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authorChristopher Speller <crspeller@gmail.com>2016-05-12 15:08:58 -0400
committerChristopher Speller <crspeller@gmail.com>2016-05-12 16:37:29 -0400
commit84d2482ddbff9564c9ad75b2d30af66e3ddfd44d (patch)
tree8bfa567d2b6381f4a996ada2deff8a16aa85a3ac /vendor/github.com/disintegration
parentd1efb66ad7b017f0fbfe6f0c20843b30f396e504 (diff)
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Updating go depencancies. Switching to go1.6 vendoring (#2949)
Diffstat (limited to 'vendor/github.com/disintegration')
-rw-r--r--vendor/github.com/disintegration/imaging/.travis.yml19
-rw-r--r--vendor/github.com/disintegration/imaging/LICENSE21
-rw-r--r--vendor/github.com/disintegration/imaging/README.md198
-rw-r--r--vendor/github.com/disintegration/imaging/adjust.go200
-rw-r--r--vendor/github.com/disintegration/imaging/effects.go187
-rw-r--r--vendor/github.com/disintegration/imaging/helpers.go400
-rw-r--r--vendor/github.com/disintegration/imaging/resize.go583
-rw-r--r--vendor/github.com/disintegration/imaging/tools.go201
-rw-r--r--vendor/github.com/disintegration/imaging/transform.go201
-rw-r--r--vendor/github.com/disintegration/imaging/utils.go77
10 files changed, 2087 insertions, 0 deletions
diff --git a/vendor/github.com/disintegration/imaging/.travis.yml b/vendor/github.com/disintegration/imaging/.travis.yml
new file mode 100644
index 000000000..3bfcffd01
--- /dev/null
+++ b/vendor/github.com/disintegration/imaging/.travis.yml
@@ -0,0 +1,19 @@
+language: go
+
+sudo: false
+
+go:
+ - 1.2
+ - 1.3
+ - 1.4
+ - 1.5
+ - 1.6
+ - tip
+
+before_install:
+ - go get golang.org/x/tools/cmd/cover
+ - go get github.com/mattn/goveralls
+
+script:
+ - go test -v -covermode=count -coverprofile=coverage.out
+ - $HOME/gopath/bin/goveralls -service=travis-ci -coverprofile=coverage.out
diff --git a/vendor/github.com/disintegration/imaging/LICENSE b/vendor/github.com/disintegration/imaging/LICENSE
new file mode 100644
index 000000000..95ae410c3
--- /dev/null
+++ b/vendor/github.com/disintegration/imaging/LICENSE
@@ -0,0 +1,21 @@
+The MIT License (MIT)
+
+Copyright (c) 2012-2014 Grigory Dryapak
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE. \ No newline at end of file
diff --git a/vendor/github.com/disintegration/imaging/README.md b/vendor/github.com/disintegration/imaging/README.md
new file mode 100644
index 000000000..3dcea2000
--- /dev/null
+++ b/vendor/github.com/disintegration/imaging/README.md
@@ -0,0 +1,198 @@
+# Imaging
+
+[![GoDoc](https://godoc.org/github.com/disintegration/imaging?status.svg)](https://godoc.org/github.com/disintegration/imaging)
+[![Build Status](https://travis-ci.org/disintegration/imaging.svg?branch=master)](https://travis-ci.org/disintegration/imaging)
+[![Coverage Status](https://coveralls.io/repos/github/disintegration/imaging/badge.svg?branch=master)](https://coveralls.io/github/disintegration/imaging?branch=master)
+
+Package imaging provides basic image manipulation functions (resize, rotate, flip, crop, etc.).
+This package is based on the standard Go image package and works best along with it.
+
+Image manipulation functions provided by the package take any image type
+that implements `image.Image` interface as an input, and return a new image of
+`*image.NRGBA` type (32bit RGBA colors, not premultiplied by alpha).
+
+## Installation
+
+Imaging requires Go version 1.2 or greater.
+
+ go get -u github.com/disintegration/imaging
+
+## Documentation
+
+http://godoc.org/github.com/disintegration/imaging
+
+## Usage examples
+
+A few usage examples can be found below. See the documentation for the full list of supported functions.
+
+### Image resizing
+```go
+// resize srcImage to size = 128x128px using the Lanczos filter
+dstImage128 := imaging.Resize(srcImage, 128, 128, imaging.Lanczos)
+
+// resize srcImage to width = 800px preserving the aspect ratio
+dstImage800 := imaging.Resize(srcImage, 800, 0, imaging.Lanczos)
+
+// scale down srcImage to fit the 800x600px bounding box
+dstImageFit := imaging.Fit(srcImage, 800, 600, imaging.Lanczos)
+
+// resize and crop the srcImage to fill the 100x100px area
+dstImageFill := imaging.Fill(srcImage, 100, 100, imaging.Center, imaging.Lanczos)
+```
+
+Imaging supports image resizing using various resampling filters. The most notable ones:
+- `NearestNeighbor` - Fastest resampling filter, no antialiasing.
+- `Box` - Simple and fast averaging filter appropriate for downscaling. When upscaling it's similar to NearestNeighbor.
+- `Linear` - Bilinear filter, smooth and reasonably fast.
+- `MitchellNetravali` - А smooth bicubic filter.
+- `CatmullRom` - A sharp bicubic filter.
+- `Gaussian` - Blurring filter that uses gaussian function, useful for noise removal.
+- `Lanczos` - High-quality resampling filter for photographic images yielding sharp results, but it's slower than cubic filters.
+
+The full list of supported filters: NearestNeighbor, Box, Linear, Hermite, MitchellNetravali, CatmullRom, BSpline, Gaussian, Lanczos, Hann, Hamming, Blackman, Bartlett, Welch, Cosine. Custom filters can be created using ResampleFilter struct.
+
+**Resampling filters comparison**
+
+Original image. Will be resized from 512x512px to 128x128px.
+
+![srcImage](http://disintegration.github.io/imaging/in_lena_bw_512.png)
+
+Filter | Resize result
+---|---
+`imaging.NearestNeighbor` | ![dstImage](http://disintegration.github.io/imaging/out_resize_down_nearest.png)
+`imaging.Box` | ![dstImage](http://disintegration.github.io/imaging/out_resize_down_box.png)
+`imaging.Linear` | ![dstImage](http://disintegration.github.io/imaging/out_resize_down_linear.png)
+`imaging.MitchellNetravali` | ![dstImage](http://disintegration.github.io/imaging/out_resize_down_mitchell.png)
+`imaging.CatmullRom` | ![dstImage](http://disintegration.github.io/imaging/out_resize_down_catrom.png)
+`imaging.Gaussian` | ![dstImage](http://disintegration.github.io/imaging/out_resize_down_gaussian.png)
+`imaging.Lanczos` | ![dstImage](http://disintegration.github.io/imaging/out_resize_down_lanczos.png)
+
+**Resize functions comparison**
+
+Original image:
+
+![srcImage](http://disintegration.github.io/imaging/in.jpg)
+
+Resize the image to width=100px and height=100px:
+
+```go
+dstImage := imaging.Resize(srcImage, 100, 100, imaging.Lanczos)
+```
+![dstImage](http://disintegration.github.io/imaging/out-comp-resize.jpg)
+
+Resize the image to width=100px preserving the aspect ratio:
+
+```go
+dstImage := imaging.Resize(srcImage, 100, 0, imaging.Lanczos)
+```
+![dstImage](http://disintegration.github.io/imaging/out-comp-fit.jpg)
+
+Resize the image to fit the 100x100px boundng box preserving the aspect ratio:
+
+```go
+dstImage := imaging.Fit(srcImage, 100, 100, imaging.Lanczos)
+```
+![dstImage](http://disintegration.github.io/imaging/out-comp-fit.jpg)
+
+Resize and crop the image with a center anchor point to fill the 100x100px area:
+
+```go
+dstImage := imaging.Fill(srcImage, 100, 100, imaging.Center, imaging.Lanczos)
+```
+![dstImage](http://disintegration.github.io/imaging/out-comp-fill.jpg)
+
+### Gaussian Blur
+```go
+dstImage := imaging.Blur(srcImage, 0.5)
+```
+
+Sigma parameter allows to control the strength of the blurring effect.
+
+Original image | Sigma = 0.5 | Sigma = 1.5
+---|---|---
+![srcImage](http://disintegration.github.io/imaging/in_lena_bw_128.png) | ![dstImage](http://disintegration.github.io/imaging/out_blur_0.5.png) | ![dstImage](http://disintegration.github.io/imaging/out_blur_1.5.png)
+
+### Sharpening
+```go
+dstImage := imaging.Sharpen(srcImage, 0.5)
+```
+
+Uses gaussian function internally. Sigma parameter allows to control the strength of the sharpening effect.
+
+Original image | Sigma = 0.5 | Sigma = 1.5
+---|---|---
+![srcImage](http://disintegration.github.io/imaging/in_lena_bw_128.png) | ![dstImage](http://disintegration.github.io/imaging/out_sharpen_0.5.png) | ![dstImage](http://disintegration.github.io/imaging/out_sharpen_1.5.png)
+
+### Gamma correction
+```go
+dstImage := imaging.AdjustGamma(srcImage, 0.75)
+```
+
+Original image | Gamma = 0.75 | Gamma = 1.25
+---|---|---
+![srcImage](http://disintegration.github.io/imaging/in_lena_bw_128.png) | ![dstImage](http://disintegration.github.io/imaging/out_gamma_0.75.png) | ![dstImage](http://disintegration.github.io/imaging/out_gamma_1.25.png)
+
+### Contrast adjustment
+```go
+dstImage := imaging.AdjustContrast(srcImage, 20)
+```
+
+Original image | Contrast = 20 | Contrast = -20
+---|---|---
+![srcImage](http://disintegration.github.io/imaging/in_lena_bw_128.png) | ![dstImage](http://disintegration.github.io/imaging/out_contrast_p20.png) | ![dstImage](http://disintegration.github.io/imaging/out_contrast_m20.png)
+
+### Brightness adjustment
+```go
+dstImage := imaging.AdjustBrightness(srcImage, 20)
+```
+
+Original image | Brightness = 20 | Brightness = -20
+---|---|---
+![srcImage](http://disintegration.github.io/imaging/in_lena_bw_128.png) | ![dstImage](http://disintegration.github.io/imaging/out_brightness_p20.png) | ![dstImage](http://disintegration.github.io/imaging/out_brightness_m20.png)
+
+
+### Complete code example
+Here is the code example that loads several images, makes thumbnails of them
+and combines them together side-by-side.
+
+```go
+package main
+
+import (
+ "image"
+ "image/color"
+
+ "github.com/disintegration/imaging"
+)
+
+func main() {
+
+ // input files
+ files := []string{"01.jpg", "02.jpg", "03.jpg"}
+
+ // load images and make 100x100 thumbnails of them
+ var thumbnails []image.Image
+ for _, file := range files {
+ img, err := imaging.Open(file)
+ if err != nil {
+ panic(err)
+ }
+ thumb := imaging.Thumbnail(img, 100, 100, imaging.CatmullRom)
+ thumbnails = append(thumbnails, thumb)
+ }
+
+ // create a new blank image
+ dst := imaging.New(100*len(thumbnails), 100, color.NRGBA{0, 0, 0, 0})
+
+ // paste thumbnails into the new image side by side
+ for i, thumb := range thumbnails {
+ dst = imaging.Paste(dst, thumb, image.Pt(i*100, 0))
+ }
+
+ // save the combined image to file
+ err := imaging.Save(dst, "dst.jpg")
+ if err != nil {
+ panic(err)
+ }
+}
+```
diff --git a/vendor/github.com/disintegration/imaging/adjust.go b/vendor/github.com/disintegration/imaging/adjust.go
new file mode 100644
index 000000000..9b1b83a4f
--- /dev/null
+++ b/vendor/github.com/disintegration/imaging/adjust.go
@@ -0,0 +1,200 @@
+package imaging
+
+import (
+ "image"
+ "image/color"
+ "math"
+)
+
+// AdjustFunc applies the fn function to each pixel of the img image and returns the adjusted image.
+//
+// Example:
+//
+// dstImage = imaging.AdjustFunc(
+// srcImage,
+// func(c color.NRGBA) color.NRGBA {
+// // shift the red channel by 16
+// r := int(c.R) + 16
+// if r > 255 {
+// r = 255
+// }
+// return color.NRGBA{uint8(r), c.G, c.B, c.A}
+// }
+// )
+//
+func AdjustFunc(img image.Image, fn func(c color.NRGBA) color.NRGBA) *image.NRGBA {
+ src := toNRGBA(img)
+ 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
+ j := y*dst.Stride + x*4
+
+ r := src.Pix[i+0]
+ g := src.Pix[i+1]
+ b := src.Pix[i+2]
+ a := src.Pix[i+3]
+
+ c := fn(color.NRGBA{r, g, b, a})
+
+ dst.Pix[j+0] = c.R
+ dst.Pix[j+1] = c.G
+ dst.Pix[j+2] = c.B
+ dst.Pix[j+3] = c.A
+ }
+ }
+ })
+
+ return dst
+}
+
+// AdjustGamma performs a gamma correction on the image and returns the adjusted image.
+// Gamma parameter must be positive. Gamma = 1.0 gives the original image.
+// Gamma less than 1.0 darkens the image and gamma greater than 1.0 lightens it.
+//
+// Example:
+//
+// dstImage = imaging.AdjustGamma(srcImage, 0.7)
+//
+func AdjustGamma(img image.Image, gamma float64) *image.NRGBA {
+ e := 1.0 / math.Max(gamma, 0.0001)
+ lut := make([]uint8, 256)
+
+ for i := 0; i < 256; i++ {
+ lut[i] = clamp(math.Pow(float64(i)/255.0, e) * 255.0)
+ }
+
+ fn := func(c color.NRGBA) color.NRGBA {
+ return color.NRGBA{lut[c.R], lut[c.G], lut[c.B], c.A}
+ }
+
+ return AdjustFunc(img, fn)
+}
+
+func sigmoid(a, b, x float64) float64 {
+ return 1 / (1 + math.Exp(b*(a-x)))
+}
+
+// AdjustSigmoid changes the contrast of the image using a sigmoidal function and returns the adjusted image.
+// It's a non-linear contrast change useful for photo adjustments as it preserves highlight and shadow detail.
+// The midpoint parameter is the midpoint of contrast that must be between 0 and 1, typically 0.5.
+// The factor parameter indicates how much to increase or decrease the contrast, typically in range (-10, 10).
+// If the factor parameter is positive the image contrast is increased otherwise the contrast is decreased.
+//
+// Examples:
+//
+// dstImage = imaging.AdjustSigmoid(srcImage, 0.5, 3.0) // increase the contrast
+// dstImage = imaging.AdjustSigmoid(srcImage, 0.5, -3.0) // decrease the contrast
+//
+func AdjustSigmoid(img image.Image, midpoint, factor float64) *image.NRGBA {
+ if factor == 0 {
+ return Clone(img)
+ }
+
+ lut := make([]uint8, 256)
+ a := math.Min(math.Max(midpoint, 0.0), 1.0)
+ b := math.Abs(factor)
+ sig0 := sigmoid(a, b, 0)
+ sig1 := sigmoid(a, b, 1)
+ e := 1.0e-6
+
+ if factor > 0 {
+ for i := 0; i < 256; i++ {
+ x := float64(i) / 255.0
+ sigX := sigmoid(a, b, x)
+ f := (sigX - sig0) / (sig1 - sig0)
+ lut[i] = clamp(f * 255.0)
+ }
+ } else {
+ for i := 0; i < 256; i++ {
+ x := float64(i) / 255.0
+ arg := math.Min(math.Max((sig1-sig0)*x+sig0, e), 1.0-e)
+ f := a - math.Log(1.0/arg-1.0)/b
+ lut[i] = clamp(f * 255.0)
+ }
+ }
+
+ fn := func(c color.NRGBA) color.NRGBA {
+ return color.NRGBA{lut[c.R], lut[c.G], lut[c.B], c.A}
+ }
+
+ return AdjustFunc(img, fn)
+}
+
+// AdjustContrast changes the contrast of the image using the percentage parameter and returns the adjusted image.
+// The percentage must be in range (-100, 100). The percentage = 0 gives the original image.
+// The percentage = -100 gives solid grey image.
+//
+// Examples:
+//
+// dstImage = imaging.AdjustContrast(srcImage, -10) // decrease image contrast by 10%
+// dstImage = imaging.AdjustContrast(srcImage, 20) // increase image contrast by 20%
+//
+func AdjustContrast(img image.Image, percentage float64) *image.NRGBA {
+ percentage = math.Min(math.Max(percentage, -100.0), 100.0)
+ lut := make([]uint8, 256)
+
+ v := (100.0 + percentage) / 100.0
+ for i := 0; i < 256; i++ {
+ if 0 <= v && v <= 1 {
+ lut[i] = clamp((0.5 + (float64(i)/255.0-0.5)*v) * 255.0)
+ } else if 1 < v && v < 2 {
+ lut[i] = clamp((0.5 + (float64(i)/255.0-0.5)*(1/(2.0-v))) * 255.0)
+ } else {
+ lut[i] = uint8(float64(i)/255.0+0.5) * 255
+ }
+ }
+
+ fn := func(c color.NRGBA) color.NRGBA {
+ return color.NRGBA{lut[c.R], lut[c.G], lut[c.B], c.A}
+ }
+
+ return AdjustFunc(img, fn)
+}
+
+// AdjustBrightness changes the brightness of the image using the percentage parameter and returns the adjusted image.
+// The percentage must be in range (-100, 100). The percentage = 0 gives the original image.
+// The percentage = -100 gives solid black image. The percentage = 100 gives solid white image.
+//
+// Examples:
+//
+// dstImage = imaging.AdjustBrightness(srcImage, -15) // decrease image brightness by 15%
+// dstImage = imaging.AdjustBrightness(srcImage, 10) // increase image brightness by 10%
+//
+func AdjustBrightness(img image.Image, percentage float64) *image.NRGBA {
+ percentage = math.Min(math.Max(percentage, -100.0), 100.0)
+ lut := make([]uint8, 256)
+
+ shift := 255.0 * percentage / 100.0
+ for i := 0; i < 256; i++ {
+ lut[i] = clamp(float64(i) + shift)
+ }
+
+ fn := func(c color.NRGBA) color.NRGBA {
+ return color.NRGBA{lut[c.R], lut[c.G], lut[c.B], c.A}
+ }
+
+ return AdjustFunc(img, fn)
+}
+
+// Grayscale produces grayscale version of the image.
+func Grayscale(img image.Image) *image.NRGBA {
+ fn := func(c color.NRGBA) color.NRGBA {
+ f := 0.299*float64(c.R) + 0.587*float64(c.G) + 0.114*float64(c.B)
+ y := uint8(f + 0.5)
+ return color.NRGBA{y, y, y, c.A}
+ }
+ return AdjustFunc(img, fn)
+}
+
+// Invert produces inverted (negated) version of the image.
+func Invert(img image.Image) *image.NRGBA {
+ fn := func(c color.NRGBA) color.NRGBA {
+ return color.NRGBA{255 - c.R, 255 - c.G, 255 - c.B, c.A}
+ }
+ return AdjustFunc(img, fn)
+}
diff --git a/vendor/github.com/disintegration/imaging/effects.go b/vendor/github.com/disintegration/imaging/effects.go
new file mode 100644
index 000000000..fe92e10a2
--- /dev/null
+++ b/vendor/github.com/disintegration/imaging/effects.go
@@ -0,0 +1,187 @@
+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
+}
diff --git a/vendor/github.com/disintegration/imaging/helpers.go b/vendor/github.com/disintegration/imaging/helpers.go
new file mode 100644
index 000000000..79967ae44
--- /dev/null
+++ b/vendor/github.com/disintegration/imaging/helpers.go
@@ -0,0 +1,400 @@
+/*
+Package imaging provides basic image manipulation functions (resize, rotate, flip, crop, etc.).
+This package is based on the standard Go image package and works best along with it.
+
+Image manipulation functions provided by the package take any image type
+that implements `image.Image` interface as an input, and return a new image of
+`*image.NRGBA` type (32bit RGBA colors, not premultiplied by alpha).
+*/
+package imaging
+
+import (
+ "errors"
+ "image"
+ "image/color"
+ "image/gif"
+ "image/jpeg"
+ "image/png"
+ "io"
+ "os"
+ "path/filepath"
+ "strings"
+
+ "golang.org/x/image/bmp"
+ "golang.org/x/image/tiff"
+)
+
+type Format int
+
+const (
+ JPEG Format = iota
+ PNG
+ GIF
+ TIFF
+ BMP
+)
+
+func (f Format) String() string {
+ switch f {
+ case JPEG:
+ return "JPEG"
+ case PNG:
+ return "PNG"
+ case GIF:
+ return "GIF"
+ case TIFF:
+ return "TIFF"
+ case BMP:
+ return "BMP"
+ default:
+ return "Unsupported"
+ }
+}
+
+var (
+ ErrUnsupportedFormat = errors.New("imaging: unsupported image format")
+)
+
+// Decode reads an image from r.
+func Decode(r io.Reader) (image.Image, error) {
+ img, _, err := image.Decode(r)
+ if err != nil {
+ return nil, err
+ }
+ return toNRGBA(img), nil
+}
+
+// Open loads an image from file
+func Open(filename string) (image.Image, error) {
+ file, err := os.Open(filename)
+ if err != nil {
+ return nil, err
+ }
+ defer file.Close()
+ img, err := Decode(file)
+ return img, err
+}
+
+// Encode writes the image img to w in the specified format (JPEG, PNG, GIF, TIFF or BMP).
+func Encode(w io.Writer, img image.Image, format Format) error {
+ var err error
+ switch format {
+ case JPEG:
+ var rgba *image.RGBA
+ if nrgba, ok := img.(*image.NRGBA); ok {
+ if nrgba.Opaque() {
+ rgba = &image.RGBA{
+ Pix: nrgba.Pix,
+ Stride: nrgba.Stride,
+ Rect: nrgba.Rect,
+ }
+ }
+ }
+ if rgba != nil {
+ err = jpeg.Encode(w, rgba, &jpeg.Options{Quality: 95})
+ } else {
+ err = jpeg.Encode(w, img, &jpeg.Options{Quality: 95})
+ }
+
+ case PNG:
+ err = png.Encode(w, img)
+ case GIF:
+ err = gif.Encode(w, img, &gif.Options{NumColors: 256})
+ case TIFF:
+ err = tiff.Encode(w, img, &tiff.Options{Compression: tiff.Deflate, Predictor: true})
+ case BMP:
+ err = bmp.Encode(w, img)
+ default:
+ err = ErrUnsupportedFormat
+ }
+ return err
+}
+
+// Save saves the image to file with the specified filename.
+// The format is determined from the filename extension: "jpg" (or "jpeg"), "png", "gif", "tif" (or "tiff") and "bmp" are supported.
+func Save(img image.Image, filename string) (err error) {
+ formats := map[string]Format{
+ ".jpg": JPEG,
+ ".jpeg": JPEG,
+ ".png": PNG,
+ ".tif": TIFF,
+ ".tiff": TIFF,
+ ".bmp": BMP,
+ ".gif": GIF,
+ }
+
+ ext := strings.ToLower(filepath.Ext(filename))
+ f, ok := formats[ext]
+ if !ok {
+ return ErrUnsupportedFormat
+ }
+
+ file, err := os.Create(filename)
+ if err != nil {
+ return err
+ }
+ defer file.Close()
+
+ return Encode(file, img, f)
+}
+
+// New creates a new image with the specified width and height, and fills it with the specified color.
+func New(width, height int, fillColor color.Color) *image.NRGBA {
+ if width <= 0 || height <= 0 {
+ return &image.NRGBA{}
+ }
+
+ dst := image.NewNRGBA(image.Rect(0, 0, width, height))
+ c := color.NRGBAModel.Convert(fillColor).(color.NRGBA)
+
+ if c.R == 0 && c.G == 0 && c.B == 0 && c.A == 0 {
+ return dst
+ }
+
+ cs := []uint8{c.R, c.G, c.B, c.A}
+
+ // fill the first row
+ for x := 0; x < width; x++ {
+ copy(dst.Pix[x*4:(x+1)*4], cs)
+ }
+ // copy the first row to other rows
+ for y := 1; y < height; y++ {
+ copy(dst.Pix[y*dst.Stride:y*dst.Stride+width*4], dst.Pix[0:width*4])
+ }
+
+ return dst
+}
+
+// Clone returns a copy of the given image.
+func Clone(img image.Image) *image.NRGBA {
+ srcBounds := img.Bounds()
+ srcMinX := srcBounds.Min.X
+ srcMinY := srcBounds.Min.Y
+
+ dstBounds := srcBounds.Sub(srcBounds.Min)
+ dstW := dstBounds.Dx()
+ dstH := dstBounds.Dy()
+ dst := image.NewNRGBA(dstBounds)
+
+ switch src := img.(type) {
+
+ case *image.NRGBA:
+ rowSize := srcBounds.Dx() * 4
+ parallel(dstH, func(partStart, partEnd int) {
+ for dstY := partStart; dstY < partEnd; dstY++ {
+ di := dst.PixOffset(0, dstY)
+ si := src.PixOffset(srcMinX, srcMinY+dstY)
+ copy(dst.Pix[di:di+rowSize], src.Pix[si:si+rowSize])
+ }
+ })
+
+ case *image.NRGBA64:
+ parallel(dstH, func(partStart, partEnd int) {
+ for dstY := partStart; dstY < partEnd; dstY++ {
+ di := dst.PixOffset(0, dstY)
+ si := src.PixOffset(srcMinX, srcMinY+dstY)
+ for dstX := 0; dstX < dstW; dstX++ {
+
+ dst.Pix[di+0] = src.Pix[si+0]
+ dst.Pix[di+1] = src.Pix[si+2]
+ dst.Pix[di+2] = src.Pix[si+4]
+ dst.Pix[di+3] = src.Pix[si+6]
+
+ di += 4
+ si += 8
+
+ }
+ }
+ })
+
+ case *image.RGBA:
+ parallel(dstH, func(partStart, partEnd int) {
+ for dstY := partStart; dstY < partEnd; dstY++ {
+ di := dst.PixOffset(0, dstY)
+ si := src.PixOffset(srcMinX, srcMinY+dstY)
+ for dstX := 0; dstX < dstW; dstX++ {
+
+ a := src.Pix[si+3]
+ dst.Pix[di+3] = a
+ switch a {
+ case 0:
+ dst.Pix[di+0] = 0
+ dst.Pix[di+1] = 0
+ dst.Pix[di+2] = 0
+ case 0xff:
+ dst.Pix[di+0] = src.Pix[si+0]
+ dst.Pix[di+1] = src.Pix[si+1]
+ dst.Pix[di+2] = src.Pix[si+2]
+ default:
+ var tmp uint16
+ tmp = uint16(src.Pix[si+0]) * 0xff / uint16(a)
+ dst.Pix[di+0] = uint8(tmp)
+ tmp = uint16(src.Pix[si+1]) * 0xff / uint16(a)
+ dst.Pix[di+1] = uint8(tmp)
+ tmp = uint16(src.Pix[si+2]) * 0xff / uint16(a)
+ dst.Pix[di+2] = uint8(tmp)
+ }
+
+ di += 4
+ si += 4
+
+ }
+ }
+ })
+
+ case *image.RGBA64:
+ parallel(dstH, func(partStart, partEnd int) {
+ for dstY := partStart; dstY < partEnd; dstY++ {
+ di := dst.PixOffset(0, dstY)
+ si := src.PixOffset(srcMinX, srcMinY+dstY)
+ for dstX := 0; dstX < dstW; dstX++ {
+
+ a := src.Pix[si+6]
+ dst.Pix[di+3] = a
+ switch a {
+ case 0:
+ dst.Pix[di+0] = 0
+ dst.Pix[di+1] = 0
+ dst.Pix[di+2] = 0
+ case 0xff:
+ dst.Pix[di+0] = src.Pix[si+0]
+ dst.Pix[di+1] = src.Pix[si+2]
+ dst.Pix[di+2] = src.Pix[si+4]
+ default:
+ var tmp uint16
+ tmp = uint16(src.Pix[si+0]) * 0xff / uint16(a)
+ dst.Pix[di+0] = uint8(tmp)
+ tmp = uint16(src.Pix[si+2]) * 0xff / uint16(a)
+ dst.Pix[di+1] = uint8(tmp)
+ tmp = uint16(src.Pix[si+4]) * 0xff / uint16(a)
+ dst.Pix[di+2] = uint8(tmp)
+ }
+
+ di += 4
+ si += 8
+
+ }
+ }
+ })
+
+ case *image.Gray:
+ parallel(dstH, func(partStart, partEnd int) {
+ for dstY := partStart; dstY < partEnd; dstY++ {
+ di := dst.PixOffset(0, dstY)
+ si := src.PixOffset(srcMinX, srcMinY+dstY)
+ for dstX := 0; dstX < dstW; dstX++ {
+
+ c := src.Pix[si]
+ dst.Pix[di+0] = c
+ dst.Pix[di+1] = c
+ dst.Pix[di+2] = c
+ dst.Pix[di+3] = 0xff
+
+ di += 4
+ si += 1
+
+ }
+ }
+ })
+
+ case *image.Gray16:
+ parallel(dstH, func(partStart, partEnd int) {
+ for dstY := partStart; dstY < partEnd; dstY++ {
+ di := dst.PixOffset(0, dstY)
+ si := src.PixOffset(srcMinX, srcMinY+dstY)
+ for dstX := 0; dstX < dstW; dstX++ {
+
+ c := src.Pix[si]
+ dst.Pix[di+0] = c
+ dst.Pix[di+1] = c
+ dst.Pix[di+2] = c
+ dst.Pix[di+3] = 0xff
+
+ di += 4
+ si += 2
+
+ }
+ }
+ })
+
+ case *image.YCbCr:
+ parallel(dstH, func(partStart, partEnd int) {
+ for dstY := partStart; dstY < partEnd; dstY++ {
+ di := dst.PixOffset(0, dstY)
+ for dstX := 0; dstX < dstW; dstX++ {
+
+ srcX := srcMinX + dstX
+ srcY := srcMinY + dstY
+ siy := src.YOffset(srcX, srcY)
+ sic := src.COffset(srcX, srcY)
+ r, g, b := color.YCbCrToRGB(src.Y[siy], src.Cb[sic], src.Cr[sic])
+ dst.Pix[di+0] = r
+ dst.Pix[di+1] = g
+ dst.Pix[di+2] = b
+ dst.Pix[di+3] = 0xff
+
+ di += 4
+
+ }
+ }
+ })
+
+ case *image.Paletted:
+ plen := len(src.Palette)
+ pnew := make([]color.NRGBA, plen)
+ for i := 0; i < plen; i++ {
+ pnew[i] = color.NRGBAModel.Convert(src.Palette[i]).(color.NRGBA)
+ }
+
+ parallel(dstH, func(partStart, partEnd int) {
+ for dstY := partStart; dstY < partEnd; dstY++ {
+ di := dst.PixOffset(0, dstY)
+ si := src.PixOffset(srcMinX, srcMinY+dstY)
+ for dstX := 0; dstX < dstW; dstX++ {
+
+ c := pnew[src.Pix[si]]
+ dst.Pix[di+0] = c.R
+ dst.Pix[di+1] = c.G
+ dst.Pix[di+2] = c.B
+ dst.Pix[di+3] = c.A
+
+ di += 4
+ si += 1
+
+ }
+ }
+ })
+
+ default:
+ parallel(dstH, func(partStart, partEnd int) {
+ for dstY := partStart; dstY < partEnd; dstY++ {
+ di := dst.PixOffset(0, dstY)
+ for dstX := 0; dstX < dstW; dstX++ {
+
+ c := color.NRGBAModel.Convert(img.At(srcMinX+dstX, srcMinY+dstY)).(color.NRGBA)
+ dst.Pix[di+0] = c.R
+ dst.Pix[di+1] = c.G
+ dst.Pix[di+2] = c.B
+ dst.Pix[di+3] = c.A
+
+ di += 4
+
+ }
+ }
+ })
+
+ }
+
+ return dst
+}
+
+// This function used internally to convert any image type to NRGBA if needed.
+func toNRGBA(img image.Image) *image.NRGBA {
+ srcBounds := img.Bounds()
+ if srcBounds.Min.X == 0 && srcBounds.Min.Y == 0 {
+ if src0, ok := img.(*image.NRGBA); ok {
+ return src0
+ }
+ }
+ return Clone(img)
+}
diff --git a/vendor/github.com/disintegration/imaging/resize.go b/vendor/github.com/disintegration/imaging/resize.go
new file mode 100644
index 000000000..3c792e904
--- /dev/null
+++ b/vendor/github.com/disintegration/imaging/resize.go
@@ -0,0 +1,583 @@
+package imaging
+
+import (
+ "image"
+ "math"
+)
+
+type iwpair struct {
+ i int
+ w int32
+}
+
+type pweights struct {
+ iwpairs []iwpair
+ wsum int32
+}
+
+func precomputeWeights(dstSize, srcSize int, filter ResampleFilter) []pweights {
+ du := float64(srcSize) / float64(dstSize)
+ scale := du
+ if scale < 1.0 {
+ scale = 1.0
+ }
+ ru := math.Ceil(scale * filter.Support)
+
+ out := make([]pweights, dstSize)
+
+ for v := 0; v < dstSize; v++ {
+ fu := (float64(v)+0.5)*du - 0.5
+
+ startu := int(math.Ceil(fu - ru))
+ if startu < 0 {
+ startu = 0
+ }
+ endu := int(math.Floor(fu + ru))
+ if endu > srcSize-1 {
+ endu = srcSize - 1
+ }
+
+ wsum := int32(0)
+ for u := startu; u <= endu; u++ {
+ w := int32(0xff * filter.Kernel((float64(u)-fu)/scale))
+ if w != 0 {
+ wsum += w
+ out[v].iwpairs = append(out[v].iwpairs, iwpair{u, w})
+ }
+ }
+ out[v].wsum = wsum
+ }
+
+ return out
+}
+
+// Resize resizes the image to the specified width and height using the specified resampling
+// filter and returns the transformed image. If one of width or height is 0, the image aspect
+// ratio is preserved.
+//
+// Supported resample filters: NearestNeighbor, Box, Linear, Hermite, MitchellNetravali,
+// CatmullRom, BSpline, Gaussian, Lanczos, Hann, Hamming, Blackman, Bartlett, Welch, Cosine.
+//
+// Usage example:
+//
+// dstImage := imaging.Resize(srcImage, 800, 600, imaging.Lanczos)
+//
+func Resize(img image.Image, width, height int, filter ResampleFilter) *image.NRGBA {
+ dstW, dstH := width, height
+
+ if dstW < 0 || dstH < 0 {
+ return &image.NRGBA{}
+ }
+ if dstW == 0 && dstH == 0 {
+ return &image.NRGBA{}
+ }
+
+ src := toNRGBA(img)
+
+ srcW := src.Bounds().Max.X
+ srcH := src.Bounds().Max.Y
+
+ if srcW <= 0 || srcH <= 0 {
+ return &image.NRGBA{}
+ }
+
+ // if new width or height is 0 then preserve aspect ratio, minimum 1px
+ if dstW == 0 {
+ tmpW := float64(dstH) * float64(srcW) / float64(srcH)
+ dstW = int(math.Max(1.0, math.Floor(tmpW+0.5)))
+ }
+ if dstH == 0 {
+ tmpH := float64(dstW) * float64(srcH) / float64(srcW)
+ dstH = int(math.Max(1.0, math.Floor(tmpH+0.5)))
+ }
+
+ var dst *image.NRGBA
+
+ if filter.Support <= 0.0 {
+ // nearest-neighbor special case
+ dst = resizeNearest(src, dstW, dstH)
+
+ } else {
+ // two-pass resize
+ if srcW != dstW {
+ dst = resizeHorizontal(src, dstW, filter)
+ } else {
+ dst = src
+ }
+
+ if srcH != dstH {
+ dst = resizeVertical(dst, dstH, filter)
+ }
+ }
+
+ return dst
+}
+
+func resizeHorizontal(src *image.NRGBA, width int, filter ResampleFilter) *image.NRGBA {
+ srcBounds := src.Bounds()
+ srcW := srcBounds.Max.X
+ srcH := srcBounds.Max.Y
+
+ dstW := width
+ dstH := srcH
+
+ dst := image.NewNRGBA(image.Rect(0, 0, dstW, dstH))
+
+ weights := precomputeWeights(dstW, srcW, filter)
+
+ parallel(dstH, func(partStart, partEnd int) {
+ for dstY := partStart; dstY < partEnd; dstY++ {
+ for dstX := 0; dstX < dstW; dstX++ {
+ var c [4]int32
+ for _, iw := range weights[dstX].iwpairs {
+ i := dstY*src.Stride + iw.i*4
+ c[0] += int32(src.Pix[i+0]) * iw.w
+ c[1] += int32(src.Pix[i+1]) * iw.w
+ c[2] += int32(src.Pix[i+2]) * iw.w
+ c[3] += int32(src.Pix[i+3]) * iw.w
+ }
+ j := dstY*dst.Stride + dstX*4
+ sum := weights[dstX].wsum
+ dst.Pix[j+0] = clampint32(int32(float32(c[0])/float32(sum) + 0.5))
+ dst.Pix[j+1] = clampint32(int32(float32(c[1])/float32(sum) + 0.5))
+ dst.Pix[j+2] = clampint32(int32(float32(c[2])/float32(sum) + 0.5))
+ dst.Pix[j+3] = clampint32(int32(float32(c[3])/float32(sum) + 0.5))
+ }
+ }
+ })
+
+ return dst
+}
+
+func resizeVertical(src *image.NRGBA, height int, filter ResampleFilter) *image.NRGBA {
+ srcBounds := src.Bounds()
+ srcW := srcBounds.Max.X
+ srcH := srcBounds.Max.Y
+
+ dstW := srcW
+ dstH := height
+
+ dst := image.NewNRGBA(image.Rect(0, 0, dstW, dstH))
+
+ weights := precomputeWeights(dstH, srcH, filter)
+
+ parallel(dstW, func(partStart, partEnd int) {
+
+ for dstX := partStart; dstX < partEnd; dstX++ {
+ for dstY := 0; dstY < dstH; dstY++ {
+ var c [4]int32
+ for _, iw := range weights[dstY].iwpairs {
+ i := iw.i*src.Stride + dstX*4
+ c[0] += int32(src.Pix[i+0]) * iw.w
+ c[1] += int32(src.Pix[i+1]) * iw.w
+ c[2] += int32(src.Pix[i+2]) * iw.w
+ c[3] += int32(src.Pix[i+3]) * iw.w
+ }
+ j := dstY*dst.Stride + dstX*4
+ sum := weights[dstY].wsum
+ dst.Pix[j+0] = clampint32(int32(float32(c[0])/float32(sum) + 0.5))
+ dst.Pix[j+1] = clampint32(int32(float32(c[1])/float32(sum) + 0.5))
+ dst.Pix[j+2] = clampint32(int32(float32(c[2])/float32(sum) + 0.5))
+ dst.Pix[j+3] = clampint32(int32(float32(c[3])/float32(sum) + 0.5))
+ }
+ }
+
+ })
+
+ return dst
+}
+
+// fast nearest-neighbor resize, no filtering
+func resizeNearest(src *image.NRGBA, width, height int) *image.NRGBA {
+ dstW, dstH := width, height
+
+ srcBounds := src.Bounds()
+ srcW := srcBounds.Max.X
+ srcH := srcBounds.Max.Y
+
+ dst := image.NewNRGBA(image.Rect(0, 0, dstW, dstH))
+
+ dx := float64(srcW) / float64(dstW)
+ dy := float64(srcH) / float64(dstH)
+
+ parallel(dstH, func(partStart, partEnd int) {
+
+ for dstY := partStart; dstY < partEnd; dstY++ {
+ fy := (float64(dstY)+0.5)*dy - 0.5
+
+ for dstX := 0; dstX < dstW; dstX++ {
+ fx := (float64(dstX)+0.5)*dx - 0.5
+
+ srcX := int(math.Min(math.Max(math.Floor(fx+0.5), 0.0), float64(srcW)))
+ srcY := int(math.Min(math.Max(math.Floor(fy+0.5), 0.0), float64(srcH)))
+
+ srcOff := srcY*src.Stride + srcX*4
+ dstOff := dstY*dst.Stride + dstX*4
+
+ copy(dst.Pix[dstOff:dstOff+4], src.Pix[srcOff:srcOff+4])
+ }
+ }
+
+ })
+
+ return dst
+}
+
+// Fit scales down the image using the specified resample filter to fit the specified
+// maximum width and height and returns the transformed image.
+//
+// Supported resample filters: NearestNeighbor, Box, Linear, Hermite, MitchellNetravali,
+// CatmullRom, BSpline, Gaussian, Lanczos, Hann, Hamming, Blackman, Bartlett, Welch, Cosine.
+//
+// Usage example:
+//
+// dstImage := imaging.Fit(srcImage, 800, 600, imaging.Lanczos)
+//
+func Fit(img image.Image, width, height int, filter ResampleFilter) *image.NRGBA {
+ maxW, maxH := width, height
+
+ if maxW <= 0 || maxH <= 0 {
+ return &image.NRGBA{}
+ }
+
+ srcBounds := img.Bounds()
+ srcW := srcBounds.Dx()
+ srcH := srcBounds.Dy()
+
+ if srcW <= 0 || srcH <= 0 {
+ return &image.NRGBA{}
+ }
+
+ if srcW <= maxW && srcH <= maxH {
+ return Clone(img)
+ }
+
+ srcAspectRatio := float64(srcW) / float64(srcH)
+ maxAspectRatio := float64(maxW) / float64(maxH)
+
+ var newW, newH int
+ if srcAspectRatio > maxAspectRatio {
+ newW = maxW
+ newH = int(float64(newW) / srcAspectRatio)
+ } else {
+ newH = maxH
+ newW = int(float64(newH) * srcAspectRatio)
+ }
+
+ return Resize(img, newW, newH, filter)
+}
+
+// Fill scales the image to the smallest possible size that will cover the specified dimensions,
+// crops the resized image to the specified dimensions using the given anchor point and returns
+// the transformed image.
+//
+// Supported resample filters: NearestNeighbor, Box, Linear, Hermite, MitchellNetravali,
+// CatmullRom, BSpline, Gaussian, Lanczos, Hann, Hamming, Blackman, Bartlett, Welch, Cosine.
+//
+// Usage example:
+//
+// dstImage := imaging.Fill(srcImage, 800, 600, imaging.Center, imaging.Lanczos)
+//
+func Fill(img image.Image, width, height int, anchor Anchor, filter ResampleFilter) *image.NRGBA {
+ minW, minH := width, height
+
+ if minW <= 0 || minH <= 0 {
+ return &image.NRGBA{}
+ }
+
+ srcBounds := img.Bounds()
+ srcW := srcBounds.Dx()
+ srcH := srcBounds.Dy()
+
+ if srcW <= 0 || srcH <= 0 {
+ return &image.NRGBA{}
+ }
+
+ if srcW == minW && srcH == minH {
+ return Clone(img)
+ }
+
+ srcAspectRatio := float64(srcW) / float64(srcH)
+ minAspectRatio := float64(minW) / float64(minH)
+
+ var tmp *image.NRGBA
+ if srcAspectRatio < minAspectRatio {
+ tmp = Resize(img, minW, 0, filter)
+ } else {
+ tmp = Resize(img, 0, minH, filter)
+ }
+
+ return CropAnchor(tmp, minW, minH, anchor)
+}
+
+// Thumbnail scales the image up or down using the specified resample filter, crops it
+// to the specified width and hight and returns the transformed image.
+//
+// Supported resample filters: NearestNeighbor, Box, Linear, Hermite, MitchellNetravali,
+// CatmullRom, BSpline, Gaussian, Lanczos, Hann, Hamming, Blackman, Bartlett, Welch, Cosine.
+//
+// Usage example:
+//
+// dstImage := imaging.Thumbnail(srcImage, 100, 100, imaging.Lanczos)
+//
+func Thumbnail(img image.Image, width, height int, filter ResampleFilter) *image.NRGBA {
+ return Fill(img, width, height, Center, filter)
+}
+
+// Resample filter struct. It can be used to make custom filters.
+//
+// Supported resample filters: NearestNeighbor, Box, Linear, Hermite, MitchellNetravali,
+// CatmullRom, BSpline, Gaussian, Lanczos, Hann, Hamming, Blackman, Bartlett, Welch, Cosine.
+//
+// General filter recommendations:
+//
+// - Lanczos
+// Probably the best resampling filter for photographic images yielding sharp results,
+// but it's slower than cubic filters (see below).
+//
+// - CatmullRom
+// A sharp cubic filter. It's a good filter for both upscaling and downscaling if sharp results are needed.
+//
+// - MitchellNetravali
+// A high quality cubic filter that produces smoother results with less ringing than CatmullRom.
+//
+// - BSpline
+// A good filter if a very smooth output is needed.
+//
+// - Linear
+// Bilinear interpolation filter, produces reasonably good, smooth output. It's faster than cubic filters.
+//
+// - Box
+// Simple and fast resampling filter appropriate for downscaling.
+// When upscaling it's similar to NearestNeighbor.
+//
+// - NearestNeighbor
+// Fastest resample filter, no antialiasing at all. Rarely used.
+//
+type ResampleFilter struct {
+ Support float64
+ Kernel func(float64) float64
+}
+
+// Nearest-neighbor filter, no anti-aliasing.
+var NearestNeighbor ResampleFilter
+
+// Box filter (averaging pixels).
+var Box ResampleFilter
+
+// Linear filter.
+var Linear ResampleFilter
+
+// Hermite cubic spline filter (BC-spline; B=0; C=0).
+var Hermite ResampleFilter
+
+// Mitchell-Netravali cubic filter (BC-spline; B=1/3; C=1/3).
+var MitchellNetravali ResampleFilter
+
+// Catmull-Rom - sharp cubic filter (BC-spline; B=0; C=0.5).
+var CatmullRom ResampleFilter
+
+// Cubic B-spline - smooth cubic filter (BC-spline; B=1; C=0).
+var BSpline ResampleFilter
+
+// Gaussian Blurring Filter.
+var Gaussian ResampleFilter
+
+// Bartlett-windowed sinc filter (3 lobes).
+var Bartlett ResampleFilter
+
+// Lanczos filter (3 lobes).
+var Lanczos ResampleFilter
+
+// Hann-windowed sinc filter (3 lobes).
+var Hann ResampleFilter
+
+// Hamming-windowed sinc filter (3 lobes).
+var Hamming ResampleFilter
+
+// Blackman-windowed sinc filter (3 lobes).
+var Blackman ResampleFilter
+
+// Welch-windowed sinc filter (parabolic window, 3 lobes).
+var Welch ResampleFilter
+
+// Cosine-windowed sinc filter (3 lobes).
+var Cosine ResampleFilter
+
+func bcspline(x, b, c float64) float64 {
+ x = math.Abs(x)
+ if x < 1.0 {
+ return ((12-9*b-6*c)*x*x*x + (-18+12*b+6*c)*x*x + (6 - 2*b)) / 6
+ }
+ if x < 2.0 {
+ return ((-b-6*c)*x*x*x + (6*b+30*c)*x*x + (-12*b-48*c)*x + (8*b + 24*c)) / 6
+ }
+ return 0
+}
+
+func sinc(x float64) float64 {
+ if x == 0 {
+ return 1
+ }
+ return math.Sin(math.Pi*x) / (math.Pi * x)
+}
+
+func init() {
+ NearestNeighbor = ResampleFilter{
+ Support: 0.0, // special case - not applying the filter
+ }
+
+ Box = ResampleFilter{
+ Support: 0.5,
+ Kernel: func(x float64) float64 {
+ x = math.Abs(x)
+ if x <= 0.5 {
+ return 1.0
+ }
+ return 0
+ },
+ }
+
+ Linear = ResampleFilter{
+ Support: 1.0,
+ Kernel: func(x float64) float64 {
+ x = math.Abs(x)
+ if x < 1.0 {
+ return 1.0 - x
+ }
+ return 0
+ },
+ }
+
+ Hermite = ResampleFilter{
+ Support: 1.0,
+ Kernel: func(x float64) float64 {
+ x = math.Abs(x)
+ if x < 1.0 {
+ return bcspline(x, 0.0, 0.0)
+ }
+ return 0
+ },
+ }
+
+ MitchellNetravali = ResampleFilter{
+ Support: 2.0,
+ Kernel: func(x float64) float64 {
+ x = math.Abs(x)
+ if x < 2.0 {
+ return bcspline(x, 1.0/3.0, 1.0/3.0)
+ }
+ return 0
+ },
+ }
+
+ CatmullRom = ResampleFilter{
+ Support: 2.0,
+ Kernel: func(x float64) float64 {
+ x = math.Abs(x)
+ if x < 2.0 {
+ return bcspline(x, 0.0, 0.5)
+ }
+ return 0
+ },
+ }
+
+ BSpline = ResampleFilter{
+ Support: 2.0,
+ Kernel: func(x float64) float64 {
+ x = math.Abs(x)
+ if x < 2.0 {
+ return bcspline(x, 1.0, 0.0)
+ }
+ return 0
+ },
+ }
+
+ Gaussian = ResampleFilter{
+ Support: 2.0,
+ Kernel: func(x float64) float64 {
+ x = math.Abs(x)
+ if x < 2.0 {
+ return math.Exp(-2 * x * x)
+ }
+ return 0
+ },
+ }
+
+ Bartlett = ResampleFilter{
+ Support: 3.0,
+ Kernel: func(x float64) float64 {
+ x = math.Abs(x)
+ if x < 3.0 {
+ return sinc(x) * (3.0 - x) / 3.0
+ }
+ return 0
+ },
+ }
+
+ Lanczos = ResampleFilter{
+ Support: 3.0,
+ Kernel: func(x float64) float64 {
+ x = math.Abs(x)
+ if x < 3.0 {
+ return sinc(x) * sinc(x/3.0)
+ }
+ return 0
+ },
+ }
+
+ Hann = ResampleFilter{
+ Support: 3.0,
+ Kernel: func(x float64) float64 {
+ x = math.Abs(x)
+ if x < 3.0 {
+ return sinc(x) * (0.5 + 0.5*math.Cos(math.Pi*x/3.0))
+ }
+ return 0
+ },
+ }
+
+ Hamming = ResampleFilter{
+ Support: 3.0,
+ Kernel: func(x float64) float64 {
+ x = math.Abs(x)
+ if x < 3.0 {
+ return sinc(x) * (0.54 + 0.46*math.Cos(math.Pi*x/3.0))
+ }
+ return 0
+ },
+ }
+
+ Blackman = ResampleFilter{
+ Support: 3.0,
+ Kernel: func(x float64) float64 {
+ x = math.Abs(x)
+ if x < 3.0 {
+ return sinc(x) * (0.42 - 0.5*math.Cos(math.Pi*x/3.0+math.Pi) + 0.08*math.Cos(2.0*math.Pi*x/3.0))
+ }
+ return 0
+ },
+ }
+
+ Welch = ResampleFilter{
+ Support: 3.0,
+ Kernel: func(x float64) float64 {
+ x = math.Abs(x)
+ if x < 3.0 {
+ return sinc(x) * (1.0 - (x * x / 9.0))
+ }
+ return 0
+ },
+ }
+
+ Cosine = ResampleFilter{
+ Support: 3.0,
+ Kernel: func(x float64) float64 {
+ x = math.Abs(x)
+ if x < 3.0 {
+ return sinc(x) * math.Cos((math.Pi/2.0)*(x/3.0))
+ }
+ return 0
+ },
+ }
+}
diff --git a/vendor/github.com/disintegration/imaging/tools.go b/vendor/github.com/disintegration/imaging/tools.go
new file mode 100644
index 000000000..76f14447b
--- /dev/null
+++ b/vendor/github.com/disintegration/imaging/tools.go
@@ -0,0 +1,201 @@
+package imaging
+
+import (
+ "image"
+ "math"
+)
+
+// Anchor is the anchor point for image alignment.
+type Anchor int
+
+const (
+ Center Anchor = iota
+ TopLeft
+ Top
+ TopRight
+ Left
+ Right
+ BottomLeft
+ Bottom
+ BottomRight
+)
+
+func anchorPt(b image.Rectangle, w, h int, anchor Anchor) image.Point {
+ var x, y int
+ switch anchor {
+ case TopLeft:
+ x = b.Min.X
+ y = b.Min.Y
+ case Top:
+ x = b.Min.X + (b.Dx()-w)/2
+ y = b.Min.Y
+ case TopRight:
+ x = b.Max.X - w
+ y = b.Min.Y
+ case Left:
+ x = b.Min.X
+ y = b.Min.Y + (b.Dy()-h)/2
+ case Right:
+ x = b.Max.X - w
+ y = b.Min.Y + (b.Dy()-h)/2
+ case BottomLeft:
+ x = b.Min.X
+ y = b.Max.Y - h
+ case Bottom:
+ x = b.Min.X + (b.Dx()-w)/2
+ y = b.Max.Y - h
+ case BottomRight:
+ x = b.Max.X - w
+ y = b.Max.Y - h
+ default:
+ x = b.Min.X + (b.Dx()-w)/2
+ y = b.Min.Y + (b.Dy()-h)/2
+ }
+ return image.Pt(x, y)
+}
+
+// Crop cuts out a rectangular region with the specified bounds
+// from the image and returns the cropped image.
+func Crop(img image.Image, rect image.Rectangle) *image.NRGBA {
+ src := toNRGBA(img)
+ srcRect := rect.Sub(img.Bounds().Min)
+ sub := src.SubImage(srcRect)
+ return Clone(sub) // New image Bounds().Min point will be (0, 0)
+}
+
+// CropAnchor cuts out a rectangular region with the specified size
+// from the image using the specified anchor point and returns the cropped image.
+func CropAnchor(img image.Image, width, height int, anchor Anchor) *image.NRGBA {
+ srcBounds := img.Bounds()
+ pt := anchorPt(srcBounds, width, height, anchor)
+ r := image.Rect(0, 0, width, height).Add(pt)
+ b := srcBounds.Intersect(r)
+ return Crop(img, b)
+}
+
+// CropCenter cuts out a rectangular region with the specified size
+// from the center of the image and returns the cropped image.
+func CropCenter(img image.Image, width, height int) *image.NRGBA {
+ return CropAnchor(img, width, height, Center)
+}
+
+// Paste pastes the img image to the background image at the specified position and returns the combined image.
+func Paste(background, img image.Image, pos image.Point) *image.NRGBA {
+ src := toNRGBA(img)
+ dst := Clone(background) // cloned image bounds start at (0, 0)
+ startPt := pos.Sub(background.Bounds().Min) // so we should translate start point
+ endPt := startPt.Add(src.Bounds().Size())
+ pasteBounds := image.Rectangle{startPt, endPt}
+
+ if dst.Bounds().Overlaps(pasteBounds) {
+ intersectBounds := dst.Bounds().Intersect(pasteBounds)
+
+ rowSize := intersectBounds.Dx() * 4
+ numRows := intersectBounds.Dy()
+
+ srcStartX := intersectBounds.Min.X - pasteBounds.Min.X
+ srcStartY := intersectBounds.Min.Y - pasteBounds.Min.Y
+
+ i0 := dst.PixOffset(intersectBounds.Min.X, intersectBounds.Min.Y)
+ j0 := src.PixOffset(srcStartX, srcStartY)
+
+ di := dst.Stride
+ dj := src.Stride
+
+ for row := 0; row < numRows; row++ {
+ copy(dst.Pix[i0:i0+rowSize], src.Pix[j0:j0+rowSize])
+ i0 += di
+ j0 += dj
+ }
+ }
+
+ return dst
+}
+
+// PasteCenter pastes the img image to the center of the background image and returns the combined image.
+func PasteCenter(background, img image.Image) *image.NRGBA {
+ bgBounds := background.Bounds()
+ bgW := bgBounds.Dx()
+ bgH := bgBounds.Dy()
+ bgMinX := bgBounds.Min.X
+ bgMinY := bgBounds.Min.Y
+
+ centerX := bgMinX + bgW/2
+ centerY := bgMinY + bgH/2
+
+ x0 := centerX - img.Bounds().Dx()/2
+ y0 := centerY - img.Bounds().Dy()/2
+
+ return Paste(background, img, image.Pt(x0, y0))
+}
+
+// Overlay draws the img image over the background image at given position
+// and returns the combined image. Opacity parameter is the opacity of the img
+// image layer, used to compose the images, it must be from 0.0 to 1.0.
+//
+// Usage examples:
+//
+// // draw the sprite over the background at position (50, 50)
+// dstImage := imaging.Overlay(backgroundImage, spriteImage, image.Pt(50, 50), 1.0)
+//
+// // blend two opaque images of the same size
+// dstImage := imaging.Overlay(imageOne, imageTwo, image.Pt(0, 0), 0.5)
+//
+func Overlay(background, img image.Image, pos image.Point, opacity float64) *image.NRGBA {
+ opacity = math.Min(math.Max(opacity, 0.0), 1.0) // check: 0.0 <= opacity <= 1.0
+
+ src := toNRGBA(img)
+ dst := Clone(background) // cloned image bounds start at (0, 0)
+ startPt := pos.Sub(background.Bounds().Min) // so we should translate start point
+ endPt := startPt.Add(src.Bounds().Size())
+ pasteBounds := image.Rectangle{startPt, endPt}
+
+ if dst.Bounds().Overlaps(pasteBounds) {
+ intersectBounds := dst.Bounds().Intersect(pasteBounds)
+
+ for y := intersectBounds.Min.Y; y < intersectBounds.Max.Y; y++ {
+ for x := intersectBounds.Min.X; x < intersectBounds.Max.X; x++ {
+ i := y*dst.Stride + x*4
+
+ srcX := x - pasteBounds.Min.X
+ srcY := y - pasteBounds.Min.Y
+ j := srcY*src.Stride + srcX*4
+
+ a1 := float64(dst.Pix[i+3])
+ a2 := float64(src.Pix[j+3])
+
+ coef2 := opacity * a2 / 255.0
+ coef1 := (1 - coef2) * a1 / 255.0
+ coefSum := coef1 + coef2
+ coef1 /= coefSum
+ coef2 /= coefSum
+
+ dst.Pix[i+0] = uint8(float64(dst.Pix[i+0])*coef1 + float64(src.Pix[j+0])*coef2)
+ dst.Pix[i+1] = uint8(float64(dst.Pix[i+1])*coef1 + float64(src.Pix[j+1])*coef2)
+ dst.Pix[i+2] = uint8(float64(dst.Pix[i+2])*coef1 + float64(src.Pix[j+2])*coef2)
+ dst.Pix[i+3] = uint8(math.Min(a1+a2*opacity*(255.0-a1)/255.0, 255.0))
+ }
+ }
+ }
+
+ return dst
+}
+
+// OverlayCenter overlays the img image to the center of the background image and
+// returns the combined image. Opacity parameter is the opacity of the img
+// image layer, used to compose the images, it must be from 0.0 to 1.0.
+func OverlayCenter(background, img image.Image, opacity float64) *image.NRGBA {
+ bgBounds := background.Bounds()
+ bgW := bgBounds.Dx()
+ bgH := bgBounds.Dy()
+ bgMinX := bgBounds.Min.X
+ bgMinY := bgBounds.Min.Y
+
+ centerX := bgMinX + bgW/2
+ centerY := bgMinY + bgH/2
+
+ x0 := centerX - img.Bounds().Dx()/2
+ y0 := centerY - img.Bounds().Dy()/2
+
+ return Overlay(background, img, image.Point{x0, y0}, opacity)
+}
diff --git a/vendor/github.com/disintegration/imaging/transform.go b/vendor/github.com/disintegration/imaging/transform.go
new file mode 100644
index 000000000..a11601bba
--- /dev/null
+++ b/vendor/github.com/disintegration/imaging/transform.go
@@ -0,0 +1,201 @@
+package imaging
+
+import (
+ "image"
+)
+
+// Rotate90 rotates the image 90 degrees counterclockwise and returns the transformed image.
+func Rotate90(img image.Image) *image.NRGBA {
+ src := toNRGBA(img)
+ srcW := src.Bounds().Max.X
+ srcH := src.Bounds().Max.Y
+ dstW := srcH
+ dstH := srcW
+ dst := image.NewNRGBA(image.Rect(0, 0, dstW, dstH))
+
+ parallel(dstH, func(partStart, partEnd int) {
+
+ for dstY := partStart; dstY < partEnd; dstY++ {
+ for dstX := 0; dstX < dstW; dstX++ {
+ srcX := dstH - dstY - 1
+ srcY := dstX
+
+ srcOff := srcY*src.Stride + srcX*4
+ dstOff := dstY*dst.Stride + dstX*4
+
+ copy(dst.Pix[dstOff:dstOff+4], src.Pix[srcOff:srcOff+4])
+ }
+ }
+
+ })
+
+ return dst
+}
+
+// Rotate180 rotates the image 180 degrees counterclockwise and returns the transformed image.
+func Rotate180(img image.Image) *image.NRGBA {
+ src := toNRGBA(img)
+ srcW := src.Bounds().Max.X
+ srcH := src.Bounds().Max.Y
+ dstW := srcW
+ dstH := srcH
+ dst := image.NewNRGBA(image.Rect(0, 0, dstW, dstH))
+
+ parallel(dstH, func(partStart, partEnd int) {
+
+ for dstY := partStart; dstY < partEnd; dstY++ {
+ for dstX := 0; dstX < dstW; dstX++ {
+ srcX := dstW - dstX - 1
+ srcY := dstH - dstY - 1
+
+ srcOff := srcY*src.Stride + srcX*4
+ dstOff := dstY*dst.Stride + dstX*4
+
+ copy(dst.Pix[dstOff:dstOff+4], src.Pix[srcOff:srcOff+4])
+ }
+ }
+
+ })
+
+ return dst
+}
+
+// Rotate270 rotates the image 270 degrees counterclockwise and returns the transformed image.
+func Rotate270(img image.Image) *image.NRGBA {
+ src := toNRGBA(img)
+ srcW := src.Bounds().Max.X
+ srcH := src.Bounds().Max.Y
+ dstW := srcH
+ dstH := srcW
+ dst := image.NewNRGBA(image.Rect(0, 0, dstW, dstH))
+
+ parallel(dstH, func(partStart, partEnd int) {
+
+ for dstY := partStart; dstY < partEnd; dstY++ {
+ for dstX := 0; dstX < dstW; dstX++ {
+ srcX := dstY
+ srcY := dstW - dstX - 1
+
+ srcOff := srcY*src.Stride + srcX*4
+ dstOff := dstY*dst.Stride + dstX*4
+
+ copy(dst.Pix[dstOff:dstOff+4], src.Pix[srcOff:srcOff+4])
+ }
+ }
+
+ })
+
+ return dst
+}
+
+// FlipH flips the image horizontally (from left to right) and returns the transformed image.
+func FlipH(img image.Image) *image.NRGBA {
+ src := toNRGBA(img)
+ srcW := src.Bounds().Max.X
+ srcH := src.Bounds().Max.Y
+ dstW := srcW
+ dstH := srcH
+ dst := image.NewNRGBA(image.Rect(0, 0, dstW, dstH))
+
+ parallel(dstH, func(partStart, partEnd int) {
+
+ for dstY := partStart; dstY < partEnd; dstY++ {
+ for dstX := 0; dstX < dstW; dstX++ {
+ srcX := dstW - dstX - 1
+ srcY := dstY
+
+ srcOff := srcY*src.Stride + srcX*4
+ dstOff := dstY*dst.Stride + dstX*4
+
+ copy(dst.Pix[dstOff:dstOff+4], src.Pix[srcOff:srcOff+4])
+ }
+ }
+
+ })
+
+ return dst
+}
+
+// FlipV flips the image vertically (from top to bottom) and returns the transformed image.
+func FlipV(img image.Image) *image.NRGBA {
+ src := toNRGBA(img)
+ srcW := src.Bounds().Max.X
+ srcH := src.Bounds().Max.Y
+ dstW := srcW
+ dstH := srcH
+ dst := image.NewNRGBA(image.Rect(0, 0, dstW, dstH))
+
+ parallel(dstH, func(partStart, partEnd int) {
+
+ for dstY := partStart; dstY < partEnd; dstY++ {
+ for dstX := 0; dstX < dstW; dstX++ {
+ srcX := dstX
+ srcY := dstH - dstY - 1
+
+ srcOff := srcY*src.Stride + srcX*4
+ dstOff := dstY*dst.Stride + dstX*4
+
+ copy(dst.Pix[dstOff:dstOff+4], src.Pix[srcOff:srcOff+4])
+ }
+ }
+
+ })
+
+ return dst
+}
+
+// Transpose flips the image horizontally and rotates 90 degrees counter-clockwise.
+func Transpose(img image.Image) *image.NRGBA {
+ src := toNRGBA(img)
+ srcW := src.Bounds().Max.X
+ srcH := src.Bounds().Max.Y
+ dstW := srcH
+ dstH := srcW
+ dst := image.NewNRGBA(image.Rect(0, 0, dstW, dstH))
+
+ parallel(dstH, func(partStart, partEnd int) {
+
+ for dstY := partStart; dstY < partEnd; dstY++ {
+ for dstX := 0; dstX < dstW; dstX++ {
+ srcX := dstY
+ srcY := dstX
+
+ srcOff := srcY*src.Stride + srcX*4
+ dstOff := dstY*dst.Stride + dstX*4
+
+ copy(dst.Pix[dstOff:dstOff+4], src.Pix[srcOff:srcOff+4])
+ }
+ }
+
+ })
+
+ return dst
+}
+
+// Transverse flips the image vertically and rotates 90 degrees counter-clockwise.
+func Transverse(img image.Image) *image.NRGBA {
+ src := toNRGBA(img)
+ srcW := src.Bounds().Max.X
+ srcH := src.Bounds().Max.Y
+ dstW := srcH
+ dstH := srcW
+ dst := image.NewNRGBA(image.Rect(0, 0, dstW, dstH))
+
+ parallel(dstH, func(partStart, partEnd int) {
+
+ for dstY := partStart; dstY < partEnd; dstY++ {
+ for dstX := 0; dstX < dstW; dstX++ {
+ srcX := dstH - dstY - 1
+ srcY := dstW - dstX - 1
+
+ srcOff := srcY*src.Stride + srcX*4
+ dstOff := dstY*dst.Stride + dstX*4
+
+ copy(dst.Pix[dstOff:dstOff+4], src.Pix[srcOff:srcOff+4])
+ }
+ }
+
+ })
+
+ return dst
+}
diff --git a/vendor/github.com/disintegration/imaging/utils.go b/vendor/github.com/disintegration/imaging/utils.go
new file mode 100644
index 000000000..8b1ab8adb
--- /dev/null
+++ b/vendor/github.com/disintegration/imaging/utils.go
@@ -0,0 +1,77 @@
+package imaging
+
+import (
+ "math"
+ "runtime"
+ "sync"
+ "sync/atomic"
+)
+
+var parallelizationEnabled = true
+
+// if GOMAXPROCS = 1: no goroutines used
+// if GOMAXPROCS > 1: spawn N=GOMAXPROCS workers in separate goroutines
+func parallel(dataSize int, fn func(partStart, partEnd int)) {
+ numGoroutines := 1
+ partSize := dataSize
+
+ if parallelizationEnabled {
+ numProcs := runtime.GOMAXPROCS(0)
+ if numProcs > 1 {
+ numGoroutines = numProcs
+ partSize = dataSize / (numGoroutines * 10)
+ if partSize < 1 {
+ partSize = 1
+ }
+ }
+ }
+
+ if numGoroutines == 1 {
+ fn(0, dataSize)
+ } else {
+ var wg sync.WaitGroup
+ wg.Add(numGoroutines)
+ idx := uint64(0)
+
+ for p := 0; p < numGoroutines; p++ {
+ go func() {
+ defer wg.Done()
+ for {
+ partStart := int(atomic.AddUint64(&idx, uint64(partSize))) - partSize
+ if partStart >= dataSize {
+ break
+ }
+ partEnd := partStart + partSize
+ if partEnd > dataSize {
+ partEnd = dataSize
+ }
+ fn(partStart, partEnd)
+ }
+ }()
+ }
+
+ wg.Wait()
+ }
+}
+
+func absint(i int) int {
+ if i < 0 {
+ return -i
+ }
+ return i
+}
+
+// clamp & round float64 to uint8 (0..255)
+func clamp(v float64) uint8 {
+ return uint8(math.Min(math.Max(v, 0.0), 255.0) + 0.5)
+}
+
+// clamp int32 to uint8 (0..255)
+func clampint32(v int32) uint8 {
+ if v < 0 {
+ return 0
+ } else if v > 255 {
+ return 255
+ }
+ return uint8(v)
+}