summaryrefslogtreecommitdiffstats
path: root/vendor/github.com/disintegration/imaging/effects.go
diff options
context:
space:
mode:
Diffstat (limited to 'vendor/github.com/disintegration/imaging/effects.go')
-rw-r--r--vendor/github.com/disintegration/imaging/effects.go169
1 files changed, 0 insertions, 169 deletions
diff --git a/vendor/github.com/disintegration/imaging/effects.go b/vendor/github.com/disintegration/imaging/effects.go
deleted file mode 100644
index 47316b70..00000000
--- a/vendor/github.com/disintegration/imaging/effects.go
+++ /dev/null
@@ -1,169 +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.
-//
-// Example:
-//
-// dstImage := imaging.Blur(srcImage, 3.5)
-//
-func Blur(img image.Image, sigma float64) *image.NRGBA {
- if sigma <= 0 {
- return Clone(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)
- }
-
- return blurVertical(blurHorizontal(img, kernel), kernel)
-}
-
-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
-
- parallel(0, src.h, func(ys <-chan int) {
- scanLine := make([]uint8, src.w*4)
- scanLineF := make([]float64, len(scanLine))
- for y := range ys {
- src.scan(0, y, src.w, y+1, scanLine)
- for i, v := range scanLine {
- scanLineF[i] = float64(v)
- }
- 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
- }
- var r, g, b, a, wsum float64
- for ix := min; ix <= max; ix++ {
- i := ix * 4
- weight := kernel[absint(x-ix)]
- wsum += weight
- s := scanLineF[i : i+4 : i+4]
- wa := s[3] * weight
- r += s[0] * wa
- g += s[1] * wa
- b += s[2] * wa
- a += wa
- }
- if a != 0 {
- aInv := 1 / a
- j := y*dst.Stride + x*4
- d := dst.Pix[j : j+4 : j+4]
- d[0] = clamp(r * aInv)
- d[1] = clamp(g * aInv)
- d[2] = clamp(b * aInv)
- d[3] = clamp(a / wsum)
- }
- }
- }
- })
-
- return dst
-}
-
-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
-
- parallel(0, src.w, func(xs <-chan int) {
- scanLine := make([]uint8, src.h*4)
- scanLineF := make([]float64, len(scanLine))
- for x := range xs {
- src.scan(x, 0, x+1, src.h, scanLine)
- for i, v := range scanLine {
- scanLineF[i] = float64(v)
- }
- 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
- }
- var r, g, b, a, wsum float64
- for iy := min; iy <= max; iy++ {
- i := iy * 4
- weight := kernel[absint(y-iy)]
- wsum += weight
- s := scanLineF[i : i+4 : i+4]
- wa := s[3] * weight
- r += s[0] * wa
- g += s[1] * wa
- b += s[2] * wa
- a += wa
- }
- if a != 0 {
- aInv := 1 / a
- j := y*dst.Stride + x*4
- d := dst.Pix[j : j+4 : j+4]
- d[0] = clamp(r * aInv)
- d[1] = clamp(g * aInv)
- d[2] = clamp(b * aInv)
- d[3] = clamp(a / wsum)
- }
- }
- }
- })
-
- return dst
-}
-
-// Sharpen produces a sharpened version of the image.
-// Sigma parameter must be positive and indicates how much the image will be sharpened.
-//
-// Example:
-//
-// dstImage := imaging.Sharpen(srcImage, 3.5)
-//
-func Sharpen(img image.Image, sigma float64) *image.NRGBA {
- if sigma <= 0 {
- return Clone(img)
- }
-
- src := newScanner(img)
- dst := image.NewNRGBA(image.Rect(0, 0, src.w, src.h))
- blurred := Blur(img, sigma)
-
- 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++
- }
- }
- })
-
- return dst
-}