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// 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)
}
}
}
}
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