Support 411 and 410 subsampling rations for go1.5+

This commit is contained in:
Charlie Vieth 2015-10-04 23:59:20 -04:00 committed by Jan Schlicht
parent 874f89dba4
commit 14554cc7da
2 changed files with 287 additions and 122 deletions

402
ycc.go
View File

@ -88,70 +88,34 @@ func newYCC(r image.Rectangle, s image.YCbCrSubsampleRatio) *ycc {
return &ycc{Pix: buf, Stride: 3 * w, Rect: r, SubsampleRatio: s} return &ycc{Pix: buf, Stride: 3 * w, Rect: r, SubsampleRatio: s}
} }
// Copy of image.YCbCrSubsampleRatio constants - this allows us to support
// older versions of Go where these constants are not defined (i.e. Go 1.4)
const (
ycbcrSubsampleRatio444 image.YCbCrSubsampleRatio = iota
ycbcrSubsampleRatio422
ycbcrSubsampleRatio420
ycbcrSubsampleRatio440
ycbcrSubsampleRatio411
ycbcrSubsampleRatio410
)
// YCbCr converts ycc to a YCbCr image with the same subsample ratio // YCbCr converts ycc to a YCbCr image with the same subsample ratio
// as the YCbCr image that ycc was generated from. // as the YCbCr image that ycc was generated from.
func (p *ycc) YCbCr() *image.YCbCr { func (p *ycc) YCbCr() *image.YCbCr {
ycbcr := image.NewYCbCr(p.Rect, p.SubsampleRatio) ycbcr := image.NewYCbCr(p.Rect, p.SubsampleRatio)
var off int
switch ycbcr.SubsampleRatio { switch ycbcr.SubsampleRatio {
case image.YCbCrSubsampleRatio422: case ycbcrSubsampleRatio422:
for y := ycbcr.Rect.Min.Y; y < ycbcr.Rect.Max.Y; y++ { return p.ycbcr422(ycbcr)
yy := (y - ycbcr.Rect.Min.Y) * ycbcr.YStride case ycbcrSubsampleRatio420:
cy := (y - ycbcr.Rect.Min.Y) * ycbcr.CStride return p.ycbcr420(ycbcr)
for x := ycbcr.Rect.Min.X; x < ycbcr.Rect.Max.X; x++ { case ycbcrSubsampleRatio440:
xx := (x - ycbcr.Rect.Min.X) return p.ycbcr440(ycbcr)
yi := yy + xx case ycbcrSubsampleRatio444:
ci := cy + xx/2 return p.ycbcr444(ycbcr)
ycbcr.Y[yi] = p.Pix[off+0] case ycbcrSubsampleRatio411:
ycbcr.Cb[ci] = p.Pix[off+1] return p.ycbcr411(ycbcr)
ycbcr.Cr[ci] = p.Pix[off+2] case ycbcrSubsampleRatio410:
off += 3 return p.ycbcr410(ycbcr)
}
}
case image.YCbCrSubsampleRatio420:
for y := ycbcr.Rect.Min.Y; y < ycbcr.Rect.Max.Y; y++ {
yy := (y - ycbcr.Rect.Min.Y) * ycbcr.YStride
cy := (y/2 - ycbcr.Rect.Min.Y/2) * ycbcr.CStride
for x := ycbcr.Rect.Min.X; x < ycbcr.Rect.Max.X; x++ {
xx := (x - ycbcr.Rect.Min.X)
yi := yy + xx
ci := cy + xx/2
ycbcr.Y[yi] = p.Pix[off+0]
ycbcr.Cb[ci] = p.Pix[off+1]
ycbcr.Cr[ci] = p.Pix[off+2]
off += 3
}
}
case image.YCbCrSubsampleRatio440:
for y := ycbcr.Rect.Min.Y; y < ycbcr.Rect.Max.Y; y++ {
yy := (y - ycbcr.Rect.Min.Y) * ycbcr.YStride
cy := (y/2 - ycbcr.Rect.Min.Y/2) * ycbcr.CStride
for x := ycbcr.Rect.Min.X; x < ycbcr.Rect.Max.X; x++ {
xx := (x - ycbcr.Rect.Min.X)
yi := yy + xx
ci := cy + xx
ycbcr.Y[yi] = p.Pix[off+0]
ycbcr.Cb[ci] = p.Pix[off+1]
ycbcr.Cr[ci] = p.Pix[off+2]
off += 3
}
}
default:
// Default to 4:4:4 subsampling.
for y := ycbcr.Rect.Min.Y; y < ycbcr.Rect.Max.Y; y++ {
yy := (y - ycbcr.Rect.Min.Y) * ycbcr.YStride
cy := (y - ycbcr.Rect.Min.Y) * ycbcr.CStride
for x := ycbcr.Rect.Min.X; x < ycbcr.Rect.Max.X; x++ {
xx := (x - ycbcr.Rect.Min.X)
yi := yy + xx
ci := cy + xx
ycbcr.Y[yi] = p.Pix[off+0]
ycbcr.Cb[ci] = p.Pix[off+1]
ycbcr.Cr[ci] = p.Pix[off+2]
off += 3
}
}
} }
return ycbcr return ycbcr
} }
@ -159,69 +123,265 @@ func (p *ycc) YCbCr() *image.YCbCr {
// imageYCbCrToYCC converts a YCbCr image to a ycc image for resizing. // imageYCbCrToYCC converts a YCbCr image to a ycc image for resizing.
func imageYCbCrToYCC(in *image.YCbCr) *ycc { func imageYCbCrToYCC(in *image.YCbCr) *ycc {
w, h := in.Rect.Dx(), in.Rect.Dy() w, h := in.Rect.Dx(), in.Rect.Dy()
r := image.Rect(0, 0, w, h) p := ycc{
buf := make([]uint8, 3*w*h) Pix: make([]uint8, 3*w*h),
p := ycc{Pix: buf, Stride: 3 * w, Rect: r, SubsampleRatio: in.SubsampleRatio} Stride: 3 * w,
var off int Rect: image.Rect(0, 0, w, h),
SubsampleRatio: in.SubsampleRatio,
}
switch in.SubsampleRatio { switch in.SubsampleRatio {
case image.YCbCrSubsampleRatio422: case ycbcrSubsampleRatio422:
for y := in.Rect.Min.Y; y < in.Rect.Max.Y; y++ { return convertToYCC422(in, &p)
yy := (y - in.Rect.Min.Y) * in.YStride case ycbcrSubsampleRatio420:
cy := (y - in.Rect.Min.Y) * in.CStride return convertToYCC420(in, &p)
for x := in.Rect.Min.X; x < in.Rect.Max.X; x++ { case ycbcrSubsampleRatio440:
xx := (x - in.Rect.Min.X) return convertToYCC440(in, &p)
yi := yy + xx case ycbcrSubsampleRatio444:
ci := cy + xx/2 return convertToYCC444(in, &p)
p.Pix[off+0] = in.Y[yi] case ycbcrSubsampleRatio411:
p.Pix[off+1] = in.Cb[ci] return convertToYCC411(in, &p)
p.Pix[off+2] = in.Cr[ci] case ycbcrSubsampleRatio410:
off += 3 return convertToYCC410(in, &p)
}
}
case image.YCbCrSubsampleRatio420:
for y := in.Rect.Min.Y; y < in.Rect.Max.Y; y++ {
yy := (y - in.Rect.Min.Y) * in.YStride
cy := (y/2 - in.Rect.Min.Y/2) * in.CStride
for x := in.Rect.Min.X; x < in.Rect.Max.X; x++ {
xx := (x - in.Rect.Min.X)
yi := yy + xx
ci := cy + xx/2
p.Pix[off+0] = in.Y[yi]
p.Pix[off+1] = in.Cb[ci]
p.Pix[off+2] = in.Cr[ci]
off += 3
}
}
case image.YCbCrSubsampleRatio440:
for y := in.Rect.Min.Y; y < in.Rect.Max.Y; y++ {
yy := (y - in.Rect.Min.Y) * in.YStride
cy := (y/2 - in.Rect.Min.Y/2) * in.CStride
for x := in.Rect.Min.X; x < in.Rect.Max.X; x++ {
xx := (x - in.Rect.Min.X)
yi := yy + xx
ci := cy + xx
p.Pix[off+0] = in.Y[yi]
p.Pix[off+1] = in.Cb[ci]
p.Pix[off+2] = in.Cr[ci]
off += 3
}
}
default:
// Default to 4:4:4 subsampling.
for y := in.Rect.Min.Y; y < in.Rect.Max.Y; y++ {
yy := (y - in.Rect.Min.Y) * in.YStride
cy := (y - in.Rect.Min.Y) * in.CStride
for x := in.Rect.Min.X; x < in.Rect.Max.X; x++ {
xx := (x - in.Rect.Min.X)
yi := yy + xx
ci := cy + xx
p.Pix[off+0] = in.Y[yi]
p.Pix[off+1] = in.Cb[ci]
p.Pix[off+2] = in.Cr[ci]
off += 3
}
}
} }
return &p return &p
} }
func (p *ycc) ycbcr422(ycbcr *image.YCbCr) *image.YCbCr {
var off int
Pix := p.Pix
Y := ycbcr.Y
Cb := ycbcr.Cb
Cr := ycbcr.Cr
for y := 0; y < ycbcr.Rect.Max.Y-ycbcr.Rect.Min.Y; y++ {
yy := y * ycbcr.YStride
cy := y * ycbcr.CStride
for x := 0; x < ycbcr.Rect.Max.X-ycbcr.Rect.Min.X; x++ {
ci := cy + x/2
Y[yy+x] = Pix[off+0]
Cb[ci] = Pix[off+1]
Cr[ci] = Pix[off+2]
off += 3
}
}
return ycbcr
}
func (p *ycc) ycbcr420(ycbcr *image.YCbCr) *image.YCbCr {
var off int
Pix := p.Pix
Y := ycbcr.Y
Cb := ycbcr.Cb
Cr := ycbcr.Cr
for y := 0; y < ycbcr.Rect.Max.Y-ycbcr.Rect.Min.Y; y++ {
yy := y * ycbcr.YStride
cy := (y / 2) * ycbcr.CStride
for x := 0; x < ycbcr.Rect.Max.X-ycbcr.Rect.Min.X; x++ {
ci := cy + x/2
Y[yy+x] = Pix[off+0]
Cb[ci] = Pix[off+1]
Cr[ci] = Pix[off+2]
off += 3
}
}
return ycbcr
}
func (p *ycc) ycbcr440(ycbcr *image.YCbCr) *image.YCbCr {
var off int
Pix := p.Pix
Y := ycbcr.Y
Cb := ycbcr.Cb
Cr := ycbcr.Cr
for y := 0; y < ycbcr.Rect.Max.Y-ycbcr.Rect.Min.Y; y++ {
yy := y * ycbcr.YStride
cy := (y / 2) * ycbcr.CStride
for x := 0; x < ycbcr.Rect.Max.X-ycbcr.Rect.Min.X; x++ {
ci := cy + x
Y[yy+x] = Pix[off+0]
Cb[ci] = Pix[off+1]
Cr[ci] = Pix[off+2]
off += 3
}
}
return ycbcr
}
func (p *ycc) ycbcr444(ycbcr *image.YCbCr) *image.YCbCr {
var off int
Pix := p.Pix
Y := ycbcr.Y
Cb := ycbcr.Cb
Cr := ycbcr.Cr
for y := 0; y < ycbcr.Rect.Max.Y-ycbcr.Rect.Min.Y; y++ {
yy := y * ycbcr.YStride
cy := y * ycbcr.CStride
for x := 0; x < ycbcr.Rect.Max.X-ycbcr.Rect.Min.X; x++ {
ci := cy + x
Y[yy+x] = Pix[off+0]
Cb[ci] = Pix[off+1]
Cr[ci] = Pix[off+2]
off += 3
}
}
return ycbcr
}
func (p *ycc) ycbcr411(ycbcr *image.YCbCr) *image.YCbCr {
var off int
Pix := p.Pix
Y := ycbcr.Y
Cb := ycbcr.Cb
Cr := ycbcr.Cr
for y := 0; y < ycbcr.Rect.Max.Y-ycbcr.Rect.Min.Y; y++ {
yy := y * ycbcr.YStride
cy := y * ycbcr.CStride
for x := 0; x < ycbcr.Rect.Max.X-ycbcr.Rect.Min.X; x++ {
ci := cy + x/4
Y[yy+x] = Pix[off+0]
Cb[ci] = Pix[off+1]
Cr[ci] = Pix[off+2]
off += 3
}
}
return ycbcr
}
func (p *ycc) ycbcr410(ycbcr *image.YCbCr) *image.YCbCr {
var off int
Pix := p.Pix
Y := ycbcr.Y
Cb := ycbcr.Cb
Cr := ycbcr.Cr
for y := 0; y < ycbcr.Rect.Max.Y-ycbcr.Rect.Min.Y; y++ {
yy := y * ycbcr.YStride
cy := (y / 2) * ycbcr.CStride
for x := 0; x < ycbcr.Rect.Max.X-ycbcr.Rect.Min.X; x++ {
ci := cy + x/4
Y[yy+x] = Pix[off+0]
Cb[ci] = Pix[off+1]
Cr[ci] = Pix[off+2]
off += 3
}
}
return ycbcr
}
func convertToYCC422(in *image.YCbCr, p *ycc) *ycc {
var off int
Pix := p.Pix
Y := in.Y
Cb := in.Cb
Cr := in.Cr
for y := 0; y < in.Rect.Max.Y-in.Rect.Min.Y; y++ {
yy := y * in.YStride
cy := y * in.CStride
for x := 0; x < in.Rect.Max.X-in.Rect.Min.X; x++ {
ci := cy + x/2
Pix[off+0] = Y[yy+x]
Pix[off+1] = Cb[ci]
Pix[off+2] = Cr[ci]
off += 3
}
}
return p
}
func convertToYCC420(in *image.YCbCr, p *ycc) *ycc {
var off int
Pix := p.Pix
Y := in.Y
Cb := in.Cb
Cr := in.Cr
for y := 0; y < in.Rect.Max.Y-in.Rect.Min.Y; y++ {
yy := y * in.YStride
cy := (y / 2) * in.CStride
for x := 0; x < in.Rect.Max.X-in.Rect.Min.X; x++ {
ci := cy + x/2
Pix[off+0] = Y[yy+x]
Pix[off+1] = Cb[ci]
Pix[off+2] = Cr[ci]
off += 3
}
}
return p
}
func convertToYCC440(in *image.YCbCr, p *ycc) *ycc {
var off int
Pix := p.Pix
Y := in.Y
Cb := in.Cb
Cr := in.Cr
for y := 0; y < in.Rect.Max.Y-in.Rect.Min.Y; y++ {
yy := y * in.YStride
cy := (y / 2) * in.CStride
for x := 0; x < in.Rect.Max.X-in.Rect.Min.X; x++ {
ci := cy + x
Pix[off+0] = Y[yy+x]
Pix[off+1] = Cb[ci]
Pix[off+2] = Cr[ci]
off += 3
}
}
return p
}
func convertToYCC444(in *image.YCbCr, p *ycc) *ycc {
var off int
Pix := p.Pix
Y := in.Y
Cb := in.Cb
Cr := in.Cr
for y := 0; y < in.Rect.Max.Y-in.Rect.Min.Y; y++ {
yy := y * in.YStride
cy := y * in.CStride
for x := 0; x < in.Rect.Max.X-in.Rect.Min.X; x++ {
ci := cy + x
Pix[off+0] = Y[yy+x]
Pix[off+1] = Cb[ci]
Pix[off+2] = Cr[ci]
off += 3
}
}
return p
}
func convertToYCC411(in *image.YCbCr, p *ycc) *ycc {
var off int
Pix := p.Pix
Y := in.Y
Cb := in.Cb
Cr := in.Cr
for y := 0; y < in.Rect.Max.Y-in.Rect.Min.Y; y++ {
yy := y * in.YStride
cy := y * in.CStride
for x := 0; x < in.Rect.Max.X-in.Rect.Min.X; x++ {
ci := cy + x/4
Pix[off+0] = Y[yy+x]
Pix[off+1] = Cb[ci]
Pix[off+2] = Cr[ci]
off += 3
}
}
return p
}
func convertToYCC410(in *image.YCbCr, p *ycc) *ycc {
var off int
Pix := p.Pix
Y := in.Y
Cb := in.Cb
Cr := in.Cr
for y := 0; y < in.Rect.Max.Y-in.Rect.Min.Y; y++ {
yy := y * in.YStride
cy := (y / 2) * in.CStride
for x := 0; x < in.Rect.Max.X-in.Rect.Min.X; x++ {
ci := cy + x/4
Pix[off+0] = Y[yy+x]
Pix[off+1] = Cb[ci]
Pix[off+2] = Cr[ci]
off += 3
}
}
return p
}

View File

@ -1,3 +1,5 @@
// +build go1.5
/* /*
Copyright (c) 2014, Charlie Vieth <charlie.vieth@gmail.com> 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.YCbCrSubsampleRatio422),
newYCC(image.Rect(0, 0, 10, 10), image.YCbCrSubsampleRatio440), 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.YCbCrSubsampleRatio444),
newYCC(image.Rect(0, 0, 10, 10), image.YCbCrSubsampleRatio411),
newYCC(image.Rect(0, 0, 10, 10), image.YCbCrSubsampleRatio410),
} }
for _, m := range testImage { for _, m := range testImage {
if !image.Rect(0, 0, 10, 10).Eq(m.Bounds()) { 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.YCbCrSubsampleRatio422),
image.NewYCbCr(image.Rect(0, 0, 50, 50), image.YCbCrSubsampleRatio440), 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, 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 { for _, img := range testImage {
m := img.(*image.YCbCr) m := img.(*image.YCbCr)
for y := m.Rect.Min.Y; y < m.Rect.Max.Y; y++ { for y := m.Rect.Min.Y; y < m.Rect.Max.Y; y++ {