Support 411 and 410 subsampling rations for go1.5+
This commit is contained in:
Charlie Vieth
Jan Schlicht
parent
874f89dba4
commit
14554cc7da
402
ycc.go
402
ycc.go
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@ -88,70 +88,34 @@ func newYCC(r image.Rectangle, s image.YCbCrSubsampleRatio) *ycc {
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return &ycc{Pix: buf, Stride: 3 * w, Rect: r, SubsampleRatio: s}
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}
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// Copy of image.YCbCrSubsampleRatio constants - this allows us to support
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// older versions of Go where these constants are not defined (i.e. Go 1.4)
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const (
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ycbcrSubsampleRatio444 image.YCbCrSubsampleRatio = iota
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ycbcrSubsampleRatio422
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ycbcrSubsampleRatio420
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ycbcrSubsampleRatio440
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ycbcrSubsampleRatio411
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ycbcrSubsampleRatio410
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)
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// YCbCr converts ycc to a YCbCr image with the same subsample ratio
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// as the YCbCr image that ycc was generated from.
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func (p *ycc) YCbCr() *image.YCbCr {
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ycbcr := image.NewYCbCr(p.Rect, p.SubsampleRatio)
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var off int
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switch ycbcr.SubsampleRatio {
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case image.YCbCrSubsampleRatio422:
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for y := ycbcr.Rect.Min.Y; y < ycbcr.Rect.Max.Y; y++ {
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yy := (y - ycbcr.Rect.Min.Y) * ycbcr.YStride
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cy := (y - ycbcr.Rect.Min.Y) * ycbcr.CStride
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for x := ycbcr.Rect.Min.X; x < ycbcr.Rect.Max.X; x++ {
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xx := (x - ycbcr.Rect.Min.X)
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yi := yy + xx
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ci := cy + xx/2
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ycbcr.Y[yi] = p.Pix[off+0]
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ycbcr.Cb[ci] = p.Pix[off+1]
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ycbcr.Cr[ci] = p.Pix[off+2]
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off += 3
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}
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}
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case image.YCbCrSubsampleRatio420:
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for y := ycbcr.Rect.Min.Y; y < ycbcr.Rect.Max.Y; y++ {
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yy := (y - ycbcr.Rect.Min.Y) * ycbcr.YStride
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cy := (y/2 - ycbcr.Rect.Min.Y/2) * ycbcr.CStride
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for x := ycbcr.Rect.Min.X; x < ycbcr.Rect.Max.X; x++ {
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xx := (x - ycbcr.Rect.Min.X)
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yi := yy + xx
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ci := cy + xx/2
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ycbcr.Y[yi] = p.Pix[off+0]
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ycbcr.Cb[ci] = p.Pix[off+1]
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ycbcr.Cr[ci] = p.Pix[off+2]
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off += 3
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}
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}
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case image.YCbCrSubsampleRatio440:
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for y := ycbcr.Rect.Min.Y; y < ycbcr.Rect.Max.Y; y++ {
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yy := (y - ycbcr.Rect.Min.Y) * ycbcr.YStride
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cy := (y/2 - ycbcr.Rect.Min.Y/2) * ycbcr.CStride
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for x := ycbcr.Rect.Min.X; x < ycbcr.Rect.Max.X; x++ {
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xx := (x - ycbcr.Rect.Min.X)
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yi := yy + xx
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ci := cy + xx
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ycbcr.Y[yi] = p.Pix[off+0]
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ycbcr.Cb[ci] = p.Pix[off+1]
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ycbcr.Cr[ci] = p.Pix[off+2]
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off += 3
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}
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}
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default:
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// Default to 4:4:4 subsampling.
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for y := ycbcr.Rect.Min.Y; y < ycbcr.Rect.Max.Y; y++ {
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yy := (y - ycbcr.Rect.Min.Y) * ycbcr.YStride
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cy := (y - ycbcr.Rect.Min.Y) * ycbcr.CStride
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for x := ycbcr.Rect.Min.X; x < ycbcr.Rect.Max.X; x++ {
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xx := (x - ycbcr.Rect.Min.X)
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yi := yy + xx
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ci := cy + xx
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ycbcr.Y[yi] = p.Pix[off+0]
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ycbcr.Cb[ci] = p.Pix[off+1]
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ycbcr.Cr[ci] = p.Pix[off+2]
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off += 3
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}
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}
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case ycbcrSubsampleRatio422:
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return p.ycbcr422(ycbcr)
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case ycbcrSubsampleRatio420:
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return p.ycbcr420(ycbcr)
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case ycbcrSubsampleRatio440:
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return p.ycbcr440(ycbcr)
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case ycbcrSubsampleRatio444:
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return p.ycbcr444(ycbcr)
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case ycbcrSubsampleRatio411:
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return p.ycbcr411(ycbcr)
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case ycbcrSubsampleRatio410:
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return p.ycbcr410(ycbcr)
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}
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return ycbcr
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}
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@ -159,69 +123,265 @@ func (p *ycc) YCbCr() *image.YCbCr {
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// imageYCbCrToYCC converts a YCbCr image to a ycc image for resizing.
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func imageYCbCrToYCC(in *image.YCbCr) *ycc {
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w, h := in.Rect.Dx(), in.Rect.Dy()
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r := image.Rect(0, 0, w, h)
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buf := make([]uint8, 3*w*h)
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p := ycc{Pix: buf, Stride: 3 * w, Rect: r, SubsampleRatio: in.SubsampleRatio}
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var off int
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p := ycc{
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Pix: make([]uint8, 3*w*h),
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Stride: 3 * w,
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Rect: image.Rect(0, 0, w, h),
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SubsampleRatio: in.SubsampleRatio,
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}
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switch in.SubsampleRatio {
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case image.YCbCrSubsampleRatio422:
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for y := in.Rect.Min.Y; y < in.Rect.Max.Y; y++ {
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yy := (y - in.Rect.Min.Y) * in.YStride
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cy := (y - in.Rect.Min.Y) * in.CStride
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for x := in.Rect.Min.X; x < in.Rect.Max.X; x++ {
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xx := (x - in.Rect.Min.X)
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yi := yy + xx
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ci := cy + xx/2
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p.Pix[off+0] = in.Y[yi]
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p.Pix[off+1] = in.Cb[ci]
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p.Pix[off+2] = in.Cr[ci]
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off += 3
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}
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}
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case image.YCbCrSubsampleRatio420:
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for y := in.Rect.Min.Y; y < in.Rect.Max.Y; y++ {
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yy := (y - in.Rect.Min.Y) * in.YStride
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cy := (y/2 - in.Rect.Min.Y/2) * in.CStride
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for x := in.Rect.Min.X; x < in.Rect.Max.X; x++ {
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xx := (x - in.Rect.Min.X)
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yi := yy + xx
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ci := cy + xx/2
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p.Pix[off+0] = in.Y[yi]
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p.Pix[off+1] = in.Cb[ci]
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p.Pix[off+2] = in.Cr[ci]
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off += 3
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}
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}
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case image.YCbCrSubsampleRatio440:
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for y := in.Rect.Min.Y; y < in.Rect.Max.Y; y++ {
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yy := (y - in.Rect.Min.Y) * in.YStride
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cy := (y/2 - in.Rect.Min.Y/2) * in.CStride
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for x := in.Rect.Min.X; x < in.Rect.Max.X; x++ {
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xx := (x - in.Rect.Min.X)
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yi := yy + xx
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ci := cy + xx
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p.Pix[off+0] = in.Y[yi]
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p.Pix[off+1] = in.Cb[ci]
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p.Pix[off+2] = in.Cr[ci]
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off += 3
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}
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}
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default:
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// Default to 4:4:4 subsampling.
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for y := in.Rect.Min.Y; y < in.Rect.Max.Y; y++ {
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yy := (y - in.Rect.Min.Y) * in.YStride
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cy := (y - in.Rect.Min.Y) * in.CStride
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for x := in.Rect.Min.X; x < in.Rect.Max.X; x++ {
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xx := (x - in.Rect.Min.X)
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yi := yy + xx
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ci := cy + xx
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p.Pix[off+0] = in.Y[yi]
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p.Pix[off+1] = in.Cb[ci]
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p.Pix[off+2] = in.Cr[ci]
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off += 3
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}
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}
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case ycbcrSubsampleRatio422:
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return convertToYCC422(in, &p)
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case ycbcrSubsampleRatio420:
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return convertToYCC420(in, &p)
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case ycbcrSubsampleRatio440:
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return convertToYCC440(in, &p)
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case ycbcrSubsampleRatio444:
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return convertToYCC444(in, &p)
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case ycbcrSubsampleRatio411:
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return convertToYCC411(in, &p)
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case ycbcrSubsampleRatio410:
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return convertToYCC410(in, &p)
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}
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return &p
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}
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func (p *ycc) ycbcr422(ycbcr *image.YCbCr) *image.YCbCr {
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var off int
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Pix := p.Pix
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Y := ycbcr.Y
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Cb := ycbcr.Cb
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Cr := ycbcr.Cr
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for y := 0; y < ycbcr.Rect.Max.Y-ycbcr.Rect.Min.Y; y++ {
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yy := y * ycbcr.YStride
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cy := y * ycbcr.CStride
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for x := 0; x < ycbcr.Rect.Max.X-ycbcr.Rect.Min.X; x++ {
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ci := cy + x/2
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Y[yy+x] = Pix[off+0]
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Cb[ci] = Pix[off+1]
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Cr[ci] = Pix[off+2]
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off += 3
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}
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}
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return ycbcr
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}
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func (p *ycc) ycbcr420(ycbcr *image.YCbCr) *image.YCbCr {
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var off int
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Pix := p.Pix
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Y := ycbcr.Y
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Cb := ycbcr.Cb
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Cr := ycbcr.Cr
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for y := 0; y < ycbcr.Rect.Max.Y-ycbcr.Rect.Min.Y; y++ {
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yy := y * ycbcr.YStride
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cy := (y / 2) * ycbcr.CStride
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for x := 0; x < ycbcr.Rect.Max.X-ycbcr.Rect.Min.X; x++ {
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ci := cy + x/2
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Y[yy+x] = Pix[off+0]
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Cb[ci] = Pix[off+1]
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Cr[ci] = Pix[off+2]
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off += 3
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}
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}
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return ycbcr
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}
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func (p *ycc) ycbcr440(ycbcr *image.YCbCr) *image.YCbCr {
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var off int
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Pix := p.Pix
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Y := ycbcr.Y
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Cb := ycbcr.Cb
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Cr := ycbcr.Cr
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for y := 0; y < ycbcr.Rect.Max.Y-ycbcr.Rect.Min.Y; y++ {
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yy := y * ycbcr.YStride
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cy := (y / 2) * ycbcr.CStride
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for x := 0; x < ycbcr.Rect.Max.X-ycbcr.Rect.Min.X; x++ {
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ci := cy + x
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Y[yy+x] = Pix[off+0]
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Cb[ci] = Pix[off+1]
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Cr[ci] = Pix[off+2]
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off += 3
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}
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}
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return ycbcr
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}
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func (p *ycc) ycbcr444(ycbcr *image.YCbCr) *image.YCbCr {
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var off int
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Pix := p.Pix
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Y := ycbcr.Y
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Cb := ycbcr.Cb
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Cr := ycbcr.Cr
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for y := 0; y < ycbcr.Rect.Max.Y-ycbcr.Rect.Min.Y; y++ {
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yy := y * ycbcr.YStride
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cy := y * ycbcr.CStride
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for x := 0; x < ycbcr.Rect.Max.X-ycbcr.Rect.Min.X; x++ {
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ci := cy + x
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Y[yy+x] = Pix[off+0]
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Cb[ci] = Pix[off+1]
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Cr[ci] = Pix[off+2]
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off += 3
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}
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}
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return ycbcr
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}
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func (p *ycc) ycbcr411(ycbcr *image.YCbCr) *image.YCbCr {
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var off int
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Pix := p.Pix
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Y := ycbcr.Y
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Cb := ycbcr.Cb
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Cr := ycbcr.Cr
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for y := 0; y < ycbcr.Rect.Max.Y-ycbcr.Rect.Min.Y; y++ {
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yy := y * ycbcr.YStride
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cy := y * ycbcr.CStride
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for x := 0; x < ycbcr.Rect.Max.X-ycbcr.Rect.Min.X; x++ {
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ci := cy + x/4
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Y[yy+x] = Pix[off+0]
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Cb[ci] = Pix[off+1]
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Cr[ci] = Pix[off+2]
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off += 3
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}
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}
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return ycbcr
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}
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func (p *ycc) ycbcr410(ycbcr *image.YCbCr) *image.YCbCr {
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var off int
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Pix := p.Pix
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Y := ycbcr.Y
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Cb := ycbcr.Cb
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Cr := ycbcr.Cr
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for y := 0; y < ycbcr.Rect.Max.Y-ycbcr.Rect.Min.Y; y++ {
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yy := y * ycbcr.YStride
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cy := (y / 2) * ycbcr.CStride
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for x := 0; x < ycbcr.Rect.Max.X-ycbcr.Rect.Min.X; x++ {
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ci := cy + x/4
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Y[yy+x] = Pix[off+0]
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Cb[ci] = Pix[off+1]
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Cr[ci] = Pix[off+2]
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off += 3
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}
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}
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return ycbcr
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}
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func convertToYCC422(in *image.YCbCr, p *ycc) *ycc {
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var off int
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Pix := p.Pix
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Y := in.Y
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Cb := in.Cb
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Cr := in.Cr
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for y := 0; y < in.Rect.Max.Y-in.Rect.Min.Y; y++ {
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yy := y * in.YStride
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cy := y * in.CStride
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for x := 0; x < in.Rect.Max.X-in.Rect.Min.X; x++ {
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ci := cy + x/2
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Pix[off+0] = Y[yy+x]
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Pix[off+1] = Cb[ci]
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Pix[off+2] = Cr[ci]
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off += 3
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}
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}
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return p
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}
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func convertToYCC420(in *image.YCbCr, p *ycc) *ycc {
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var off int
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Pix := p.Pix
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Y := in.Y
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Cb := in.Cb
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Cr := in.Cr
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for y := 0; y < in.Rect.Max.Y-in.Rect.Min.Y; y++ {
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yy := y * in.YStride
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cy := (y / 2) * in.CStride
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for x := 0; x < in.Rect.Max.X-in.Rect.Min.X; x++ {
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ci := cy + x/2
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Pix[off+0] = Y[yy+x]
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Pix[off+1] = Cb[ci]
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Pix[off+2] = Cr[ci]
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off += 3
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}
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}
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return p
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}
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func convertToYCC440(in *image.YCbCr, p *ycc) *ycc {
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var off int
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Pix := p.Pix
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Y := in.Y
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Cb := in.Cb
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Cr := in.Cr
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for y := 0; y < in.Rect.Max.Y-in.Rect.Min.Y; y++ {
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yy := y * in.YStride
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cy := (y / 2) * in.CStride
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for x := 0; x < in.Rect.Max.X-in.Rect.Min.X; x++ {
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ci := cy + x
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Pix[off+0] = Y[yy+x]
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Pix[off+1] = Cb[ci]
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Pix[off+2] = Cr[ci]
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off += 3
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}
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}
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return p
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}
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func convertToYCC444(in *image.YCbCr, p *ycc) *ycc {
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var off int
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Pix := p.Pix
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Y := in.Y
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Cb := in.Cb
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Cr := in.Cr
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for y := 0; y < in.Rect.Max.Y-in.Rect.Min.Y; y++ {
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yy := y * in.YStride
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cy := y * in.CStride
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for x := 0; x < in.Rect.Max.X-in.Rect.Min.X; x++ {
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ci := cy + x
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Pix[off+0] = Y[yy+x]
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Pix[off+1] = Cb[ci]
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Pix[off+2] = Cr[ci]
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off += 3
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}
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}
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return p
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}
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func convertToYCC411(in *image.YCbCr, p *ycc) *ycc {
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var off int
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Pix := p.Pix
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Y := in.Y
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Cb := in.Cb
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Cr := in.Cr
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for y := 0; y < in.Rect.Max.Y-in.Rect.Min.Y; y++ {
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yy := y * in.YStride
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cy := y * in.CStride
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for x := 0; x < in.Rect.Max.X-in.Rect.Min.X; x++ {
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ci := cy + x/4
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Pix[off+0] = Y[yy+x]
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Pix[off+1] = Cb[ci]
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Pix[off+2] = Cr[ci]
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off += 3
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}
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}
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return p
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}
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func convertToYCC410(in *image.YCbCr, p *ycc) *ycc {
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var off int
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Pix := p.Pix
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Y := in.Y
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Cb := in.Cb
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Cr := in.Cr
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for y := 0; y < in.Rect.Max.Y-in.Rect.Min.Y; y++ {
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yy := y * in.YStride
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cy := (y / 2) * in.CStride
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for x := 0; x < in.Rect.Max.X-in.Rect.Min.X; x++ {
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||||
ci := cy + x/4
|
||||
Pix[off+0] = Y[yy+x]
|
||||
Pix[off+1] = Cb[ci]
|
||||
Pix[off+2] = Cr[ci]
|
||||
off += 3
|
||||
}
|
||||
}
|
||||
return p
|
||||
}
|
||||
|
|
|
|||
|
|
@ -1,3 +1,5 @@
|
|||
// +build go1.5
|
||||
|
||||
/*
|
||||
Copyright (c) 2014, Charlie Vieth <charlie.vieth@gmail.com>
|
||||
|
||||
|
|
@ -33,6 +35,8 @@ func TestImage(t *testing.T) {
|
|||
newYCC(image.Rect(0, 0, 10, 10), image.YCbCrSubsampleRatio422),
|
||||
newYCC(image.Rect(0, 0, 10, 10), image.YCbCrSubsampleRatio440),
|
||||
newYCC(image.Rect(0, 0, 10, 10), image.YCbCrSubsampleRatio444),
|
||||
newYCC(image.Rect(0, 0, 10, 10), image.YCbCrSubsampleRatio411),
|
||||
newYCC(image.Rect(0, 0, 10, 10), image.YCbCrSubsampleRatio410),
|
||||
}
|
||||
for _, m := range testImage {
|
||||
if !image.Rect(0, 0, 10, 10).Eq(m.Bounds()) {
|
||||
|
|
@ -60,8 +64,9 @@ func TestConvertYCbCr(t *testing.T) {
|
|||
image.NewYCbCr(image.Rect(0, 0, 50, 50), image.YCbCrSubsampleRatio422),
|
||||
image.NewYCbCr(image.Rect(0, 0, 50, 50), image.YCbCrSubsampleRatio440),
|
||||
image.NewYCbCr(image.Rect(0, 0, 50, 50), image.YCbCrSubsampleRatio444),
|
||||
image.NewYCbCr(image.Rect(0, 0, 10, 10), image.YCbCrSubsampleRatio411),
|
||||
image.NewYCbCr(image.Rect(0, 0, 10, 10), image.YCbCrSubsampleRatio410),
|
||||
}
|
||||
|
||||
for _, img := range testImage {
|
||||
m := img.(*image.YCbCr)
|
||||
for y := m.Rect.Min.Y; y < m.Rect.Max.Y; y++ {
|
||||
|
|
|
|||
Loading…
Reference in New Issue
Block a user