diff options
Diffstat (limited to 'Godeps/_workspace/src/github.com/disintegration/imaging/effects.go')
| -rw-r--r-- | Godeps/_workspace/src/github.com/disintegration/imaging/effects.go | 187 |
1 files changed, 0 insertions, 187 deletions
diff --git a/Godeps/_workspace/src/github.com/disintegration/imaging/effects.go b/Godeps/_workspace/src/github.com/disintegration/imaging/effects.go deleted file mode 100644 index fe92e10a2..000000000 --- a/Godeps/_workspace/src/github.com/disintegration/imaging/effects.go +++ /dev/null @@ -1,187 +0,0 @@ -package imaging - -import ( - "image" - "math" -) - -func gaussianBlurKernel(x, sigma float64) float64 { - return math.Exp(-(x*x)/(2*sigma*sigma)) / (sigma * math.Sqrt(2*math.Pi)) -} - -// Blur produces a blurred version of the image using a Gaussian function. -// Sigma parameter must be positive and indicates how much the image will be blurred. -// -// Usage example: -// -// dstImage := imaging.Blur(srcImage, 3.5) -// -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) - - for i := 0; i <= radius; i++ { - kernel[i] = gaussianBlurKernel(float64(i), sigma) - } - - var dst *image.NRGBA - dst = blurHorizontal(src, kernel) - dst = blurVertical(dst, kernel) - - return dst -} - -func blurHorizontal(src *image.NRGBA, kernel []float64) *image.NRGBA { - 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)] - } - - for y := 0; y < height; y++ { - - r, g, b, a := 0.0, 0.0, 0.0, 0.0 - for ix := start; ix <= end; ix++ { - weight := kernel[absint(x-ix)] - i := y*src.Stride + ix*4 - r += float64(src.Pix[i+0]) * weight - g += float64(src.Pix[i+1]) * weight - b += float64(src.Pix[i+2]) * weight - a += float64(src.Pix[i+3]) * weight - } - - r = math.Min(math.Max(r/weightSum, 0.0), 255.0) - g = math.Min(math.Max(g/weightSum, 0.0), 255.0) - b = math.Min(math.Max(b/weightSum, 0.0), 255.0) - a = math.Min(math.Max(a/weightSum, 0.0), 255.0) - - j := y*dst.Stride + x*4 - dst.Pix[j+0] = uint8(r + 0.5) - dst.Pix[j+1] = uint8(g + 0.5) - dst.Pix[j+2] = uint8(b + 0.5) - dst.Pix[j+3] = uint8(a + 0.5) - - } - } - }) - - return dst -} - -func blurVertical(src *image.NRGBA, kernel []float64) *image.NRGBA { - 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)] - } - - for x := 0; x < width; x++ { - - r, g, b, a := 0.0, 0.0, 0.0, 0.0 - for iy := start; iy <= end; iy++ { - weight := kernel[absint(y-iy)] - i := iy*src.Stride + x*4 - r += float64(src.Pix[i+0]) * weight - g += float64(src.Pix[i+1]) * weight - b += float64(src.Pix[i+2]) * weight - a += float64(src.Pix[i+3]) * weight - } - - r = math.Min(math.Max(r/weightSum, 0.0), 255.0) - g = math.Min(math.Max(g/weightSum, 0.0), 255.0) - b = math.Min(math.Max(b/weightSum, 0.0), 255.0) - a = math.Min(math.Max(a/weightSum, 0.0), 255.0) - - j := y*dst.Stride + x*4 - dst.Pix[j+0] = uint8(r + 0.5) - dst.Pix[j+1] = uint8(g + 0.5) - dst.Pix[j+2] = uint8(b + 0.5) - dst.Pix[j+3] = uint8(a + 0.5) - - } - } - }) - - return dst -} - -// Sharpen produces a sharpened version of the image. -// Sigma parameter must be positive and indicates how much the image will be sharpened. -// -// Usage example: -// -// dstImage := imaging.Sharpen(srcImage, 3.5) -// -func Sharpen(img image.Image, sigma float64) *image.NRGBA { - if sigma <= 0 { - // sigma parameter must be positive! - return Clone(img) - } - - src := toNRGBA(img) - 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]) + (int(src.Pix[k]) - int(blurred.Pix[k])) - if val < 0 { - val = 0 - } else if val > 255 { - val = 255 - } - dst.Pix[k] = uint8(val) - } - } - } - }) - - return dst -} |