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Diffstat (limited to 'src/image/ycbcr_test.go')
-rw-r--r-- | src/image/ycbcr_test.go | 133 |
1 files changed, 133 insertions, 0 deletions
diff --git a/src/image/ycbcr_test.go b/src/image/ycbcr_test.go new file mode 100644 index 0000000..4996bc8 --- /dev/null +++ b/src/image/ycbcr_test.go @@ -0,0 +1,133 @@ +// 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, + YCbCrSubsampleRatio411, + YCbCrSubsampleRatio410, + } + 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) + } + } + } +} |