Subversion Repositories openrisc

// 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_test

import (
        . "image"
        "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,
        }
        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)
                        }
                }
        }
}

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
                                                        }
                                                }
                                        }
                                }
                        }
                }
        }
}