diff options
Diffstat (limited to 'Godeps/_workspace/src/github.com/nfnt/resize/resize.go')
| -rw-r--r-- | Godeps/_workspace/src/github.com/nfnt/resize/resize.go | 614 |
1 files changed, 0 insertions, 614 deletions
diff --git a/Godeps/_workspace/src/github.com/nfnt/resize/resize.go b/Godeps/_workspace/src/github.com/nfnt/resize/resize.go deleted file mode 100644 index c1672432e..000000000 --- a/Godeps/_workspace/src/github.com/nfnt/resize/resize.go +++ /dev/null @@ -1,614 +0,0 @@ -/* -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 implements various image resizing methods. -// -// The package works with the Image interface described in the image package. -// Various interpolation methods are provided and multiple processors may be -// utilized in the computations. -// -// Example: -// imgResized := resize.Resize(1000, 0, imgOld, resize.MitchellNetravali) -package resize - -import ( - "image" - "runtime" - "sync" -) - -// 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 int - -// 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 -) - -// kernal, returns an InterpolationFunctions taps and kernel. -func (i InterpolationFunction) kernel() (int, func(float64) float64) { - switch i { - case Bilinear: - return 2, linear - case Bicubic: - return 4, cubic - case MitchellNetravali: - return 4, mitchellnetravali - case Lanczos2: - return 4, lanczos2 - case Lanczos3: - return 6, lanczos3 - default: - // Default to NearestNeighbor. - return 2, nearest - } -} - -// values <1 will sharpen the image -var blur = 1.0 - -// Resize scales an image to new width and height using the interpolation function interp. -// A new image with the given dimensions will be returned. -// If one of the parameters width or height is set to 0, its size will be calculated so that -// the aspect ratio is that of the originating image. -// The resizing algorithm uses channels for parallel computation. -func Resize(width, height uint, img image.Image, interp InterpolationFunction) image.Image { - scaleX, scaleY := calcFactors(width, height, float64(img.Bounds().Dx()), float64(img.Bounds().Dy())) - if width == 0 { - width = uint(0.7 + float64(img.Bounds().Dx())/scaleX) - } - if height == 0 { - height = uint(0.7 + float64(img.Bounds().Dy())/scaleY) - } - - // Trivial case: return input image - if int(width) == img.Bounds().Dx() && int(height) == img.Bounds().Dy() { - return img - } - - if interp == NearestNeighbor { - return resizeNearest(width, height, scaleX, scaleY, img, interp) - } - - taps, kernel := interp.kernel() - cpus := runtime.GOMAXPROCS(0) - wg := sync.WaitGroup{} - - // Generic access to image.Image is slow in tight loops. - // The optimal access has to be determined from the concrete image type. - switch input := img.(type) { - case *image.RGBA: - // 8-bit precision - temp := image.NewNRGBA(image.Rect(0, 0, input.Bounds().Dy(), int(width))) - result := image.NewNRGBA(image.Rect(0, 0, int(width), int(height))) - - // horizontal filter, results in transposed temporary image - coeffs, offset, filterLength := createWeights8(temp.Bounds().Dy(), taps, blur, scaleX, kernel) - wg.Add(cpus) - for i := 0; i < cpus; i++ { - slice := makeSlice(temp, i, cpus).(*image.NRGBA) - go func() { - defer wg.Done() - resizeRGBA(input, slice, scaleX, coeffs, offset, filterLength) - }() - } - wg.Wait() - - // horizontal filter on transposed image, result is not transposed - coeffs, offset, filterLength = createWeights8(result.Bounds().Dy(), taps, blur, scaleY, kernel) - wg.Add(cpus) - for i := 0; i < cpus; i++ { - slice := makeSlice(result, i, cpus).(*image.NRGBA) - go func() { - defer wg.Done() - resizeNRGBA(temp, slice, scaleY, coeffs, offset, filterLength) - }() - } - wg.Wait() - return result - case *image.NRGBA: - // 8-bit precision - temp := image.NewNRGBA(image.Rect(0, 0, input.Bounds().Dy(), int(width))) - result := image.NewNRGBA(image.Rect(0, 0, int(width), int(height))) - - // horizontal filter, results in transposed temporary image - coeffs, offset, filterLength := createWeights8(temp.Bounds().Dy(), taps, blur, scaleX, kernel) - wg.Add(cpus) - for i := 0; i < cpus; i++ { - slice := makeSlice(temp, i, cpus).(*image.NRGBA) - go func() { - defer wg.Done() - resizeNRGBA(input, slice, scaleX, coeffs, offset, filterLength) - }() - } - wg.Wait() - - // horizontal filter on transposed image, result is not transposed - coeffs, offset, filterLength = createWeights8(result.Bounds().Dy(), taps, blur, scaleY, kernel) - wg.Add(cpus) - for i := 0; i < cpus; i++ { - slice := makeSlice(result, i, cpus).(*image.NRGBA) - go func() { - defer wg.Done() - resizeNRGBA(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)), image.YCbCrSubsampleRatio444) - - coeffs, offset, filterLength := createWeights8(temp.Bounds().Dy(), taps, blur, scaleX, kernel) - in := imageYCbCrToYCC(input) - wg.Add(cpus) - for i := 0; i < cpus; i++ { - slice := makeSlice(temp, i, cpus).(*ycc) - go func() { - defer wg.Done() - resizeYCbCr(in, slice, scaleX, coeffs, offset, filterLength) - }() - } - wg.Wait() - - coeffs, offset, filterLength = createWeights8(result.Bounds().Dy(), taps, blur, scaleY, kernel) - wg.Add(cpus) - for i := 0; i < cpus; i++ { - slice := makeSlice(result, i, cpus).(*ycc) - go func() { - defer wg.Done() - resizeYCbCr(temp, slice, scaleY, coeffs, offset, filterLength) - }() - } - wg.Wait() - return result.YCbCr() - case *image.RGBA64: - // 16-bit precision - temp := image.NewNRGBA64(image.Rect(0, 0, input.Bounds().Dy(), int(width))) - result := image.NewNRGBA64(image.Rect(0, 0, int(width), int(height))) - - // horizontal filter, results in transposed temporary image - coeffs, offset, filterLength := createWeights16(temp.Bounds().Dy(), taps, blur, scaleX, kernel) - wg.Add(cpus) - for i := 0; i < cpus; i++ { - slice := makeSlice(temp, i, cpus).(*image.NRGBA64) - go func() { - defer wg.Done() - resizeRGBA64(input, slice, scaleX, coeffs, offset, filterLength) - }() - } - wg.Wait() - - // horizontal filter on transposed image, result is not transposed - coeffs, offset, filterLength = createWeights16(result.Bounds().Dy(), taps, blur, scaleY, kernel) - wg.Add(cpus) - for i := 0; i < cpus; i++ { - slice := makeSlice(result, i, cpus).(*image.NRGBA64) - go func() { - defer wg.Done() - resizeNRGBA64(temp, slice, scaleY, coeffs, offset, filterLength) - }() - } - wg.Wait() - return result - case *image.NRGBA64: - // 16-bit precision - temp := image.NewNRGBA64(image.Rect(0, 0, input.Bounds().Dy(), int(width))) - result := image.NewNRGBA64(image.Rect(0, 0, int(width), int(height))) - - // horizontal filter, results in transposed temporary image - coeffs, offset, filterLength := createWeights16(temp.Bounds().Dy(), taps, blur, scaleX, kernel) - wg.Add(cpus) - for i := 0; i < cpus; i++ { - slice := makeSlice(temp, i, cpus).(*image.NRGBA64) - go func() { - defer wg.Done() - resizeNRGBA64(input, slice, scaleX, coeffs, offset, filterLength) - }() - } - wg.Wait() - - // horizontal filter on transposed image, result is not transposed - coeffs, offset, filterLength = createWeights16(result.Bounds().Dy(), taps, blur, scaleY, kernel) - wg.Add(cpus) - for i := 0; i < cpus; i++ { - slice := makeSlice(result, i, cpus).(*image.NRGBA64) - go func() { - defer wg.Done() - resizeNRGBA64(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 := createWeights8(temp.Bounds().Dy(), 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, offset, filterLength) - }() - } - wg.Wait() - - // horizontal filter on transposed image, result is not transposed - coeffs, offset, filterLength = createWeights8(result.Bounds().Dy(), 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, 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 := createWeights16(temp.Bounds().Dy(), 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, offset, filterLength) - }() - } - wg.Wait() - - // horizontal filter on transposed image, result is not transposed - coeffs, offset, filterLength = createWeights16(result.Bounds().Dy(), 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, offset, filterLength) - }() - } - wg.Wait() - return result - default: - // 16-bit precision - temp := image.NewNRGBA64(image.Rect(0, 0, img.Bounds().Dy(), int(width))) - result := image.NewNRGBA64(image.Rect(0, 0, int(width), int(height))) - - // horizontal filter, results in transposed temporary image - coeffs, offset, filterLength := createWeights16(temp.Bounds().Dy(), taps, blur, scaleX, kernel) - wg.Add(cpus) - for i := 0; i < cpus; i++ { - slice := makeSlice(temp, i, cpus).(*image.NRGBA64) - go func() { - defer wg.Done() - resizeGeneric(img, slice, scaleX, coeffs, offset, filterLength) - }() - } - wg.Wait() - - // horizontal filter on transposed image, result is not transposed - coeffs, offset, filterLength = createWeights16(result.Bounds().Dy(), taps, blur, scaleY, kernel) - wg.Add(cpus) - for i := 0; i < cpus; i++ { - slice := makeSlice(result, i, cpus).(*image.NRGBA64) - go func() { - defer wg.Done() - resizeNRGBA64(temp, slice, scaleY, coeffs, offset, filterLength) - }() - } - wg.Wait() - return result - } -} - -func resizeNearest(width, height uint, scaleX, scaleY float64, img image.Image, interp InterpolationFunction) image.Image { - taps, _ := interp.kernel() - cpus := runtime.GOMAXPROCS(0) - 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(), 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(), 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.NRGBA: - // 8-bit precision - temp := image.NewNRGBA(image.Rect(0, 0, input.Bounds().Dy(), int(width))) - result := image.NewNRGBA(image.Rect(0, 0, int(width), int(height))) - - // horizontal filter, results in transposed temporary image - coeffs, offset, filterLength := createWeightsNearest(temp.Bounds().Dy(), taps, blur, scaleX) - wg.Add(cpus) - for i := 0; i < cpus; i++ { - slice := makeSlice(temp, i, cpus).(*image.NRGBA) - go func() { - defer wg.Done() - nearestNRGBA(input, slice, scaleX, coeffs, offset, filterLength) - }() - } - wg.Wait() - - // horizontal filter on transposed image, result is not transposed - coeffs, offset, filterLength = createWeightsNearest(result.Bounds().Dy(), taps, blur, scaleY) - wg.Add(cpus) - for i := 0; i < cpus; i++ { - slice := makeSlice(result, i, cpus).(*image.NRGBA) - go func() { - defer wg.Done() - nearestNRGBA(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)), image.YCbCrSubsampleRatio444) - - coeffs, offset, filterLength := createWeightsNearest(temp.Bounds().Dy(), 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(), 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(), 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(), 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 - case *image.NRGBA64: - // 16-bit precision - temp := image.NewNRGBA64(image.Rect(0, 0, input.Bounds().Dy(), int(width))) - result := image.NewNRGBA64(image.Rect(0, 0, int(width), int(height))) - - // horizontal filter, results in transposed temporary image - coeffs, offset, filterLength := createWeightsNearest(temp.Bounds().Dy(), taps, blur, scaleX) - wg.Add(cpus) - for i := 0; i < cpus; i++ { - slice := makeSlice(temp, i, cpus).(*image.NRGBA64) - go func() { - defer wg.Done() - nearestNRGBA64(input, slice, scaleX, coeffs, offset, filterLength) - }() - } - wg.Wait() - - // horizontal filter on transposed image, result is not transposed - coeffs, offset, filterLength = createWeightsNearest(result.Bounds().Dy(), taps, blur, scaleY) - wg.Add(cpus) - for i := 0; i < cpus; i++ { - slice := makeSlice(result, i, cpus).(*image.NRGBA64) - go func() { - defer wg.Done() - nearestNRGBA64(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(), 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(), 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(), 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(), 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(), 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(), 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 { - if height == 0 { - scaleX = 1.0 - scaleY = 1.0 - } else { - scaleY = oldHeight / float64(height) - scaleX = scaleY - } - } else { - scaleX = oldWidth / float64(width) - if height == 0 { - scaleY = scaleX - } else { - scaleY = oldHeight / float64(height) - } - } - return -} - -type imageWithSubImage interface { - image.Image - SubImage(image.Rectangle) image.Image -} - -func makeSlice(img imageWithSubImage, i, n int) image.Image { - return img.SubImage(image.Rect(img.Bounds().Min.X, img.Bounds().Min.Y+i*img.Bounds().Dy()/n, img.Bounds().Max.X, img.Bounds().Min.Y+(i+1)*img.Bounds().Dy()/n)) -} |