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 // Grayscale images. 40 {"testdata/video-005.gray.png", "testdata/video-005.gray.jpeg", 8 << 8}, 41 {"testdata/video-005.gray.png", "testdata/video-005.gray.png", 0}, 42 } 43 44 func decode(filename string) (image.Image, string, error) { 45 f, err := os.Open(filename) 46 if err != nil { 47 return nil, "", err 48 } 49 defer f.Close() 50 return image.Decode(bufio.NewReader(f)) 51 } 52 53 func decodeConfig(filename string) (image.Config, string, error) { 54 f, err := os.Open(filename) 55 if err != nil { 56 return image.Config{}, "", err 57 } 58 defer f.Close() 59 return image.DecodeConfig(bufio.NewReader(f)) 60 } 61 62 func delta(u0, u1 uint32) int { 63 d := int(u0) - int(u1) 64 if d < 0 { 65 return -d 66 } 67 return d 68 } 69 70 func withinTolerance(c0, c1 color.Color, tolerance int) bool { 71 r0, g0, b0, a0 := c0.RGBA() 72 r1, g1, b1, a1 := c1.RGBA() 73 r := delta(r0, r1) 74 g := delta(g0, g1) 75 b := delta(b0, b1) 76 a := delta(a0, a1) 77 return r <= tolerance && g <= tolerance && b <= tolerance && a <= tolerance 78 } 79 80 func TestDecode(t *testing.T) { 81 rgba := func(c color.Color) string { 82 r, g, b, a := c.RGBA() 83 return fmt.Sprintf("rgba = 0x%04x, 0x%04x, 0x%04x, 0x%04x for %T%v", r, g, b, a, c, c) 84 } 85 86 golden := make(map[string]image.Image) 87 loop: 88 for _, it := range imageTests { 89 g := golden[it.goldenFilename] 90 if g == nil { 91 var err error 92 g, _, err = decode(it.goldenFilename) 93 if err != nil { 94 t.Errorf("%s: %v", it.goldenFilename, err) 95 continue loop 96 } 97 golden[it.goldenFilename] = g 98 } 99 m, imageFormat, err := decode(it.filename) 100 if err != nil { 101 t.Errorf("%s: %v", it.filename, err) 102 continue loop 103 } 104 b := g.Bounds() 105 if !b.Eq(m.Bounds()) { 106 t.Errorf("%s: got bounds %v want %v", it.filename, m.Bounds(), b) 107 continue loop 108 } 109 for y := b.Min.Y; y < b.Max.Y; y++ { 110 for x := b.Min.X; x < b.Max.X; x++ { 111 if !withinTolerance(g.At(x, y), m.At(x, y), it.tolerance) { 112 t.Errorf("%s: at (%d, %d):\ngot %v\nwant %v", 113 it.filename, x, y, rgba(m.At(x, y)), rgba(g.At(x, y))) 114 continue loop 115 } 116 } 117 } 118 if imageFormat == "gif" { 119 // Each frame of a GIF can have a frame-local palette override the 120 // GIF-global palette. Thus, image.Decode can yield a different ColorModel 121 // than image.DecodeConfig. 122 continue 123 } 124 c, _, err := decodeConfig(it.filename) 125 if m.ColorModel() != c.ColorModel { 126 t.Errorf("%s: color models differ", it.filename) 127 continue loop 128 } 129 } 130 } 131
