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Diffstat (limited to 'src/pkg/image/png/reader_test.go')
| -rw-r--r-- | src/pkg/image/png/reader_test.go | 241 |
1 files changed, 241 insertions, 0 deletions
diff --git a/src/pkg/image/png/reader_test.go b/src/pkg/image/png/reader_test.go new file mode 100644 index 000000000..bcc1a3db4 --- /dev/null +++ b/src/pkg/image/png/reader_test.go @@ -0,0 +1,241 @@ +// 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" + "fmt" + "image" + "io" + "os" + "testing" +) + +var filenames = []string{ + "basn0g01", + "basn0g01-30", + "basn0g02", + "basn0g02-29", + "basn0g04", + "basn0g04-31", + "basn0g08", + "basn0g16", + "basn2c08", + "basn2c16", + "basn3p01", + "basn3p02", + "basn3p04", + "basn3p08", + "basn3p08-trns", + "basn4a08", + "basn4a16", + "basn6a08", + "basn6a16", +} + +var filenamesShort = []string{ + "basn0g01", + "basn0g04-31", + "basn6a16", +} + +func readPng(filename string) (image.Image, os.Error) { + f, err := os.Open(filename) + if err != nil { + return nil, err + } + defer f.Close() + return Decode(f) +} + +// 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 image.RGBAColorModel, image.NRGBAColorModel, image.AlphaColorModel, image.GrayColorModel: + bitdepth = 8 + default: + bitdepth = 16 + } + cpm, _ := cm.(image.PalettedColorModel) + 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) + switch { + case cm == image.RGBAColorModel, cm == image.RGBA64ColorModel: + io.WriteString(w, " using color;\n") + case cm == image.NRGBAColorModel, cm == image.NRGBA64ColorModel: + io.WriteString(w, " using color alpha;\n") + case cm == image.GrayColorModel, cm == image.Gray16ColorModel: + 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 output. 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"). + io.WriteString(w, "gAMA {1.0000}\n") + + // Write the PLTE and tRNS (if applicable). + if cpm != nil { + lastAlpha := -1 + io.WriteString(w, "PLTE {\n") + for i, c := range cpm { + r, g, b, a := c.RGBA() + if a != 0xffff { + lastAlpha = i + } + r >>= 8 + g >>= 8 + b >>= 8 + 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 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") + } + } + + // Write the IMAGE. + io.WriteString(w, "IMAGE {\n pixels hex\n") + for y := bounds.Min.Y; y < bounds.Max.Y; y++ { + switch { + case cm == image.GrayColorModel: + for x := bounds.Min.X; x < bounds.Max.X; x++ { + gray := png.At(x, y).(image.GrayColor) + fmt.Fprintf(w, "%02x", gray.Y) + } + case cm == image.Gray16ColorModel: + for x := bounds.Min.X; x < bounds.Max.X; x++ { + gray16 := png.At(x, y).(image.Gray16Color) + fmt.Fprintf(w, "%04x ", gray16.Y) + } + case cm == image.RGBAColorModel: + for x := bounds.Min.X; x < bounds.Max.X; x++ { + rgba := png.At(x, y).(image.RGBAColor) + fmt.Fprintf(w, "%02x%02x%02x ", rgba.R, rgba.G, rgba.B) + } + case cm == image.RGBA64ColorModel: + for x := bounds.Min.X; x < bounds.Max.X; x++ { + rgba64 := png.At(x, y).(image.RGBA64Color) + fmt.Fprintf(w, "%04x%04x%04x ", rgba64.R, rgba64.G, rgba64.B) + } + case cm == image.NRGBAColorModel: + for x := bounds.Min.X; x < bounds.Max.X; x++ { + nrgba := png.At(x, y).(image.NRGBAColor) + fmt.Fprintf(w, "%02x%02x%02x%02x ", nrgba.R, nrgba.G, nrgba.B, nrgba.A) + } + case cm == image.NRGBA64ColorModel: + for x := bounds.Min.X; x < bounds.Max.X; x++ { + nrgba64 := png.At(x, y).(image.NRGBA64Color) + 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 + } + } + } + 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).(image.NRGBA64Color) + 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.NewReader(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.NewReader(sf) + if err != nil { + t.Error(fn, err) + continue + } + + // Compare the two, in SNG format, line by line. + for { + ps, perr := pb.ReadString('\n') + ss, serr := sb.ReadString('\n') + if perr == os.EOF && serr == os.EOF { + break + } + if perr != nil { + t.Error(fn, perr) + break + } + if serr != nil { + t.Error(fn, serr) + break + } + if ps != ss { + t.Errorf("%s: Mismatch\n%sversus\n%s\n", fn, ps, ss) + break + } + } + } +} |