Merge branch 'charlievieth-master'
This commit is contained in:
jst
commit
ccddecd1bf
280
converter.go
280
converter.go
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@ -16,10 +16,7 @@ THIS SOFTWARE.
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package resize
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import (
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"image"
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"image/color"
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)
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import "image"
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// Keep value in [0,255] range.
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func clampUint8(in int32) uint8 {
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@ -43,33 +40,36 @@ func clampUint16(in int64) uint16 {
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return uint16(in)
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}
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func resizeGeneric(in image.Image, out *image.RGBA64, scale float64, coeffs []int32, filterLength int) {
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func resizeGeneric(in image.Image, out *image.RGBA64, scale float64, coeffs []int32, offset []int, filterLength int) {
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oldBounds := in.Bounds()
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newBounds := out.Bounds()
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for x := newBounds.Min.X; x < newBounds.Max.X; x++ {
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for y := newBounds.Min.Y; y < newBounds.Max.Y; y++ {
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interpX := scale*(float64(y)+0.5) + float64(oldBounds.Min.X)
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start := int(interpX) - filterLength/2 + 1
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var rgba [4]int64
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var sum int64
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start := offset[y]
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ci := (y - newBounds.Min.Y) * filterLength
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for i := 0; i < filterLength; i++ {
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xx := start + i
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if xx < oldBounds.Min.X {
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xx = oldBounds.Min.X
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} else if xx >= oldBounds.Max.X {
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xx = oldBounds.Max.X - 1
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coeff := coeffs[ci+i]
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if coeff != 0 {
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xi := start + i
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switch {
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case uint(xi) < uint(oldBounds.Max.X):
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break
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case xi >= oldBounds.Max.X:
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xi = oldBounds.Min.X
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default:
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xi = oldBounds.Max.X - 1
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}
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coeff := coeffs[(y-newBounds.Min.Y)*filterLength+i]
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r, g, b, a := in.At(xx, x).RGBA()
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r, g, b, a := in.At(xi, x).RGBA()
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rgba[0] += int64(coeff) * int64(r)
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rgba[1] += int64(coeff) * int64(g)
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rgba[2] += int64(coeff) * int64(b)
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rgba[3] += int64(coeff) * int64(a)
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sum += int64(coeff)
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}
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}
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offset := (y-newBounds.Min.Y)*out.Stride + (x-newBounds.Min.X)*8
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value := clampUint16(rgba[0] / sum)
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@ -88,115 +88,127 @@ func resizeGeneric(in image.Image, out *image.RGBA64, scale float64, coeffs []in
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}
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}
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func resizeRGBA(in *image.RGBA, out *image.RGBA, scale float64, coeffs []int16, filterLength int) {
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func resizeRGBA(in *image.RGBA, out *image.RGBA, scale float64, coeffs []int16, offset []int, filterLength int) {
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oldBounds := in.Bounds()
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newBounds := out.Bounds()
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minX := oldBounds.Min.X * 4
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maxX := (oldBounds.Max.X - oldBounds.Min.X - 1) * 4
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for x := newBounds.Min.X; x < newBounds.Max.X; x++ {
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row := in.Pix[(x-oldBounds.Min.Y)*in.Stride:]
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for y := newBounds.Min.Y; y < newBounds.Max.Y; y++ {
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interpX := scale*(float64(y)+0.5) + float64(oldBounds.Min.X)
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start := int(interpX) - filterLength/2 + 1
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var rgba [4]int32
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var sum int32
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start := offset[y]
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ci := (y - newBounds.Min.Y) * filterLength
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for i := 0; i < filterLength; i++ {
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xx := start + i
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if xx < oldBounds.Min.X {
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xx = oldBounds.Min.X
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} else if xx >= oldBounds.Max.X {
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xx = oldBounds.Max.X - 1
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coeff := coeffs[ci+i]
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if coeff != 0 {
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xi := start + i
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switch {
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case uint(xi) < uint(oldBounds.Max.X):
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xi *= 4
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case xi >= oldBounds.Max.X:
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xi = maxX
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default:
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xi = minX
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}
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coeff := coeffs[(y-newBounds.Min.Y)*filterLength+i]
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offset := (xx - oldBounds.Min.X) * 4
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rgba[0] += int32(coeff) * int32(row[offset+0])
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rgba[1] += int32(coeff) * int32(row[offset+1])
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rgba[2] += int32(coeff) * int32(row[offset+2])
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rgba[3] += int32(coeff) * int32(row[offset+3])
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rgba[0] += int32(coeff) * int32(row[xi+0])
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rgba[1] += int32(coeff) * int32(row[xi+1])
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rgba[2] += int32(coeff) * int32(row[xi+2])
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rgba[3] += int32(coeff) * int32(row[xi+3])
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sum += int32(coeff)
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}
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}
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offset := (y-newBounds.Min.Y)*out.Stride + (x-newBounds.Min.X)*4
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out.Pix[offset+0] = clampUint8(rgba[0] / sum)
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out.Pix[offset+1] = clampUint8(rgba[1] / sum)
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out.Pix[offset+2] = clampUint8(rgba[2] / sum)
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out.Pix[offset+3] = clampUint8(rgba[3] / sum)
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xo := (y-newBounds.Min.Y)*out.Stride + (x-newBounds.Min.X)*4
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out.Pix[xo+0] = clampUint8(rgba[0] / sum)
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out.Pix[xo+1] = clampUint8(rgba[1] / sum)
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out.Pix[xo+2] = clampUint8(rgba[2] / sum)
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out.Pix[xo+3] = clampUint8(rgba[3] / sum)
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}
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}
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}
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func resizeRGBA64(in *image.RGBA64, out *image.RGBA64, scale float64, coeffs []int32, filterLength int) {
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func resizeRGBA64(in *image.RGBA64, out *image.RGBA64, scale float64, coeffs []int32, offset []int, filterLength int) {
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oldBounds := in.Bounds()
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newBounds := out.Bounds()
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minX := oldBounds.Min.X * 8
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maxX := (oldBounds.Max.X - oldBounds.Min.X - 1) * 8
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for x := newBounds.Min.X; x < newBounds.Max.X; x++ {
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row := in.Pix[(x-oldBounds.Min.Y)*in.Stride:]
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for y := newBounds.Min.Y; y < newBounds.Max.Y; y++ {
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interpX := scale*(float64(y)+0.5) + float64(oldBounds.Min.X)
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start := int(interpX) - filterLength/2 + 1
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var rgba [4]int64
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var sum int64
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start := offset[y]
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ci := (y - newBounds.Min.Y) * filterLength
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for i := 0; i < filterLength; i++ {
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xx := start + i
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if xx < oldBounds.Min.X {
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xx = oldBounds.Min.X
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} else if xx >= oldBounds.Max.X {
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xx = oldBounds.Max.X - 1
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coeff := coeffs[ci+i]
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if coeff != 0 {
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xi := start + i
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switch {
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case uint(xi) < uint(oldBounds.Max.X):
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xi *= 8
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case xi >= oldBounds.Max.X:
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xi = maxX
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default:
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xi = minX
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}
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coeff := coeffs[(y-newBounds.Min.Y)*filterLength+i]
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offset := (xx - oldBounds.Min.X) * 8
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rgba[0] += int64(coeff) * int64(uint16(row[offset+0])<<8|uint16(row[offset+1]))
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rgba[1] += int64(coeff) * int64(uint16(row[offset+2])<<8|uint16(row[offset+3]))
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rgba[2] += int64(coeff) * int64(uint16(row[offset+4])<<8|uint16(row[offset+5]))
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rgba[3] += int64(coeff) * int64(uint16(row[offset+6])<<8|uint16(row[offset+7]))
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rgba[0] += int64(coeff) * int64(uint16(row[xi+0])<<8|uint16(row[xi+1]))
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rgba[1] += int64(coeff) * int64(uint16(row[xi+2])<<8|uint16(row[xi+3]))
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rgba[2] += int64(coeff) * int64(uint16(row[xi+4])<<8|uint16(row[xi+5]))
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rgba[3] += int64(coeff) * int64(uint16(row[xi+6])<<8|uint16(row[xi+7]))
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sum += int64(coeff)
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}
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}
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offset := (y-newBounds.Min.Y)*out.Stride + (x-newBounds.Min.X)*8
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xo := (y-newBounds.Min.Y)*out.Stride + (x-newBounds.Min.X)*8
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value := clampUint16(rgba[0] / sum)
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out.Pix[offset+0] = uint8(value >> 8)
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out.Pix[offset+1] = uint8(value)
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out.Pix[xo+0] = uint8(value >> 8)
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out.Pix[xo+1] = uint8(value)
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value = clampUint16(rgba[1] / sum)
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out.Pix[offset+2] = uint8(value >> 8)
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out.Pix[offset+3] = uint8(value)
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out.Pix[xo+2] = uint8(value >> 8)
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out.Pix[xo+3] = uint8(value)
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value = clampUint16(rgba[2] / sum)
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out.Pix[offset+4] = uint8(value >> 8)
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out.Pix[offset+5] = uint8(value)
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out.Pix[xo+4] = uint8(value >> 8)
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out.Pix[xo+5] = uint8(value)
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value = clampUint16(rgba[3] / sum)
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out.Pix[offset+6] = uint8(value >> 8)
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out.Pix[offset+7] = uint8(value)
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out.Pix[xo+6] = uint8(value >> 8)
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out.Pix[xo+7] = uint8(value)
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}
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}
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}
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func resizeGray(in *image.Gray, out *image.Gray, scale float64, coeffs []int16, filterLength int) {
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func resizeGray(in *image.Gray, out *image.Gray, scale float64, coeffs []int16, offset []int, filterLength int) {
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oldBounds := in.Bounds()
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newBounds := out.Bounds()
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minX := oldBounds.Min.X
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maxX := (oldBounds.Max.X - oldBounds.Min.X - 1)
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for x := newBounds.Min.X; x < newBounds.Max.X; x++ {
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row := in.Pix[(x-oldBounds.Min.Y)*in.Stride:]
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for y := newBounds.Min.Y; y < newBounds.Max.Y; y++ {
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interpX := scale*(float64(y)+0.5) + float64(oldBounds.Min.X)
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start := int(interpX) - filterLength/2 + 1
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var gray int32
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var sum int32
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start := offset[y]
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ci := (y - newBounds.Min.Y) * filterLength
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for i := 0; i < filterLength; i++ {
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xx := start + i
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if xx < oldBounds.Min.X {
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xx = oldBounds.Min.X
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} else if xx >= oldBounds.Max.X {
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xx = oldBounds.Max.X - 1
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coeff := coeffs[ci+i]
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if coeff != 0 {
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xi := start + i
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switch {
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case uint(xi) < uint(oldBounds.Max.X):
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break
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case xi >= oldBounds.Max.X:
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xi = maxX
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default:
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xi = minX
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}
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coeff := coeffs[(y-newBounds.Min.Y)*filterLength+i]
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offset := (xx - oldBounds.Min.X)
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gray += int32(coeff) * int32(row[offset])
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gray += int32(coeff) * int32(row[xi])
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sum += int32(coeff)
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}
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}
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offset := (y-newBounds.Min.Y)*out.Stride + (x - newBounds.Min.X)
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out.Pix[offset] = clampUint8(gray / sum)
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@ -204,31 +216,35 @@ func resizeGray(in *image.Gray, out *image.Gray, scale float64, coeffs []int16,
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}
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}
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func resizeGray16(in *image.Gray16, out *image.Gray16, scale float64, coeffs []int32, filterLength int) {
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func resizeGray16(in *image.Gray16, out *image.Gray16, scale float64, coeffs []int32, offset []int, filterLength int) {
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oldBounds := in.Bounds()
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newBounds := out.Bounds()
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minX := oldBounds.Min.X * 2
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maxX := (oldBounds.Max.X - oldBounds.Min.X - 1) * 2
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for x := newBounds.Min.X; x < newBounds.Max.X; x++ {
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row := in.Pix[(x-oldBounds.Min.Y)*in.Stride:]
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for y := newBounds.Min.Y; y < newBounds.Max.Y; y++ {
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interpX := scale*(float64(y)+0.5) + float64(oldBounds.Min.X)
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start := int(interpX) - filterLength/2 + 1
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var gray int64
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var sum int64
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start := offset[y]
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ci := (y - newBounds.Min.Y) * filterLength
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for i := 0; i < filterLength; i++ {
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xx := start + i
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if xx < oldBounds.Min.X {
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xx = oldBounds.Min.X
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} else if xx >= oldBounds.Max.X {
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xx = oldBounds.Max.X - 1
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coeff := coeffs[ci+i]
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if coeff != 0 {
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xi := start + i
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switch {
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case uint(xi) < uint(oldBounds.Max.X):
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xi *= 2
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case xi >= oldBounds.Max.X:
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xi = maxX
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default:
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xi = minX
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}
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coeff := coeffs[(y-newBounds.Min.Y)*filterLength+i]
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offset := (xx - oldBounds.Min.X) * 2
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gray += int64(coeff) * int64(uint16(row[offset+0])<<8|uint16(row[offset+1]))
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gray += int64(coeff) * int64(uint16(row[xi+0])<<8|uint16(row[xi+1]))
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sum += int64(coeff)
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}
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}
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offset := (y-newBounds.Min.Y)*out.Stride + (x-newBounds.Min.X)*2
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value := clampUint16(gray / sum)
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@ -238,19 +254,81 @@ func resizeGray16(in *image.Gray16, out *image.Gray16, scale float64, coeffs []i
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}
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}
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func convertYCbCrToRGBA(in *image.YCbCr) *image.RGBA {
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out := image.NewRGBA(in.Bounds())
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for y := 0; y < out.Bounds().Dy(); y++ {
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for x := 0; x < out.Bounds().Dx(); x++ {
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p := out.Pix[y*out.Stride+4*x:]
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yi := in.YOffset(x, y)
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ci := in.COffset(x, y)
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r, g, b := color.YCbCrToRGB(in.Y[yi], in.Cb[ci], in.Cr[ci])
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p[0] = r
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p[1] = g
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p[2] = b
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p[3] = 0xff
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func resizeYCbCr(in *ycc, out *ycc, scale float64, coeffs []int16, offset []int, filterLength int) {
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oldBounds := in.Bounds()
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newBounds := out.Bounds()
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minX := oldBounds.Min.X * 3
|
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maxX := (oldBounds.Max.X - oldBounds.Min.X - 1) * 3
|
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|
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for x := newBounds.Min.X; x < newBounds.Max.X; x++ {
|
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row := in.Pix[(x-oldBounds.Min.Y)*in.Stride:]
|
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for y := newBounds.Min.Y; y < newBounds.Max.Y; y++ {
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var p [3]int32
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var sum int32
|
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start := offset[y]
|
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ci := (y - newBounds.Min.Y) * filterLength
|
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for i := 0; i < filterLength; i++ {
|
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coeff := coeffs[ci+i]
|
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if coeff != 0 {
|
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xi := start + i
|
||||
switch {
|
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case uint(xi) < uint(oldBounds.Max.X):
|
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xi *= 3
|
||||
case xi >= oldBounds.Max.X:
|
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xi = maxX
|
||||
default:
|
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xi = minX
|
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}
|
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p[0] += int32(coeff) * int32(row[xi+0])
|
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p[1] += int32(coeff) * int32(row[xi+1])
|
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p[2] += int32(coeff) * int32(row[xi+2])
|
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sum += int32(coeff)
|
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}
|
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}
|
||||
|
||||
xo := (y-newBounds.Min.Y)*out.Stride + (x-newBounds.Min.X)*3
|
||||
out.Pix[xo+0] = clampUint8(p[0] / sum)
|
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out.Pix[xo+1] = clampUint8(p[1] / sum)
|
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out.Pix[xo+2] = clampUint8(p[2] / sum)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
func nearestYCbCr(in *ycc, out *ycc, scale float64, coeffs []bool, offset []int, filterLength int) {
|
||||
oldBounds := in.Bounds()
|
||||
newBounds := out.Bounds()
|
||||
minX := oldBounds.Min.X * 3
|
||||
maxX := (oldBounds.Max.X - oldBounds.Min.X - 1) * 3
|
||||
|
||||
for x := newBounds.Min.X; x < newBounds.Max.X; x++ {
|
||||
row := in.Pix[(x-oldBounds.Min.Y)*in.Stride:]
|
||||
for y := newBounds.Min.Y; y < newBounds.Max.Y; y++ {
|
||||
var p [3]float32
|
||||
var sum float32
|
||||
start := offset[y]
|
||||
ci := (y - newBounds.Min.Y) * filterLength
|
||||
for i := 0; i < filterLength; i++ {
|
||||
if coeffs[ci+i] {
|
||||
xi := start + i
|
||||
switch {
|
||||
case uint(xi) < uint(oldBounds.Max.X):
|
||||
xi *= 3
|
||||
case xi >= oldBounds.Max.X:
|
||||
xi = maxX
|
||||
default:
|
||||
xi = minX
|
||||
}
|
||||
p[0] += float32(row[xi+0])
|
||||
p[1] += float32(row[xi+1])
|
||||
p[2] += float32(row[xi+2])
|
||||
sum++
|
||||
}
|
||||
}
|
||||
|
||||
xo := (y-newBounds.Min.Y)*out.Stride + (x-newBounds.Min.X)*3
|
||||
out.Pix[xo+0] = floatToUint8(p[0] / sum)
|
||||
out.Pix[xo+1] = floatToUint8(p[1] / sum)
|
||||
out.Pix[xo+2] = floatToUint8(p[2] / sum)
|
||||
}
|
||||
}
|
||||
return out
|
||||
}
|
||||
|
|
|
|||
43
filters.go
43
filters.go
|
|
@ -80,37 +80,64 @@ func lanczos3(in float64) float64 {
|
|||
}
|
||||
|
||||
// range [-256,256]
|
||||
func createWeights8(dy, minx, filterLength int, blur, scale float64, kernel func(float64) float64) ([]int16, int) {
|
||||
func createWeights8(dy, minx, filterLength int, blur, scale float64, kernel func(float64) float64) ([]int16, []int, int) {
|
||||
filterLength = filterLength * int(math.Max(math.Ceil(blur*scale), 1))
|
||||
filterFactor := math.Min(1./(blur*scale), 1)
|
||||
|
||||
coeffs := make([]int16, dy*filterLength)
|
||||
start := make([]int, dy)
|
||||
for y := 0; y < dy; y++ {
|
||||
interpX := scale*(float64(y)+0.5) + float64(minx)
|
||||
start := int(interpX) - filterLength/2 + 1
|
||||
start[y] = int(interpX) - filterLength/2 + 1
|
||||
interpX -= float64(start[y])
|
||||
for i := 0; i < filterLength; i++ {
|
||||
in := (interpX - float64(start) - float64(i)) * filterFactor
|
||||
in := (interpX - float64(i)) * filterFactor
|
||||
coeffs[y*filterLength+i] = int16(kernel(in) * 256)
|
||||
}
|
||||
}
|
||||
|
||||
return coeffs, filterLength
|
||||
return coeffs, start, filterLength
|
||||
}
|
||||
|
||||
// range [-65536,65536]
|
||||
func createWeights16(dy, minx, filterLength int, blur, scale float64, kernel func(float64) float64) ([]int32, int) {
|
||||
func createWeights16(dy, minx, filterLength int, blur, scale float64, kernel func(float64) float64) ([]int32, []int, int) {
|
||||
filterLength = filterLength * int(math.Max(math.Ceil(blur*scale), 1))
|
||||
filterFactor := math.Min(1./(blur*scale), 1)
|
||||
|
||||
coeffs := make([]int32, dy*filterLength)
|
||||
start := make([]int, dy)
|
||||
for y := 0; y < dy; y++ {
|
||||
interpX := scale*(float64(y)+0.5) + float64(minx)
|
||||
start := int(interpX) - filterLength/2 + 1
|
||||
start[y] = int(interpX) - filterLength/2 + 1
|
||||
interpX -= float64(start[y])
|
||||
for i := 0; i < filterLength; i++ {
|
||||
in := (interpX - float64(start) - float64(i)) * filterFactor
|
||||
in := (interpX - float64(i)) * filterFactor
|
||||
coeffs[y*filterLength+i] = int32(kernel(in) * 65536)
|
||||
}
|
||||
}
|
||||
|
||||
return coeffs, filterLength
|
||||
return coeffs, start, filterLength
|
||||
}
|
||||
|
||||
func createWeightsNearest(dy, minx, filterLength int, blur, scale float64) ([]bool, []int, int) {
|
||||
filterLength = filterLength * int(math.Max(math.Ceil(blur*scale), 1))
|
||||
filterFactor := math.Min(1./(blur*scale), 1)
|
||||
|
||||
coeffs := make([]bool, dy*filterLength)
|
||||
start := make([]int, dy)
|
||||
for y := 0; y < dy; y++ {
|
||||
interpX := scale*(float64(y)+0.5) + float64(minx)
|
||||
start[y] = int(interpX) - filterLength/2 + 1
|
||||
interpX -= float64(start[y])
|
||||
for i := 0; i < filterLength; i++ {
|
||||
in := (interpX - float64(i)) * filterFactor
|
||||
if in >= -0.5 && in < 0.5 {
|
||||
coeffs[y*filterLength+i] = true
|
||||
} else {
|
||||
coeffs[y*filterLength+i] = false
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
return coeffs, start, filterLength
|
||||
}
|
||||
|
|
|
|||
244
nearest.go
Normal file
244
nearest.go
Normal file
|
|
@ -0,0 +1,244 @@
|
|||
/*
|
||||
Copyright (c) 2014, Charlie Vieth <charlie.vieth@gmail.com>
|
||||
|
||||
Permission to use, copy, modify, and/or distribute this software for any purpose
|
||||
with or without fee is hereby granted, provided that the above copyright notice
|
||||
and this permission notice appear in all copies.
|
||||
|
||||
THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
|
||||
REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
|
||||
FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
|
||||
INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
|
||||
OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
|
||||
TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF
|
||||
THIS SOFTWARE.
|
||||
*/
|
||||
|
||||
package resize
|
||||
|
||||
import "image"
|
||||
|
||||
func floatToUint8(x float32) uint8 {
|
||||
// Nearest-neighbor values are always
|
||||
// positive no need to check lower-bound.
|
||||
if x > 0xfe {
|
||||
return 0xff
|
||||
}
|
||||
return uint8(x)
|
||||
}
|
||||
|
||||
func floatToUint16(x float32) uint16 {
|
||||
if x > 0xfffe {
|
||||
return 0xffff
|
||||
}
|
||||
return uint16(x)
|
||||
}
|
||||
|
||||
func nearestGeneric(in image.Image, out *image.RGBA64, scale float64, coeffs []bool, offset []int, filterLength int) {
|
||||
oldBounds := in.Bounds()
|
||||
newBounds := out.Bounds()
|
||||
|
||||
for x := newBounds.Min.X; x < newBounds.Max.X; x++ {
|
||||
for y := newBounds.Min.Y; y < newBounds.Max.Y; y++ {
|
||||
var rgba [4]float32
|
||||
var sum float32
|
||||
start := offset[y]
|
||||
ci := (y - newBounds.Min.Y) * filterLength
|
||||
for i := 0; i < filterLength; i++ {
|
||||
if coeffs[ci+i] {
|
||||
xi := start + i
|
||||
switch {
|
||||
case uint(xi) < uint(oldBounds.Max.X):
|
||||
break
|
||||
case xi >= oldBounds.Max.X:
|
||||
xi = oldBounds.Min.X
|
||||
default:
|
||||
xi = oldBounds.Max.X - 1
|
||||
}
|
||||
r, g, b, a := in.At(xi, x).RGBA()
|
||||
rgba[0] += float32(r)
|
||||
rgba[1] += float32(g)
|
||||
rgba[2] += float32(b)
|
||||
rgba[3] += float32(a)
|
||||
sum++
|
||||
}
|
||||
}
|
||||
|
||||
offset := (y-newBounds.Min.Y)*out.Stride + (x-newBounds.Min.X)*8
|
||||
value := floatToUint16(rgba[0] / sum)
|
||||
out.Pix[offset+0] = uint8(value >> 8)
|
||||
out.Pix[offset+1] = uint8(value)
|
||||
value = floatToUint16(rgba[1] / sum)
|
||||
out.Pix[offset+2] = uint8(value >> 8)
|
||||
out.Pix[offset+3] = uint8(value)
|
||||
value = floatToUint16(rgba[2] / sum)
|
||||
out.Pix[offset+4] = uint8(value >> 8)
|
||||
out.Pix[offset+5] = uint8(value)
|
||||
value = floatToUint16(rgba[3] / sum)
|
||||
out.Pix[offset+6] = uint8(value >> 8)
|
||||
out.Pix[offset+7] = uint8(value)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
func nearestRGBA(in *image.RGBA, out *image.RGBA, scale float64, coeffs []bool, offset []int, filterLength int) {
|
||||
oldBounds := in.Bounds()
|
||||
newBounds := out.Bounds()
|
||||
minX := oldBounds.Min.X * 4
|
||||
maxX := (oldBounds.Max.X - oldBounds.Min.X - 1) * 4
|
||||
|
||||
for x := newBounds.Min.X; x < newBounds.Max.X; x++ {
|
||||
row := in.Pix[(x-oldBounds.Min.Y)*in.Stride:]
|
||||
for y := newBounds.Min.Y; y < newBounds.Max.Y; y++ {
|
||||
var rgba [4]float32
|
||||
var sum float32
|
||||
start := offset[y]
|
||||
ci := (y - newBounds.Min.Y) * filterLength
|
||||
for i := 0; i < filterLength; i++ {
|
||||
if coeffs[ci+i] {
|
||||
xi := start + i
|
||||
switch {
|
||||
case uint(xi) < uint(oldBounds.Max.X):
|
||||
xi *= 4
|
||||
case xi >= oldBounds.Max.X:
|
||||
xi = maxX
|
||||
default:
|
||||
xi = minX
|
||||
}
|
||||
rgba[0] += float32(row[xi+0])
|
||||
rgba[1] += float32(row[xi+1])
|
||||
rgba[2] += float32(row[xi+2])
|
||||
rgba[3] += float32(row[xi+3])
|
||||
sum++
|
||||
}
|
||||
}
|
||||
|
||||
xo := (y-newBounds.Min.Y)*out.Stride + (x-newBounds.Min.X)*4
|
||||
out.Pix[xo+0] = floatToUint8(rgba[0] / sum)
|
||||
out.Pix[xo+1] = floatToUint8(rgba[1] / sum)
|
||||
out.Pix[xo+2] = floatToUint8(rgba[2] / sum)
|
||||
out.Pix[xo+3] = floatToUint8(rgba[3] / sum)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
func nearestRGBA64(in *image.RGBA64, out *image.RGBA64, scale float64, coeffs []bool, offset []int, filterLength int) {
|
||||
oldBounds := in.Bounds()
|
||||
newBounds := out.Bounds()
|
||||
minX := oldBounds.Min.X * 8
|
||||
maxX := (oldBounds.Max.X - oldBounds.Min.X - 1) * 8
|
||||
|
||||
for x := newBounds.Min.X; x < newBounds.Max.X; x++ {
|
||||
row := in.Pix[(x-oldBounds.Min.Y)*in.Stride:]
|
||||
for y := newBounds.Min.Y; y < newBounds.Max.Y; y++ {
|
||||
var rgba [4]float32
|
||||
var sum float32
|
||||
start := offset[y]
|
||||
ci := (y - newBounds.Min.Y) * filterLength
|
||||
for i := 0; i < filterLength; i++ {
|
||||
if coeffs[ci+i] {
|
||||
xi := start + i
|
||||
switch {
|
||||
case uint(xi) < uint(oldBounds.Max.X):
|
||||
xi *= 8
|
||||
case xi >= oldBounds.Max.X:
|
||||
xi = maxX
|
||||
default:
|
||||
xi = minX
|
||||
}
|
||||
rgba[0] += float32(uint16(row[xi+0])<<8 | uint16(row[xi+1]))
|
||||
rgba[1] += float32(uint16(row[xi+2])<<8 | uint16(row[xi+3]))
|
||||
rgba[2] += float32(uint16(row[xi+4])<<8 | uint16(row[xi+5]))
|
||||
rgba[3] += float32(uint16(row[xi+6])<<8 | uint16(row[xi+7]))
|
||||
sum++
|
||||
}
|
||||
}
|
||||
|
||||
xo := (y-newBounds.Min.Y)*out.Stride + (x-newBounds.Min.X)*8
|
||||
value := floatToUint16(rgba[0] / sum)
|
||||
out.Pix[xo+0] = uint8(value >> 8)
|
||||
out.Pix[xo+1] = uint8(value)
|
||||
value = floatToUint16(rgba[1] / sum)
|
||||
out.Pix[xo+2] = uint8(value >> 8)
|
||||
out.Pix[xo+3] = uint8(value)
|
||||
value = floatToUint16(rgba[2] / sum)
|
||||
out.Pix[xo+4] = uint8(value >> 8)
|
||||
out.Pix[xo+5] = uint8(value)
|
||||
value = floatToUint16(rgba[3] / sum)
|
||||
out.Pix[xo+6] = uint8(value >> 8)
|
||||
out.Pix[xo+7] = uint8(value)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
func nearestGray(in *image.Gray, out *image.Gray, scale float64, coeffs []bool, offset []int, filterLength int) {
|
||||
oldBounds := in.Bounds()
|
||||
newBounds := out.Bounds()
|
||||
minX := oldBounds.Min.X
|
||||
maxX := (oldBounds.Max.X - oldBounds.Min.X - 1)
|
||||
|
||||
for x := newBounds.Min.X; x < newBounds.Max.X; x++ {
|
||||
row := in.Pix[(x-oldBounds.Min.Y)*in.Stride:]
|
||||
for y := newBounds.Min.Y; y < newBounds.Max.Y; y++ {
|
||||
var gray float32
|
||||
var sum float32
|
||||
start := offset[y]
|
||||
ci := (y - newBounds.Min.Y) * filterLength
|
||||
for i := 0; i < filterLength; i++ {
|
||||
if coeffs[ci+i] {
|
||||
xi := start + i
|
||||
switch {
|
||||
case uint(xi) < uint(oldBounds.Max.X):
|
||||
break
|
||||
case xi >= oldBounds.Max.X:
|
||||
xi = maxX
|
||||
default:
|
||||
xi = minX
|
||||
}
|
||||
gray += float32(row[xi])
|
||||
sum++
|
||||
}
|
||||
}
|
||||
|
||||
offset := (y-newBounds.Min.Y)*out.Stride + (x - newBounds.Min.X)
|
||||
out.Pix[offset] = floatToUint8(gray / sum)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
func nearestGray16(in *image.Gray16, out *image.Gray16, scale float64, coeffs []bool, offset []int, filterLength int) {
|
||||
oldBounds := in.Bounds()
|
||||
newBounds := out.Bounds()
|
||||
minX := oldBounds.Min.X * 2
|
||||
maxX := (oldBounds.Max.X - oldBounds.Min.X - 1) * 2
|
||||
|
||||
for x := newBounds.Min.X; x < newBounds.Max.X; x++ {
|
||||
row := in.Pix[(x-oldBounds.Min.Y)*in.Stride:]
|
||||
for y := newBounds.Min.Y; y < newBounds.Max.Y; y++ {
|
||||
var gray float32
|
||||
var sum float32
|
||||
start := offset[y]
|
||||
ci := (y - newBounds.Min.Y) * filterLength
|
||||
for i := 0; i < filterLength; i++ {
|
||||
if coeffs[ci+i] {
|
||||
xi := start + i
|
||||
switch {
|
||||
case uint(xi) < uint(oldBounds.Max.X):
|
||||
xi *= 2
|
||||
case xi >= oldBounds.Max.X:
|
||||
xi = maxX
|
||||
default:
|
||||
xi = minX
|
||||
}
|
||||
gray += float32(uint16(row[xi+0])<<8 | uint16(row[xi+1]))
|
||||
sum++
|
||||
}
|
||||
}
|
||||
|
||||
offset := (y-newBounds.Min.Y)*out.Stride + (x-newBounds.Min.X)*2
|
||||
value := floatToUint16(gray / sum)
|
||||
out.Pix[offset+0] = uint8(value >> 8)
|
||||
out.Pix[offset+1] = uint8(value)
|
||||
}
|
||||
}
|
||||
}
|
||||
57
nearest_test.go
Normal file
57
nearest_test.go
Normal file
|
|
@ -0,0 +1,57 @@
|
|||
/*
|
||||
Copyright (c) 2014, Charlie Vieth <charlie.vieth@gmail.com>
|
||||
|
||||
Permission to use, copy, modify, and/or distribute this software for any purpose
|
||||
with or without fee is hereby granted, provided that the above copyright notice
|
||||
and this permission notice appear in all copies.
|
||||
|
||||
THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
|
||||
REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
|
||||
FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
|
||||
INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
|
||||
OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
|
||||
TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF
|
||||
THIS SOFTWARE.
|
||||
*/
|
||||
|
||||
package resize
|
||||
|
||||
import "testing"
|
||||
|
||||
func Test_FloatToUint8(t *testing.T) {
|
||||
var testData = []struct {
|
||||
in float32
|
||||
expected uint8
|
||||
}{
|
||||
{0, 0},
|
||||
{255, 255},
|
||||
{128, 128},
|
||||
{1, 1},
|
||||
{256, 255},
|
||||
}
|
||||
for _, test := range testData {
|
||||
actual := floatToUint8(test.in)
|
||||
if actual != test.expected {
|
||||
t.Fail()
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
func Test_FloatToUint16(t *testing.T) {
|
||||
var testData = []struct {
|
||||
in float32
|
||||
expected uint16
|
||||
}{
|
||||
{0, 0},
|
||||
{65535, 65535},
|
||||
{128, 128},
|
||||
{1, 1},
|
||||
{65536, 65535},
|
||||
}
|
||||
for _, test := range testData {
|
||||
actual := floatToUint16(test.in)
|
||||
if actual != test.expected {
|
||||
t.Fail()
|
||||
}
|
||||
}
|
||||
}
|
||||
305
resize.go
305
resize.go
|
|
@ -33,36 +33,41 @@ import (
|
|||
// An InterpolationFunction provides the parameters that describe an
|
||||
// interpolation kernel. It returns the number of samples to take
|
||||
// and the kernel function to use for sampling.
|
||||
type InterpolationFunction func() (int, func(float64) float64)
|
||||
type InterpolationFunction int
|
||||
|
||||
// Nearest-neighbor interpolation
|
||||
func NearestNeighbor() (int, func(float64) float64) {
|
||||
return 2, nearest
|
||||
}
|
||||
// InterpolationFunction constants
|
||||
const (
|
||||
// Nearest-neighbor interpolation
|
||||
NearestNeighbor InterpolationFunction = iota
|
||||
// Bilinear interpolation
|
||||
Bilinear
|
||||
// Bicubic interpolation (with cubic hermite spline)
|
||||
Bicubic
|
||||
// Mitchell-Netravali interpolation
|
||||
MitchellNetravali
|
||||
// Lanczos interpolation (a=2)
|
||||
Lanczos2
|
||||
// Lanczos interpolation (a=3)
|
||||
Lanczos3
|
||||
)
|
||||
|
||||
// Bilinear interpolation
|
||||
func Bilinear() (int, func(float64) float64) {
|
||||
// kernal, returns an InterpolationFunctions taps and kernel.
|
||||
func (i InterpolationFunction) kernel() (int, func(float64) float64) {
|
||||
switch i {
|
||||
case Bilinear:
|
||||
return 2, linear
|
||||
}
|
||||
|
||||
// Bicubic interpolation (with cubic hermite spline)
|
||||
func Bicubic() (int, func(float64) float64) {
|
||||
case Bicubic:
|
||||
return 4, cubic
|
||||
}
|
||||
|
||||
// Mitchell-Netravali interpolation
|
||||
func MitchellNetravali() (int, func(float64) float64) {
|
||||
case MitchellNetravali:
|
||||
return 4, mitchellnetravali
|
||||
}
|
||||
|
||||
// Lanczos interpolation (a=2)
|
||||
func Lanczos2() (int, func(float64) float64) {
|
||||
case Lanczos2:
|
||||
return 4, lanczos2
|
||||
}
|
||||
|
||||
// Lanczos interpolation (a=3)
|
||||
func Lanczos3() (int, func(float64) float64) {
|
||||
case Lanczos3:
|
||||
return 6, lanczos3
|
||||
default:
|
||||
// Default to NearestNeighbor.
|
||||
return 2, nearest
|
||||
}
|
||||
}
|
||||
|
||||
// values <1 will sharpen the image
|
||||
|
|
@ -81,8 +86,11 @@ func Resize(width, height uint, img image.Image, interp InterpolationFunction) i
|
|||
if height == 0 {
|
||||
height = uint(0.7 + float64(img.Bounds().Dy())/scaleY)
|
||||
}
|
||||
if interp == NearestNeighbor {
|
||||
return resizeNearest(width, height, scaleX, scaleY, img, interp)
|
||||
}
|
||||
|
||||
taps, kernel := interp()
|
||||
taps, kernel := interp.kernel()
|
||||
cpus := runtime.NumCPU()
|
||||
wg := sync.WaitGroup{}
|
||||
|
||||
|
|
@ -95,25 +103,25 @@ func Resize(width, height uint, img image.Image, interp InterpolationFunction) i
|
|||
result := image.NewRGBA(image.Rect(0, 0, int(width), int(height)))
|
||||
|
||||
// horizontal filter, results in transposed temporary image
|
||||
coeffs, filterLength := createWeights8(temp.Bounds().Dy(), input.Bounds().Min.X, taps, blur, scaleX, kernel)
|
||||
coeffs, offset, filterLength := createWeights8(temp.Bounds().Dy(), input.Bounds().Min.X, taps, blur, scaleX, kernel)
|
||||
wg.Add(cpus)
|
||||
for i := 0; i < cpus; i++ {
|
||||
slice := makeSlice(temp, i, cpus).(*image.RGBA)
|
||||
go func() {
|
||||
defer wg.Done()
|
||||
resizeRGBA(input, slice, scaleX, coeffs, filterLength)
|
||||
resizeRGBA(input, slice, scaleX, coeffs, offset, filterLength)
|
||||
}()
|
||||
}
|
||||
wg.Wait()
|
||||
|
||||
// horizontal filter on transposed image, result is not transposed
|
||||
coeffs, filterLength = createWeights8(result.Bounds().Dy(), temp.Bounds().Min.X, taps, blur, scaleY, kernel)
|
||||
coeffs, offset, filterLength = createWeights8(result.Bounds().Dy(), temp.Bounds().Min.X, taps, blur, scaleY, kernel)
|
||||
wg.Add(cpus)
|
||||
for i := 0; i < cpus; i++ {
|
||||
slice := makeSlice(result, i, cpus).(*image.RGBA)
|
||||
go func() {
|
||||
defer wg.Done()
|
||||
resizeRGBA(temp, slice, scaleY, coeffs, filterLength)
|
||||
resizeRGBA(temp, slice, scaleY, coeffs, offset, filterLength)
|
||||
}()
|
||||
}
|
||||
wg.Wait()
|
||||
|
|
@ -121,60 +129,58 @@ func Resize(width, height uint, img image.Image, interp InterpolationFunction) i
|
|||
case *image.YCbCr:
|
||||
// 8-bit precision
|
||||
// accessing the YCbCr arrays in a tight loop is slow.
|
||||
// converting the image before filtering will improve performance.
|
||||
inputAsRGBA := convertYCbCrToRGBA(input)
|
||||
temp := image.NewRGBA(image.Rect(0, 0, input.Bounds().Dy(), int(width)))
|
||||
result := image.NewRGBA(image.Rect(0, 0, int(width), int(height)))
|
||||
// converting the image to ycc increases performance by 2x.
|
||||
temp := newYCC(image.Rect(0, 0, input.Bounds().Dy(), int(width)), input.SubsampleRatio)
|
||||
result := newYCC(image.Rect(0, 0, int(width), int(height)), input.SubsampleRatio)
|
||||
|
||||
// horizontal filter, results in transposed temporary image
|
||||
coeffs, filterLength := createWeights8(temp.Bounds().Dy(), input.Bounds().Min.X, taps, blur, scaleX, kernel)
|
||||
coeffs, offset, filterLength := createWeights8(temp.Bounds().Dy(), input.Bounds().Min.X, taps, blur, scaleX, kernel)
|
||||
in := imageYCbCrToYCC(input)
|
||||
wg.Add(cpus)
|
||||
for i := 0; i < cpus; i++ {
|
||||
slice := makeSlice(temp, i, cpus).(*image.RGBA)
|
||||
slice := makeSlice(temp, i, cpus).(*ycc)
|
||||
go func() {
|
||||
defer wg.Done()
|
||||
resizeRGBA(inputAsRGBA, slice, scaleX, coeffs, filterLength)
|
||||
resizeYCbCr(in, slice, scaleX, coeffs, offset, filterLength)
|
||||
}()
|
||||
}
|
||||
wg.Wait()
|
||||
|
||||
// horizontal filter on transposed image, result is not transposed
|
||||
coeffs, filterLength = createWeights8(result.Bounds().Dy(), temp.Bounds().Min.X, taps, blur, scaleY, kernel)
|
||||
coeffs, offset, filterLength = createWeights8(result.Bounds().Dy(), temp.Bounds().Min.X, taps, blur, scaleY, kernel)
|
||||
wg.Add(cpus)
|
||||
for i := 0; i < cpus; i++ {
|
||||
slice := makeSlice(result, i, cpus).(*image.RGBA)
|
||||
slice := makeSlice(result, i, cpus).(*ycc)
|
||||
go func() {
|
||||
defer wg.Done()
|
||||
resizeRGBA(temp, slice, scaleY, coeffs, filterLength)
|
||||
resizeYCbCr(temp, slice, scaleY, coeffs, offset, filterLength)
|
||||
}()
|
||||
}
|
||||
wg.Wait()
|
||||
return result
|
||||
return result.YCbCr()
|
||||
case *image.RGBA64:
|
||||
// 16-bit precision
|
||||
temp := image.NewRGBA64(image.Rect(0, 0, input.Bounds().Dy(), int(width)))
|
||||
result := image.NewRGBA64(image.Rect(0, 0, int(width), int(height)))
|
||||
|
||||
// horizontal filter, results in transposed temporary image
|
||||
coeffs, filterLength := createWeights16(temp.Bounds().Dy(), input.Bounds().Min.X, taps, blur, scaleX, kernel)
|
||||
coeffs, offset, filterLength := createWeights16(temp.Bounds().Dy(), input.Bounds().Min.X, taps, blur, scaleX, kernel)
|
||||
wg.Add(cpus)
|
||||
for i := 0; i < cpus; i++ {
|
||||
slice := makeSlice(temp, i, cpus).(*image.RGBA64)
|
||||
go func() {
|
||||
defer wg.Done()
|
||||
resizeRGBA64(input, slice, scaleX, coeffs, filterLength)
|
||||
resizeRGBA64(input, slice, scaleX, coeffs, offset, filterLength)
|
||||
}()
|
||||
}
|
||||
wg.Wait()
|
||||
|
||||
// horizontal filter on transposed image, result is not transposed
|
||||
coeffs, filterLength = createWeights16(result.Bounds().Dy(), temp.Bounds().Min.X, taps, blur, scaleY, kernel)
|
||||
coeffs, offset, filterLength = createWeights16(result.Bounds().Dy(), temp.Bounds().Min.X, taps, blur, scaleY, kernel)
|
||||
wg.Add(cpus)
|
||||
for i := 0; i < cpus; i++ {
|
||||
slice := makeSlice(result, i, cpus).(*image.RGBA64)
|
||||
go func() {
|
||||
defer wg.Done()
|
||||
resizeGeneric(temp, slice, scaleY, coeffs, filterLength)
|
||||
resizeGeneric(temp, slice, scaleY, coeffs, offset, filterLength)
|
||||
}()
|
||||
}
|
||||
wg.Wait()
|
||||
|
|
@ -185,25 +191,25 @@ func Resize(width, height uint, img image.Image, interp InterpolationFunction) i
|
|||
result := image.NewGray(image.Rect(0, 0, int(width), int(height)))
|
||||
|
||||
// horizontal filter, results in transposed temporary image
|
||||
coeffs, filterLength := createWeights8(temp.Bounds().Dy(), input.Bounds().Min.X, taps, blur, scaleX, kernel)
|
||||
coeffs, offset, filterLength := createWeights8(temp.Bounds().Dy(), input.Bounds().Min.X, taps, blur, scaleX, kernel)
|
||||
wg.Add(cpus)
|
||||
for i := 0; i < cpus; i++ {
|
||||
slice := makeSlice(temp, i, cpus).(*image.Gray)
|
||||
go func() {
|
||||
defer wg.Done()
|
||||
resizeGray(input, slice, scaleX, coeffs, filterLength)
|
||||
resizeGray(input, slice, scaleX, coeffs, offset, filterLength)
|
||||
}()
|
||||
}
|
||||
wg.Wait()
|
||||
|
||||
// horizontal filter on transposed image, result is not transposed
|
||||
coeffs, filterLength = createWeights8(result.Bounds().Dy(), temp.Bounds().Min.X, taps, blur, scaleY, kernel)
|
||||
coeffs, offset, filterLength = createWeights8(result.Bounds().Dy(), temp.Bounds().Min.X, taps, blur, scaleY, kernel)
|
||||
wg.Add(cpus)
|
||||
for i := 0; i < cpus; i++ {
|
||||
slice := makeSlice(result, i, cpus).(*image.Gray)
|
||||
go func() {
|
||||
defer wg.Done()
|
||||
resizeGray(temp, slice, scaleY, coeffs, filterLength)
|
||||
resizeGray(temp, slice, scaleY, coeffs, offset, filterLength)
|
||||
}()
|
||||
}
|
||||
wg.Wait()
|
||||
|
|
@ -214,25 +220,25 @@ func Resize(width, height uint, img image.Image, interp InterpolationFunction) i
|
|||
result := image.NewGray16(image.Rect(0, 0, int(width), int(height)))
|
||||
|
||||
// horizontal filter, results in transposed temporary image
|
||||
coeffs, filterLength := createWeights16(temp.Bounds().Dy(), input.Bounds().Min.X, taps, blur, scaleX, kernel)
|
||||
coeffs, offset, filterLength := createWeights16(temp.Bounds().Dy(), input.Bounds().Min.X, taps, blur, scaleX, kernel)
|
||||
wg.Add(cpus)
|
||||
for i := 0; i < cpus; i++ {
|
||||
slice := makeSlice(temp, i, cpus).(*image.Gray16)
|
||||
go func() {
|
||||
defer wg.Done()
|
||||
resizeGray16(input, slice, scaleX, coeffs, filterLength)
|
||||
resizeGray16(input, slice, scaleX, coeffs, offset, filterLength)
|
||||
}()
|
||||
}
|
||||
wg.Wait()
|
||||
|
||||
// horizontal filter on transposed image, result is not transposed
|
||||
coeffs, filterLength = createWeights16(result.Bounds().Dy(), temp.Bounds().Min.X, taps, blur, scaleY, kernel)
|
||||
coeffs, offset, filterLength = createWeights16(result.Bounds().Dy(), temp.Bounds().Min.X, taps, blur, scaleY, kernel)
|
||||
wg.Add(cpus)
|
||||
for i := 0; i < cpus; i++ {
|
||||
slice := makeSlice(result, i, cpus).(*image.Gray16)
|
||||
go func() {
|
||||
defer wg.Done()
|
||||
resizeGray16(temp, slice, scaleY, coeffs, filterLength)
|
||||
resizeGray16(temp, slice, scaleY, coeffs, offset, filterLength)
|
||||
}()
|
||||
}
|
||||
wg.Wait()
|
||||
|
|
@ -243,25 +249,25 @@ func Resize(width, height uint, img image.Image, interp InterpolationFunction) i
|
|||
result := image.NewRGBA64(image.Rect(0, 0, int(width), int(height)))
|
||||
|
||||
// horizontal filter, results in transposed temporary image
|
||||
coeffs, filterLength := createWeights16(temp.Bounds().Dy(), img.Bounds().Min.X, taps, blur, scaleX, kernel)
|
||||
coeffs, offset, filterLength := createWeights16(temp.Bounds().Dy(), img.Bounds().Min.X, taps, blur, scaleX, kernel)
|
||||
wg.Add(cpus)
|
||||
for i := 0; i < cpus; i++ {
|
||||
slice := makeSlice(temp, i, cpus).(*image.RGBA64)
|
||||
go func() {
|
||||
defer wg.Done()
|
||||
resizeGeneric(img, slice, scaleX, coeffs, filterLength)
|
||||
resizeGeneric(img, slice, scaleX, coeffs, offset, filterLength)
|
||||
}()
|
||||
}
|
||||
wg.Wait()
|
||||
|
||||
// horizontal filter on transposed image, result is not transposed
|
||||
coeffs, filterLength = createWeights16(result.Bounds().Dy(), temp.Bounds().Min.X, taps, blur, scaleY, kernel)
|
||||
coeffs, offset, filterLength = createWeights16(result.Bounds().Dy(), temp.Bounds().Min.X, taps, blur, scaleY, kernel)
|
||||
wg.Add(cpus)
|
||||
for i := 0; i < cpus; i++ {
|
||||
slice := makeSlice(result, i, cpus).(*image.RGBA64)
|
||||
go func() {
|
||||
defer wg.Done()
|
||||
resizeRGBA64(temp, slice, scaleY, coeffs, filterLength)
|
||||
resizeRGBA64(temp, slice, scaleY, coeffs, offset, filterLength)
|
||||
}()
|
||||
}
|
||||
wg.Wait()
|
||||
|
|
@ -269,6 +275,191 @@ func Resize(width, height uint, img image.Image, interp InterpolationFunction) i
|
|||
}
|
||||
}
|
||||
|
||||
func resizeNearest(width, height uint, scaleX, scaleY float64, img image.Image, interp InterpolationFunction) image.Image {
|
||||
taps, _ := interp.kernel()
|
||||
cpus := runtime.NumCPU()
|
||||
wg := sync.WaitGroup{}
|
||||
|
||||
switch input := img.(type) {
|
||||
case *image.RGBA:
|
||||
// 8-bit precision
|
||||
temp := image.NewRGBA(image.Rect(0, 0, input.Bounds().Dy(), int(width)))
|
||||
result := image.NewRGBA(image.Rect(0, 0, int(width), int(height)))
|
||||
|
||||
// horizontal filter, results in transposed temporary image
|
||||
coeffs, offset, filterLength := createWeightsNearest(temp.Bounds().Dy(), input.Bounds().Min.X, taps, blur, scaleX)
|
||||
wg.Add(cpus)
|
||||
for i := 0; i < cpus; i++ {
|
||||
slice := makeSlice(temp, i, cpus).(*image.RGBA)
|
||||
go func() {
|
||||
defer wg.Done()
|
||||
nearestRGBA(input, slice, scaleX, coeffs, offset, filterLength)
|
||||
}()
|
||||
}
|
||||
wg.Wait()
|
||||
|
||||
// horizontal filter on transposed image, result is not transposed
|
||||
coeffs, offset, filterLength = createWeightsNearest(result.Bounds().Dy(), temp.Bounds().Min.X, taps, blur, scaleY)
|
||||
wg.Add(cpus)
|
||||
for i := 0; i < cpus; i++ {
|
||||
slice := makeSlice(result, i, cpus).(*image.RGBA)
|
||||
go func() {
|
||||
defer wg.Done()
|
||||
nearestRGBA(temp, slice, scaleY, coeffs, offset, filterLength)
|
||||
}()
|
||||
}
|
||||
wg.Wait()
|
||||
return result
|
||||
case *image.YCbCr:
|
||||
// 8-bit precision
|
||||
// accessing the YCbCr arrays in a tight loop is slow.
|
||||
// converting the image to ycc increases performance by 2x.
|
||||
temp := newYCC(image.Rect(0, 0, input.Bounds().Dy(), int(width)), input.SubsampleRatio)
|
||||
result := newYCC(image.Rect(0, 0, int(width), int(height)), input.SubsampleRatio)
|
||||
|
||||
coeffs, offset, filterLength := createWeightsNearest(temp.Bounds().Dy(), input.Bounds().Min.X, taps, blur, scaleX)
|
||||
in := imageYCbCrToYCC(input)
|
||||
wg.Add(cpus)
|
||||
for i := 0; i < cpus; i++ {
|
||||
slice := makeSlice(temp, i, cpus).(*ycc)
|
||||
go func() {
|
||||
defer wg.Done()
|
||||
nearestYCbCr(in, slice, scaleX, coeffs, offset, filterLength)
|
||||
}()
|
||||
}
|
||||
wg.Wait()
|
||||
|
||||
coeffs, offset, filterLength = createWeightsNearest(result.Bounds().Dy(), temp.Bounds().Min.X, taps, blur, scaleY)
|
||||
wg.Add(cpus)
|
||||
for i := 0; i < cpus; i++ {
|
||||
slice := makeSlice(result, i, cpus).(*ycc)
|
||||
go func() {
|
||||
defer wg.Done()
|
||||
nearestYCbCr(temp, slice, scaleY, coeffs, offset, filterLength)
|
||||
}()
|
||||
}
|
||||
wg.Wait()
|
||||
return result.YCbCr()
|
||||
case *image.RGBA64:
|
||||
// 16-bit precision
|
||||
temp := image.NewRGBA64(image.Rect(0, 0, input.Bounds().Dy(), int(width)))
|
||||
result := image.NewRGBA64(image.Rect(0, 0, int(width), int(height)))
|
||||
|
||||
// horizontal filter, results in transposed temporary image
|
||||
coeffs, offset, filterLength := createWeightsNearest(temp.Bounds().Dy(), input.Bounds().Min.X, taps, blur, scaleX)
|
||||
wg.Add(cpus)
|
||||
for i := 0; i < cpus; i++ {
|
||||
slice := makeSlice(temp, i, cpus).(*image.RGBA64)
|
||||
go func() {
|
||||
defer wg.Done()
|
||||
nearestRGBA64(input, slice, scaleX, coeffs, offset, filterLength)
|
||||
}()
|
||||
}
|
||||
wg.Wait()
|
||||
|
||||
// horizontal filter on transposed image, result is not transposed
|
||||
coeffs, offset, filterLength = createWeightsNearest(result.Bounds().Dy(), temp.Bounds().Min.X, taps, blur, scaleY)
|
||||
wg.Add(cpus)
|
||||
for i := 0; i < cpus; i++ {
|
||||
slice := makeSlice(result, i, cpus).(*image.RGBA64)
|
||||
go func() {
|
||||
defer wg.Done()
|
||||
nearestGeneric(temp, slice, scaleY, coeffs, offset, filterLength)
|
||||
}()
|
||||
}
|
||||
wg.Wait()
|
||||
return result
|
||||
case *image.Gray:
|
||||
// 8-bit precision
|
||||
temp := image.NewGray(image.Rect(0, 0, input.Bounds().Dy(), int(width)))
|
||||
result := image.NewGray(image.Rect(0, 0, int(width), int(height)))
|
||||
|
||||
// horizontal filter, results in transposed temporary image
|
||||
coeffs, offset, filterLength := createWeightsNearest(temp.Bounds().Dy(), input.Bounds().Min.X, taps, blur, scaleX)
|
||||
wg.Add(cpus)
|
||||
for i := 0; i < cpus; i++ {
|
||||
slice := makeSlice(temp, i, cpus).(*image.Gray)
|
||||
go func() {
|
||||
defer wg.Done()
|
||||
nearestGray(input, slice, scaleX, coeffs, offset, filterLength)
|
||||
}()
|
||||
}
|
||||
wg.Wait()
|
||||
|
||||
// horizontal filter on transposed image, result is not transposed
|
||||
coeffs, offset, filterLength = createWeightsNearest(result.Bounds().Dy(), temp.Bounds().Min.X, taps, blur, scaleY)
|
||||
wg.Add(cpus)
|
||||
for i := 0; i < cpus; i++ {
|
||||
slice := makeSlice(result, i, cpus).(*image.Gray)
|
||||
go func() {
|
||||
defer wg.Done()
|
||||
nearestGray(temp, slice, scaleY, coeffs, offset, filterLength)
|
||||
}()
|
||||
}
|
||||
wg.Wait()
|
||||
return result
|
||||
case *image.Gray16:
|
||||
// 16-bit precision
|
||||
temp := image.NewGray16(image.Rect(0, 0, input.Bounds().Dy(), int(width)))
|
||||
result := image.NewGray16(image.Rect(0, 0, int(width), int(height)))
|
||||
|
||||
// horizontal filter, results in transposed temporary image
|
||||
coeffs, offset, filterLength := createWeightsNearest(temp.Bounds().Dy(), input.Bounds().Min.X, taps, blur, scaleX)
|
||||
wg.Add(cpus)
|
||||
for i := 0; i < cpus; i++ {
|
||||
slice := makeSlice(temp, i, cpus).(*image.Gray16)
|
||||
go func() {
|
||||
defer wg.Done()
|
||||
nearestGray16(input, slice, scaleX, coeffs, offset, filterLength)
|
||||
}()
|
||||
}
|
||||
wg.Wait()
|
||||
|
||||
// horizontal filter on transposed image, result is not transposed
|
||||
coeffs, offset, filterLength = createWeightsNearest(result.Bounds().Dy(), temp.Bounds().Min.X, taps, blur, scaleY)
|
||||
wg.Add(cpus)
|
||||
for i := 0; i < cpus; i++ {
|
||||
slice := makeSlice(result, i, cpus).(*image.Gray16)
|
||||
go func() {
|
||||
defer wg.Done()
|
||||
nearestGray16(temp, slice, scaleY, coeffs, offset, filterLength)
|
||||
}()
|
||||
}
|
||||
wg.Wait()
|
||||
return result
|
||||
default:
|
||||
// 16-bit precision
|
||||
temp := image.NewRGBA64(image.Rect(0, 0, img.Bounds().Dy(), int(width)))
|
||||
result := image.NewRGBA64(image.Rect(0, 0, int(width), int(height)))
|
||||
|
||||
// horizontal filter, results in transposed temporary image
|
||||
coeffs, offset, filterLength := createWeightsNearest(temp.Bounds().Dy(), img.Bounds().Min.X, taps, blur, scaleX)
|
||||
wg.Add(cpus)
|
||||
for i := 0; i < cpus; i++ {
|
||||
slice := makeSlice(temp, i, cpus).(*image.RGBA64)
|
||||
go func() {
|
||||
defer wg.Done()
|
||||
nearestGeneric(img, slice, scaleX, coeffs, offset, filterLength)
|
||||
}()
|
||||
}
|
||||
wg.Wait()
|
||||
|
||||
// horizontal filter on transposed image, result is not transposed
|
||||
coeffs, offset, filterLength = createWeightsNearest(result.Bounds().Dy(), temp.Bounds().Min.X, taps, blur, scaleY)
|
||||
wg.Add(cpus)
|
||||
for i := 0; i < cpus; i++ {
|
||||
slice := makeSlice(result, i, cpus).(*image.RGBA64)
|
||||
go func() {
|
||||
defer wg.Done()
|
||||
nearestRGBA64(temp, slice, scaleY, coeffs, offset, filterLength)
|
||||
}()
|
||||
}
|
||||
wg.Wait()
|
||||
return result
|
||||
}
|
||||
|
||||
}
|
||||
|
||||
// Calculates scaling factors using old and new image dimensions.
|
||||
func calcFactors(width, height uint, oldWidth, oldHeight float64) (scaleX, scaleY float64) {
|
||||
if width == 0 {
|
||||
|
|
|
|||
226
ycc.go
Normal file
226
ycc.go
Normal file
|
|
@ -0,0 +1,226 @@
|
|||
/*
|
||||
Copyright (c) 2014, Charlie Vieth <charlie.vieth@gmail.com>
|
||||
|
||||
Permission to use, copy, modify, and/or distribute this software for any purpose
|
||||
with or without fee is hereby granted, provided that the above copyright notice
|
||||
and this permission notice appear in all copies.
|
||||
|
||||
THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
|
||||
REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
|
||||
FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
|
||||
INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
|
||||
OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
|
||||
TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF
|
||||
THIS SOFTWARE.
|
||||
*/
|
||||
|
||||
package resize
|
||||
|
||||
import (
|
||||
"image"
|
||||
"image/color"
|
||||
)
|
||||
|
||||
// ycc is an in memory YCbCr image. The Y, Cb and Cr samples are held in a
|
||||
// single slice to increase resizing performance.
|
||||
type ycc struct {
|
||||
// Pix holds the image's pixels, in Y, Cb, Cr order. The pixel at
|
||||
// (x, y) starts at Pix[(y-Rect.Min.Y)*Stride + (x-Rect.Min.X)*3].
|
||||
Pix []uint8
|
||||
// Stride is the Pix stride (in bytes) between vertically adjacent pixels.
|
||||
Stride int
|
||||
// Rect is the image's bounds.
|
||||
Rect image.Rectangle
|
||||
// SubsampleRatio is the subsample ratio of the original YCbCr image.
|
||||
SubsampleRatio image.YCbCrSubsampleRatio
|
||||
}
|
||||
|
||||
// PixOffset returns the index of the first element of Pix that corresponds to
|
||||
// the pixel at (x, y).
|
||||
func (p *ycc) PixOffset(x, y int) int {
|
||||
return (y * p.Stride) + (x * 3)
|
||||
}
|
||||
|
||||
func (p *ycc) Bounds() image.Rectangle {
|
||||
return p.Rect
|
||||
}
|
||||
|
||||
func (p *ycc) ColorModel() color.Model {
|
||||
return color.YCbCrModel
|
||||
}
|
||||
|
||||
func (p *ycc) At(x, y int) color.Color {
|
||||
if !(image.Point{x, y}.In(p.Rect)) {
|
||||
return color.YCbCr{}
|
||||
}
|
||||
i := p.PixOffset(x, y)
|
||||
return color.YCbCr{
|
||||
p.Pix[i+0],
|
||||
p.Pix[i+1],
|
||||
p.Pix[i+2],
|
||||
}
|
||||
}
|
||||
|
||||
func (p *ycc) Opaque() bool {
|
||||
return true
|
||||
}
|
||||
|
||||
// SubImage returns an image representing the portion of the image p visible
|
||||
// through r. The returned value shares pixels with the original image.
|
||||
func (p *ycc) SubImage(r image.Rectangle) image.Image {
|
||||
r = r.Intersect(p.Rect)
|
||||
if r.Empty() {
|
||||
return &ycc{SubsampleRatio: p.SubsampleRatio}
|
||||
}
|
||||
i := p.PixOffset(r.Min.X, r.Min.Y)
|
||||
return &ycc{
|
||||
Pix: p.Pix[i:],
|
||||
Stride: p.Stride,
|
||||
Rect: r,
|
||||
SubsampleRatio: p.SubsampleRatio,
|
||||
}
|
||||
}
|
||||
|
||||
// newYCC returns a new ycc with the given bounds and subsample ratio.
|
||||
func newYCC(r image.Rectangle, s image.YCbCrSubsampleRatio) *ycc {
|
||||
w, h := r.Dx(), r.Dy()
|
||||
buf := make([]uint8, 3*w*h)
|
||||
return &ycc{Pix: buf, Stride: 3 * w, Rect: r, SubsampleRatio: s}
|
||||
}
|
||||
|
||||
// YCbCr converts ycc to a YCbCr image with the same subsample ratio
|
||||
// as the YCbCr image that ycc was generated from.
|
||||
func (p *ycc) YCbCr() *image.YCbCr {
|
||||
ycbcr := image.NewYCbCr(p.Rect, p.SubsampleRatio)
|
||||
var off int
|
||||
|
||||
switch ycbcr.SubsampleRatio {
|
||||
case image.YCbCrSubsampleRatio422:
|
||||
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/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.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
|
||||
}
|
||||
|
||||
// imageYCbCrToYCC converts a YCbCr image to a ycc image for resizing.
|
||||
func imageYCbCrToYCC(in *image.YCbCr) *ycc {
|
||||
w, h := in.Rect.Dx(), in.Rect.Dy()
|
||||
buf := make([]uint8, 3*w*h)
|
||||
p := ycc{Pix: buf, Stride: 3 * w, Rect: in.Rect, SubsampleRatio: in.SubsampleRatio}
|
||||
var off int
|
||||
|
||||
switch in.SubsampleRatio {
|
||||
case image.YCbCrSubsampleRatio422:
|
||||
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/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.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
|
||||
}
|
||||
121
ycc_test.go
Normal file
121
ycc_test.go
Normal file
|
|
@ -0,0 +1,121 @@
|
|||
/*
|
||||
Copyright (c) 2014, Charlie Vieth <charlie.vieth@gmail.com>
|
||||
|
||||
Permission to use, copy, modify, and/or distribute this software for any purpose
|
||||
with or without fee is hereby granted, provided that the above copyright notice
|
||||
and this permission notice appear in all copies.
|
||||
|
||||
THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
|
||||
REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
|
||||
FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
|
||||
INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
|
||||
OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
|
||||
TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF
|
||||
THIS SOFTWARE.
|
||||
*/
|
||||
|
||||
package resize
|
||||
|
||||
import (
|
||||
"image"
|
||||
"testing"
|
||||
)
|
||||
|
||||
type Image interface {
|
||||
image.Image
|
||||
SubImage(image.Rectangle) image.Image
|
||||
}
|
||||
|
||||
func TestImage(t *testing.T) {
|
||||
testImage := []Image{
|
||||
newYCC(image.Rect(0, 0, 10, 10), image.YCbCrSubsampleRatio420),
|
||||
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),
|
||||
}
|
||||
for _, m := range testImage {
|
||||
if !image.Rect(0, 0, 10, 10).Eq(m.Bounds()) {
|
||||
t.Errorf("%T: want bounds %v, got %v",
|
||||
m, image.Rect(0, 0, 10, 10), m.Bounds())
|
||||
continue
|
||||
}
|
||||
m = m.SubImage(image.Rect(3, 2, 9, 8)).(Image)
|
||||
if !image.Rect(3, 2, 9, 8).Eq(m.Bounds()) {
|
||||
t.Errorf("%T: sub-image want bounds %v, got %v",
|
||||
m, image.Rect(3, 2, 9, 8), m.Bounds())
|
||||
continue
|
||||
}
|
||||
// Test that taking an empty sub-image starting at a corner does not panic.
|
||||
m.SubImage(image.Rect(0, 0, 0, 0))
|
||||
m.SubImage(image.Rect(10, 0, 10, 0))
|
||||
m.SubImage(image.Rect(0, 10, 0, 10))
|
||||
m.SubImage(image.Rect(10, 10, 10, 10))
|
||||
}
|
||||
}
|
||||
|
||||
func TestConvertYCbCr(t *testing.T) {
|
||||
testImage := []Image{
|
||||
image.NewYCbCr(image.Rect(0, 0, 50, 50), image.YCbCrSubsampleRatio420),
|
||||
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),
|
||||
}
|
||||
|
||||
for _, img := range testImage {
|
||||
m := img.(*image.YCbCr)
|
||||
for y := m.Rect.Min.Y; y < m.Rect.Max.Y; y++ {
|
||||
for x := m.Rect.Min.X; x < m.Rect.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)
|
||||
}
|
||||
}
|
||||
|
||||
// test conversion from YCbCr to ycc
|
||||
yc := imageYCbCrToYCC(m)
|
||||
for y := m.Rect.Min.Y; y < m.Rect.Max.Y; y++ {
|
||||
for x := m.Rect.Min.X; x < m.Rect.Max.X; x++ {
|
||||
ystride := 3 * (m.Rect.Max.X - m.Rect.Min.X)
|
||||
xstride := 3
|
||||
yi := m.YOffset(x, y)
|
||||
ci := m.COffset(x, y)
|
||||
si := (y * ystride) + (x * xstride)
|
||||
if m.Y[yi] != yc.Pix[si] {
|
||||
t.Errorf("Err Y - found: %d expected: %d x: %d y: %d yi: %d si: %d",
|
||||
m.Y[yi], yc.Pix[si], x, y, yi, si)
|
||||
}
|
||||
if m.Cb[ci] != yc.Pix[si+1] {
|
||||
t.Errorf("Err Cb - found: %d expected: %d x: %d y: %d ci: %d si: %d",
|
||||
m.Cb[ci], yc.Pix[si+1], x, y, ci, si+1)
|
||||
}
|
||||
if m.Cr[ci] != yc.Pix[si+2] {
|
||||
t.Errorf("Err Cr - found: %d expected: %d x: %d y: %d ci: %d si: %d",
|
||||
m.Cr[ci], yc.Pix[si+2], x, y, ci, si+2)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// test conversion from ycc back to YCbCr
|
||||
ym := yc.YCbCr()
|
||||
for y := m.Rect.Min.Y; y < m.Rect.Max.Y; y++ {
|
||||
for x := m.Rect.Min.X; x < m.Rect.Max.X; x++ {
|
||||
yi := m.YOffset(x, y)
|
||||
ci := m.COffset(x, y)
|
||||
if m.Y[yi] != ym.Y[yi] {
|
||||
t.Errorf("Err Y - found: %d expected: %d x: %d y: %d yi: %d",
|
||||
m.Y[yi], ym.Y[yi], x, y, yi)
|
||||
}
|
||||
if m.Cb[ci] != ym.Cb[ci] {
|
||||
t.Errorf("Err Cb - found: %d expected: %d x: %d y: %d ci: %d",
|
||||
m.Cb[ci], ym.Cb[ci], x, y, ci)
|
||||
}
|
||||
if m.Cr[ci] != ym.Cr[ci] {
|
||||
t.Errorf("Err Cr - found: %d expected: %d x: %d y: %d ci: %d",
|
||||
m.Cr[ci], ym.Cr[ci], x, y, ci)
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
Loading…
Reference in New Issue
Block a user