diff options
Diffstat (limited to 'vendor/github.com/disintegration/imaging/effects.go')
| -rw-r--r-- | vendor/github.com/disintegration/imaging/effects.go | 174 |
1 files changed, 82 insertions, 92 deletions
diff --git a/vendor/github.com/disintegration/imaging/effects.go b/vendor/github.com/disintegration/imaging/effects.go index f358a48ea..b16781f12 100644 --- a/vendor/github.com/disintegration/imaging/effects.go +++ b/vendor/github.com/disintegration/imaging/effects.go @@ -18,11 +18,9 @@ func gaussianBlurKernel(x, sigma float64) float64 { // func Blur(img image.Image, sigma float64) *image.NRGBA { if sigma <= 0 { - // sigma parameter must be positive! return Clone(img) } - src := toNRGBA(img) radius := int(math.Ceil(sigma * 3.0)) kernel := make([]float64, radius+1) @@ -30,54 +28,50 @@ func Blur(img image.Image, sigma float64) *image.NRGBA { kernel[i] = gaussianBlurKernel(float64(i), sigma) } - var dst *image.NRGBA - dst = blurHorizontal(src, kernel) - dst = blurVertical(dst, kernel) - - return dst + return blurVertical(blurHorizontal(img, kernel), kernel) } -func blurHorizontal(src *image.NRGBA, kernel []float64) *image.NRGBA { +func blurHorizontal(img image.Image, kernel []float64) *image.NRGBA { + src := newScanner(img) + dst := image.NewNRGBA(image.Rect(0, 0, src.w, src.h)) radius := len(kernel) - 1 - width := src.Bounds().Max.X - height := src.Bounds().Max.Y - - dst := image.NewNRGBA(image.Rect(0, 0, width, height)) - - parallel(width, func(partStart, partEnd int) { - for x := partStart; x < partEnd; x++ { - start := x - radius - if start < 0 { - start = 0 - } - end := x + radius - if end > width-1 { - end = width - 1 - } - - weightSum := 0.0 - for ix := start; ix <= end; ix++ { - weightSum += kernel[absint(x-ix)] - } + parallel(0, src.h, func(ys <-chan int) { + scanLine := make([]uint8, src.w*4) + for y := range ys { + src.scan(0, y, src.w, y+1, scanLine) + for x := 0; x < src.w; x++ { + min := x - radius + if min < 0 { + min = 0 + } + max := x + radius + if max > src.w-1 { + max = src.w - 1 + } - for y := 0; y < height; y++ { - var r, g, b, a float64 - for ix := start; ix <= end; ix++ { + var r, g, b, a, wsum float64 + for ix := min; ix <= max; ix++ { + i := ix * 4 weight := kernel[absint(x-ix)] - i := y*src.Stride + ix*4 - wa := float64(src.Pix[i+3]) * weight - r += float64(src.Pix[i+0]) * wa - g += float64(src.Pix[i+1]) * wa - b += float64(src.Pix[i+2]) * wa + wsum += weight + wa := float64(scanLine[i+3]) * weight + r += float64(scanLine[i+0]) * wa + g += float64(scanLine[i+1]) * wa + b += float64(scanLine[i+2]) * wa a += wa } + if a != 0 { + r /= a + g /= a + b /= a + } j := y*dst.Stride + x*4 - dst.Pix[j+0] = clamp(r / a) - dst.Pix[j+1] = clamp(g / a) - dst.Pix[j+2] = clamp(b / a) - dst.Pix[j+3] = clamp(a / weightSum) + dst.Pix[j+0] = clamp(r) + dst.Pix[j+1] = clamp(g) + dst.Pix[j+2] = clamp(b) + dst.Pix[j+3] = clamp(a / wsum) } } }) @@ -85,47 +79,47 @@ func blurHorizontal(src *image.NRGBA, kernel []float64) *image.NRGBA { return dst } -func blurVertical(src *image.NRGBA, kernel []float64) *image.NRGBA { +func blurVertical(img image.Image, kernel []float64) *image.NRGBA { + src := newScanner(img) + dst := image.NewNRGBA(image.Rect(0, 0, src.w, src.h)) radius := len(kernel) - 1 - width := src.Bounds().Max.X - height := src.Bounds().Max.Y - - dst := image.NewNRGBA(image.Rect(0, 0, width, height)) - - parallel(height, func(partStart, partEnd int) { - for y := partStart; y < partEnd; y++ { - start := y - radius - if start < 0 { - start = 0 - } - - end := y + radius - if end > height-1 { - end = height - 1 - } - weightSum := 0.0 - for iy := start; iy <= end; iy++ { - weightSum += kernel[absint(y-iy)] - } + parallel(0, src.w, func(xs <-chan int) { + scanLine := make([]uint8, src.h*4) + for x := range xs { + src.scan(x, 0, x+1, src.h, scanLine) + for y := 0; y < src.h; y++ { + min := y - radius + if min < 0 { + min = 0 + } + max := y + radius + if max > src.h-1 { + max = src.h - 1 + } - for x := 0; x < width; x++ { - var r, g, b, a float64 - for iy := start; iy <= end; iy++ { + var r, g, b, a, wsum float64 + for iy := min; iy <= max; iy++ { + i := iy * 4 weight := kernel[absint(y-iy)] - i := iy*src.Stride + x*4 - wa := float64(src.Pix[i+3]) * weight - r += float64(src.Pix[i+0]) * wa - g += float64(src.Pix[i+1]) * wa - b += float64(src.Pix[i+2]) * wa + wsum += weight + wa := float64(scanLine[i+3]) * weight + r += float64(scanLine[i+0]) * wa + g += float64(scanLine[i+1]) * wa + b += float64(scanLine[i+2]) * wa a += wa } + if a != 0 { + r /= a + g /= a + b /= a + } j := y*dst.Stride + x*4 - dst.Pix[j+0] = clamp(r / a) - dst.Pix[j+1] = clamp(g / a) - dst.Pix[j+2] = clamp(b / a) - dst.Pix[j+3] = clamp(a / weightSum) + dst.Pix[j+0] = clamp(r) + dst.Pix[j+1] = clamp(g) + dst.Pix[j+2] = clamp(b) + dst.Pix[j+3] = clamp(a / wsum) } } }) @@ -142,31 +136,27 @@ func blurVertical(src *image.NRGBA, kernel []float64) *image.NRGBA { // func Sharpen(img image.Image, sigma float64) *image.NRGBA { if sigma <= 0 { - // sigma parameter must be positive! return Clone(img) } - src := toNRGBA(img) + src := newScanner(img) + dst := image.NewNRGBA(image.Rect(0, 0, src.w, src.h)) blurred := Blur(img, sigma) - width := src.Bounds().Max.X - height := src.Bounds().Max.Y - dst := image.NewNRGBA(image.Rect(0, 0, width, height)) - - parallel(height, func(partStart, partEnd int) { - for y := partStart; y < partEnd; y++ { - for x := 0; x < width; x++ { - i := y*src.Stride + x*4 - for j := 0; j < 4; j++ { - k := i + j - val := int(src.Pix[k])<<1 - int(blurred.Pix[k]) - if val < 0 { - val = 0 - } else if val > 255 { - val = 255 - } - dst.Pix[k] = uint8(val) + parallel(0, src.h, func(ys <-chan int) { + scanLine := make([]uint8, src.w*4) + for y := range ys { + src.scan(0, y, src.w, y+1, scanLine) + j := y * dst.Stride + for i := 0; i < src.w*4; i++ { + val := int(scanLine[i])<<1 - int(blurred.Pix[j]) + if val < 0 { + val = 0 + } else if val > 0xff { + val = 0xff } + dst.Pix[j] = uint8(val) + j++ } } }) |