s: palette not initialized", fn)
+ continue
+ }
+ }
+}
+
+func TestInterlaced(t *testing.T) {
+ a, err := readPNG("testdata/gray-gradient.png")
+ if err != nil {
+ t.Fatal(err)
+ }
+ b, err := readPNG("testdata/gray-gradient.interlaced.png")
+ if err != nil {
+ t.Fatal(err)
+ }
+ if !reflect.DeepEqual(a, b) {
+ t.Fatalf("decodings differ:\nnon-interlaced:\n%#v\ninterlaced:\n%#v", a, b)
+ }
+}
+
+func TestIncompleteIDATOnRowBoundary(t *testing.T) {
+ // The following is an invalid 1x2 grayscale PNG image. The header is OK,
+ // but the zlib-compressed IDAT payload contains two bytes "\x02\x00",
+ // which is only one row of data (the leading "\x02" is a row filter).
+ const (
+ ihdr = "\x00\x00\x00\x0dIHDR\x00\x00\x00\x01\x00\x00\x00\x02\x08\x00\x00\x00\x00\xbc\xea\xe9\xfb"
+ idat = "\x00\x00\x00\x0eIDAT\x78\x9c\x62\x62\x00\x04\x00\x00\xff\xff\x00\x06\x00\x03\xfa\xd0\x59\xae"
+ iend = "\x00\x00\x00\x00IEND\xae\x42\x60\x82"
+ )
+ _, err := Decode(strings.NewReader(pngHeader + ihdr + idat + iend))
+ if err == nil {
+ t.Fatal("got nil error, want non-nil")
+ }
+}
+
+func TestTrailingIDATChunks(t *testing.T) {
+ // The following is a valid 1x1 PNG image containing color.Gray{255} and
+ // a trailing zero-length IDAT chunk (see PNG specification section 12.9):
+ const (
+ ihdr = "\x00\x00\x00\x0dIHDR\x00\x00\x00\x01\x00\x00\x00\x01\x08\x00\x00\x00\x00\x3a\x7e\x9b\x55"
+ idatWhite = "\x00\x00\x00\x0eIDAT\x78\x9c\x62\xfa\x0f\x08\x00\x00\xff\xff\x01\x05\x01\x02\x5a\xdd\x39\xcd"
+ idatZero = "\x00\x00\x00\x00IDAT\x35\xaf\x06\x1e"
+ iend = "\x00\x00\x00\x00IEND\xae\x42\x60\x82"
+ )
+ _, err := Decode(strings.NewReader(pngHeader + ihdr + idatWhite + idatZero + iend))
+ if err != nil {
+ t.Fatalf("decoding valid image: %v", err)
+ }
+
+ // Non-zero-length trailing IDAT chunks should be ignored (recoverable error).
+ // The following chunk contains a single pixel with color.Gray{0}.
+ const idatBlack = "\x00\x00\x00\x0eIDAT\x78\x9c\x62\x62\x00\x04\x00\x00\xff\xff\x00\x06\x00\x03\xfa\xd0\x59\xae"
+
+ img, err := Decode(strings.NewReader(pngHeader + ihdr + idatWhite + idatBlack + iend))
+ if err != nil {
+ t.Fatalf("trailing IDAT not ignored: %v", err)
+ }
+ if img.At(0, 0) == (color.Gray{0}) {
+ t.Fatal("decoded image from trailing IDAT chunk")
+ }
+}
+
+func TestMultipletRNSChunks(t *testing.T) {
+ /*
+ The following is a valid 1x1 paletted PNG image with a 1-element palette
+ containing color.NRGBA{0xff, 0x00, 0x00, 0x7f}:
+ 0000000: 8950 4e47 0d0a 1a0a 0000 000d 4948 4452 .PNG........IHDR
+ 0000010: 0000 0001 0000 0001 0803 0000 0028 cb34 .............(.4
+ 0000020: bb00 0000 0350 4c54 45ff 0000 19e2 0937 .....PLTE......7
+ 0000030: 0000 0001 7452 4e53 7f80 5cb4 cb00 0000 ....tRNS..\.....
+ 0000040: 0e49 4441 5478 9c62 6200 0400 00ff ff00 .IDATx.bb.......
+ 0000050: 0600 03fa d059 ae00 0000 0049 454e 44ae .....Y.....IEND.
+ 0000060: 4260 82 B`.
+ Dropping the tRNS chunk makes that color's alpha 0xff instead of 0x7f.
+ */
+ const (
+ ihdr = "\x00\x00\x00\x0dIHDR\x00\x00\x00\x01\x00\x00\x00\x01\x08\x03\x00\x00\x00\x28\xcb\x34\xbb"
+ plte = "\x00\x00\x00\x03PLTE\xff\x00\x00\x19\xe2\x09\x37"
+ trns = "\x00\x00\x00\x01tRNS\x7f\x80\x5c\xb4\xcb"
+ idat = "\x00\x00\x00\x0eIDAT\x78\x9c\x62\x62\x00\x04\x00\x00\xff\xff\x00\x06\x00\x03\xfa\xd0\x59\xae"
+ iend = "\x00\x00\x00\x00IEND\xae\x42\x60\x82"
+ )
+ for i := 0; i < 4; i++ {
+ var b []byte
+ b = append(b, pngHeader...)
+ b = append(b, ihdr...)
+ b = append(b, plte...)
+ for j := 0; j < i; j++ {
+ b = append(b, trns...)
+ }
+ b = append(b, idat...)
+ b = append(b, iend...)
+
+ var want color.Color
+ m, err := Decode(bytes.NewReader(b))
+ switch i {
+ case 0:
+ if err != nil {
+ t.Errorf("%d tRNS chunks: %v", i, err)
+ continue
+ }
+ want = color.RGBA{0xff, 0x00, 0x00, 0xff}
+ case 1:
+ if err != nil {
+ t.Errorf("%d tRNS chunks: %v", i, err)
+ continue
+ }
+ want = color.NRGBA{0xff, 0x00, 0x00, 0x7f}
+ default:
+ if err == nil {
+ t.Errorf("%d tRNS chunks: got nil error, want non-nil", i)
+ }
+ continue
+ }
+ if got := m.At(0, 0); got != want {
+ t.Errorf("%d tRNS chunks: got %T %v, want %T %v", i, got, got, want, want)
+ }
+ }
+}
+
+func TestUnknownChunkLengthUnderflow(t *testing.T) {
+ data := []byte{0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a, 0xff, 0xff,
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x06, 0xf4, 0x7c, 0x55, 0x04, 0x1a,
+ 0xd3, 0x11, 0x9a, 0x73, 0x00, 0x00, 0xf8, 0x1e, 0xf3, 0x2e, 0x00, 0x00,
+ 0x01, 0x00, 0xff, 0xff, 0xff, 0xff, 0x07, 0xf4, 0x7c, 0x55, 0x04, 0x1a,
+ 0xd3}
+ _, err := Decode(bytes.NewReader(data))
+ if err == nil {
+ t.Errorf("Didn't fail reading an unknown chunk with length 0xffffffff")
+ }
+}
+
+func TestPaletted8OutOfRangePixel(t *testing.T) {
+ // IDAT contains a reference to a palette index that does not exist in the file.
+ img, err := readPNG("testdata/invalid-palette.png")
+ if err != nil {
+ t.Errorf("decoding invalid-palette.png: unexpected error %v", err)
+ return
+ }
+
+ // Expect that the palette is extended with opaque black.
+ want := color.RGBA{0x00, 0x00, 0x00, 0xff}
+ if got := img.At(15, 15); got != want {
+ t.Errorf("got %F %v, expected %T %v", got, got, want, want)
+ }
+}
+
+func TestGray8Transparent(t *testing.T) {
+ // These bytes come from https://golang.org/issues/19553
+ m, err := Decode(bytes.NewReader([]byte{
+ 0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a, 0x00, 0x00, 0x00, 0x0d, 0x49, 0x48, 0x44, 0x52,
+ 0x00, 0x00, 0x00, 0x0f, 0x00, 0x00, 0x00, 0x0b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x85, 0x2c, 0x88,
+ 0x80, 0x00, 0x00, 0x00, 0x02, 0x74, 0x52, 0x4e, 0x53, 0x00, 0xff, 0x5b, 0x91, 0x22, 0xb5, 0x00,
+ 0x00, 0x00, 0x02, 0x62, 0x4b, 0x47, 0x44, 0x00, 0xff, 0x87, 0x8f, 0xcc, 0xbf, 0x00, 0x00, 0x00,
+ 0x09, 0x70, 0x48, 0x59, 0x73, 0x00, 0x00, 0x0a, 0xf0, 0x00, 0x00, 0x0a, 0xf0, 0x01, 0x42, 0xac,
+ 0x34, 0x98, 0x00, 0x00, 0x00, 0x07, 0x74, 0x49, 0x4d, 0x45, 0x07, 0xd5, 0x04, 0x02, 0x12, 0x11,
+ 0x11, 0xf7, 0x65, 0x3d, 0x8b, 0x00, 0x00, 0x00, 0x4f, 0x49, 0x44, 0x41, 0x54, 0x08, 0xd7, 0x63,
+ 0xf8, 0xff, 0xff, 0xff, 0xb9, 0xbd, 0x70, 0xf0, 0x8c, 0x01, 0xc8, 0xaf, 0x6e, 0x99, 0x02, 0x05,
+ 0xd9, 0x7b, 0xc1, 0xfc, 0x6b, 0xff, 0xa1, 0xa0, 0x87, 0x30, 0xff, 0xd9, 0xde, 0xbd, 0xd5, 0x4b,
+ 0xf7, 0xee, 0xfd, 0x0e, 0xe3, 0xef, 0xcd, 0x06, 0x19, 0x14, 0xf5, 0x1e, 0xce, 0xef, 0x01, 0x31,
+ 0x92, 0xd7, 0x82, 0x41, 0x31, 0x9c, 0x3f, 0x07, 0x02, 0xee, 0xa1, 0xaa, 0xff, 0xff, 0x9f, 0xe1,
+ 0xd9, 0x56, 0x30, 0xf8, 0x0e, 0xe5, 0x03, 0x00, 0xa9, 0x42, 0x84, 0x3d, 0xdf, 0x8f, 0xa6, 0x8f,
+ 0x00, 0x00, 0x00, 0x00, 0x49, 0x45, 0x4e, 0x44, 0xae, 0x42, 0x60, 0x82,
+ }))
+ if err != nil {
+ t.Fatalf("Decode: %v", err)
+ }
+
+ const hex = "0123456789abcdef"
+ var got []byte
+ bounds := m.Bounds()
+ for y := bounds.Min.Y; y < bounds.Max.Y; y++ {
+ for x := bounds.Min.X; x < bounds.Max.X; x++ {
+ if r, _, _, a := m.At(x, y).RGBA(); a != 0 {
+ got = append(got,
+ hex[0x0f&(r>>12)],
+ hex[0x0f&(r>>8)],
+ ' ',
+ )
+ } else {
+ got = append(got,
+ '.',
+ '.',
+ ' ',
+ )
+ }
+ }
+ got = append(got, '\n')
+ }
+
+ const want = "" +
+ ".. .. .. ce bd bd bd bd bd bd bd bd bd bd e6 \n" +
+ ".. .. .. 7b 84 94 94 94 94 94 94 94 94 6b bd \n" +
+ ".. .. .. 7b d6 .. .. .. .. .. .. .. .. 8c bd \n" +
+ ".. .. .. 7b d6 .. .. .. .. .. .. .. .. 8c bd \n" +
+ ".. .. .. 7b d6 .. .. .. .. .. .. .. .. 8c bd \n" +
+ "e6 bd bd 7b a5 bd bd f7 .. .. .. .. .. 8c bd \n" +
+ "bd 6b 94 94 94 94 5a ef .. .. .. .. .. 8c bd \n" +
+ "bd 8c .. .. .. .. 63 ad ad ad ad ad ad 73 bd \n" +
+ "bd 8c .. .. .. .. 63 9c 9c 9c 9c 9c 9c 9c de \n" +
+ "bd 6b 94 94 94 94 5a ef .. .. .. .. .. .. .. \n" +
+ "e6 b5 b5 b5 b5 b5 b5 f7 .. .. .. .. .. .. .. \n"
+
+ if string(got) != want {
+ t.Errorf("got:\n%swant:\n%s", got, want)
+ }
+}
+
+func TestDimensionOverflow(t *testing.T) {
+ maxInt32AsInt := int((1 << 31) - 1)
+ have32BitInts := 0 > (1 + maxInt32AsInt)
+
+ testCases := []struct {
+ src []byte
+ unsupportedConfig bool
+ width int
+ height int
+ }{
+ // These bytes come from https://golang.org/issues/22304
+ //
+ // It encodes a 2147483646 × 2147483646 (i.e. 0x7ffffffe × 0x7ffffffe)
+ // NRGBA image. The (width × height) per se doesn't overflow an int64, but
+ // (width × height × bytesPerPixel) will.
+ {
+ src: []byte{
+ 0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a, 0x00, 0x00, 0x00, 0x0d, 0x49, 0x48, 0x44, 0x52,
+ 0x7f, 0xff, 0xff, 0xfe, 0x7f, 0xff, 0xff, 0xfe, 0x08, 0x06, 0x00, 0x00, 0x00, 0x30, 0x57, 0xb3,
+ 0xfd, 0x00, 0x00, 0x00, 0x15, 0x49, 0x44, 0x41, 0x54, 0x78, 0x9c, 0x62, 0x62, 0x20, 0x12, 0x8c,
+ 0x2a, 0xa4, 0xb3, 0x42, 0x40, 0x00, 0x00, 0x00, 0xff, 0xff, 0x13, 0x38, 0x00, 0x15, 0x2d, 0xef,
+ 0x5f, 0x0f, 0x00, 0x00, 0x00, 0x00, 0x49, 0x45, 0x4e, 0x44, 0xae, 0x42, 0x60, 0x82,
+ },
+ // It's debatable whether DecodeConfig (which does not allocate a
+ // pixel buffer, unlike Decode) should fail in this case. The Go
+ // standard library has made its choice, and the standard library
+ // has compatibility constraints.
+ unsupportedConfig: true,
+ width: 0x7ffffffe,
+ height: 0x7ffffffe,
+ },
+
+ // The next three cases come from https://golang.org/issues/38435
+
+ {
+ src: []byte{
+ 0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a, 0x00, 0x00, 0x00, 0x0d, 0x49, 0x48, 0x44, 0x52,
+ 0x00, 0x00, 0xb5, 0x04, 0x00, 0x00, 0xb5, 0x04, 0x08, 0x06, 0x00, 0x00, 0x00, 0xf5, 0x60, 0x2c,
+ 0xb8, 0x00, 0x00, 0x00, 0x15, 0x49, 0x44, 0x41, 0x54, 0x78, 0x9c, 0x62, 0x62, 0x20, 0x12, 0x8c,
+ 0x2a, 0xa4, 0xb3, 0x42, 0x40, 0x00, 0x00, 0x00, 0xff, 0xff, 0x13, 0x38, 0x00, 0x15, 0x2d, 0xef,
+ 0x5f, 0x0f, 0x00, 0x00, 0x00, 0x00, 0x49, 0x45, 0x4e, 0x44, 0xae, 0x42, 0x60, 0x82,
+ },
+ // Here, width * height = 0x7ffea810, just under MaxInt32, but at 4
+ // bytes per pixel, the number of pixels overflows an int32.
+ unsupportedConfig: have32BitInts,
+ width: 0x0000b504,
+ height: 0x0000b504,
+ },
+
+ {
+ src: []byte{
+ 0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a, 0x00, 0x00, 0x00, 0x0d, 0x49, 0x48, 0x44, 0x52,
+ 0x04, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x08, 0x06, 0x00, 0x00, 0x00, 0x30, 0x6e, 0xc5,
+ 0x21, 0x00, 0x00, 0x00, 0x15, 0x49, 0x44, 0x41, 0x54, 0x78, 0x9c, 0x62, 0x62, 0x20, 0x12, 0x8c,
+ 0x2a, 0xa4, 0xb3, 0x42, 0x40, 0x00, 0x00, 0x00, 0xff, 0xff, 0x13, 0x38, 0x00, 0x15, 0x2d, 0xef,
+ 0x5f, 0x0f, 0x00, 0x00, 0x00, 0x00, 0x49, 0x45, 0x4e, 0x44, 0xae, 0x42, 0x60, 0x82,
+ },
+ unsupportedConfig: false,
+ width: 0x04000000,
+ height: 0x00000001,
+ },
+
+ {
+ src: []byte{
+ 0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a, 0x00, 0x00, 0x00, 0x0d, 0x49, 0x48, 0x44, 0x52,
+ 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x08, 0x06, 0x00, 0x00, 0x00, 0xaa, 0xd4, 0x7c,
+ 0xda, 0x00, 0x00, 0x00, 0x15, 0x49, 0x44, 0x41, 0x54, 0x78, 0x9c, 0x62, 0x66, 0x20, 0x12, 0x30,
+ 0x8d, 0x2a, 0xa4, 0xaf, 0x42, 0x40, 0x00, 0x00, 0x00, 0xff, 0xff, 0x14, 0xd2, 0x00, 0x16, 0x00,
+ 0x00, 0x00,
+ },
+ unsupportedConfig: false,
+ width: 0x08000000,
+ height: 0x00000001,
+ },
+ }
+
+ for i, tc := range testCases {
+ cfg, err := DecodeConfig(bytes.NewReader(tc.src))
+ if tc.unsupportedConfig {
+ if err == nil {
+ t.Errorf("i=%d: DecodeConfig: got nil error, want non-nil", i)
+ } else if _, ok := err.(UnsupportedError); !ok {
+ t.Fatalf("Decode: got %v (of type %T), want non-nil error (of type png.UnsupportedError)", err, err)
+ }
+ continue
+ } else if err != nil {
+ t.Errorf("i=%d: DecodeConfig: %v", i, err)
+ continue
+ } else if cfg.Width != tc.width {
+ t.Errorf("i=%d: width: got %d, want %d", i, cfg.Width, tc.width)
+ continue
+ } else if cfg.Height != tc.height {
+ t.Errorf("i=%d: height: got %d, want %d", i, cfg.Height, tc.height)
+ continue
+ }
+
+ if nPixels := int64(cfg.Width) * int64(cfg.Height); nPixels > 0x7f000000 {
+ // In theory, calling Decode would succeed, given several gigabytes
+ // of memory. In practice, trying to make a []uint8 big enough to
+ // hold all of the pixels can often result in OOM (out of memory).
+ // OOM is unrecoverable; we can't write a test that passes when OOM
+ // happens. Instead we skip the Decode call (and its tests).
+ continue
+ } else if testing.Short() {
+ // Even for smaller image dimensions, calling Decode might allocate
+ // 1 GiB or more of memory. This is usually feasible, and we want
+ // to check that calling Decode doesn't panic if there's enough
+ // memory, but we provide a runtime switch (testing.Short) to skip
+ // these if it would OOM. See also http://golang.org/issue/5050
+ // "decoding... images can cause huge memory allocations".
+ continue
+ }
+
+ // Even if we don't panic, these aren't valid PNG images.
+ if _, err := Decode(bytes.NewReader(tc.src)); err == nil {
+ t.Errorf("i=%d: Decode: got nil error, want non-nil", i)
+ }
+ }
+
+ if testing.Short() {
+ t.Skip("skipping tests which allocate large pixel buffers")
+ }
+}
+
+func TestDecodePalettedWithTransparency(t *testing.T) {
+ // These bytes come from https://go.dev/issue/54325
+ //
+ // Per the PNG spec, a PLTE chunk contains 3 (not 4) bytes per palette
+ // entry: RGB (not RGBA). The alpha value comes from the optional tRNS
+ // chunk. Here, the PLTE chunk (0x50, 0x4c, 0x54, 0x45, etc) has 16 entries
+ // (0x30 = 48 bytes) and the tRNS chunk (0x74, 0x52, 0x4e, 0x53, etc) has 1
+ // entry (0x01 = 1 byte) that sets the first palette entry's alpha to zero.
+ //
+ // Both Decode and DecodeConfig should pick up that the first palette
+ // entry's alpha is zero.
+ src := []byte{
+ 0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a, 0x00, 0x00, 0x00, 0x0d, 0x49, 0x48, 0x44, 0x52,
+ 0x00, 0x00, 0x00, 0x20, 0x00, 0x00, 0x00, 0x20, 0x04, 0x03, 0x00, 0x00, 0x00, 0x81, 0x54, 0x67,
+ 0xc7, 0x00, 0x00, 0x00, 0x30, 0x50, 0x4c, 0x54, 0x45, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff, 0x0e,
+ 0x00, 0x23, 0x27, 0x7b, 0xb1, 0x2d, 0x0a, 0x49, 0x3f, 0x19, 0x78, 0x5f, 0xcd, 0xe4, 0x69, 0x69,
+ 0xe4, 0x71, 0x59, 0x53, 0x80, 0x11, 0x14, 0x8b, 0x00, 0xa9, 0x8d, 0x95, 0xcb, 0x99, 0x2f, 0x6b,
+ 0xd7, 0x29, 0x91, 0xd7, 0x7b, 0xba, 0xff, 0xe3, 0xd7, 0x13, 0xc6, 0xd3, 0x58, 0x00, 0x00, 0x00,
+ 0x01, 0x74, 0x52, 0x4e, 0x53, 0x00, 0x40, 0xe6, 0xd8, 0x66, 0x00, 0x00, 0x00, 0xfd, 0x49, 0x44,
+ 0x41, 0x54, 0x28, 0xcf, 0x63, 0x60, 0x00, 0x83, 0x55, 0x0c, 0x68, 0x60, 0x9d, 0x02, 0x9a, 0x80,
+ 0xde, 0x23, 0x74, 0x15, 0xef, 0x50, 0x94, 0x70, 0x2d, 0xd2, 0x7b, 0x87, 0xa2, 0x84, 0xeb, 0xee,
+ 0xbb, 0x77, 0x6f, 0x51, 0x94, 0xe8, 0xbd, 0x7d, 0xf7, 0xee, 0x12, 0xb2, 0x80, 0xd2, 0x3d, 0x54,
+ 0x01, 0x26, 0x10, 0x1f, 0x59, 0x40, 0x0f, 0xc8, 0xd7, 0x7e, 0x84, 0x70, 0x1c, 0xd7, 0xba, 0xb7,
+ 0x4a, 0xda, 0xda, 0x77, 0x11, 0xf6, 0xac, 0x5a, 0xa5, 0xf4, 0xf9, 0xbf, 0xfd, 0x3d, 0x24, 0x6b,
+ 0x98, 0x94, 0xf4, 0xff, 0x7f, 0x52, 0x42, 0x16, 0x30, 0x0e, 0xd9, 0xed, 0x6a, 0x8c, 0xec, 0x10,
+ 0x65, 0x53, 0x97, 0x60, 0x23, 0x64, 0x1d, 0x8a, 0x2e, 0xc6, 0x2e, 0x42, 0x08, 0x3d, 0x4c, 0xca,
+ 0x81, 0xc1, 0x82, 0xa6, 0xa2, 0x46, 0x08, 0x3d, 0x4a, 0xa1, 0x82, 0xc6, 0x82, 0xa1, 0x4a, 0x08,
+ 0x3d, 0xfa, 0xa6, 0x81, 0xa1, 0xa2, 0xc1, 0x9f, 0x10, 0x66, 0xd4, 0x2b, 0x87, 0x0a, 0x86, 0x1a,
+ 0x7d, 0x57, 0x80, 0x9b, 0x99, 0xaf, 0x62, 0x1a, 0x1a, 0xec, 0xf0, 0x0d, 0x66, 0x2a, 0x7b, 0x5a,
+ 0xba, 0xd2, 0x64, 0x63, 0x4b, 0xa6, 0xb2, 0xb4, 0x02, 0xa8, 0x12, 0xb5, 0x24, 0xa5, 0x99, 0x2e,
+ 0x33, 0x95, 0xd4, 0x92, 0x10, 0xee, 0xd0, 0x59, 0xb9, 0x6a, 0xd6, 0x21, 0x24, 0xb7, 0x33, 0x9d,
+ 0x01, 0x01, 0x64, 0xbf, 0xac, 0x59, 0xb2, 0xca, 0xeb, 0x14, 0x92, 0x80, 0xd6, 0x9a, 0x53, 0x4a,
+ 0x6b, 0x4e, 0x2d, 0x42, 0x52, 0xa1, 0x73, 0x28, 0x54, 0xe7, 0x90, 0x6a, 0x00, 0x92, 0x92, 0x45,
+ 0xa1, 0x40, 0x84, 0x2c, 0xe0, 0xc4, 0xa0, 0xb2, 0x28, 0x14, 0xc1, 0x67, 0xe9, 0x50, 0x60, 0x60,
+ 0xea, 0x70, 0x40, 0x12, 0x00, 0x79, 0x54, 0x09, 0x22, 0x00, 0x00, 0x30, 0xf3, 0x52, 0x87, 0xc6,
+ 0xe4, 0xbd, 0x70, 0x00, 0x00, 0x00, 0x00, 0x49, 0x45, 0x4e, 0x44, 0xae, 0x42, 0x60, 0x82,
+ }
+
+ cfg, err := DecodeConfig(bytes.NewReader(src))
+ if err != nil {
+ t.Fatalf("DecodeConfig: %v", err)
+ } else if _, _, _, alpha := cfg.ColorModel.(color.Palette)[0].RGBA(); alpha != 0 {
+ t.Errorf("DecodeConfig: got %d, want 0", alpha)
+ }
+
+ img, err := Decode(bytes.NewReader(src))
+ if err != nil {
+ t.Fatalf("Decode: %v", err)
+ } else if _, _, _, alpha := img.ColorModel().(color.Palette)[0].RGBA(); alpha != 0 {
+ t.Errorf("Decode: got %d, want 0", alpha)
+ }
+}
+
+func benchmarkDecode(b *testing.B, filename string, bytesPerPixel int) {
+ data, err := os.ReadFile(filename)
+ if err != nil {
+ b.Fatal(err)
+ }
+ cfg, err := DecodeConfig(bytes.NewReader(data))
+ if err != nil {
+ b.Fatal(err)
+ }
+ b.SetBytes(int64(cfg.Width * cfg.Height * bytesPerPixel))
+ b.ReportAllocs()
+ b.ResetTimer()
+ for i := 0; i < b.N; i++ {
+ Decode(bytes.NewReader(data))
+ }
+}
+
+func BenchmarkDecodeGray(b *testing.B) {
+ benchmarkDecode(b, "testdata/benchGray.png", 1)
+}
+
+func BenchmarkDecodeNRGBAGradient(b *testing.B) {
+ benchmarkDecode(b, "testdata/benchNRGBA-gradient.png", 4)
+}
+
+func BenchmarkDecodeNRGBAOpaque(b *testing.B) {
+ benchmarkDecode(b, "testdata/benchNRGBA-opaque.png", 4)
+}
+
+func BenchmarkDecodePaletted(b *testing.B) {
+ benchmarkDecode(b, "testdata/benchPaletted.png", 1)
+}
+
+func BenchmarkDecodeRGB(b *testing.B) {
+ benchmarkDecode(b, "testdata/benchRGB.png", 4)
+}
+
+func BenchmarkDecodeInterlacing(b *testing.B) {
+ benchmarkDecode(b, "testdata/benchRGB-interlace.png", 4)
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-09-13 13:46:33 +0000