diff options
Diffstat (limited to 'Godeps/_workspace/src/github.com/nfnt/resize/converter.go')
-rw-r--r-- | Godeps/_workspace/src/github.com/nfnt/resize/converter.go | 452 |
1 files changed, 452 insertions, 0 deletions
diff --git a/Godeps/_workspace/src/github.com/nfnt/resize/converter.go b/Godeps/_workspace/src/github.com/nfnt/resize/converter.go new file mode 100644 index 000000000..84bd284ba --- /dev/null +++ b/Godeps/_workspace/src/github.com/nfnt/resize/converter.go @@ -0,0 +1,452 @@ +/* +Copyright (c) 2012, Jan Schlicht <jan.schlicht@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" + +// Keep value in [0,255] range. +func clampUint8(in int32) uint8 { + // casting a negative int to an uint will result in an overflown + // large uint. this behavior will be exploited here and in other functions + // to achieve a higher performance. + if uint32(in) < 256 { + return uint8(in) + } + if in > 255 { + return 255 + } + return 0 +} + +// Keep value in [0,65535] range. +func clampUint16(in int64) uint16 { + if uint64(in) < 65536 { + return uint16(in) + } + if in > 65535 { + return 65535 + } + return 0 +} + +func resizeGeneric(in image.Image, out *image.NRGBA64, scale float64, coeffs []int32, offset []int, filterLength int) { + newBounds := out.Bounds() + maxX := in.Bounds().Dx() - 1 + + for x := newBounds.Min.X; x < newBounds.Max.X; x++ { + for y := newBounds.Min.Y; y < newBounds.Max.Y; y++ { + var rgba [4]int64 + var sum int64 + start := offset[y] + ci := y * filterLength + for i := 0; i < filterLength; i++ { + coeff := coeffs[ci+i] + if coeff != 0 { + xi := start + i + switch { + case xi < 0: + xi = 0 + case xi >= maxX: + xi = maxX + } + r, g, b, a := in.At(xi+in.Bounds().Min.X, x+in.Bounds().Min.Y).RGBA() + + // reverse alpha-premultiplication. + if a != 0 { + r *= 0xffff + r /= a + g *= 0xffff + g /= a + b *= 0xffff + b /= a + } + + rgba[0] += int64(coeff) * int64(r) + rgba[1] += int64(coeff) * int64(g) + rgba[2] += int64(coeff) * int64(b) + rgba[3] += int64(coeff) * int64(a) + sum += int64(coeff) + } + } + + offset := (y-newBounds.Min.Y)*out.Stride + (x-newBounds.Min.X)*8 + value := clampUint16(rgba[0] / sum) + out.Pix[offset+0] = uint8(value >> 8) + out.Pix[offset+1] = uint8(value) + value = clampUint16(rgba[1] / sum) + out.Pix[offset+2] = uint8(value >> 8) + out.Pix[offset+3] = uint8(value) + value = clampUint16(rgba[2] / sum) + out.Pix[offset+4] = uint8(value >> 8) + out.Pix[offset+5] = uint8(value) + value = clampUint16(rgba[3] / sum) + out.Pix[offset+6] = uint8(value >> 8) + out.Pix[offset+7] = uint8(value) + } + } +} + +func resizeRGBA(in *image.RGBA, out *image.NRGBA, scale float64, coeffs []int16, offset []int, filterLength int) { + newBounds := out.Bounds() + maxX := in.Bounds().Dx() - 1 + + for x := newBounds.Min.X; x < newBounds.Max.X; x++ { + row := in.Pix[x*in.Stride:] + for y := newBounds.Min.Y; y < newBounds.Max.Y; y++ { + var rgba [4]int32 + var sum int32 + start := offset[y] + ci := y * filterLength + for i := 0; i < filterLength; i++ { + coeff := coeffs[ci+i] + if coeff != 0 { + xi := start + i + switch { + case uint(xi) < uint(maxX): + xi *= 4 + case xi >= maxX: + xi = 4 * maxX + default: + xi = 0 + } + + r := uint32(row[xi+0]) + g := uint32(row[xi+1]) + b := uint32(row[xi+2]) + a := uint32(row[xi+3]) + + // reverse alpha-premultiplication. + if a != 0 { + r *= 0xffff + r /= a + g *= 0xffff + g /= a + b *= 0xffff + b /= a + } + + rgba[0] += int32(coeff) * int32(r) + rgba[1] += int32(coeff) * int32(g) + rgba[2] += int32(coeff) * int32(b) + rgba[3] += int32(coeff) * int32(a) + sum += int32(coeff) + } + } + + xo := (y-newBounds.Min.Y)*out.Stride + (x-newBounds.Min.X)*4 + out.Pix[xo+0] = clampUint8(rgba[0] / sum) + out.Pix[xo+1] = clampUint8(rgba[1] / sum) + out.Pix[xo+2] = clampUint8(rgba[2] / sum) + out.Pix[xo+3] = clampUint8(rgba[3] / sum) + } + } +} + +func resizeNRGBA(in *image.NRGBA, out *image.NRGBA, scale float64, coeffs []int16, offset []int, filterLength int) { + newBounds := out.Bounds() + maxX := in.Bounds().Dx() - 1 + + for x := newBounds.Min.X; x < newBounds.Max.X; x++ { + row := in.Pix[x*in.Stride:] + for y := newBounds.Min.Y; y < newBounds.Max.Y; y++ { + var rgba [4]int32 + var sum int32 + start := offset[y] + ci := y * filterLength + for i := 0; i < filterLength; i++ { + coeff := coeffs[ci+i] + if coeff != 0 { + xi := start + i + switch { + case uint(xi) < uint(maxX): + xi *= 4 + case xi >= maxX: + xi = 4 * maxX + default: + xi = 0 + } + rgba[0] += int32(coeff) * int32(row[xi+0]) + rgba[1] += int32(coeff) * int32(row[xi+1]) + rgba[2] += int32(coeff) * int32(row[xi+2]) + rgba[3] += int32(coeff) * int32(row[xi+3]) + sum += int32(coeff) + } + } + + xo := (y-newBounds.Min.Y)*out.Stride + (x-newBounds.Min.X)*4 + out.Pix[xo+0] = clampUint8(rgba[0] / sum) + out.Pix[xo+1] = clampUint8(rgba[1] / sum) + out.Pix[xo+2] = clampUint8(rgba[2] / sum) + out.Pix[xo+3] = clampUint8(rgba[3] / sum) + } + } +} + +func resizeRGBA64(in *image.RGBA64, out *image.NRGBA64, scale float64, coeffs []int32, offset []int, filterLength int) { + newBounds := out.Bounds() + maxX := in.Bounds().Dx() - 1 + + for x := newBounds.Min.X; x < newBounds.Max.X; x++ { + row := in.Pix[x*in.Stride:] + for y := newBounds.Min.Y; y < newBounds.Max.Y; y++ { + var rgba [4]int64 + var sum int64 + start := offset[y] + ci := y * filterLength + for i := 0; i < filterLength; i++ { + coeff := coeffs[ci+i] + if coeff != 0 { + xi := start + i + switch { + case uint(xi) < uint(maxX): + xi *= 8 + case xi >= maxX: + xi = 8 * maxX + default: + xi = 0 + } + + r := uint32(uint16(row[xi+0])<<8 | uint16(row[xi+1])) + g := uint32(uint16(row[xi+2])<<8 | uint16(row[xi+3])) + b := uint32(uint16(row[xi+4])<<8 | uint16(row[xi+5])) + a := uint32(uint16(row[xi+6])<<8 | uint16(row[xi+7])) + + // reverse alpha-premultiplication. + if a != 0 { + r *= 0xffff + r /= a + g *= 0xffff + g /= a + b *= 0xffff + b /= a + } + + rgba[0] += int64(coeff) * int64(r) + rgba[1] += int64(coeff) * int64(g) + rgba[2] += int64(coeff) * int64(b) + rgba[3] += int64(coeff) * int64(a) + sum += int64(coeff) + } + } + + xo := (y-newBounds.Min.Y)*out.Stride + (x-newBounds.Min.X)*8 + value := clampUint16(rgba[0] / sum) + out.Pix[xo+0] = uint8(value >> 8) + out.Pix[xo+1] = uint8(value) + value = clampUint16(rgba[1] / sum) + out.Pix[xo+2] = uint8(value >> 8) + out.Pix[xo+3] = uint8(value) + value = clampUint16(rgba[2] / sum) + out.Pix[xo+4] = uint8(value >> 8) + out.Pix[xo+5] = uint8(value) + value = clampUint16(rgba[3] / sum) + out.Pix[xo+6] = uint8(value >> 8) + out.Pix[xo+7] = uint8(value) + } + } +} + +func resizeNRGBA64(in *image.NRGBA64, out *image.NRGBA64, scale float64, coeffs []int32, offset []int, filterLength int) { + newBounds := out.Bounds() + maxX := in.Bounds().Dx() - 1 + + for x := newBounds.Min.X; x < newBounds.Max.X; x++ { + row := in.Pix[x*in.Stride:] + for y := newBounds.Min.Y; y < newBounds.Max.Y; y++ { + var rgba [4]int64 + var sum int64 + start := offset[y] + ci := y * filterLength + for i := 0; i < filterLength; i++ { + coeff := coeffs[ci+i] + if coeff != 0 { + xi := start + i + switch { + case uint(xi) < uint(maxX): + xi *= 8 + case xi >= maxX: + xi = 8 * maxX + default: + xi = 0 + } + rgba[0] += int64(coeff) * int64(uint16(row[xi+0])<<8|uint16(row[xi+1])) + rgba[1] += int64(coeff) * int64(uint16(row[xi+2])<<8|uint16(row[xi+3])) + rgba[2] += int64(coeff) * int64(uint16(row[xi+4])<<8|uint16(row[xi+5])) + rgba[3] += int64(coeff) * int64(uint16(row[xi+6])<<8|uint16(row[xi+7])) + sum += int64(coeff) + } + } + + xo := (y-newBounds.Min.Y)*out.Stride + (x-newBounds.Min.X)*8 + value := clampUint16(rgba[0] / sum) + out.Pix[xo+0] = uint8(value >> 8) + out.Pix[xo+1] = uint8(value) + value = clampUint16(rgba[1] / sum) + out.Pix[xo+2] = uint8(value >> 8) + out.Pix[xo+3] = uint8(value) + value = clampUint16(rgba[2] / sum) + out.Pix[xo+4] = uint8(value >> 8) + out.Pix[xo+5] = uint8(value) + value = clampUint16(rgba[3] / sum) + out.Pix[xo+6] = uint8(value >> 8) + out.Pix[xo+7] = uint8(value) + } + } +} + +func resizeGray(in *image.Gray, out *image.Gray, scale float64, coeffs []int16, offset []int, filterLength int) { + newBounds := out.Bounds() + maxX := in.Bounds().Dx() - 1 + + for x := newBounds.Min.X; x < newBounds.Max.X; x++ { + row := in.Pix[(x-newBounds.Min.X)*in.Stride:] + for y := newBounds.Min.Y; y < newBounds.Max.Y; y++ { + var gray int32 + var sum int32 + start := offset[y] + ci := y * filterLength + for i := 0; i < filterLength; i++ { + coeff := coeffs[ci+i] + if coeff != 0 { + xi := start + i + switch { + case xi < 0: + xi = 0 + case xi >= maxX: + xi = maxX + } + gray += int32(coeff) * int32(row[xi]) + sum += int32(coeff) + } + } + + offset := (y-newBounds.Min.Y)*out.Stride + (x - newBounds.Min.X) + out.Pix[offset] = clampUint8(gray / sum) + } + } +} + +func resizeGray16(in *image.Gray16, out *image.Gray16, scale float64, coeffs []int32, offset []int, filterLength int) { + newBounds := out.Bounds() + maxX := in.Bounds().Dx() - 1 + + for x := newBounds.Min.X; x < newBounds.Max.X; x++ { + row := in.Pix[x*in.Stride:] + for y := newBounds.Min.Y; y < newBounds.Max.Y; y++ { + var gray int64 + var sum int64 + start := offset[y] + ci := y * filterLength + for i := 0; i < filterLength; i++ { + coeff := coeffs[ci+i] + if coeff != 0 { + xi := start + i + switch { + case uint(xi) < uint(maxX): + xi *= 2 + case xi >= maxX: + xi = 2 * maxX + default: + xi = 0 + } + gray += int64(coeff) * int64(uint16(row[xi+0])<<8|uint16(row[xi+1])) + sum += int64(coeff) + } + } + + offset := (y-newBounds.Min.Y)*out.Stride + (x-newBounds.Min.X)*2 + value := clampUint16(gray / sum) + out.Pix[offset+0] = uint8(value >> 8) + out.Pix[offset+1] = uint8(value) + } + } +} + +func resizeYCbCr(in *ycc, out *ycc, scale float64, coeffs []int16, offset []int, filterLength int) { + newBounds := out.Bounds() + maxX := in.Bounds().Dx() - 1 + + for x := newBounds.Min.X; x < newBounds.Max.X; x++ { + row := in.Pix[x*in.Stride:] + for y := newBounds.Min.Y; y < newBounds.Max.Y; y++ { + var p [3]int32 + var sum int32 + start := offset[y] + ci := y * filterLength + for i := 0; i < filterLength; i++ { + coeff := coeffs[ci+i] + if coeff != 0 { + xi := start + i + switch { + case uint(xi) < uint(maxX): + xi *= 3 + case xi >= maxX: + xi = 3 * maxX + default: + xi = 0 + } + p[0] += int32(coeff) * int32(row[xi+0]) + p[1] += int32(coeff) * int32(row[xi+1]) + p[2] += int32(coeff) * int32(row[xi+2]) + sum += int32(coeff) + } + } + + xo := (y-newBounds.Min.Y)*out.Stride + (x-newBounds.Min.X)*3 + out.Pix[xo+0] = clampUint8(p[0] / sum) + out.Pix[xo+1] = clampUint8(p[1] / sum) + out.Pix[xo+2] = clampUint8(p[2] / sum) + } + } +} + +func nearestYCbCr(in *ycc, out *ycc, scale float64, coeffs []bool, offset []int, filterLength int) { + newBounds := out.Bounds() + maxX := in.Bounds().Dx() - 1 + + for x := newBounds.Min.X; x < newBounds.Max.X; x++ { + row := in.Pix[x*in.Stride:] + for y := newBounds.Min.Y; y < newBounds.Max.Y; y++ { + var p [3]float32 + var sum float32 + start := offset[y] + ci := y * filterLength + for i := 0; i < filterLength; i++ { + if coeffs[ci+i] { + xi := start + i + switch { + case uint(xi) < uint(maxX): + xi *= 3 + case xi >= maxX: + xi = 3 * maxX + default: + xi = 0 + } + 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) + } + } +} |