// 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) } } } }