From dd94a3df5de6cbb4e3351c4731221d3142b60500 Mon Sep 17 00:00:00 2001 From: Jack Date: Wed, 23 Sep 2015 20:00:36 -0700 Subject: add imaging --- .../src/github.com/disintegration/imaging/LICENSE | 21 + .../github.com/disintegration/imaging/README.md | 160 ++++++ .../github.com/disintegration/imaging/adjust.go | 200 ++++++++ .../github.com/disintegration/imaging/effects.go | 187 +++++++ .../github.com/disintegration/imaging/helpers.go | 392 ++++++++++++++ .../github.com/disintegration/imaging/resize.go | 564 +++++++++++++++++++++ .../src/github.com/disintegration/imaging/tools.go | 182 +++++++ .../github.com/disintegration/imaging/transform.go | 201 ++++++++ .../src/github.com/disintegration/imaging/utils.go | 77 +++ 9 files changed, 1984 insertions(+) create mode 100644 Godeps/_workspace/src/github.com/disintegration/imaging/LICENSE create mode 100644 Godeps/_workspace/src/github.com/disintegration/imaging/README.md create mode 100644 Godeps/_workspace/src/github.com/disintegration/imaging/adjust.go create mode 100644 Godeps/_workspace/src/github.com/disintegration/imaging/effects.go create mode 100644 Godeps/_workspace/src/github.com/disintegration/imaging/helpers.go create mode 100644 Godeps/_workspace/src/github.com/disintegration/imaging/resize.go create mode 100644 Godeps/_workspace/src/github.com/disintegration/imaging/tools.go create mode 100644 Godeps/_workspace/src/github.com/disintegration/imaging/transform.go create mode 100644 Godeps/_workspace/src/github.com/disintegration/imaging/utils.go (limited to 'Godeps/_workspace/src/github.com/disintegration/imaging') diff --git a/Godeps/_workspace/src/github.com/disintegration/imaging/LICENSE b/Godeps/_workspace/src/github.com/disintegration/imaging/LICENSE new file mode 100644 index 000000000..95ae410c3 --- /dev/null +++ b/Godeps/_workspace/src/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/Godeps/_workspace/src/github.com/disintegration/imaging/README.md b/Godeps/_workspace/src/github.com/disintegration/imaging/README.md new file mode 100644 index 000000000..16ac8cf6c --- /dev/null +++ b/Godeps/_workspace/src/github.com/disintegration/imaging/README.md @@ -0,0 +1,160 @@ +# Imaging + +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 make a 100x100px thumbnail +dstImageThumb := imaging.Thumbnail(srcImage, 100, 100, 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) + +### 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/Godeps/_workspace/src/github.com/disintegration/imaging/adjust.go b/Godeps/_workspace/src/github.com/disintegration/imaging/adjust.go new file mode 100644 index 000000000..9b1b83a4f --- /dev/null +++ b/Godeps/_workspace/src/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/Godeps/_workspace/src/github.com/disintegration/imaging/effects.go b/Godeps/_workspace/src/github.com/disintegration/imaging/effects.go new file mode 100644 index 000000000..fe92e10a2 --- /dev/null +++ b/Godeps/_workspace/src/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/Godeps/_workspace/src/github.com/disintegration/imaging/helpers.go b/Godeps/_workspace/src/github.com/disintegration/imaging/helpers.go new file mode 100644 index 000000000..983b64d71 --- /dev/null +++ b/Godeps/_workspace/src/github.com/disintegration/imaging/helpers.go @@ -0,0 +1,392 @@ +/* +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: + dst.Pix[di+0] = uint8(uint16(src.Pix[si+0]) * 0xff / uint16(a)) + dst.Pix[di+1] = uint8(uint16(src.Pix[si+1]) * 0xff / uint16(a)) + dst.Pix[di+2] = uint8(uint16(src.Pix[si+2]) * 0xff / uint16(a)) + } + + 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: + dst.Pix[di+0] = uint8(uint16(src.Pix[si+0]) * 0xff / uint16(a)) + dst.Pix[di+1] = uint8(uint16(src.Pix[si+2]) * 0xff / uint16(a)) + dst.Pix[di+2] = uint8(uint16(src.Pix[si+4]) * 0xff / uint16(a)) + } + + 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/Godeps/_workspace/src/github.com/disintegration/imaging/resize.go b/Godeps/_workspace/src/github.com/disintegration/imaging/resize.go new file mode 100644 index 000000000..d2efd5c83 --- /dev/null +++ b/Godeps/_workspace/src/github.com/disintegration/imaging/resize.go @@ -0,0 +1,564 @@ +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) +} + +// 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 { + thumbW, thumbH := width, height + + if thumbW <= 0 || thumbH <= 0 { + return &image.NRGBA{} + } + + srcBounds := img.Bounds() + srcW := srcBounds.Dx() + srcH := srcBounds.Dy() + + if srcW <= 0 || srcH <= 0 { + return &image.NRGBA{} + } + + srcAspectRatio := float64(srcW) / float64(srcH) + thumbAspectRatio := float64(thumbW) / float64(thumbH) + + var tmp image.Image + if srcAspectRatio > thumbAspectRatio { + tmp = Resize(img, 0, thumbH, filter) + } else { + tmp = Resize(img, thumbW, 0, filter) + } + + return CropCenter(tmp, thumbW, thumbH) +} + +// 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/Godeps/_workspace/src/github.com/disintegration/imaging/tools.go b/Godeps/_workspace/src/github.com/disintegration/imaging/tools.go new file mode 100644 index 000000000..2c39c900a --- /dev/null +++ b/Godeps/_workspace/src/github.com/disintegration/imaging/tools.go @@ -0,0 +1,182 @@ +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 +} diff --git a/Godeps/_workspace/src/github.com/disintegration/imaging/transform.go b/Godeps/_workspace/src/github.com/disintegration/imaging/transform.go new file mode 100644 index 000000000..a11601bba --- /dev/null +++ b/Godeps/_workspace/src/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/Godeps/_workspace/src/github.com/disintegration/imaging/utils.go b/Godeps/_workspace/src/github.com/disintegration/imaging/utils.go new file mode 100644 index 000000000..8b1ab8adb --- /dev/null +++ b/Godeps/_workspace/src/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) +} -- cgit v1.2.3-1-g7c22