| // Copyright 2012 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 image |
| |
| import ( |
| "image/color" |
| "testing" |
| ) |
| |
| func TestYCbCr(t *testing.T) { |
| rects := []Rectangle{ |
| Rect(0, 0, 16, 16), |
| Rect(1, 0, 16, 16), |
| Rect(0, 1, 16, 16), |
| Rect(1, 1, 16, 16), |
| Rect(1, 1, 15, 16), |
| Rect(1, 1, 16, 15), |
| Rect(1, 1, 15, 15), |
| Rect(2, 3, 14, 15), |
| Rect(7, 0, 7, 16), |
| Rect(0, 8, 16, 8), |
| Rect(0, 0, 10, 11), |
| Rect(5, 6, 16, 16), |
| Rect(7, 7, 8, 8), |
| Rect(7, 8, 8, 9), |
| Rect(8, 7, 9, 8), |
| Rect(8, 8, 9, 9), |
| Rect(7, 7, 17, 17), |
| Rect(8, 8, 17, 17), |
| Rect(9, 9, 17, 17), |
| Rect(10, 10, 17, 17), |
| } |
| subsampleRatios := []YCbCrSubsampleRatio{ |
| YCbCrSubsampleRatio444, |
| YCbCrSubsampleRatio422, |
| YCbCrSubsampleRatio420, |
| YCbCrSubsampleRatio440, |
| } |
| deltas := []Point{ |
| Pt(0, 0), |
| Pt(1000, 1001), |
| Pt(5001, -400), |
| Pt(-701, -801), |
| } |
| for _, r := range rects { |
| for _, subsampleRatio := range subsampleRatios { |
| for _, delta := range deltas { |
| testYCbCr(t, r, subsampleRatio, delta) |
| } |
| } |
| if testing.Short() { |
| break |
| } |
| } |
| } |
| |
| func testYCbCr(t *testing.T, r Rectangle, subsampleRatio YCbCrSubsampleRatio, delta Point) { |
| // Create a YCbCr image m, whose bounds are r translated by (delta.X, delta.Y). |
| r1 := r.Add(delta) |
| m := NewYCbCr(r1, subsampleRatio) |
| |
| // Test that the image buffer is reasonably small even if (delta.X, delta.Y) is far from the origin. |
| if len(m.Y) > 100*100 { |
| t.Errorf("r=%v, subsampleRatio=%v, delta=%v: image buffer is too large", |
| r, subsampleRatio, delta) |
| return |
| } |
| |
| // Initialize m's pixels. For 422 and 420 subsampling, some of the Cb and Cr elements |
| // will be set multiple times. That's OK. We just want to avoid a uniform image. |
| for y := r1.Min.Y; y < r1.Max.Y; y++ { |
| for x := r1.Min.X; x < r1.Max.X; x++ { |
| yi := m.YOffset(x, y) |
| ci := m.COffset(x, y) |
| m.Y[yi] = uint8(16*y + x) |
| m.Cb[ci] = uint8(y + 16*x) |
| m.Cr[ci] = uint8(y + 16*x) |
| } |
| } |
| |
| // Make various sub-images of m. |
| for y0 := delta.Y + 3; y0 < delta.Y+7; y0++ { |
| for y1 := delta.Y + 8; y1 < delta.Y+13; y1++ { |
| for x0 := delta.X + 3; x0 < delta.X+7; x0++ { |
| for x1 := delta.X + 8; x1 < delta.X+13; x1++ { |
| subRect := Rect(x0, y0, x1, y1) |
| sub := m.SubImage(subRect).(*YCbCr) |
| |
| // For each point in the sub-image's bounds, check that m.At(x, y) equals sub.At(x, y). |
| for y := sub.Rect.Min.Y; y < sub.Rect.Max.Y; y++ { |
| for x := sub.Rect.Min.X; x < sub.Rect.Max.X; x++ { |
| color0 := m.At(x, y).(color.YCbCr) |
| color1 := sub.At(x, y).(color.YCbCr) |
| if color0 != color1 { |
| t.Errorf("r=%v, subsampleRatio=%v, delta=%v, x=%d, y=%d, color0=%v, color1=%v", |
| r, subsampleRatio, delta, x, y, color0, color1) |
| return |
| } |
| } |
| } |
| } |
| } |
| } |
| } |
| } |
| |
| func TestYCbCrSlicesDontOverlap(t *testing.T) { |
| m := NewYCbCr(Rect(0, 0, 8, 8), YCbCrSubsampleRatio420) |
| names := []string{"Y", "Cb", "Cr"} |
| slices := [][]byte{ |
| m.Y[:cap(m.Y)], |
| m.Cb[:cap(m.Cb)], |
| m.Cr[:cap(m.Cr)], |
| } |
| for i, slice := range slices { |
| want := uint8(10 + i) |
| for j := range slice { |
| slice[j] = want |
| } |
| } |
| for i, slice := range slices { |
| want := uint8(10 + i) |
| for j, got := range slice { |
| if got != want { |
| t.Fatalf("m.%s[%d]: got %d, want %d", names[i], j, got, want) |
| } |
| } |
| } |
| } |