/* 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.RGBA64, 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() 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.RGBA, 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 resizeNRGBA(in *image.NRGBA, out *image.RGBA, 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 } // Forward alpha-premultiplication a := int32(row[xi+3]) r := int32(row[xi+0]) * a r /= 0xff g := int32(row[xi+1]) * a g /= 0xff b := int32(row[xi+2]) * a b /= 0xff rgba[0] += int32(coeff) * r rgba[1] += int32(coeff) * g rgba[2] += int32(coeff) * b rgba[3] += int32(coeff) * 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 resizeRGBA64(in *image.RGBA64, out *image.RGBA64, 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(row[xi+0])<<8 | int64(row[xi+1])) rgba[1] += int64(coeff) * (int64(row[xi+2])<<8 | int64(row[xi+3])) rgba[2] += int64(coeff) * (int64(row[xi+4])<<8 | int64(row[xi+5])) rgba[3] += int64(coeff) * (int64(row[xi+6])<<8 | int64(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 resizeNRGBA64(in *image.NRGBA64, out *image.RGBA64, 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 } // Forward alpha-premultiplication a := int64(uint16(row[xi+6])<<8 | uint16(row[xi+7])) r := int64(uint16(row[xi+0])<<8|uint16(row[xi+1])) * a r /= 0xffff g := int64(uint16(row[xi+2])<<8|uint16(row[xi+3])) * a g /= 0xffff b := int64(uint16(row[xi+4])<<8|uint16(row[xi+5])) * a b /= 0xffff rgba[0] += int64(coeff) * r rgba[1] += int64(coeff) * g rgba[2] += int64(coeff) * b rgba[3] += int64(coeff) * 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 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) } } }