diff options
Diffstat (limited to 'src/image/png/writer_test.go')
-rw-r--r-- | src/image/png/writer_test.go | 210 |
1 files changed, 210 insertions, 0 deletions
diff --git a/src/image/png/writer_test.go b/src/image/png/writer_test.go new file mode 100644 index 000000000..d67a81569 --- /dev/null +++ b/src/image/png/writer_test.go @@ -0,0 +1,210 @@ +// 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 ( + "bytes" + "fmt" + "image" + "image/color" + "io/ioutil" + "testing" +) + +func diff(m0, m1 image.Image) error { + b0, b1 := m0.Bounds(), m1.Bounds() + if !b0.Size().Eq(b1.Size()) { + return fmt.Errorf("dimensions differ: %v vs %v", b0, b1) + } + dx := b1.Min.X - b0.Min.X + dy := b1.Min.Y - b0.Min.Y + for y := b0.Min.Y; y < b0.Max.Y; y++ { + for x := b0.Min.X; x < b0.Max.X; x++ { + c0 := m0.At(x, y) + c1 := m1.At(x+dx, y+dy) + r0, g0, b0, a0 := c0.RGBA() + r1, g1, b1, a1 := c1.RGBA() + if r0 != r1 || g0 != g1 || b0 != b1 || a0 != a1 { + return fmt.Errorf("colors differ at (%d, %d): %v vs %v", x, y, c0, c1) + } + } + } + return nil +} + +func encodeDecode(m image.Image) (image.Image, error) { + var b bytes.Buffer + err := Encode(&b, m) + if err != nil { + return nil, err + } + return Decode(&b) +} + +func TestWriter(t *testing.T) { + // The filenames variable is declared in reader_test.go. + names := filenames + if testing.Short() { + names = filenamesShort + } + for _, fn := range names { + qfn := "testdata/pngsuite/" + fn + ".png" + // Read the image. + m0, err := readPNG(qfn) + if err != nil { + t.Error(fn, err) + continue + } + // Read the image again, encode it, and decode it. + m1, err := readPNG(qfn) + if err != nil { + t.Error(fn, err) + return + } + m2, err := encodeDecode(m1) + if err != nil { + t.Error(fn, err) + return + } + // Compare the two. + err = diff(m0, m2) + if err != nil { + t.Error(fn, err) + continue + } + } +} + +func TestWriterLevels(t *testing.T) { + m := image.NewNRGBA(image.Rect(0, 0, 100, 100)) + + var b1, b2 bytes.Buffer + if err := (&Encoder{}).Encode(&b1, m); err != nil { + t.Fatal(err) + } + noenc := &Encoder{CompressionLevel: NoCompression} + if err := noenc.Encode(&b2, m); err != nil { + t.Fatal(err) + } + + if b2.Len() <= b1.Len() { + t.Error("DefaultCompression encoding was larger than NoCompression encoding") + } + if _, err := Decode(&b1); err != nil { + t.Error("cannot decode DefaultCompression") + } + if _, err := Decode(&b2); err != nil { + t.Error("cannot decode NoCompression") + } +} + +func TestSubImage(t *testing.T) { + m0 := image.NewRGBA(image.Rect(0, 0, 256, 256)) + for y := 0; y < 256; y++ { + for x := 0; x < 256; x++ { + m0.Set(x, y, color.RGBA{uint8(x), uint8(y), 0, 255}) + } + } + m0 = m0.SubImage(image.Rect(50, 30, 250, 130)).(*image.RGBA) + m1, err := encodeDecode(m0) + if err != nil { + t.Error(err) + return + } + err = diff(m0, m1) + if err != nil { + t.Error(err) + return + } +} + +func BenchmarkEncodeGray(b *testing.B) { + b.StopTimer() + img := image.NewGray(image.Rect(0, 0, 640, 480)) + b.SetBytes(640 * 480 * 1) + b.StartTimer() + for i := 0; i < b.N; i++ { + Encode(ioutil.Discard, img) + } +} + +func BenchmarkEncodeNRGBOpaque(b *testing.B) { + b.StopTimer() + img := image.NewNRGBA(image.Rect(0, 0, 640, 480)) + // Set all pixels to 0xFF alpha to force opaque mode. + bo := img.Bounds() + for y := bo.Min.Y; y < bo.Max.Y; y++ { + for x := bo.Min.X; x < bo.Max.X; x++ { + img.Set(x, y, color.NRGBA{0, 0, 0, 255}) + } + } + if !img.Opaque() { + b.Fatal("expected image to be opaque") + } + b.SetBytes(640 * 480 * 4) + b.StartTimer() + for i := 0; i < b.N; i++ { + Encode(ioutil.Discard, img) + } +} + +func BenchmarkEncodeNRGBA(b *testing.B) { + b.StopTimer() + img := image.NewNRGBA(image.Rect(0, 0, 640, 480)) + if img.Opaque() { + b.Fatal("expected image not to be opaque") + } + b.SetBytes(640 * 480 * 4) + b.StartTimer() + for i := 0; i < b.N; i++ { + Encode(ioutil.Discard, img) + } +} + +func BenchmarkEncodePaletted(b *testing.B) { + b.StopTimer() + img := image.NewPaletted(image.Rect(0, 0, 640, 480), color.Palette{ + color.RGBA{0, 0, 0, 255}, + color.RGBA{255, 255, 255, 255}, + }) + b.SetBytes(640 * 480 * 1) + b.StartTimer() + for i := 0; i < b.N; i++ { + Encode(ioutil.Discard, img) + } +} + +func BenchmarkEncodeRGBOpaque(b *testing.B) { + b.StopTimer() + img := image.NewRGBA(image.Rect(0, 0, 640, 480)) + // Set all pixels to 0xFF alpha to force opaque mode. + bo := img.Bounds() + for y := bo.Min.Y; y < bo.Max.Y; y++ { + for x := bo.Min.X; x < bo.Max.X; x++ { + img.Set(x, y, color.RGBA{0, 0, 0, 255}) + } + } + if !img.Opaque() { + b.Fatal("expected image to be opaque") + } + b.SetBytes(640 * 480 * 4) + b.StartTimer() + for i := 0; i < b.N; i++ { + Encode(ioutil.Discard, img) + } +} + +func BenchmarkEncodeRGBA(b *testing.B) { + b.StopTimer() + img := image.NewRGBA(image.Rect(0, 0, 640, 480)) + if img.Opaque() { + b.Fatal("expected image not to be opaque") + } + b.SetBytes(640 * 480 * 4) + b.StartTimer() + for i := 0; i < b.N; i++ { + Encode(ioutil.Discard, img) + } +} |