1 // Copyright 2011 The Go Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style 3 // license that can be found in the LICENSE file. 4 5 package image_test 6 7 import ( 8 "bufio" 9 "fmt" 10 "image" 11 "image/color" 12 "os" 13 "testing" 14 15 _ "image/gif" 16 _ "image/jpeg" 17 _ "image/png" 18 ) 19 20 type imageTest struct { 21 goldenFilename string 22 filename string 23 tolerance int 24 } 25 26 var imageTests = []imageTest{ 27 {"testdata/video-001.png", "testdata/video-001.png", 0}, 28 // GIF images are restricted to a 256-color palette and the conversion 29 // to GIF loses significant image quality. 30 {"testdata/video-001.png", "testdata/video-001.gif", 64 << 8}, 31 {"testdata/video-001.png", "testdata/video-001.interlaced.gif", 64 << 8}, 32 {"testdata/video-001.png", "testdata/video-001.5bpp.gif", 128 << 8}, 33 // JPEG is a lossy format and hence needs a non-zero tolerance. 34 {"testdata/video-001.png", "testdata/video-001.jpeg", 8 << 8}, 35 {"testdata/video-001.png", "testdata/video-001.progressive.jpeg", 8 << 8}, 36 {"testdata/video-001.221212.png", "testdata/video-001.221212.jpeg", 8 << 8}, 37 {"testdata/video-001.cmyk.png", "testdata/video-001.cmyk.jpeg", 8 << 8}, 38 {"testdata/video-001.rgb.png", "testdata/video-001.rgb.jpeg", 8 << 8}, 39 {"testdata/video-001.progressive.truncated.png", "testdata/video-001.progressive.truncated.jpeg", 8 << 8}, 40 // Grayscale images. 41 {"testdata/video-005.gray.png", "testdata/video-005.gray.jpeg", 8 << 8}, 42 {"testdata/video-005.gray.png", "testdata/video-005.gray.png", 0}, 43 } 44 45 func decode(filename string) (image.Image, string, error) { 46 f, err := os.Open(filename) 47 if err != nil { 48 return nil, "", err 49 } 50 defer f.Close() 51 return image.Decode(bufio.NewReader(f)) 52 } 53 54 func decodeConfig(filename string) (image.Config, string, error) { 55 f, err := os.Open(filename) 56 if err != nil { 57 return image.Config{}, "", err 58 } 59 defer f.Close() 60 return image.DecodeConfig(bufio.NewReader(f)) 61 } 62 63 func delta(u0, u1 uint32) int { 64 d := int(u0) - int(u1) 65 if d < 0 { 66 return -d 67 } 68 return d 69 } 70 71 func withinTolerance(c0, c1 color.Color, tolerance int) bool { 72 r0, g0, b0, a0 := c0.RGBA() 73 r1, g1, b1, a1 := c1.RGBA() 74 r := delta(r0, r1) 75 g := delta(g0, g1) 76 b := delta(b0, b1) 77 a := delta(a0, a1) 78 return r <= tolerance && g <= tolerance && b <= tolerance && a <= tolerance 79 } 80 81 func TestDecode(t *testing.T) { 82 rgba := func(c color.Color) string { 83 r, g, b, a := c.RGBA() 84 return fmt.Sprintf("rgba = 0x%04x, 0x%04x, 0x%04x, 0x%04x for %T%v", r, g, b, a, c, c) 85 } 86 87 golden := make(map[string]image.Image) 88 loop: 89 for _, it := range imageTests { 90 g := golden[it.goldenFilename] 91 if g == nil { 92 var err error 93 g, _, err = decode(it.goldenFilename) 94 if err != nil { 95 t.Errorf("%s: %v", it.goldenFilename, err) 96 continue loop 97 } 98 golden[it.goldenFilename] = g 99 } 100 m, imageFormat, err := decode(it.filename) 101 if err != nil { 102 t.Errorf("%s: %v", it.filename, err) 103 continue loop 104 } 105 b := g.Bounds() 106 if !b.Eq(m.Bounds()) { 107 t.Errorf("%s: got bounds %v want %v", it.filename, m.Bounds(), b) 108 continue loop 109 } 110 for y := b.Min.Y; y < b.Max.Y; y++ { 111 for x := b.Min.X; x < b.Max.X; x++ { 112 if !withinTolerance(g.At(x, y), m.At(x, y), it.tolerance) { 113 t.Errorf("%s: at (%d, %d):\ngot %v\nwant %v", 114 it.filename, x, y, rgba(m.At(x, y)), rgba(g.At(x, y))) 115 continue loop 116 } 117 } 118 } 119 if imageFormat == "gif" { 120 // Each frame of a GIF can have a frame-local palette override the 121 // GIF-global palette. Thus, image.Decode can yield a different ColorModel 122 // than image.DecodeConfig. 123 continue 124 } 125 c, _, err := decodeConfig(it.filename) 126 if m.ColorModel() != c.ColorModel { 127 t.Errorf("%s: color models differ", it.filename) 128 continue loop 129 } 130 } 131 } 132
