├── .gitignore ├── README.md ├── README_EN.md ├── README_ZH.md ├── errorF2F.go ├── example_test.go ├── go.mod ├── graphics ├── Makefile ├── affine.go ├── blur.go ├── blur_test.go ├── convolve │ ├── Makefile │ ├── convolve.go │ └── convolve_test.go ├── detect │ ├── Makefile │ ├── detect.go │ ├── detect_test.go │ ├── doc.go │ ├── integral.go │ ├── integral_test.go │ ├── opencv_parser.go │ ├── opencv_parser_test.go │ ├── projector.go │ └── projector_test.go ├── graphicstest │ ├── Makefile │ └── graphicstest.go ├── interp │ ├── Makefile │ ├── bilinear.go │ ├── bilinear_test.go │ ├── doc.go │ └── interp.go ├── rotate.go ├── rotate_test.go ├── scale.go ├── scale_test.go ├── shared_test.go ├── thumbnail.go └── thumbnail_test.go ├── imageF2F.go ├── lib └── codereview │ └── codereview.cfg └── testdata ├── gopher.png ├── gopher500.png └── gopher500_800.png /.gitignore: -------------------------------------------------------------------------------- 1 | .idea/* -------------------------------------------------------------------------------- /README.md: -------------------------------------------------------------------------------- 1 | # Simple Golang Picture transformation lib | Thumbnail | Scale 2 | 3 | [中文说明](README_ZH.md) 4 | 5 | ## What 6 | 7 | 1. Very hard to find such lib so I make this. 8 | 2. Scale the size of Picture such the format of jpg or png. 9 | 10 | 11 | ## New 12 | 13 | - 2019/5/12 Support Bytes Stream of Picture to Scale. 14 | 15 | ## How 16 | 17 | ### Install 18 | 19 | ``` 20 | go get -v -u github.com/hunterhug/go_image 21 | ``` 22 | 23 | ### Main funciton 24 | 25 | - Scale by width，input and output is bytes: 26 | 27 | ``` 28 | func ScaleB2B(InRaw []byte, width int) (OutRaw []byte, err error) 29 | ``` 30 | 31 | - Scale by width，input and output is the location(filename) of picture: 32 | 33 | ``` 34 | func ScaleF2F(filename string, savepath string, width int) (err error) 35 | ``` 36 | 37 | - Scale by width and height，input and output is bytes: 38 | 39 | ``` 40 | func ThumbnailB2B(InRaw []byte, width int, height int) (OutRaw []byte, err error) 41 | ``` 42 | 43 | - Scale by width and height，input and output is the location(filename) of picture: 44 | 45 | ``` 46 | func ThumbnailF2F(filename string, savepath string, width int, height int) (err error) 47 | ``` 48 | 49 | - Check the image real file type, such 4.jpg return 4.png(input is the location of file): 50 | 51 | ``` 52 | func RealImageName(filename string) (filerealname string, err error) 53 | ``` 54 | 55 | - Rename the file,if file exist will throw err if force is false, when force is true overwrite: 56 | 57 | ``` 58 | func ChangeImageName(oldname string, newname string, force bool) (err error) 59 | ``` 60 | 61 | ## Example 62 | 63 | ### example_test.go 64 | 65 | ``` 66 | package go_image 67 | 68 | import ( 69 | "fmt" 70 | "testing" 71 | ) 72 | 73 | //将某一图片文件进行缩放后存入另外的文件中 74 | func TestImage(t *testing.T) { 75 | //打印当前文件夹位置 76 | fmt.Printf("本文件文件夹位置:%s\n", CurDir()) 77 | 78 | //图像位置 79 | filename := "./testdata/gopher.png" 80 | 81 | //宽度,高度 82 | width := 500 83 | height := 800 84 | 85 | //保存位置 86 | save1 := "./testdata/gopher500.jpg" 87 | save2 := "./testdata/gopher500_800.png" 88 | 89 | //按照宽度进行等比例缩放 90 | err := ScaleF2F(filename, save1, width) 91 | if err != nil { 92 | fmt.Printf("生成按宽度缩放图失败：%s\n", err.Error()) 93 | } else { 94 | fmt.Printf("生成按宽度缩放图：%s\n", save1) 95 | } 96 | 97 | //按照宽度和高度进行等比例缩放 98 | err = ThumbnailF2F(filename, save2, width, height) 99 | if err != nil { 100 | fmt.Printf("生成按宽度高度缩放图:%s\n", err.Error()) 101 | } else { 102 | fmt.Printf("生成按宽度高度缩放图:%s\n", save2) 103 | } 104 | 105 | //查看图像文件的真正名字 106 | //如 ./testdata/gopher500.jpg其实是png类型,但是命名错误,需要纠正! 107 | realfilename, err := RealImageName(save1) 108 | if err != nil { 109 | fmt.Printf("真正的文件名: %s->? err:%s\n", save1, err.Error()) 110 | } else { 111 | fmt.Printf("真正的文件名:%s->%s\n", save1, realfilename) 112 | } 113 | 114 | //文件改名,强制性 115 | err = ChangeImageName(save1, realfilename, true) 116 | if err != nil { 117 | fmt.Printf("文件改名失败:%s->%s,%s\n", save1, realfilename, err.Error()) 118 | } else { 119 | fmt.Println("改名成功") 120 | } 121 | 122 | //文件改名,不强制性 123 | err = ChangeImageName(save1, realfilename, false) 124 | if err != nil { 125 | fmt.Printf("文件改名失败:%s->%s,%s\n", save1, realfilename, err.Error()) 126 | } 127 | } 128 | 129 | ``` 130 | 131 | ### Result 132 | 133 | ``` 134 | === RUN TestImage 135 | 本文件文件夹位置:E:\gocode\src\github.com\hunterhug\go_image 136 | 生成按宽度缩放图：./testdata/gopher500.jpg 137 | 生成按宽度高度缩放图:./testdata/gopher500_800.png 138 | 真正的文件名:./testdata/gopher500.jpg->./testdata/gopher500.png 139 | 改名成功 140 | 文件改名失败:./testdata/gopher500.jpg->./testdata/gopher500.png,File already exist error 141 | --- PASS: TestImage (1.66s) 142 | PASS 143 | ``` 144 | 145 | Origin: 146 | 147 | ![/testdata/gopher.png](/testdata/gopher.png) 148 | 149 | 150 | Width 500px Scale: 151 | 152 | 153 | ![testdata/gopher500.png](testdata/gopher500.png) 154 | 155 | Width 500px,Height 800px Scale: 156 | 157 | ![/testdata/gopher500_800.png](/testdata/gopher500_800.png) 158 | 159 | ## Come from 160 | 161 | This is a Graphics library for the Go programming language. 162 | 163 | Unless otherwise noted, the graphics-go source files are distributed 164 | under the BSD-style license found in the LICENSE file. 165 | 166 | Contributions should follow the same procedure as for the Go project: 167 | http://golang.org/doc/contribute.html 168 | 169 | -------------------------------------------------------------------------------- /README_EN.md: -------------------------------------------------------------------------------- 1 | # Simple Golang Picture transformation lib | Thumbnail | Scale 2 | 3 | [中文说明](README_ZH.md) 4 | 5 | ## What 6 | 7 | 1. Very hard to find such lib so I make this. 8 | 2. Scale the size of Picture such the format of jpg or png. 9 | 10 | 11 | ## New 12 | 13 | - 2019/5/12 Support Bytes Stream of Picture to Scale. 14 | 15 | ## How 16 | 17 | ### Install 18 | 19 | ``` 20 | go get -v -u github.com/hunterhug/go_image 21 | ``` 22 | 23 | ### Main funciton 24 | 25 | - Scale by width，input and output is bytes: 26 | 27 | ``` 28 | func ScaleB2B(InRaw []byte, width int) (OutRaw []byte, err error) 29 | ``` 30 | 31 | - Scale by width，input and output is the location(filename) of picture: 32 | 33 | ``` 34 | func ScaleF2F(filename string, savepath string, width int) (err error) 35 | ``` 36 | 37 | - Scale by width and height，input and output is bytes: 38 | 39 | ``` 40 | func ThumbnailB2B(InRaw []byte, width int, height int) (OutRaw []byte, err error) 41 | ``` 42 | 43 | - Scale by width and height，input and output is the location(filename) of picture: 44 | 45 | ``` 46 | func ThumbnailF2F(filename string, savepath string, width int, height int) (err error) 47 | ``` 48 | 49 | - Check the image real file type, such 4.jpg return 4.png(input is the location of file): 50 | 51 | ``` 52 | func RealImageName(filename string) (filerealname string, err error) 53 | ``` 54 | 55 | - Rename the file,if file exist will throw err if force is false, when force is true overwrite: 56 | 57 | ``` 58 | func ChangeImageName(oldname string, newname string, force bool) (err error) 59 | ``` 60 | 61 | ## Example 62 | 63 | ### example_test.go 64 | 65 | ``` 66 | package go_image 67 | 68 | import ( 69 | "fmt" 70 | "testing" 71 | ) 72 | 73 | //将某一图片文件进行缩放后存入另外的文件中 74 | func TestImage(t *testing.T) { 75 | //打印当前文件夹位置 76 | fmt.Printf("本文件文件夹位置:%s\n", CurDir()) 77 | 78 | //图像位置 79 | filename := "./testdata/gopher.png" 80 | 81 | //宽度,高度 82 | width := 500 83 | height := 800 84 | 85 | //保存位置 86 | save1 := "./testdata/gopher500.jpg" 87 | save2 := "./testdata/gopher500_800.png" 88 | 89 | //按照宽度进行等比例缩放 90 | err := ScaleF2F(filename, save1, width) 91 | if err != nil { 92 | fmt.Printf("生成按宽度缩放图失败：%s\n", err.Error()) 93 | } else { 94 | fmt.Printf("生成按宽度缩放图：%s\n", save1) 95 | } 96 | 97 | //按照宽度和高度进行等比例缩放 98 | err = ThumbnailF2F(filename, save2, width, height) 99 | if err != nil { 100 | fmt.Printf("生成按宽度高度缩放图:%s\n", err.Error()) 101 | } else { 102 | fmt.Printf("生成按宽度高度缩放图:%s\n", save2) 103 | } 104 | 105 | //查看图像文件的真正名字 106 | //如 ./testdata/gopher500.jpg其实是png类型,但是命名错误,需要纠正! 107 | realfilename, err := RealImageName(save1) 108 | if err != nil { 109 | fmt.Printf("真正的文件名: %s->? err:%s\n", save1, err.Error()) 110 | } else { 111 | fmt.Printf("真正的文件名:%s->%s\n", save1, realfilename) 112 | } 113 | 114 | //文件改名,强制性 115 | err = ChangeImageName(save1, realfilename, true) 116 | if err != nil { 117 | fmt.Printf("文件改名失败:%s->%s,%s\n", save1, realfilename, err.Error()) 118 | } else { 119 | fmt.Println("改名成功") 120 | } 121 | 122 | //文件改名,不强制性 123 | err = ChangeImageName(save1, realfilename, false) 124 | if err != nil { 125 | fmt.Printf("文件改名失败:%s->%s,%s\n", save1, realfilename, err.Error()) 126 | } 127 | } 128 | 129 | ``` 130 | 131 | ### Result 132 | 133 | ``` 134 | === RUN TestImage 135 | 本文件文件夹位置:E:\gocode\src\github.com\hunterhug\go_image 136 | 生成按宽度缩放图：./testdata/gopher500.jpg 137 | 生成按宽度高度缩放图:./testdata/gopher500_800.png 138 | 真正的文件名:./testdata/gopher500.jpg->./testdata/gopher500.png 139 | 改名成功 140 | 文件改名失败:./testdata/gopher500.jpg->./testdata/gopher500.png,File already exist error 141 | --- PASS: TestImage (1.66s) 142 | PASS 143 | ``` 144 | 145 | Origin: 146 | 147 | ![/testdata/gopher.png](/testdata/gopher.png) 148 | 149 | 150 | Width 500px Scale: 151 | 152 | 153 | ![testdata/gopher500.png](testdata/gopher500.png) 154 | 155 | Width 500px,Height 800px Scale: 156 | 157 | ![/testdata/gopher500_800.png](/testdata/gopher500_800.png) 158 | 159 | ## Come from 160 | 161 | This is a Graphics library for the Go programming language. 162 | 163 | Unless otherwise noted, the graphics-go source files are distributed 164 | under the BSD-style license found in the LICENSE file. 165 | 166 | Contributions should follow the same procedure as for the Go project: 167 | http://golang.org/doc/contribute.html 168 | 169 | -------------------------------------------------------------------------------- /README_ZH.md: -------------------------------------------------------------------------------- 1 | # 简单二次封装的golang图像处理库:图片裁剪 2 | 3 | [English Version Here](README_EN.md) 4 | 5 | ## 功能 6 | 7 | 1. Go语言下的官方图像处理库，貌似已经找不到了，所以收藏起来 8 | 2. 简单封装后对jpg和png图像进行缩放|裁剪的库 9 | 10 | ## 最新支持 11 | 12 | - 2019/5/12 支持传入图片字节数组来进行裁剪。 13 | 14 | ## 使用说明 15 | 16 | ### 首先下载 17 | 18 | ``` 19 | go get -v -u github.com/hunterhug/go_image 20 | ``` 21 | 22 | ### 主要函数 23 | 24 | - 按宽度进行比例缩放，输入和输出都是图片字节数组: 25 | 26 | ``` 27 | func ScaleB2B(InRaw []byte, width int) (OutRaw []byte, err error) 28 | ``` 29 | 30 | - 按宽度进行比例缩放，输入输出都是文件: 31 | 32 | ``` 33 | func ScaleF2F(filename string, savepath string, width int) (err error) 34 | ``` 35 | 36 | - 按宽度和高度进行比例缩放，输入和输出都是图片字节数组: 37 | 38 | ``` 39 | func ThumbnailB2B(InRaw []byte, width int, height int) (OutRaw []byte, err error) 40 | ``` 41 | 42 | - 按宽度和高度进行比例缩放，输入和输出都是文件: 43 | 44 | ``` 45 | func ThumbnailF2F(filename string, savepath string, width int, height int) (err error) 46 | ``` 47 | 48 | - 检测图像文件真正文件类型,并返回真实文件名,参数为图像文件位置 49 | 50 | ``` 51 | func RealImageName(filename string) (filerealname string, err error) 52 | ``` 53 | 54 | - 文件改名,如果force为假,且新的文件名已经存在,那么抛出错误 55 | 56 | ``` 57 | func ChangeImageName(oldname string, newname string, force bool) (err error) 58 | ``` 59 | 60 | ## 使用示例 61 | 62 | ### example_test.go 63 | 64 | ``` 65 | package go_image 66 | 67 | import ( 68 | "fmt" 69 | "testing" 70 | ) 71 | 72 | //将某一图片文件进行缩放后存入另外的文件中 73 | func TestImage(t *testing.T) { 74 | //打印当前文件夹位置 75 | fmt.Printf("本文件文件夹位置:%s\n", CurDir()) 76 | 77 | //图像位置 78 | filename := "./testdata/gopher.png" 79 | 80 | //宽度,高度 81 | width := 500 82 | height := 800 83 | 84 | //保存位置 85 | save1 := "./testdata/gopher500.jpg" 86 | save2 := "./testdata/gopher500_800.png" 87 | 88 | //按照宽度进行等比例缩放 89 | err := ScaleF2F(filename, save1, width) 90 | if err != nil { 91 | fmt.Printf("生成按宽度缩放图失败：%s\n", err.Error()) 92 | } else { 93 | fmt.Printf("生成按宽度缩放图：%s\n", save1) 94 | } 95 | 96 | //按照宽度和高度进行等比例缩放 97 | err = ThumbnailF2F(filename, save2, width, height) 98 | if err != nil { 99 | fmt.Printf("生成按宽度高度缩放图:%s\n", err.Error()) 100 | } else { 101 | fmt.Printf("生成按宽度高度缩放图:%s\n", save2) 102 | } 103 | 104 | //查看图像文件的真正名字 105 | //如 ./testdata/gopher500.jpg其实是png类型,但是命名错误,需要纠正! 106 | realfilename, err := RealImageName(save1) 107 | if err != nil { 108 | fmt.Printf("真正的文件名: %s->? err:%s\n", save1, err.Error()) 109 | } else { 110 | fmt.Printf("真正的文件名:%s->%s\n", save1, realfilename) 111 | } 112 | 113 | //文件改名,强制性 114 | err = ChangeImageName(save1, realfilename, true) 115 | if err != nil { 116 | fmt.Printf("文件改名失败:%s->%s,%s\n", save1, realfilename, err.Error()) 117 | } else { 118 | fmt.Println("改名成功") 119 | } 120 | 121 | //文件改名,不强制性 122 | err = ChangeImageName(save1, realfilename, false) 123 | if err != nil { 124 | fmt.Printf("文件改名失败:%s->%s,%s\n", save1, realfilename, err.Error()) 125 | } 126 | } 127 | 128 | ``` 129 | 130 | ### 结果 131 | 132 | ``` 133 | === RUN TestImage 134 | 本文件文件夹位置:E:\gocode\src\github.com\hunterhug\go_image 135 | 生成按宽度缩放图：./testdata/gopher500.jpg 136 | 生成按宽度高度缩放图:./testdata/gopher500_800.png 137 | 真正的文件名:./testdata/gopher500.jpg->./testdata/gopher500.png 138 | 改名成功 139 | 文件改名失败:./testdata/gopher500.jpg->./testdata/gopher500.png,File already exist error 140 | --- PASS: TestImage (1.66s) 141 | PASS 142 | ``` 143 | 144 | 原始图片: 145 | 146 | ![/testdata/gopher.png](/testdata/gopher.png) 147 | 148 | 149 | 宽度500px等比例缩放裁剪: 150 | 151 | 152 | ![testdata/gopher500.png](testdata/gopher500.png) 153 | 154 | 宽度500px,高度800px等比例缩放裁剪: 155 | 156 | ![/testdata/gopher500_800.png](/testdata/gopher500_800.png) 157 | 158 | ## 来自 159 | 160 | This is a Graphics library for the Go programming language. 161 | 162 | Unless otherwise noted, the graphics-go source files are distributed 163 | under the BSD-style license found in the LICENSE file. 164 | 165 | Contributions should follow the same procedure as for the Go project: 166 | http://golang.org/doc/contribute.html 167 | 168 | -------------------------------------------------------------------------------- /errorF2F.go: -------------------------------------------------------------------------------- 1 | package go_image 2 | 3 | import "errors" 4 | 5 | var ( 6 | ExtNotSupportError = errors.New("ext of filename not support") 7 | FileNameError = errors.New("filename error") 8 | FileExistError = errors.New("File already exist error") 9 | ) 10 | -------------------------------------------------------------------------------- /example_test.go: -------------------------------------------------------------------------------- 1 | package go_image 2 | 3 | import ( 4 | "fmt" 5 | "testing" 6 | ) 7 | 8 | //将某一图片文件进行缩放后存入另外的文件中 9 | func TestImage(t *testing.T) { 10 | //打印当前文件夹位置 11 | fmt.Printf("本文件文件夹位置:%s\n", CurDir()) 12 | 13 | //图像位置 14 | filename := "./testdata/gopher.png" 15 | 16 | //宽度,高度 17 | width := 500 18 | height := 800 19 | 20 | //保存位置 21 | save1 := "./testdata/gopher500.jpg" 22 | save2 := "./testdata/gopher500_800.png" 23 | 24 | //按照宽度进行等比例缩放 25 | err := ScaleF2F(filename, save1, width) 26 | if err != nil { 27 | fmt.Printf("生成按宽度缩放图失败：%s\n", err.Error()) 28 | } else { 29 | fmt.Printf("生成按宽度缩放图：%s\n", save1) 30 | } 31 | 32 | //按照宽度和高度进行等比例缩放 33 | err = ThumbnailF2F(filename, save2, width, height) 34 | if err != nil { 35 | fmt.Printf("生成按宽度高度缩放图:%s\n", err.Error()) 36 | } else { 37 | fmt.Printf("生成按宽度高度缩放图:%s\n", save2) 38 | } 39 | 40 | //查看图像文件的真正名字 41 | //如 ./testdata/gopher500.jpg其实是png类型,但是命名错误,需要纠正! 42 | realfilename, err := RealImageName(save1) 43 | if err != nil { 44 | fmt.Printf("真正的文件名: %s->? err:%s\n", save1, err.Error()) 45 | } else { 46 | fmt.Printf("真正的文件名:%s->%s\n", save1, realfilename) 47 | } 48 | 49 | //文件改名,强制性 50 | err = ChangeImageName(save1, realfilename, true) 51 | if err != nil { 52 | fmt.Printf("文件改名失败:%s->%s,%s\n", save1, realfilename, err.Error()) 53 | } else { 54 | fmt.Println("改名成功") 55 | } 56 | 57 | //文件改名,不强制性 58 | err = ChangeImageName(save1, realfilename, false) 59 | if err != nil { 60 | fmt.Printf("文件改名失败:%s->%s,%s\n", save1, realfilename, err.Error()) 61 | } 62 | } 63 | -------------------------------------------------------------------------------- /go.mod: -------------------------------------------------------------------------------- 1 | module github.com/hunterhug/go_image 2 | 3 | go 1.15 4 | -------------------------------------------------------------------------------- /graphics/Makefile: -------------------------------------------------------------------------------- 1 | # Copyright 2011 The Graphics-Go Authors. All rights reserved. 2 | # Use of this source code is governed by a BSD-style 3 | # license that can be found in the LICENSE file. 4 | 5 | include $(GOROOT)/src/Make.inc 6 | 7 | TARG=code.google.com/p/graphics-go/graphics 8 | GOFILES=\ 9 | affine.go\ 10 | blur.go\ 11 | rotate.go\ 12 | scale.go\ 13 | thumbnail.go\ 14 | 15 | include $(GOROOT)/src/Make.pkg 16 | -------------------------------------------------------------------------------- /graphics/affine.go: -------------------------------------------------------------------------------- 1 | // Copyright 2011 The Graphics-Go Authors. All rights reserved. 2 | // Use of this source code is governed by a BSD-style 3 | // license that can be found in the LICENSE file. 4 | 5 | package graphics 6 | 7 | import ( 8 | "github.com/hunterhug/go_image/graphics/interp" 9 | "errors" 10 | "image" 11 | "image/draw" 12 | "math" 13 | ) 14 | 15 | // I is the identity Affine transform matrix. 16 | var I = Affine{ 17 | 1, 0, 0, 18 | 0, 1, 0, 19 | 0, 0, 1, 20 | } 21 | 22 | // Affine is a 3x3 2D affine transform matrix. 23 | // M(i,j) is Affine[i*3+j]. 24 | type Affine [9]float64 25 | 26 | // Mul returns the multiplication of two affine transform matrices. 27 | func (a Affine) Mul(b Affine) Affine { 28 | return Affine{ 29 | a[0]*b[0] + a[1]*b[3] + a[2]*b[6], 30 | a[0]*b[1] + a[1]*b[4] + a[2]*b[7], 31 | a[0]*b[2] + a[1]*b[5] + a[2]*b[8], 32 | a[3]*b[0] + a[4]*b[3] + a[5]*b[6], 33 | a[3]*b[1] + a[4]*b[4] + a[5]*b[7], 34 | a[3]*b[2] + a[4]*b[5] + a[5]*b[8], 35 | a[6]*b[0] + a[7]*b[3] + a[8]*b[6], 36 | a[6]*b[1] + a[7]*b[4] + a[8]*b[7], 37 | a[6]*b[2] + a[7]*b[5] + a[8]*b[8], 38 | } 39 | } 40 | 41 | func (a Affine) transformRGBA(dst *image.RGBA, src *image.RGBA, i interp.RGBA) error { 42 | srcb := src.Bounds() 43 | b := dst.Bounds() 44 | for y := b.Min.Y; y < b.Max.Y; y++ { 45 | for x := b.Min.X; x < b.Max.X; x++ { 46 | sx, sy := a.pt(x, y) 47 | if inBounds(srcb, sx, sy) { 48 | c := i.RGBA(src, sx, sy) 49 | off := (y-dst.Rect.Min.Y)*dst.Stride + (x-dst.Rect.Min.X)*4 50 | dst.Pix[off+0] = c.R 51 | dst.Pix[off+1] = c.G 52 | dst.Pix[off+2] = c.B 53 | dst.Pix[off+3] = c.A 54 | } 55 | } 56 | } 57 | return nil 58 | } 59 | 60 | // Transform applies the affine transform to src and produces dst. 61 | func (a Affine) Transform(dst draw.Image, src image.Image, i interp.Interp) error { 62 | if dst == nil { 63 | return errors.New("graphics: dst is nil") 64 | } 65 | if src == nil { 66 | return errors.New("graphics: src is nil") 67 | } 68 | 69 | // RGBA fast path. 70 | dstRGBA, dstOk := dst.(*image.RGBA) 71 | srcRGBA, srcOk := src.(*image.RGBA) 72 | interpRGBA, interpOk := i.(interp.RGBA) 73 | if dstOk && srcOk && interpOk { 74 | return a.transformRGBA(dstRGBA, srcRGBA, interpRGBA) 75 | } 76 | 77 | srcb := src.Bounds() 78 | b := dst.Bounds() 79 | for y := b.Min.Y; y < b.Max.Y; y++ { 80 | for x := b.Min.X; x < b.Max.X; x++ { 81 | sx, sy := a.pt(x, y) 82 | if inBounds(srcb, sx, sy) { 83 | dst.Set(x, y, i.Interp(src, sx, sy)) 84 | } 85 | } 86 | } 87 | return nil 88 | } 89 | 90 | func inBounds(b image.Rectangle, x, y float64) bool { 91 | if x < float64(b.Min.X) || x >= float64(b.Max.X) { 92 | return false 93 | } 94 | if y < float64(b.Min.Y) || y >= float64(b.Max.Y) { 95 | return false 96 | } 97 | return true 98 | } 99 | 100 | func (a Affine) pt(x0, y0 int) (x1, y1 float64) { 101 | fx := float64(x0) + 0.5 102 | fy := float64(y0) + 0.5 103 | x1 = fx*a[0] + fy*a[1] + a[2] 104 | y1 = fx*a[3] + fy*a[4] + a[5] 105 | return x1, y1 106 | } 107 | 108 | // TransformCenter applies the affine transform to src and produces dst. 109 | // Equivalent to 110 | // a.CenterFit(dst, src).Transform(dst, src, i). 111 | func (a Affine) TransformCenter(dst draw.Image, src image.Image, i interp.Interp) error { 112 | if dst == nil { 113 | return errors.New("graphics: dst is nil") 114 | } 115 | if src == nil { 116 | return errors.New("graphics: src is nil") 117 | } 118 | 119 | return a.CenterFit(dst.Bounds(), src.Bounds()).Transform(dst, src, i) 120 | } 121 | 122 | // Scale produces a scaling transform of factors x and y. 123 | func (a Affine) Scale(x, y float64) Affine { 124 | return a.Mul(Affine{ 125 | 1 / x, 0, 0, 126 | 0, 1 / y, 0, 127 | 0, 0, 1, 128 | }) 129 | } 130 | 131 | // Rotate produces a clockwise rotation transform of angle, in radians. 132 | func (a Affine) Rotate(angle float64) Affine { 133 | s, c := math.Sincos(angle) 134 | return a.Mul(Affine{ 135 | +c, +s, +0, 136 | -s, +c, +0, 137 | +0, +0, +1, 138 | }) 139 | } 140 | 141 | // Shear produces a shear transform by the slopes x and y. 142 | func (a Affine) Shear(x, y float64) Affine { 143 | d := 1 - x*y 144 | return a.Mul(Affine{ 145 | +1 / d, -x / d, 0, 146 | -y / d, +1 / d, 0, 147 | 0, 0, 1, 148 | }) 149 | } 150 | 151 | // Translate produces a translation transform with pixel distances x and y. 152 | func (a Affine) Translate(x, y float64) Affine { 153 | return a.Mul(Affine{ 154 | 1, 0, -x, 155 | 0, 1, -y, 156 | 0, 0, +1, 157 | }) 158 | } 159 | 160 | // Center produces the affine transform, centered around the provided point. 161 | func (a Affine) Center(x, y float64) Affine { 162 | return I.Translate(-x, -y).Mul(a).Translate(x, y) 163 | } 164 | 165 | // CenterFit produces the affine transform, centered around the rectangles. 166 | // It is equivalent to 167 | // I.Translate(-
).Mul(a).Translate(
) 168 | func (a Affine) CenterFit(dst, src image.Rectangle) Affine { 169 | dx := float64(dst.Min.X) + float64(dst.Dx())/2 170 | dy := float64(dst.Min.Y) + float64(dst.Dy())/2 171 | sx := float64(src.Min.X) + float64(src.Dx())/2 172 | sy := float64(src.Min.Y) + float64(src.Dy())/2 173 | return I.Translate(-sx, -sy).Mul(a).Translate(dx, dy) 174 | } 175 | -------------------------------------------------------------------------------- /graphics/blur.go: -------------------------------------------------------------------------------- 1 | // Copyright 2011 The Graphics-Go Authors. All rights reserved. 2 | // Use of this source code is governed by a BSD-style 3 | // license that can be found in the LICENSE file. 4 | 5 | package graphics 6 | 7 | import ( 8 | "github.com/hunterhug/go_image/graphics/convolve" 9 | "errors" 10 | "image" 11 | "image/draw" 12 | "math" 13 | ) 14 | 15 | // DefaultStdDev is the default blurring parameter. 16 | var DefaultStdDev = 0.5 17 | 18 | // BlurOptions are the blurring parameters. 19 | // StdDev is the standard deviation of the normal, higher is blurrier. 20 | // Size is the size of the kernel. If zero, it is set to Ceil(6 * StdDev). 21 | type BlurOptions struct { 22 | StdDev float64 23 | Size int 24 | } 25 | 26 | // Blur produces a blurred version of the image, using a Gaussian blur. 27 | func Blur(dst draw.Image, src image.Image, opt *BlurOptions) error { 28 | if dst == nil { 29 | return errors.New("graphics: dst is nil") 30 | } 31 | if src == nil { 32 | return errors.New("graphics: src is nil") 33 | } 34 | 35 | sd := DefaultStdDev 36 | size := 0 37 | 38 | if opt != nil { 39 | sd = opt.StdDev 40 | size = opt.Size 41 | } 42 | 43 | if size < 1 { 44 | size = int(math.Ceil(sd * 6)) 45 | } 46 | 47 | kernel := make([]float64, 2*size+1) 48 | for i := 0; i <= size; i++ { 49 | x := float64(i) / sd 50 | x = math.Pow(1/math.SqrtE, x*x) 51 | kernel[size-i] = x 52 | kernel[size+i] = x 53 | } 54 | 55 | // Normalize the weights to sum to 1.0. 56 | kSum := 0.0 57 | for _, k := range kernel { 58 | kSum += k 59 | } 60 | for i, k := range kernel { 61 | kernel[i] = k / kSum 62 | } 63 | 64 | return convolve.Convolve(dst, src, &convolve.SeparableKernel{ 65 | X: kernel, 66 | Y: kernel, 67 | }) 68 | } 69 | -------------------------------------------------------------------------------- /graphics/blur_test.go: -------------------------------------------------------------------------------- 1 | // Copyright 2011 The Graphics-Go Authors. All rights reserved. 2 | // Use of this source code is governed by a BSD-style 3 | // license that can be found in the LICENSE file. 4 | 5 | package graphics 6 | 7 | import ( 8 | "github.com/hunterhug/go_image/graphics/graphicstest" 9 | "image" 10 | "image/color" 11 | "testing" 12 | 13 | _ "image/png" 14 | ) 15 | 16 | var blurOneColorTests = []transformOneColorTest{ 17 | { 18 | "1x1-blank", 1, 1, 1, 1, 19 | &BlurOptions{0.83, 1}, 20 | []uint8{0xff}, 21 | []uint8{0xff}, 22 | }, 23 | { 24 | "1x1-spreadblank", 1, 1, 1, 1, 25 | &BlurOptions{0.83, 2}, 26 | []uint8{0xff}, 27 | []uint8{0xff}, 28 | }, 29 | { 30 | "3x3-blank", 3, 3, 3, 3, 31 | &BlurOptions{0.83, 2}, 32 | []uint8{ 33 | 0xff, 0xff, 0xff, 34 | 0xff, 0xff, 0xff, 35 | 0xff, 0xff, 0xff, 36 | }, 37 | []uint8{ 38 | 0xff, 0xff, 0xff, 39 | 0xff, 0xff, 0xff, 40 | 0xff, 0xff, 0xff, 41 | }, 42 | }, 43 | { 44 | "3x3-dot", 3, 3, 3, 3, 45 | &BlurOptions{0.34, 1}, 46 | []uint8{ 47 | 0x00, 0x00, 0x00, 48 | 0x00, 0xff, 0x00, 49 | 0x00, 0x00, 0x00, 50 | }, 51 | []uint8{ 52 | 0x00, 0x03, 0x00, 53 | 0x03, 0xf2, 0x03, 54 | 0x00, 0x03, 0x00, 55 | }, 56 | }, 57 | { 58 | "5x5-dot", 5, 5, 5, 5, 59 | &BlurOptions{0.34, 1}, 60 | []uint8{ 61 | 0x00, 0x00, 0x00, 0x00, 0x00, 62 | 0x00, 0x00, 0x00, 0x00, 0x00, 63 | 0x00, 0x00, 0xff, 0x00, 0x00, 64 | 0x00, 0x00, 0x00, 0x00, 0x00, 65 | 0x00, 0x00, 0x00, 0x00, 0x00, 66 | }, 67 | []uint8{ 68 | 0x00, 0x00, 0x00, 0x00, 0x00, 69 | 0x00, 0x00, 0x03, 0x00, 0x00, 70 | 0x00, 0x03, 0xf2, 0x03, 0x00, 71 | 0x00, 0x00, 0x03, 0x00, 0x00, 72 | 0x00, 0x00, 0x00, 0x00, 0x00, 73 | }, 74 | }, 75 | { 76 | "5x5-dot-spread", 5, 5, 5, 5, 77 | &BlurOptions{0.85, 1}, 78 | []uint8{ 79 | 0x00, 0x00, 0x00, 0x00, 0x00, 80 | 0x00, 0x00, 0x00, 0x00, 0x00, 81 | 0x00, 0x00, 0xff, 0x00, 0x00, 82 | 0x00, 0x00, 0x00, 0x00, 0x00, 83 | 0x00, 0x00, 0x00, 0x00, 0x00, 84 | }, 85 | []uint8{ 86 | 0x00, 0x00, 0x00, 0x00, 0x00, 87 | 0x00, 0x10, 0x20, 0x10, 0x00, 88 | 0x00, 0x20, 0x40, 0x20, 0x00, 89 | 0x00, 0x10, 0x20, 0x10, 0x00, 90 | 0x00, 0x00, 0x00, 0x00, 0x00, 91 | }, 92 | }, 93 | { 94 | "4x4-box", 4, 4, 4, 4, 95 | &BlurOptions{0.34, 1}, 96 | []uint8{ 97 | 0x00, 0x00, 0x00, 0x00, 98 | 0x00, 0xff, 0xff, 0x00, 99 | 0x00, 0xff, 0xff, 0x00, 100 | 0x00, 0x00, 0x00, 0x00, 101 | }, 102 | []uint8{ 103 | 0x00, 0x03, 0x03, 0x00, 104 | 0x03, 0xf8, 0xf8, 0x03, 105 | 0x03, 0xf8, 0xf8, 0x03, 106 | 0x00, 0x03, 0x03, 0x00, 107 | }, 108 | }, 109 | { 110 | "5x5-twodots", 5, 5, 5, 5, 111 | &BlurOptions{0.34, 1}, 112 | []uint8{ 113 | 0x00, 0x00, 0x00, 0x00, 0x00, 114 | 0x00, 0x00, 0x00, 0x00, 0x00, 115 | 0x00, 0x96, 0x00, 0x96, 0x00, 116 | 0x00, 0x00, 0x00, 0x00, 0x00, 117 | 0x00, 0x00, 0x00, 0x00, 0x00, 118 | }, 119 | []uint8{ 120 | 0x00, 0x00, 0x00, 0x00, 0x00, 121 | 0x00, 0x02, 0x00, 0x02, 0x00, 122 | 0x02, 0x8e, 0x04, 0x8e, 0x02, 123 | 0x00, 0x02, 0x00, 0x02, 0x00, 124 | 0x00, 0x00, 0x00, 0x00, 0x00, 125 | }, 126 | }, 127 | } 128 | 129 | func TestBlurOneColor(t *testing.T) { 130 | for _, oc := range blurOneColorTests { 131 | dst := oc.newDst() 132 | src := oc.newSrc() 133 | opt := oc.opt.(*BlurOptions) 134 | if err := Blur(dst, src, opt); err != nil { 135 | t.Fatal(err) 136 | } 137 | 138 | if !checkTransformTest(t, &oc, dst) { 139 | continue 140 | } 141 | } 142 | } 143 | 144 | func TestBlurEmpty(t *testing.T) { 145 | empty := image.NewRGBA(image.Rect(0, 0, 0, 0)) 146 | if err := Blur(empty, empty, nil); err != nil { 147 | t.Fatal(err) 148 | } 149 | } 150 | 151 | func TestBlurGopher(t *testing.T) { 152 | src, err := graphicstest.LoadImage("../testdata/gopher.png") 153 | if err != nil { 154 | t.Fatal(err) 155 | } 156 | 157 | dst := image.NewRGBA(src.Bounds()) 158 | if err = Blur(dst, src, &BlurOptions{StdDev: 1.1}); err != nil { 159 | t.Fatal(err) 160 | } 161 | 162 | cmp, err := graphicstest.LoadImage("../testdata/gopher-blur.png") 163 | if err != nil { 164 | t.Fatal(err) 165 | } 166 | err = graphicstest.ImageWithinTolerance(dst, cmp, 0x101) 167 | if err != nil { 168 | t.Fatal(err) 169 | } 170 | } 171 | 172 | func benchBlur(b *testing.B, bounds image.Rectangle) { 173 | b.StopTimer() 174 | 175 | // Construct a fuzzy image. 176 | src := image.NewRGBA(bounds) 177 | for y := bounds.Min.Y; y < bounds.Max.Y; y++ { 178 | for x := bounds.Min.X; x < bounds.Max.X; x++ { 179 | src.SetRGBA(x, y, color.RGBA{ 180 | uint8(5 * x % 0x100), 181 | uint8(7 * y % 0x100), 182 | uint8((7*x + 5*y) % 0x100), 183 | 0xff, 184 | }) 185 | } 186 | } 187 | dst := image.NewRGBA(bounds) 188 | 189 | b.StartTimer() 190 | for i := 0; i < b.N; i++ { 191 | Blur(dst, src, &BlurOptions{0.84, 3}) 192 | } 193 | } 194 | 195 | func BenchmarkBlur400x400x3(b *testing.B) { 196 | benchBlur(b, image.Rect(0, 0, 400, 400)) 197 | } 198 | 199 | // Exactly twice the pixel count of 400x400. 200 | func BenchmarkBlur400x800x3(b *testing.B) { 201 | benchBlur(b, image.Rect(0, 0, 400, 800)) 202 | } 203 | 204 | // Exactly twice the pixel count of 400x800 205 | func BenchmarkBlur400x1600x3(b *testing.B) { 206 | benchBlur(b, image.Rect(0, 0, 400, 1600)) 207 | } 208 | -------------------------------------------------------------------------------- /graphics/convolve/Makefile: -------------------------------------------------------------------------------- 1 | # Copyright 2011 The Graphics-Go Authors. All rights reserved. 2 | # Use of this source code is governed by a BSD-style 3 | # license that can be found in the LICENSE file. 4 | 5 | include $(GOROOT)/src/Make.inc 6 | 7 | TARG=code.google.com/p/graphics-go/graphics/convolve 8 | GOFILES=\ 9 | convolve.go\ 10 | 11 | include $(GOROOT)/src/Make.pkg 12 | -------------------------------------------------------------------------------- /graphics/convolve/convolve.go: -------------------------------------------------------------------------------- 1 | // Copyright 2011 The Graphics-Go Authors. All rights reserved. 2 | // Use of this source code is governed by a BSD-style 3 | // license that can be found in the LICENSE file. 4 | 5 | package convolve 6 | 7 | import ( 8 | "errors" 9 | "fmt" 10 | "image" 11 | "image/draw" 12 | "math" 13 | ) 14 | 15 | // clamp clamps x to the range [x0, x1]. 16 | func clamp(x, x0, x1 float64) float64 { 17 | if x < x0 { 18 | return x0 19 | } 20 | if x > x1 { 21 | return x1 22 | } 23 | return x 24 | } 25 | 26 | // Kernel is a square matrix that defines a convolution. 27 | type Kernel interface { 28 | // Weights returns the square matrix of weights in row major order. 29 | Weights() []float64 30 | } 31 | 32 | // SeparableKernel is a linearly separable, square convolution kernel. 33 | // X and Y are the per-axis weights. Each slice must be the same length, and 34 | // have an odd length. The middle element of each slice is the weight for the 35 | // central pixel. For example, the horizontal Sobel kernel is: 36 | // sobelX := &SeparableKernel{ 37 | // X: []float64{-1, 0, +1}, 38 | // Y: []float64{1, 2, 1}, 39 | // } 40 | type SeparableKernel struct { 41 | X, Y []float64 42 | } 43 | 44 | func (k *SeparableKernel) Weights() []float64 { 45 | n := len(k.X) 46 | w := make([]float64, n*n) 47 | for y := 0; y < n; y++ { 48 | for x := 0; x < n; x++ { 49 | w[y*n+x] = k.X[x] * k.Y[y] 50 | } 51 | } 52 | return w 53 | } 54 | 55 | // fullKernel is a square convolution kernel. 56 | type fullKernel []float64 57 | 58 | func (k fullKernel) Weights() []float64 { return k } 59 | 60 | func kernelSize(w []float64) (size int, err error) { 61 | size = int(math.Sqrt(float64(len(w)))) 62 | if size*size != len(w) { 63 | return 0, errors.New("graphics: kernel is not square") 64 | } 65 | if size%2 != 1 { 66 | return 0, errors.New("graphics: kernel size is not odd") 67 | } 68 | return size, nil 69 | } 70 | 71 | // NewKernel returns a square convolution kernel. 72 | func NewKernel(w []float64) (Kernel, error) { 73 | if _, err := kernelSize(w); err != nil { 74 | return nil, err 75 | } 76 | return fullKernel(w), nil 77 | } 78 | 79 | func convolveRGBASep(dst *image.RGBA, src image.Image, k *SeparableKernel) error { 80 | if len(k.X) != len(k.Y) { 81 | return fmt.Errorf("graphics: kernel not square (x %d, y %d)", len(k.X), len(k.Y)) 82 | } 83 | if len(k.X)%2 != 1 { 84 | return fmt.Errorf("graphics: kernel length (%d) not odd", len(k.X)) 85 | } 86 | radius := (len(k.X) - 1) / 2 87 | 88 | // buf holds the result of vertically blurring src. 89 | bounds := dst.Bounds() 90 | width, height := bounds.Dx(), bounds.Dy() 91 | buf := make([]float64, width*height*4) 92 | for y := bounds.Min.Y; y < bounds.Max.Y; y++ { 93 | for x := bounds.Min.X; x < bounds.Max.X; x++ { 94 | var r, g, b, a float64 95 | // k0 is the kernel weight for the center pixel. This may be greater 96 | // than kernel[0], near the boundary of the source image, to avoid 97 | // vignetting. 98 | k0 := k.X[radius] 99 | 100 | // Add the pixels from above. 101 | for i := 1; i <= radius; i++ { 102 | f := k.Y[radius-i] 103 | if y-i < bounds.Min.Y { 104 | k0 += f 105 | } else { 106 | or, og, ob, oa := src.At(x, y-i).RGBA() 107 | r += float64(or>>8) * f 108 | g += float64(og>>8) * f 109 | b += float64(ob>>8) * f 110 | a += float64(oa>>8) * f 111 | } 112 | } 113 | 114 | // Add the pixels from below. 115 | for i := 1; i <= radius; i++ { 116 | f := k.Y[radius+i] 117 | if y+i >= bounds.Max.Y { 118 | k0 += f 119 | } else { 120 | or, og, ob, oa := src.At(x, y+i).RGBA() 121 | r += float64(or>>8) * f 122 | g += float64(og>>8) * f 123 | b += float64(ob>>8) * f 124 | a += float64(oa>>8) * f 125 | } 126 | } 127 | 128 | // Add the central pixel. 129 | or, og, ob, oa := src.At(x, y).RGBA() 130 | r += float64(or>>8) * k0 131 | g += float64(og>>8) * k0 132 | b += float64(ob>>8) * k0 133 | a += float64(oa>>8) * k0 134 | 135 | // Write to buf. 136 | o := (y-bounds.Min.Y)*width*4 + (x-bounds.Min.X)*4 137 | buf[o+0] = r 138 | buf[o+1] = g 139 | buf[o+2] = b 140 | buf[o+3] = a 141 | } 142 | } 143 | 144 | // dst holds the result of horizontally blurring buf. 145 | for y := 0; y < height; y++ { 146 | for x := 0; x < width; x++ { 147 | var r, g, b, a float64 148 | k0, off := k.X[radius], y*width*4+x*4 149 | 150 | // Add the pixels from the left. 151 | for i := 1; i <= radius; i++ { 152 | f := k.X[radius-i] 153 | if x-i < 0 { 154 | k0 += f 155 | } else { 156 | o := off - i*4 157 | r += buf[o+0] * f 158 | g += buf[o+1] * f 159 | b += buf[o+2] * f 160 | a += buf[o+3] * f 161 | } 162 | } 163 | 164 | // Add the pixels from the right. 165 | for i := 1; i <= radius; i++ { 166 | f := k.X[radius+i] 167 | if x+i >= width { 168 | k0 += f 169 | } else { 170 | o := off + i*4 171 | r += buf[o+0] * f 172 | g += buf[o+1] * f 173 | b += buf[o+2] * f 174 | a += buf[o+3] * f 175 | } 176 | } 177 | 178 | // Add the central pixel. 179 | r += buf[off+0] * k0 180 | g += buf[off+1] * k0 181 | b += buf[off+2] * k0 182 | a += buf[off+3] * k0 183 | 184 | // Write to dst, clamping to the range [0, 255]. 185 | dstOff := (y-dst.Rect.Min.Y)*dst.Stride + (x-dst.Rect.Min.X)*4 186 | dst.Pix[dstOff+0] = uint8(clamp(r+0.5, 0, 255)) 187 | dst.Pix[dstOff+1] = uint8(clamp(g+0.5, 0, 255)) 188 | dst.Pix[dstOff+2] = uint8(clamp(b+0.5, 0, 255)) 189 | dst.Pix[dstOff+3] = uint8(clamp(a+0.5, 0, 255)) 190 | } 191 | } 192 | 193 | return nil 194 | } 195 | 196 | func convolveRGBA(dst *image.RGBA, src image.Image, k Kernel) error { 197 | b := dst.Bounds() 198 | bs := src.Bounds() 199 | w := k.Weights() 200 | size, err := kernelSize(w) 201 | if err != nil { 202 | return err 203 | } 204 | radius := (size - 1) / 2 205 | 206 | for y := b.Min.Y; y < b.Max.Y; y++ { 207 | for x := b.Min.X; x < b.Max.X; x++ { 208 | if !image.Pt(x, y).In(bs) { 209 | continue 210 | } 211 | 212 | var r, g, b, a, adj float64 213 | for cy := y - radius; cy <= y+radius; cy++ { 214 | for cx := x - radius; cx <= x+radius; cx++ { 215 | factor := w[(cy-y+radius)*size+cx-x+radius] 216 | if !image.Pt(cx, cy).In(bs) { 217 | adj += factor 218 | } else { 219 | sr, sg, sb, sa := src.At(cx, cy).RGBA() 220 | r += float64(sr>>8) * factor 221 | g += float64(sg>>8) * factor 222 | b += float64(sb>>8) * factor 223 | a += float64(sa>>8) * factor 224 | } 225 | } 226 | } 227 | 228 | if adj != 0 { 229 | sr, sg, sb, sa := src.At(x, y).RGBA() 230 | r += float64(sr>>8) * adj 231 | g += float64(sg>>8) * adj 232 | b += float64(sb>>8) * adj 233 | a += float64(sa>>8) * adj 234 | } 235 | 236 | off := (y-dst.Rect.Min.Y)*dst.Stride + (x-dst.Rect.Min.X)*4 237 | dst.Pix[off+0] = uint8(clamp(r+0.5, 0, 0xff)) 238 | dst.Pix[off+1] = uint8(clamp(g+0.5, 0, 0xff)) 239 | dst.Pix[off+2] = uint8(clamp(b+0.5, 0, 0xff)) 240 | dst.Pix[off+3] = uint8(clamp(a+0.5, 0, 0xff)) 241 | } 242 | } 243 | 244 | return nil 245 | } 246 | 247 | // Convolve produces dst by applying the convolution kernel k to src. 248 | func Convolve(dst draw.Image, src image.Image, k Kernel) (err error) { 249 | if dst == nil || src == nil || k == nil { 250 | return nil 251 | } 252 | 253 | b := dst.Bounds() 254 | dstRgba, ok := dst.(*image.RGBA) 255 | if !ok { 256 | dstRgba = image.NewRGBA(b) 257 | } 258 | 259 | switch k := k.(type) { 260 | case *SeparableKernel: 261 | err = convolveRGBASep(dstRgba, src, k) 262 | default: 263 | err = convolveRGBA(dstRgba, src, k) 264 | } 265 | 266 | if err != nil { 267 | return err 268 | } 269 | 270 | if !ok { 271 | draw.Draw(dst, b, dstRgba, b.Min, draw.Src) 272 | } 273 | return nil 274 | } 275 | -------------------------------------------------------------------------------- /graphics/convolve/convolve_test.go: -------------------------------------------------------------------------------- 1 | // Copyright 2011 The Graphics-Go Authors. All rights reserved. 2 | // Use of this source code is governed by a BSD-style 3 | // license that can be found in the LICENSE file. 4 | 5 | package convolve 6 | 7 | import ( 8 | "github.com/hunterhug/go_image/graphics/graphicstest" 9 | "image" 10 | "reflect" 11 | "testing" 12 | 13 | _ "image/png" 14 | ) 15 | 16 | func TestSeparableWeights(t *testing.T) { 17 | sobelXFull := []float64{ 18 | -1, 0, 1, 19 | -2, 0, 2, 20 | -1, 0, 1, 21 | } 22 | sobelXSep := &SeparableKernel{ 23 | X: []float64{-1, 0, +1}, 24 | Y: []float64{1, 2, 1}, 25 | } 26 | w := sobelXSep.Weights() 27 | if !reflect.DeepEqual(w, sobelXFull) { 28 | t.Errorf("got %v want %v", w, sobelXFull) 29 | } 30 | } 31 | 32 | func TestConvolve(t *testing.T) { 33 | kernFull, err := NewKernel([]float64{ 34 | 0, 0, 0, 35 | 1, 1, 1, 36 | 0, 0, 0, 37 | }) 38 | if err != nil { 39 | t.Fatal(err) 40 | } 41 | 42 | kernSep := &SeparableKernel{ 43 | X: []float64{1, 1, 1}, 44 | Y: []float64{0, 1, 0}, 45 | } 46 | 47 | src, err := graphicstest.LoadImage("../../testdata/gopher.png") 48 | if err != nil { 49 | t.Fatal(err) 50 | } 51 | b := src.Bounds() 52 | 53 | sep := image.NewRGBA(b) 54 | if err = Convolve(sep, src, kernSep); err != nil { 55 | t.Fatal(err) 56 | } 57 | 58 | full := image.NewRGBA(b) 59 | Convolve(full, src, kernFull) 60 | 61 | err = graphicstest.ImageWithinTolerance(sep, full, 0x101) 62 | if err != nil { 63 | t.Fatal(err) 64 | } 65 | } 66 | 67 | func TestConvolveNil(t *testing.T) { 68 | if err := Convolve(nil, nil, nil); err != nil { 69 | t.Fatal(err) 70 | } 71 | } 72 | 73 | func TestConvolveEmpty(t *testing.T) { 74 | empty := image.NewRGBA(image.Rect(0, 0, 0, 0)) 75 | if err := Convolve(empty, empty, nil); err != nil { 76 | t.Fatal(err) 77 | } 78 | } 79 | -------------------------------------------------------------------------------- /graphics/detect/Makefile: -------------------------------------------------------------------------------- 1 | # Copyright 2011 The Graphics-Go Authors. All rights reserved. 2 | # Use of this source code is governed by a BSD-style 3 | # license that can be found in the LICENSE file. 4 | 5 | include $(GOROOT)/src/Make.inc 6 | 7 | TARG=code.google.com/p/graphics-go/graphics 8 | GOFILES=\ 9 | detect.go\ 10 | doc.go\ 11 | integral.go\ 12 | opencv_parser.go\ 13 | projector.go\ 14 | 15 | include $(GOROOT)/src/Make.pkg 16 | -------------------------------------------------------------------------------- /graphics/detect/detect.go: -------------------------------------------------------------------------------- 1 | // Copyright 2011 The Graphics-Go Authors. All rights reserved. 2 | // Use of this source code is governed by a BSD-style 3 | // license that can be found in the LICENSE file. 4 | 5 | package detect 6 | 7 | import ( 8 | "image" 9 | "math" 10 | ) 11 | 12 | // Feature is a Haar-like feature. 13 | type Feature struct { 14 | Rect image.Rectangle 15 | Weight float64 16 | } 17 | 18 | // Classifier is a set of features with a threshold. 19 | type Classifier struct { 20 | Feature []Feature 21 | Threshold float64 22 | Left float64 23 | Right float64 24 | } 25 | 26 | // CascadeStage is a cascade of classifiers. 27 | type CascadeStage struct { 28 | Classifier []Classifier 29 | Threshold float64 30 | } 31 | 32 | // Cascade is a degenerate tree of Haar-like classifiers. 33 | type Cascade struct { 34 | Stage []CascadeStage 35 | Size image.Point 36 | } 37 | 38 | // Match returns true if the full image is classified as an object. 39 | func (c *Cascade) Match(m image.Image) bool { 40 | return c.classify(newWindow(m)) 41 | } 42 | 43 | // Find returns a set of areas of m that match the feature cascade c. 44 | func (c *Cascade) Find(m image.Image) []image.Rectangle { 45 | // TODO(crawshaw): Consider de-duping strategies. 46 | matches := []image.Rectangle{} 47 | w := newWindow(m) 48 | 49 | b := m.Bounds() 50 | origScale := c.Size 51 | for s := origScale; s.X < b.Dx() && s.Y < b.Dy(); s = s.Add(s.Div(10)) { 52 | // translate region and classify 53 | tx := image.Pt(s.X/10, 0) 54 | ty := image.Pt(0, s.Y/10) 55 | for r := image.Rect(0, 0, s.X, s.Y).Add(b.Min); r.In(b); r = r.Add(ty) { 56 | for r1 := r; r1.In(b); r1 = r1.Add(tx) { 57 | if c.classify(w.subWindow(r1)) { 58 | matches = append(matches, r1) 59 | } 60 | } 61 | } 62 | } 63 | return matches 64 | } 65 | 66 | type window struct { 67 | mi *integral 68 | miSq *integral 69 | rect image.Rectangle 70 | invArea float64 71 | stdDev float64 72 | } 73 | 74 | func (w *window) init() { 75 | w.invArea = 1 / float64(w.rect.Dx()*w.rect.Dy()) 76 | mean := float64(w.mi.sum(w.rect)) * w.invArea 77 | vr := float64(w.miSq.sum(w.rect))*w.invArea - mean*mean 78 | if vr < 0 { 79 | vr = 1 80 | } 81 | w.stdDev = math.Sqrt(vr) 82 | } 83 | 84 | func newWindow(m image.Image) *window { 85 | mi, miSq := newIntegrals(m) 86 | res := &window{ 87 | mi: mi, 88 | miSq: miSq, 89 | rect: m.Bounds(), 90 | } 91 | res.init() 92 | return res 93 | } 94 | 95 | func (w *window) subWindow(r image.Rectangle) *window { 96 | res := &window{ 97 | mi: w.mi, 98 | miSq: w.miSq, 99 | rect: r, 100 | } 101 | res.init() 102 | return res 103 | } 104 | 105 | func (c *Classifier) classify(w *window, pr *projector) float64 { 106 | s := 0.0 107 | for _, f := range c.Feature { 108 | s += float64(w.mi.sum(pr.rect(f.Rect))) * f.Weight 109 | } 110 | s *= w.invArea // normalize to maintain scale invariance 111 | if s < c.Threshold*w.stdDev { 112 | return c.Left 113 | } 114 | return c.Right 115 | } 116 | 117 | func (s *CascadeStage) classify(w *window, pr *projector) bool { 118 | sum := 0.0 119 | for _, c := range s.Classifier { 120 | sum += c.classify(w, pr) 121 | } 122 | return sum >= s.Threshold 123 | } 124 | 125 | func (c *Cascade) classify(w *window) bool { 126 | pr := newProjector(w.rect, image.Rectangle{image.Pt(0, 0), c.Size}) 127 | for _, s := range c.Stage { 128 | if !s.classify(w, pr) { 129 | return false 130 | } 131 | } 132 | return true 133 | } 134 | -------------------------------------------------------------------------------- /graphics/detect/detect_test.go: -------------------------------------------------------------------------------- 1 | // Copyright 2011 The Graphics-Go Authors. All rights reserved. 2 | // Use of this source code is governed by a BSD-style 3 | // license that can be found in the LICENSE file. 4 | 5 | package detect 6 | 7 | import ( 8 | "image" 9 | "image/draw" 10 | "testing" 11 | ) 12 | 13 | var ( 14 | c0 = Classifier{ 15 | Feature: []Feature{ 16 | Feature{Rect: image.Rect(0, 0, 3, 4), Weight: 4.0}, 17 | }, 18 | Threshold: 0.2, 19 | Left: 0.8, 20 | Right: 0.2, 21 | } 22 | c1 = Classifier{ 23 | Feature: []Feature{ 24 | Feature{Rect: image.Rect(3, 4, 4, 5), Weight: 4.0}, 25 | }, 26 | Threshold: 0.2, 27 | Left: 0.8, 28 | Right: 0.2, 29 | } 30 | c2 = Classifier{ 31 | Feature: []Feature{ 32 | Feature{Rect: image.Rect(0, 0, 1, 1), Weight: +4.0}, 33 | Feature{Rect: image.Rect(0, 0, 2, 2), Weight: -1.0}, 34 | }, 35 | Threshold: 0.2, 36 | Left: 0.8, 37 | Right: 0.2, 38 | } 39 | ) 40 | 41 | func TestClassifier(t *testing.T) { 42 | m := image.NewGray(image.Rect(0, 0, 20, 20)) 43 | b := m.Bounds() 44 | draw.Draw(m, image.Rect(0, 0, 20, 20), image.White, image.ZP, draw.Src) 45 | draw.Draw(m, image.Rect(3, 4, 4, 5), image.Black, image.ZP, draw.Src) 46 | w := newWindow(m) 47 | pr := newProjector(b, b) 48 | 49 | if res := c0.classify(w, pr); res != c0.Right { 50 | t.Errorf("c0 got %f want %f", res, c0.Right) 51 | } 52 | if res := c1.classify(w, pr); res != c1.Left { 53 | t.Errorf("c1 got %f want %f", res, c1.Left) 54 | } 55 | if res := c2.classify(w, pr); res != c1.Left { 56 | t.Errorf("c2 got %f want %f", res, c1.Left) 57 | } 58 | } 59 | 60 | func TestClassifierScale(t *testing.T) { 61 | m := image.NewGray(image.Rect(0, 0, 50, 50)) 62 | b := m.Bounds() 63 | draw.Draw(m, image.Rect(0, 0, 8, 10), image.White, b.Min, draw.Src) 64 | draw.Draw(m, image.Rect(8, 10, 10, 13), image.Black, b.Min, draw.Src) 65 | w := newWindow(m) 66 | pr := newProjector(b, image.Rect(0, 0, 20, 20)) 67 | 68 | if res := c0.classify(w, pr); res != c0.Right { 69 | t.Errorf("scaled c0 got %f want %f", res, c0.Right) 70 | } 71 | if res := c1.classify(w, pr); res != c1.Left { 72 | t.Errorf("scaled c1 got %f want %f", res, c1.Left) 73 | } 74 | if res := c2.classify(w, pr); res != c1.Left { 75 | t.Errorf("scaled c2 got %f want %f", res, c1.Left) 76 | } 77 | } 78 | -------------------------------------------------------------------------------- /graphics/detect/doc.go: -------------------------------------------------------------------------------- 1 | // Copyright 2011 The Graphics-Go Authors. All rights reserved. 2 | // Use of this source code is governed by a BSD-style 3 | // license that can be found in the LICENSE file. 4 | 5 | /* 6 | Package detect implements an object detector cascade. 7 | 8 | The technique used is a degenerate tree of Haar-like classifiers, commonly 9 | used for face detection. It is described in 10 | 11 | P. Viola, M. Jones. 12 | Rapid Object Detection using a Boosted Cascade of Simple Features, 2001 13 | IEEE Conference on Computer Vision and Pattern Recognition 14 | 15 | A Cascade can be constructed manually from a set of Classifiers in stages, 16 | or can be loaded from an XML file in the OpenCV format with 17 | 18 | classifier, _, err := detect.ParseOpenCV(r) 19 | 20 | The classifier can be used to determine if a full image is detected as an 21 | object using Detect 22 | 23 | if classifier.Match(m) { 24 | // m is an image of a face. 25 | } 26 | 27 | It is also possible to search an image for occurrences of an object 28 | 29 | objs := classifier.Find(m) 30 | */ 31 | package detect 32 | -------------------------------------------------------------------------------- /graphics/detect/integral.go: -------------------------------------------------------------------------------- 1 | // Copyright 2011 The Graphics-Go Authors. All rights reserved. 2 | // Use of this source code is governed by a BSD-style 3 | // license that can be found in the LICENSE file. 4 | 5 | package detect 6 | 7 | import ( 8 | "image" 9 | "image/draw" 10 | ) 11 | 12 | // integral is an image.Image-like structure that stores the cumulative 13 | // sum of the preceding pixels. This allows for O(1) summation of any 14 | // rectangular region within the image. 15 | type integral struct { 16 | // pix holds the cumulative sum of the image's pixels. The pixel at 17 | // (x, y) starts at pix[(y-rect.Min.Y)*stride + (x-rect.Min.X)*1]. 18 | pix []uint64 19 | stride int 20 | rect image.Rectangle 21 | } 22 | 23 | func (p *integral) at(x, y int) uint64 { 24 | return p.pix[(y-p.rect.Min.Y)*p.stride+(x-p.rect.Min.X)] 25 | } 26 | 27 | func (p *integral) sum(b image.Rectangle) uint64 { 28 | c := p.at(b.Max.X-1, b.Max.Y-1) 29 | inY := b.Min.Y > p.rect.Min.Y 30 | inX := b.Min.X > p.rect.Min.X 31 | if inY && inX { 32 | c += p.at(b.Min.X-1, b.Min.Y-1) 33 | } 34 | if inY { 35 | c -= p.at(b.Max.X-1, b.Min.Y-1) 36 | } 37 | if inX { 38 | c -= p.at(b.Min.X-1, b.Max.Y-1) 39 | } 40 | return c 41 | } 42 | 43 | func (m *integral) integrate() { 44 | b := m.rect 45 | for y := b.Min.Y; y < b.Max.Y; y++ { 46 | for x := b.Min.X; x < b.Max.X; x++ { 47 | c := uint64(0) 48 | if y > b.Min.Y && x > b.Min.X { 49 | c += m.at(x-1, y) 50 | c += m.at(x, y-1) 51 | c -= m.at(x-1, y-1) 52 | } else if y > b.Min.Y { 53 | c += m.at(b.Min.X, y-1) 54 | } else if x > b.Min.X { 55 | c += m.at(x-1, b.Min.Y) 56 | } 57 | m.pix[(y-m.rect.Min.Y)*m.stride+(x-m.rect.Min.X)] += c 58 | } 59 | } 60 | } 61 | 62 | // newIntegrals returns the integral and the squared integral. 63 | func newIntegrals(src image.Image) (*integral, *integral) { 64 | b := src.Bounds() 65 | srcg, ok := src.(*image.Gray) 66 | if !ok { 67 | srcg = image.NewGray(b) 68 | draw.Draw(srcg, b, src, b.Min, draw.Src) 69 | } 70 | 71 | m := integral{ 72 | pix: make([]uint64, b.Max.Y*b.Max.X), 73 | stride: b.Max.X, 74 | rect: b, 75 | } 76 | mSq := integral{ 77 | pix: make([]uint64, b.Max.Y*b.Max.X), 78 | stride: b.Max.X, 79 | rect: b, 80 | } 81 | for y := b.Min.Y; y < b.Max.Y; y++ { 82 | for x := b.Min.X; x < b.Max.X; x++ { 83 | os := (y-b.Min.Y)*srcg.Stride + x - b.Min.X 84 | om := (y-b.Min.Y)*m.stride + x - b.Min.X 85 | c := uint64(srcg.Pix[os]) 86 | m.pix[om] = c 87 | mSq.pix[om] = c * c 88 | } 89 | } 90 | m.integrate() 91 | mSq.integrate() 92 | return &m, &mSq 93 | } 94 | -------------------------------------------------------------------------------- /graphics/detect/integral_test.go: -------------------------------------------------------------------------------- 1 | // Copyright 2011 The Graphics-Go Authors. All rights reserved. 2 | // Use of this source code is governed by a BSD-style 3 | // license that can be found in the LICENSE file. 4 | 5 | package detect 6 | 7 | import ( 8 | "bytes" 9 | "fmt" 10 | "image" 11 | "testing" 12 | ) 13 | 14 | type integralTest struct { 15 | x int 16 | y int 17 | src []uint8 18 | res []uint8 19 | } 20 | 21 | var integralTests = []integralTest{ 22 | { 23 | 1, 1, 24 | []uint8{0x01}, 25 | []uint8{0x01}, 26 | }, 27 | { 28 | 2, 2, 29 | []uint8{ 30 | 0x01, 0x02, 31 | 0x03, 0x04, 32 | }, 33 | []uint8{ 34 | 0x01, 0x03, 35 | 0x04, 0x0a, 36 | }, 37 | }, 38 | { 39 | 4, 4, 40 | []uint8{ 41 | 0x02, 0x03, 0x00, 0x01, 42 | 0x01, 0x02, 0x01, 0x05, 43 | 0x01, 0x01, 0x01, 0x01, 44 | 0x01, 0x01, 0x01, 0x01, 45 | }, 46 | []uint8{ 47 | 0x02, 0x05, 0x05, 0x06, 48 | 0x03, 0x08, 0x09, 0x0f, 49 | 0x04, 0x0a, 0x0c, 0x13, 50 | 0x05, 0x0c, 0x0f, 0x17, 51 | }, 52 | }, 53 | } 54 | 55 | func sprintBox(box []byte, width, height int) string { 56 | buf := bytes.NewBuffer(nil) 57 | i := 0 58 | for y := 0; y < height; y++ { 59 | for x := 0; x < width; x++ { 60 | fmt.Fprintf(buf, " 0x%02x,", box[i]) 61 | i++ 62 | } 63 | buf.WriteByte('\n') 64 | } 65 | return buf.String() 66 | } 67 | 68 | func TestIntegral(t *testing.T) { 69 | for i, oc := range integralTests { 70 | src := &image.Gray{ 71 | Pix: oc.src, 72 | Stride: oc.x, 73 | Rect: image.Rect(0, 0, oc.x, oc.y), 74 | } 75 | dst, _ := newIntegrals(src) 76 | res := make([]byte, len(dst.pix)) 77 | for i, p := range dst.pix { 78 | res[i] = byte(p) 79 | } 80 | 81 | if !bytes.Equal(res, oc.res) { 82 | got := sprintBox(res, oc.x, oc.y) 83 | want := sprintBox(oc.res, oc.x, oc.y) 84 | t.Errorf("%d: got\n%s\n want\n%s", i, got, want) 85 | } 86 | } 87 | } 88 | 89 | func TestIntegralSum(t *testing.T) { 90 | src := &image.Gray{ 91 | Pix: []uint8{ 92 | 0x02, 0x03, 0x00, 0x01, 0x03, 93 | 0x01, 0x02, 0x01, 0x05, 0x05, 94 | 0x01, 0x01, 0x01, 0x01, 0x02, 95 | 0x01, 0x01, 0x01, 0x01, 0x07, 96 | 0x02, 0x01, 0x00, 0x03, 0x01, 97 | }, 98 | Stride: 5, 99 | Rect: image.Rect(0, 0, 5, 5), 100 | } 101 | img, _ := newIntegrals(src) 102 | 103 | type sumTest struct { 104 | rect image.Rectangle 105 | sum uint64 106 | } 107 | 108 | var sumTests = []sumTest{ 109 | {image.Rect(0, 0, 1, 1), 2}, 110 | {image.Rect(0, 0, 2, 1), 5}, 111 | {image.Rect(0, 0, 1, 3), 4}, 112 | {image.Rect(1, 1, 3, 3), 5}, 113 | {image.Rect(2, 2, 4, 4), 4}, 114 | {image.Rect(4, 3, 5, 5), 8}, 115 | {image.Rect(2, 4, 3, 5), 0}, 116 | } 117 | 118 | for _, st := range sumTests { 119 | s := img.sum(st.rect) 120 | if s != st.sum { 121 | t.Errorf("%v: got %d want %d", st.rect, s, st.sum) 122 | return 123 | } 124 | } 125 | } 126 | 127 | func TestIntegralSubImage(t *testing.T) { 128 | m0 := &image.Gray{ 129 | Pix: []uint8{ 130 | 0x02, 0x03, 0x00, 0x01, 0x03, 131 | 0x01, 0x02, 0x01, 0x05, 0x05, 132 | 0x01, 0x04, 0x01, 0x01, 0x02, 133 | 0x01, 0x02, 0x01, 0x01, 0x07, 134 | 0x02, 0x01, 0x09, 0x03, 0x01, 135 | }, 136 | Stride: 5, 137 | Rect: image.Rect(0, 0, 5, 5), 138 | } 139 | b := image.Rect(1, 1, 4, 4) 140 | m1 := m0.SubImage(b) 141 | mi0, _ := newIntegrals(m0) 142 | mi1, _ := newIntegrals(m1) 143 | 144 | sum0 := mi0.sum(b) 145 | sum1 := mi1.sum(b) 146 | if sum0 != sum1 { 147 | t.Errorf("b got %d want %d", sum0, sum1) 148 | } 149 | 150 | r0 := image.Rect(2, 2, 4, 4) 151 | sum0 = mi0.sum(r0) 152 | sum1 = mi1.sum(r0) 153 | if sum0 != sum1 { 154 | t.Errorf("r0 got %d want %d", sum1, sum0) 155 | } 156 | } 157 | -------------------------------------------------------------------------------- /graphics/detect/opencv_parser.go: -------------------------------------------------------------------------------- 1 | // Copyright 2011 The Graphics-Go Authors. All rights reserved. 2 | // Use of this source code is governed by a BSD-style 3 | // license that can be found in the LICENSE file. 4 | 5 | package detect 6 | 7 | import ( 8 | "bytes" 9 | "encoding/xml" 10 | "errors" 11 | "fmt" 12 | "image" 13 | "io" 14 | "io/ioutil" 15 | "strconv" 16 | "strings" 17 | ) 18 | 19 | type xmlFeature struct { 20 | Rects []string `xml:"grp>feature>rects>grp"` 21 | Tilted int `xml:"grp>feature>tilted"` 22 | Threshold float64 `xml:"grp>threshold"` 23 | Left float64 `xml:"grp>left_val"` 24 | Right float64 `xml:"grp>right_val"` 25 | } 26 | 27 | type xmlStages struct { 28 | Trees []xmlFeature `xml:"trees>grp"` 29 | Stage_threshold float64 `xml:"stage_threshold"` 30 | Parent int `xml:"parent"` 31 | Next int `xml:"next"` 32 | } 33 | 34 | type opencv_storage struct { 35 | Any struct { 36 | XMLName xml.Name 37 | Type string `xml:"type_id,attr"` 38 | Size string `xml:"size"` 39 | Stages []xmlStages `xml:"stages>grp"` 40 | } `xml:",any"` 41 | } 42 | 43 | func buildFeature(r string) (f Feature, err error) { 44 | var x, y, w, h int 45 | var weight float64 46 | _, err = fmt.Sscanf(r, "%d %d %d %d %f", &x, &y, &w, &h, &weight) 47 | if err != nil { 48 | return 49 | } 50 | f.Rect = image.Rect(x, y, x+w, y+h) 51 | f.Weight = weight 52 | return 53 | } 54 | 55 | func buildCascade(s *opencv_storage) (c *Cascade, name string, err error) { 56 | if s.Any.Type != "opencv-haar-classifier" { 57 | err = fmt.Errorf("got %s want opencv-haar-classifier", s.Any.Type) 58 | return 59 | } 60 | name = s.Any.XMLName.Local 61 | 62 | c = &Cascade{} 63 | sizes := strings.Split(s.Any.Size, " ") 64 | w, err := strconv.Atoi(sizes[0]) 65 | if err != nil { 66 | return nil, "", err 67 | } 68 | h, err := strconv.Atoi(sizes[1]) 69 | if err != nil { 70 | return nil, "", err 71 | } 72 | c.Size = image.Pt(w, h) 73 | c.Stage = []CascadeStage{} 74 | 75 | for _, stage := range s.Any.Stages { 76 | cs := CascadeStage{ 77 | Classifier: []Classifier{}, 78 | Threshold: stage.Stage_threshold, 79 | } 80 | for _, tree := range stage.Trees { 81 | if tree.Tilted != 0 { 82 | err = errors.New("Cascade does not support tilted features") 83 | return 84 | } 85 | 86 | cls := Classifier{ 87 | Feature: []Feature{}, 88 | Threshold: tree.Threshold, 89 | Left: tree.Left, 90 | Right: tree.Right, 91 | } 92 | 93 | for _, rect := range tree.Rects { 94 | f, err := buildFeature(rect) 95 | if err != nil { 96 | return nil, "", err 97 | } 98 | cls.Feature = append(cls.Feature, f) 99 | } 100 | 101 | cs.Classifier = append(cs.Classifier, cls) 102 | } 103 | c.Stage = append(c.Stage, cs) 104 | } 105 | 106 | return 107 | } 108 | 109 | // ParseOpenCV produces a detection Cascade from an OpenCV XML file. 110 | func ParseOpenCV(r io.Reader) (cascade *Cascade, name string, err error) { 111 | // BUG(crawshaw): tag-based parsing doesn't seem to work with <_> 112 | buf, err := ioutil.ReadAll(r) 113 | if err != nil { 114 | return 115 | } 116 | buf = bytes.Replace(buf, []byte("<_>"), []byte(""), -1) 117 | buf = bytes.Replace(buf, []byte(""), []byte(""), -1) 118 | 119 | s := &opencv_storage{} 120 | err = xml.Unmarshal(buf, s) 121 | if err != nil { 122 | return 123 | } 124 | return buildCascade(s) 125 | } 126 | -------------------------------------------------------------------------------- /graphics/detect/opencv_parser_test.go: -------------------------------------------------------------------------------- 1 | // Copyright 2011 The Graphics-Go Authors. All rights reserved. 2 | // Use of this source code is governed by a BSD-style 3 | // license that can be found in the LICENSE file. 4 | 5 | package detect 6 | 7 | import ( 8 | "image" 9 | "os" 10 | "reflect" 11 | "testing" 12 | ) 13 | 14 | var ( 15 | classifier0 = Classifier{ 16 | Feature: []Feature{ 17 | Feature{Rect: image.Rect(0, 0, 3, 4), Weight: -1}, 18 | Feature{Rect: image.Rect(3, 4, 5, 6), Weight: 3.1}, 19 | }, 20 | Threshold: 0.03, 21 | Left: 0.01, 22 | Right: 0.8, 23 | } 24 | classifier1 = Classifier{ 25 | Feature: []Feature{ 26 | Feature{Rect: image.Rect(3, 7, 17, 11), Weight: -3.2}, 27 | Feature{Rect: image.Rect(3, 9, 17, 11), Weight: 2.}, 28 | }, 29 | Threshold: 0.11, 30 | Left: 0.03, 31 | Right: 0.83, 32 | } 33 | classifier2 = Classifier{ 34 | Feature: []Feature{ 35 | Feature{Rect: image.Rect(1, 1, 3, 3), Weight: -1.}, 36 | Feature{Rect: image.Rect(3, 3, 5, 5), Weight: 2.5}, 37 | }, 38 | Threshold: 0.07, 39 | Left: 0.2, 40 | Right: 0.4, 41 | } 42 | cascade = Cascade{ 43 | Stage: []CascadeStage{ 44 | CascadeStage{ 45 | Classifier: []Classifier{classifier0, classifier1}, 46 | Threshold: 0.82, 47 | }, 48 | CascadeStage{ 49 | Classifier: []Classifier{classifier2}, 50 | Threshold: 0.22, 51 | }, 52 | }, 53 | Size: image.Pt(20, 20), 54 | } 55 | ) 56 | 57 | func TestParseOpenCV(t *testing.T) { 58 | file, err := os.Open("../../testdata/opencv.xml") 59 | if err != nil { 60 | t.Fatal(err) 61 | } 62 | defer file.Close() 63 | 64 | cascadeFile, name, err := ParseOpenCV(file) 65 | if err != nil { 66 | t.Fatal(err) 67 | } 68 | if name != "name_of_cascade" { 69 | t.Fatalf("name: got %s want name_of_cascade", name) 70 | } 71 | 72 | if !reflect.DeepEqual(cascade, *cascadeFile) { 73 | t.Errorf("got\n %v want\n %v", *cascadeFile, cascade) 74 | } 75 | } 76 | -------------------------------------------------------------------------------- /graphics/detect/projector.go: -------------------------------------------------------------------------------- 1 | // Copyright 2011 The Graphics-Go Authors. All rights reserved. 2 | // Use of this source code is governed by a BSD-style 3 | // license that can be found in the LICENSE file. 4 | 5 | package detect 6 | 7 | import ( 8 | "image" 9 | ) 10 | 11 | // projector allows projecting from a source Rectangle onto a target Rectangle. 12 | type projector struct { 13 | // rx, ry is the scaling factor. 14 | rx, ry float64 15 | // dx, dy is the translation factor. 16 | dx, dy float64 17 | // r is the clipping region of the target. 18 | r image.Rectangle 19 | } 20 | 21 | // newProjector creates a Projector with source src and target dst. 22 | func newProjector(dst image.Rectangle, src image.Rectangle) *projector { 23 | return &projector{ 24 | rx: float64(dst.Dx()) / float64(src.Dx()), 25 | ry: float64(dst.Dy()) / float64(src.Dy()), 26 | dx: float64(dst.Min.X - src.Min.X), 27 | dy: float64(dst.Min.Y - src.Min.Y), 28 | r: dst, 29 | } 30 | } 31 | 32 | // pt projects p from the source rectangle onto the target rectangle. 33 | func (s *projector) pt(p image.Point) image.Point { 34 | return image.Point{ 35 | clamp(s.rx*float64(p.X)+s.dx, s.r.Min.X, s.r.Max.X), 36 | clamp(s.ry*float64(p.Y)+s.dy, s.r.Min.Y, s.r.Max.Y), 37 | } 38 | } 39 | 40 | // rect projects r from the source rectangle onto the target rectangle. 41 | func (s *projector) rect(r image.Rectangle) image.Rectangle { 42 | return image.Rectangle{s.pt(r.Min), s.pt(r.Max)} 43 | } 44 | 45 | // clamp rounds and clamps o to the integer range [x0, x1]. 46 | func clamp(o float64, x0, x1 int) int { 47 | x := int(o + 0.5) 48 | if x < x0 { 49 | return x0 50 | } 51 | if x > x1 { 52 | return x1 53 | } 54 | return x 55 | } 56 | -------------------------------------------------------------------------------- /graphics/detect/projector_test.go: -------------------------------------------------------------------------------- 1 | // Copyright 2011 The Graphics-Go Authors. All rights reserved. 2 | // Use of this source code is governed by a BSD-style 3 | // license that can be found in the LICENSE file. 4 | 5 | package detect 6 | 7 | import ( 8 | "image" 9 | "reflect" 10 | "testing" 11 | ) 12 | 13 | type projectorTest struct { 14 | dst image.Rectangle 15 | src image.Rectangle 16 | pdst image.Rectangle 17 | psrc image.Rectangle 18 | } 19 | 20 | var projectorTests = []projectorTest{ 21 | { 22 | image.Rect(0, 0, 6, 6), 23 | image.Rect(0, 0, 2, 2), 24 | image.Rect(0, 0, 6, 6), 25 | image.Rect(0, 0, 2, 2), 26 | }, 27 | { 28 | image.Rect(0, 0, 6, 6), 29 | image.Rect(0, 0, 2, 2), 30 | image.Rect(3, 3, 6, 6), 31 | image.Rect(1, 1, 2, 2), 32 | }, 33 | { 34 | image.Rect(30, 30, 40, 40), 35 | image.Rect(10, 10, 20, 20), 36 | image.Rect(32, 33, 34, 37), 37 | image.Rect(12, 13, 14, 17), 38 | }, 39 | } 40 | 41 | func TestProjector(t *testing.T) { 42 | for i, tt := range projectorTests { 43 | pr := newProjector(tt.dst, tt.src) 44 | res := pr.rect(tt.psrc) 45 | if !reflect.DeepEqual(res, tt.pdst) { 46 | t.Errorf("%d: got %v want %v", i, res, tt.pdst) 47 | } 48 | } 49 | } 50 | -------------------------------------------------------------------------------- /graphics/graphicstest/Makefile: -------------------------------------------------------------------------------- 1 | # Copyright 2011 The Graphics-Go Authors. All rights reserved. 2 | # Use of this source code is governed by a BSD-style 3 | # license that can be found in the LICENSE file. 4 | 5 | include $(GOROOT)/src/Make.inc 6 | 7 | TARG=code.google.com/p/graphics-go/graphics/graphicstest 8 | GOFILES=\ 9 | graphicstest.go\ 10 | 11 | include $(GOROOT)/src/Make.pkg 12 | -------------------------------------------------------------------------------- /graphics/graphicstest/graphicstest.go: -------------------------------------------------------------------------------- 1 | // Copyright 2011 The Graphics-Go Authors. All rights reserved. 2 | // Use of this source code is governed by a BSD-style 3 | // license that can be found in the LICENSE file. 4 | 5 | package graphicstest 6 | 7 | import ( 8 | "bytes" 9 | "errors" 10 | "fmt" 11 | "image" 12 | "image/color" 13 | "os" 14 | ) 15 | 16 | // LoadImage decodes an image from a file. 17 | func LoadImage(path string) (img image.Image, err error) { 18 | file, err := os.Open(path) 19 | if err != nil { 20 | return 21 | } 22 | defer file.Close() 23 | img, _, err = image.Decode(file) 24 | return 25 | } 26 | 27 | func delta(u0, u1 uint32) int { 28 | d := int(u0) - int(u1) 29 | if d < 0 { 30 | return -d 31 | } 32 | return d 33 | } 34 | 35 | func withinTolerance(c0, c1 color.Color, tol int) bool { 36 | r0, g0, b0, a0 := c0.RGBA() 37 | r1, g1, b1, a1 := c1.RGBA() 38 | r := delta(r0, r1) 39 | g := delta(g0, g1) 40 | b := delta(b0, b1) 41 | a := delta(a0, a1) 42 | return r <= tol && g <= tol && b <= tol && a <= tol 43 | } 44 | 45 | // ImageWithinTolerance checks that each pixel varies by no more than tol. 46 | func ImageWithinTolerance(m0, m1 image.Image, tol int) error { 47 | b0 := m0.Bounds() 48 | b1 := m1.Bounds() 49 | if !b0.Eq(b1) { 50 | return errors.New(fmt.Sprintf("got bounds %v want %v", b0, b1)) 51 | } 52 | 53 | for y := b0.Min.Y; y < b0.Max.Y; y++ { 54 | for x := b0.Min.X; x < b0.Max.X; x++ { 55 | c0 := m0.At(x, y) 56 | c1 := m1.At(x, y) 57 | if !withinTolerance(c0, c1, tol) { 58 | e := fmt.Sprintf("got %v want %v at (%d, %d)", c0, c1, x, y) 59 | return errors.New(e) 60 | } 61 | } 62 | } 63 | return nil 64 | } 65 | 66 | // SprintBox pretty prints the array as a hexidecimal matrix. 67 | func SprintBox(box []byte, width, height int) string { 68 | buf := bytes.NewBuffer(nil) 69 | i := 0 70 | for y := 0; y < height; y++ { 71 | for x := 0; x < width; x++ { 72 | fmt.Fprintf(buf, " 0x%02x,", box[i]) 73 | i++ 74 | } 75 | buf.WriteByte('\n') 76 | } 77 | return buf.String() 78 | } 79 | 80 | // SprintImageR pretty prints the red channel of src. It looks like SprintBox. 81 | func SprintImageR(src *image.RGBA) string { 82 | w, h := src.Rect.Dx(), src.Rect.Dy() 83 | i := 0 84 | box := make([]byte, w*h) 85 | for y := src.Rect.Min.Y; y < src.Rect.Max.Y; y++ { 86 | for x := src.Rect.Min.X; x < src.Rect.Max.X; x++ { 87 | off := (y-src.Rect.Min.Y)*src.Stride + (x-src.Rect.Min.X)*4 88 | box[i] = src.Pix[off] 89 | i++ 90 | } 91 | } 92 | return SprintBox(box, w, h) 93 | } 94 | 95 | // MakeRGBA returns an image with R, G, B taken from src. 96 | func MakeRGBA(src []uint8, width int) *image.RGBA { 97 | b := image.Rect(0, 0, width, len(src)/width) 98 | ret := image.NewRGBA(b) 99 | i := 0 100 | for y := b.Min.Y; y < b.Max.Y; y++ { 101 | for x := b.Min.X; x < b.Max.X; x++ { 102 | ret.SetRGBA(x, y, color.RGBA{ 103 | R: src[i], 104 | G: src[i], 105 | B: src[i], 106 | A: 0xff, 107 | }) 108 | i++ 109 | } 110 | } 111 | return ret 112 | } 113 | -------------------------------------------------------------------------------- /graphics/interp/Makefile: -------------------------------------------------------------------------------- 1 | # Copyright 2012 The Graphics-Go Authors. All rights reserved. 2 | # Use of this source code is governed by a BSD-style 3 | # license that can be found in the LICENSE file. 4 | 5 | include $(GOROOT)/src/Make.inc 6 | 7 | TARG=code.google.com/p/graphics-go/graphics/interp 8 | GOFILES=\ 9 | bilinear.go\ 10 | doc.go\ 11 | interp.go\ 12 | 13 | include $(GOROOT)/src/Make.pkg 14 | -------------------------------------------------------------------------------- /graphics/interp/bilinear.go: -------------------------------------------------------------------------------- 1 | // Copyright 2012 The Graphics-Go Authors. All rights reserved. 2 | // Use of this source code is governed by a BSD-style 3 | // license that can be found in the LICENSE file. 4 | 5 | package interp 6 | 7 | import ( 8 | "image" 9 | "image/color" 10 | "math" 11 | ) 12 | 13 | // Bilinear implements bilinear interpolation. 14 | var Bilinear Interp = bilinear{} 15 | 16 | type bilinear struct{} 17 | 18 | func (i bilinear) Interp(src image.Image, x, y float64) color.Color { 19 | if src, ok := src.(*image.RGBA); ok { 20 | return i.RGBA(src, x, y) 21 | } 22 | return bilinearGeneral(src, x, y) 23 | } 24 | 25 | func bilinearGeneral(src image.Image, x, y float64) color.Color { 26 | p := findLinearSrc(src.Bounds(), x, y) 27 | var fr, fg, fb, fa float64 28 | var r, g, b, a uint32 29 | 30 | r, g, b, a = src.At(p.low.X, p.low.Y).RGBA() 31 | fr += float64(r) * p.frac00 32 | fg += float64(g) * p.frac00 33 | fb += float64(b) * p.frac00 34 | fa += float64(a) * p.frac00 35 | 36 | r, g, b, a = src.At(p.high.X, p.low.Y).RGBA() 37 | fr += float64(r) * p.frac01 38 | fg += float64(g) * p.frac01 39 | fb += float64(b) * p.frac01 40 | fa += float64(a) * p.frac01 41 | 42 | r, g, b, a = src.At(p.low.X, p.high.Y).RGBA() 43 | fr += float64(r) * p.frac10 44 | fg += float64(g) * p.frac10 45 | fb += float64(b) * p.frac10 46 | fa += float64(a) * p.frac10 47 | 48 | r, g, b, a = src.At(p.high.X, p.high.Y).RGBA() 49 | fr += float64(r) * p.frac11 50 | fg += float64(g) * p.frac11 51 | fb += float64(b) * p.frac11 52 | fa += float64(a) * p.frac11 53 | 54 | var c color.RGBA64 55 | c.R = uint16(fr + 0.5) 56 | c.G = uint16(fg + 0.5) 57 | c.B = uint16(fb + 0.5) 58 | c.A = uint16(fa + 0.5) 59 | return c 60 | } 61 | 62 | func (bilinear) RGBA(src *image.RGBA, x, y float64) color.RGBA { 63 | p := findLinearSrc(src.Bounds(), x, y) 64 | 65 | // Array offsets for the surrounding pixels. 66 | off00 := offRGBA(src, p.low.X, p.low.Y) 67 | off01 := offRGBA(src, p.high.X, p.low.Y) 68 | off10 := offRGBA(src, p.low.X, p.high.Y) 69 | off11 := offRGBA(src, p.high.X, p.high.Y) 70 | 71 | var fr, fg, fb, fa float64 72 | 73 | fr += float64(src.Pix[off00+0]) * p.frac00 74 | fg += float64(src.Pix[off00+1]) * p.frac00 75 | fb += float64(src.Pix[off00+2]) * p.frac00 76 | fa += float64(src.Pix[off00+3]) * p.frac00 77 | 78 | fr += float64(src.Pix[off01+0]) * p.frac01 79 | fg += float64(src.Pix[off01+1]) * p.frac01 80 | fb += float64(src.Pix[off01+2]) * p.frac01 81 | fa += float64(src.Pix[off01+3]) * p.frac01 82 | 83 | fr += float64(src.Pix[off10+0]) * p.frac10 84 | fg += float64(src.Pix[off10+1]) * p.frac10 85 | fb += float64(src.Pix[off10+2]) * p.frac10 86 | fa += float64(src.Pix[off10+3]) * p.frac10 87 | 88 | fr += float64(src.Pix[off11+0]) * p.frac11 89 | fg += float64(src.Pix[off11+1]) * p.frac11 90 | fb += float64(src.Pix[off11+2]) * p.frac11 91 | fa += float64(src.Pix[off11+3]) * p.frac11 92 | 93 | var c color.RGBA 94 | c.R = uint8(fr + 0.5) 95 | c.G = uint8(fg + 0.5) 96 | c.B = uint8(fb + 0.5) 97 | c.A = uint8(fa + 0.5) 98 | return c 99 | } 100 | 101 | func (bilinear) Gray(src *image.Gray, x, y float64) color.Gray { 102 | p := findLinearSrc(src.Bounds(), x, y) 103 | 104 | // Array offsets for the surrounding pixels. 105 | off00 := offGray(src, p.low.X, p.low.Y) 106 | off01 := offGray(src, p.high.X, p.low.Y) 107 | off10 := offGray(src, p.low.X, p.high.Y) 108 | off11 := offGray(src, p.high.X, p.high.Y) 109 | 110 | var fc float64 111 | fc += float64(src.Pix[off00]) * p.frac00 112 | fc += float64(src.Pix[off01]) * p.frac01 113 | fc += float64(src.Pix[off10]) * p.frac10 114 | fc += float64(src.Pix[off11]) * p.frac11 115 | 116 | var c color.Gray 117 | c.Y = uint8(fc + 0.5) 118 | return c 119 | } 120 | 121 | type bilinearSrc struct { 122 | // Top-left and bottom-right interpolation sources 123 | low, high image.Point 124 | // Fraction of each pixel to take. The 0 suffix indicates 125 | // top/left, and the 1 suffix indicates bottom/right. 126 | frac00, frac01, frac10, frac11 float64 127 | } 128 | 129 | func findLinearSrc(b image.Rectangle, sx, sy float64) bilinearSrc { 130 | maxX := float64(b.Max.X) 131 | maxY := float64(b.Max.Y) 132 | minX := float64(b.Min.X) 133 | minY := float64(b.Min.Y) 134 | lowX := math.Floor(sx - 0.5) 135 | lowY := math.Floor(sy - 0.5) 136 | if lowX < minX { 137 | lowX = minX 138 | } 139 | if lowY < minY { 140 | lowY = minY 141 | } 142 | 143 | highX := math.Ceil(sx - 0.5) 144 | highY := math.Ceil(sy - 0.5) 145 | if highX >= maxX { 146 | highX = maxX - 1 147 | } 148 | if highY >= maxY { 149 | highY = maxY - 1 150 | } 151 | 152 | // In the variables below, the 0 suffix indicates top/left, and the 153 | // 1 suffix indicates bottom/right. 154 | 155 | // Center of each surrounding pixel. 156 | x00 := lowX + 0.5 157 | y00 := lowY + 0.5 158 | x01 := highX + 0.5 159 | y01 := lowY + 0.5 160 | x10 := lowX + 0.5 161 | y10 := highY + 0.5 162 | x11 := highX + 0.5 163 | y11 := highY + 0.5 164 | 165 | p := bilinearSrc{ 166 | low: image.Pt(int(lowX), int(lowY)), 167 | high: image.Pt(int(highX), int(highY)), 168 | } 169 | 170 | // Literally, edge cases. If we are close enough to the edge of 171 | // the image, curtail the interpolation sources. 172 | if lowX == highX && lowY == highY { 173 | p.frac00 = 1.0 174 | } else if sy-minY <= 0.5 && sx-minX <= 0.5 { 175 | p.frac00 = 1.0 176 | } else if maxY-sy <= 0.5 && maxX-sx <= 0.5 { 177 | p.frac11 = 1.0 178 | } else if sy-minY <= 0.5 || lowY == highY { 179 | p.frac00 = x01 - sx 180 | p.frac01 = sx - x00 181 | } else if sx-minX <= 0.5 || lowX == highX { 182 | p.frac00 = y10 - sy 183 | p.frac10 = sy - y00 184 | } else if maxY-sy <= 0.5 { 185 | p.frac10 = x11 - sx 186 | p.frac11 = sx - x10 187 | } else if maxX-sx <= 0.5 { 188 | p.frac01 = y11 - sy 189 | p.frac11 = sy - y01 190 | } else { 191 | p.frac00 = (x01 - sx) * (y10 - sy) 192 | p.frac01 = (sx - x00) * (y11 - sy) 193 | p.frac10 = (x11 - sx) * (sy - y00) 194 | p.frac11 = (sx - x10) * (sy - y01) 195 | } 196 | 197 | return p 198 | } 199 | 200 | // TODO(crawshaw): When we have inlining, consider func (p *RGBA) Off(x, y) int 201 | func offRGBA(src *image.RGBA, x, y int) int { 202 | return (y-src.Rect.Min.Y)*src.Stride + (x-src.Rect.Min.X)*4 203 | } 204 | func offGray(src *image.Gray, x, y int) int { 205 | return (y-src.Rect.Min.Y)*src.Stride + (x - src.Rect.Min.X) 206 | } 207 | -------------------------------------------------------------------------------- /graphics/interp/bilinear_test.go: -------------------------------------------------------------------------------- 1 | // Copyright 2012 The Graphics-Go Authors. All rights reserved. 2 | // Use of this source code is governed by a BSD-style 3 | // license that can be found in the LICENSE file. 4 | 5 | package interp 6 | 7 | import ( 8 | "image" 9 | "image/color" 10 | "testing" 11 | ) 12 | 13 | type interpTest struct { 14 | desc string 15 | src []uint8 16 | srcWidth int 17 | x, y float64 18 | expect uint8 19 | } 20 | 21 | func (p *interpTest) newSrc() *image.RGBA { 22 | b := image.Rect(0, 0, p.srcWidth, len(p.src)/p.srcWidth) 23 | src := image.NewRGBA(b) 24 | i := 0 25 | for y := b.Min.Y; y < b.Max.Y; y++ { 26 | for x := b.Min.X; x < b.Max.X; x++ { 27 | src.SetRGBA(x, y, color.RGBA{ 28 | R: p.src[i], 29 | G: p.src[i], 30 | B: p.src[i], 31 | A: 0xff, 32 | }) 33 | i++ 34 | } 35 | } 36 | return src 37 | } 38 | 39 | var interpTests = []interpTest{ 40 | { 41 | desc: "center of a single white pixel should match that pixel", 42 | src: []uint8{0x00}, 43 | srcWidth: 1, 44 | x: 0.5, 45 | y: 0.5, 46 | expect: 0x00, 47 | }, 48 | { 49 | desc: "middle of a square is equally weighted", 50 | src: []uint8{ 51 | 0x00, 0xff, 52 | 0xff, 0x00, 53 | }, 54 | srcWidth: 2, 55 | x: 1.0, 56 | y: 1.0, 57 | expect: 0x80, 58 | }, 59 | { 60 | desc: "center of a pixel is just that pixel", 61 | src: []uint8{ 62 | 0x00, 0xff, 63 | 0xff, 0x00, 64 | }, 65 | srcWidth: 2, 66 | x: 1.5, 67 | y: 0.5, 68 | expect: 0xff, 69 | }, 70 | { 71 | desc: "asymmetry abounds", 72 | src: []uint8{ 73 | 0xaa, 0x11, 0x55, 74 | 0xff, 0x95, 0xdd, 75 | }, 76 | srcWidth: 3, 77 | x: 2.0, 78 | y: 1.0, 79 | expect: 0x76, // (0x11 + 0x55 + 0x95 + 0xdd) / 4 80 | }, 81 | } 82 | 83 | func TestBilinearRGBA(t *testing.T) { 84 | for _, p := range interpTests { 85 | src := p.newSrc() 86 | 87 | // Fast path. 88 | c := Bilinear.(RGBA).RGBA(src, p.x, p.y) 89 | if c.R != c.G || c.R != c.B || c.A != 0xff { 90 | t.Errorf("expect channels to match, got %v", c) 91 | continue 92 | } 93 | if c.R != p.expect { 94 | t.Errorf("%s: got 0x%02x want 0x%02x", p.desc, c.R, p.expect) 95 | continue 96 | } 97 | 98 | // Standard Interp should use the fast path. 99 | cStd := Bilinear.Interp(src, p.x, p.y) 100 | if cStd != c { 101 | t.Errorf("%s: standard mismatch got %v want %v", p.desc, cStd, c) 102 | continue 103 | } 104 | 105 | // General case should match the fast path. 106 | cGen := color.RGBAModel.Convert(bilinearGeneral(src, p.x, p.y)) 107 | r0, g0, b0, a0 := c.RGBA() 108 | r1, g1, b1, a1 := cGen.RGBA() 109 | if r0 != r1 || g0 != g1 || b0 != b1 || a0 != a1 { 110 | t.Errorf("%s: general case mismatch got %v want %v", p.desc, c, cGen) 111 | continue 112 | } 113 | } 114 | } 115 | 116 | func TestBilinearSubImage(t *testing.T) { 117 | b0 := image.Rect(0, 0, 4, 4) 118 | src0 := image.NewRGBA(b0) 119 | b1 := image.Rect(1, 1, 3, 3) 120 | src1 := src0.SubImage(b1).(*image.RGBA) 121 | src1.Set(1, 1, color.RGBA{0x11, 0, 0, 0xff}) 122 | src1.Set(2, 1, color.RGBA{0x22, 0, 0, 0xff}) 123 | src1.Set(1, 2, color.RGBA{0x33, 0, 0, 0xff}) 124 | src1.Set(2, 2, color.RGBA{0x44, 0, 0, 0xff}) 125 | 126 | tests := []struct { 127 | x, y float64 128 | want uint8 129 | }{ 130 | {1, 1, 0x11}, 131 | {3, 1, 0x22}, 132 | {1, 3, 0x33}, 133 | {3, 3, 0x44}, 134 | {2, 2, 0x2b}, 135 | } 136 | 137 | for _, p := range tests { 138 | c := Bilinear.(RGBA).RGBA(src1, p.x, p.y) 139 | if c.R != p.want { 140 | t.Errorf("(%.0f, %.0f): got 0x%02x want 0x%02x", p.x, p.y, c.R, p.want) 141 | } 142 | } 143 | } 144 | -------------------------------------------------------------------------------- /graphics/interp/doc.go: -------------------------------------------------------------------------------- 1 | // Copyright 2012 The Graphics-Go Authors. All rights reserved. 2 | // Use of this source code is governed by a BSD-style 3 | // license that can be found in the LICENSE file. 4 | 5 | /* 6 | Package interp implements image interpolation. 7 | 8 | An interpolator provides the Interp interface, which can be used 9 | to interpolate a pixel: 10 | 11 | c := interp.Bilinear.Interp(src, 1.2, 1.8) 12 | 13 | To interpolate a large number of RGBA or Gray pixels, an implementation 14 | may provide a fast-path by implementing the RGBA or Gray interfaces. 15 | 16 | i1, ok := i.(interp.RGBA) 17 | if ok { 18 | c := i1.RGBA(src, 1.2, 1.8) 19 | // use c.R, c.G, etc 20 | return 21 | } 22 | c := i.Interp(src, 1.2, 1.8) 23 | // use generic color.Color 24 | */ 25 | package interp 26 | -------------------------------------------------------------------------------- /graphics/interp/interp.go: -------------------------------------------------------------------------------- 1 | // Copyright 2012 The Graphics-Go Authors. All rights reserved. 2 | // Use of this source code is governed by a BSD-style 3 | // license that can be found in the LICENSE file. 4 | 5 | package interp 6 | 7 | import ( 8 | "image" 9 | "image/color" 10 | ) 11 | 12 | // Interp interpolates an image's color at fractional co-ordinates. 13 | type Interp interface { 14 | // Interp interpolates (x, y). 15 | Interp(src image.Image, x, y float64) color.Color 16 | } 17 | 18 | // RGBA is a fast-path interpolation implementation for image.RGBA. 19 | // It is common for an Interp to also implement RGBA. 20 | type RGBA interface { 21 | // RGBA interpolates (x, y). 22 | RGBA(src *image.RGBA, x, y float64) color.RGBA 23 | } 24 | 25 | // Gray is a fast-path interpolation implementation for image.Gray. 26 | type Gray interface { 27 | // Gray interpolates (x, y). 28 | Gray(src *image.Gray, x, y float64) color.Gray 29 | } 30 | -------------------------------------------------------------------------------- /graphics/rotate.go: -------------------------------------------------------------------------------- 1 | // Copyright 2011 The Graphics-Go Authors. All rights reserved. 2 | // Use of this source code is governed by a BSD-style 3 | // license that can be found in the LICENSE file. 4 | 5 | package graphics 6 | 7 | import ( 8 | "github.com/hunterhug/go_image/graphics/interp" 9 | "errors" 10 | "image" 11 | "image/draw" 12 | ) 13 | 14 | // RotateOptions are the rotation parameters. 15 | // Angle is the angle, in radians, to rotate the image clockwise. 16 | type RotateOptions struct { 17 | Angle float64 18 | } 19 | 20 | // Rotate produces a rotated version of src, drawn onto dst. 21 | func Rotate(dst draw.Image, src image.Image, opt *RotateOptions) error { 22 | if dst == nil { 23 | return errors.New("graphics: dst is nil") 24 | } 25 | if src == nil { 26 | return errors.New("graphics: src is nil") 27 | } 28 | 29 | angle := 0.0 30 | if opt != nil { 31 | angle = opt.Angle 32 | } 33 | 34 | return I.Rotate(angle).TransformCenter(dst, src, interp.Bilinear) 35 | } 36 | -------------------------------------------------------------------------------- /graphics/rotate_test.go: -------------------------------------------------------------------------------- 1 | // Copyright 2011 The Graphics-Go Authors. All rights reserved. 2 | // Use of this source code is governed by a BSD-style 3 | // license that can be found in the LICENSE file. 4 | 5 | package graphics 6 | 7 | import ( 8 | "github.com/hunterhug/go_image/graphics/graphicstest" 9 | "image" 10 | "math" 11 | "testing" 12 | 13 | _ "image/png" 14 | ) 15 | 16 | var rotateOneColorTests = []transformOneColorTest{ 17 | { 18 | "onepixel-onequarter", 1, 1, 1, 1, 19 | &RotateOptions{math.Pi / 2}, 20 | []uint8{0xff}, 21 | []uint8{0xff}, 22 | }, 23 | { 24 | "onepixel-partial", 1, 1, 1, 1, 25 | &RotateOptions{math.Pi * 2.0 / 3.0}, 26 | []uint8{0xff}, 27 | []uint8{0xff}, 28 | }, 29 | { 30 | "onepixel-complete", 1, 1, 1, 1, 31 | &RotateOptions{2 * math.Pi}, 32 | []uint8{0xff}, 33 | []uint8{0xff}, 34 | }, 35 | { 36 | "even-onequarter", 2, 2, 2, 2, 37 | &RotateOptions{math.Pi / 2.0}, 38 | []uint8{ 39 | 0xff, 0x00, 40 | 0x00, 0xff, 41 | }, 42 | []uint8{ 43 | 0x00, 0xff, 44 | 0xff, 0x00, 45 | }, 46 | }, 47 | { 48 | "even-complete", 2, 2, 2, 2, 49 | &RotateOptions{2.0 * math.Pi}, 50 | []uint8{ 51 | 0xff, 0x00, 52 | 0x00, 0xff, 53 | }, 54 | []uint8{ 55 | 0xff, 0x00, 56 | 0x00, 0xff, 57 | }, 58 | }, 59 | { 60 | "line-partial", 3, 3, 3, 3, 61 | &RotateOptions{math.Pi * 1.0 / 3.0}, 62 | []uint8{ 63 | 0x00, 0x00, 0x00, 64 | 0xff, 0xff, 0xff, 65 | 0x00, 0x00, 0x00, 66 | }, 67 | []uint8{ 68 | 0xa2, 0x80, 0x00, 69 | 0x22, 0xff, 0x22, 70 | 0x00, 0x80, 0xa2, 71 | }, 72 | }, 73 | { 74 | "line-offset-partial", 3, 3, 3, 3, 75 | &RotateOptions{math.Pi * 3 / 2}, 76 | []uint8{ 77 | 0x00, 0x00, 0x00, 78 | 0x00, 0xff, 0xff, 79 | 0x00, 0x00, 0x00, 80 | }, 81 | []uint8{ 82 | 0x00, 0xff, 0x00, 83 | 0x00, 0xff, 0x00, 84 | 0x00, 0x00, 0x00, 85 | }, 86 | }, 87 | { 88 | "dot-partial", 4, 4, 4, 4, 89 | &RotateOptions{math.Pi}, 90 | []uint8{ 91 | 0x00, 0x00, 0x00, 0x00, 92 | 0x00, 0xff, 0x00, 0x00, 93 | 0x00, 0x00, 0x00, 0x00, 94 | 0x00, 0x00, 0x00, 0x00, 95 | }, 96 | []uint8{ 97 | 0x00, 0x00, 0x00, 0x00, 98 | 0x00, 0x00, 0x00, 0x00, 99 | 0x00, 0x00, 0xff, 0x00, 100 | 0x00, 0x00, 0x00, 0x00, 101 | }, 102 | }, 103 | } 104 | 105 | func TestRotateOneColor(t *testing.T) { 106 | for _, oc := range rotateOneColorTests { 107 | src := oc.newSrc() 108 | dst := oc.newDst() 109 | 110 | if err := Rotate(dst, src, oc.opt.(*RotateOptions)); err != nil { 111 | t.Errorf("rotate %s: %v", oc.desc, err) 112 | continue 113 | } 114 | if !checkTransformTest(t, &oc, dst) { 115 | continue 116 | } 117 | } 118 | } 119 | 120 | func TestRotateEmpty(t *testing.T) { 121 | empty := image.NewRGBA(image.Rect(0, 0, 0, 0)) 122 | if err := Rotate(empty, empty, nil); err != nil { 123 | t.Fatal(err) 124 | } 125 | } 126 | 127 | func TestRotateGopherSide(t *testing.T) { 128 | src, err := graphicstest.LoadImage("../testdata/gopher.png") 129 | if err != nil { 130 | t.Fatal(err) 131 | } 132 | 133 | srcb := src.Bounds() 134 | dst := image.NewRGBA(image.Rect(0, 0, srcb.Dy(), srcb.Dx())) 135 | if err := Rotate(dst, src, &RotateOptions{math.Pi / 2.0}); err != nil { 136 | t.Fatal(err) 137 | } 138 | 139 | cmp, err := graphicstest.LoadImage("../testdata/gopher-rotate-side.png") 140 | if err != nil { 141 | t.Fatal(err) 142 | } 143 | err = graphicstest.ImageWithinTolerance(dst, cmp, 0x101) 144 | if err != nil { 145 | t.Fatal(err) 146 | } 147 | } 148 | 149 | func TestRotateGopherPartial(t *testing.T) { 150 | src, err := graphicstest.LoadImage("../testdata/gopher.png") 151 | if err != nil { 152 | t.Fatal(err) 153 | } 154 | 155 | srcb := src.Bounds() 156 | dst := image.NewRGBA(image.Rect(0, 0, srcb.Dx(), srcb.Dy())) 157 | if err := Rotate(dst, src, &RotateOptions{math.Pi / 3.0}); err != nil { 158 | t.Fatal(err) 159 | } 160 | 161 | cmp, err := graphicstest.LoadImage("../testdata/gopher-rotate-partial.png") 162 | if err != nil { 163 | t.Fatal(err) 164 | } 165 | err = graphicstest.ImageWithinTolerance(dst, cmp, 0x101) 166 | if err != nil { 167 | t.Fatal(err) 168 | } 169 | } 170 | -------------------------------------------------------------------------------- /graphics/scale.go: -------------------------------------------------------------------------------- 1 | // Copyright 2011 The Graphics-Go Authors. All rights reserved. 2 | // Use of this source code is governed by a BSD-style 3 | // license that can be found in the LICENSE file. 4 | 5 | package graphics 6 | 7 | import ( 8 | "github.com/hunterhug/go_image/graphics/interp" 9 | "errors" 10 | "image" 11 | "image/draw" 12 | ) 13 | 14 | // Scale produces a scaled version of the image using bilinear interpolation. 15 | func Scale(dst draw.Image, src image.Image) error { 16 | if dst == nil { 17 | return errors.New("graphics: dst is nil") 18 | } 19 | if src == nil { 20 | return errors.New("graphics: src is nil") 21 | } 22 | 23 | b := dst.Bounds() 24 | srcb := src.Bounds() 25 | if b.Empty() || srcb.Empty() { 26 | return nil 27 | } 28 | sx := float64(b.Dx()) / float64(srcb.Dx()) 29 | sy := float64(b.Dy()) / float64(srcb.Dy()) 30 | return I.Scale(sx, sy).Transform(dst, src, interp.Bilinear) 31 | } 32 | -------------------------------------------------------------------------------- /graphics/scale_test.go: -------------------------------------------------------------------------------- 1 | // Copyright 2011 The Graphics-Go Authors. All rights reserved. 2 | // Use of this source code is governed by a BSD-style 3 | // license that can be found in the LICENSE file. 4 | 5 | package graphics 6 | 7 | import ( 8 | "github.com/hunterhug/go_image/graphics/graphicstest" 9 | "image" 10 | "testing" 11 | 12 | _ "image/png" 13 | ) 14 | 15 | var scaleOneColorTests = []transformOneColorTest{ 16 | { 17 | "down-half", 18 | 1, 1, 19 | 2, 2, 20 | nil, 21 | []uint8{ 22 | 0x80, 0x00, 23 | 0x00, 0x80, 24 | }, 25 | []uint8{ 26 | 0x40, 27 | }, 28 | }, 29 | { 30 | "up-double", 31 | 4, 4, 32 | 2, 2, 33 | nil, 34 | []uint8{ 35 | 0x80, 0x00, 36 | 0x00, 0x80, 37 | }, 38 | []uint8{ 39 | 0x80, 0x60, 0x20, 0x00, 40 | 0x60, 0x50, 0x30, 0x20, 41 | 0x20, 0x30, 0x50, 0x60, 42 | 0x00, 0x20, 0x60, 0x80, 43 | }, 44 | }, 45 | { 46 | "up-doublewidth", 47 | 4, 2, 48 | 2, 2, 49 | nil, 50 | []uint8{ 51 | 0x80, 0x00, 52 | 0x00, 0x80, 53 | }, 54 | []uint8{ 55 | 0x80, 0x60, 0x20, 0x00, 56 | 0x00, 0x20, 0x60, 0x80, 57 | }, 58 | }, 59 | { 60 | "up-doubleheight", 61 | 2, 4, 62 | 2, 2, 63 | nil, 64 | []uint8{ 65 | 0x80, 0x00, 66 | 0x00, 0x80, 67 | }, 68 | []uint8{ 69 | 0x80, 0x00, 70 | 0x60, 0x20, 71 | 0x20, 0x60, 72 | 0x00, 0x80, 73 | }, 74 | }, 75 | { 76 | "up-partial", 77 | 3, 3, 78 | 2, 2, 79 | nil, 80 | []uint8{ 81 | 0x80, 0x00, 82 | 0x00, 0x80, 83 | }, 84 | []uint8{ 85 | 0x80, 0x40, 0x00, 86 | 0x40, 0x40, 0x40, 87 | 0x00, 0x40, 0x80, 88 | }, 89 | }, 90 | } 91 | 92 | func TestScaleOneColor(t *testing.T) { 93 | for _, oc := range scaleOneColorTests { 94 | dst := oc.newDst() 95 | src := oc.newSrc() 96 | if err := Scale(dst, src); err != nil { 97 | t.Errorf("scale %s: %v", oc.desc, err) 98 | continue 99 | } 100 | 101 | if !checkTransformTest(t, &oc, dst) { 102 | continue 103 | } 104 | } 105 | } 106 | 107 | func TestScaleEmpty(t *testing.T) { 108 | empty := image.NewRGBA(image.Rect(0, 0, 0, 0)) 109 | if err := Scale(empty, empty); err != nil { 110 | t.Fatal(err) 111 | } 112 | } 113 | 114 | func TestScaleGopher(t *testing.T) { 115 | dst := image.NewRGBA(image.Rect(0, 0, 100, 150)) 116 | 117 | src, err := graphicstest.LoadImage("../testdata/gopher.png") 118 | if err != nil { 119 | t.Error(err) 120 | return 121 | } 122 | 123 | // Down-sample. 124 | if err := Scale(dst, src); err != nil { 125 | t.Fatal(err) 126 | } 127 | cmp, err := graphicstest.LoadImage("../testdata/gopher-100x150.png") 128 | if err != nil { 129 | t.Error(err) 130 | return 131 | } 132 | err = graphicstest.ImageWithinTolerance(dst, cmp, 0) 133 | if err != nil { 134 | t.Error(err) 135 | return 136 | } 137 | 138 | // Up-sample. 139 | dst = image.NewRGBA(image.Rect(0, 0, 500, 750)) 140 | if err := Scale(dst, src); err != nil { 141 | t.Fatal(err) 142 | } 143 | cmp, err = graphicstest.LoadImage("../testdata/gopher-500x750.png") 144 | if err != nil { 145 | t.Error(err) 146 | return 147 | } 148 | err = graphicstest.ImageWithinTolerance(dst, cmp, 0) 149 | if err != nil { 150 | t.Error(err) 151 | return 152 | } 153 | } 154 | -------------------------------------------------------------------------------- /graphics/shared_test.go: -------------------------------------------------------------------------------- 1 | // Copyright 2011 The Graphics-Go Authors. All rights reserved. 2 | // Use of this source code is governed by a BSD-style 3 | // license that can be found in the LICENSE file. 4 | 5 | package graphics 6 | 7 | import ( 8 | "bytes" 9 | "github.com/hunterhug/go_image/graphics/graphicstest" 10 | "image" 11 | "image/color" 12 | "testing" 13 | ) 14 | 15 | type transformOneColorTest struct { 16 | desc string 17 | dstWidth int 18 | dstHeight int 19 | srcWidth int 20 | srcHeight int 21 | opt interface{} 22 | src []uint8 23 | res []uint8 24 | } 25 | 26 | func (oc *transformOneColorTest) newSrc() *image.RGBA { 27 | b := image.Rect(0, 0, oc.srcWidth, oc.srcHeight) 28 | src := image.NewRGBA(b) 29 | i := 0 30 | for y := b.Min.Y; y < b.Max.Y; y++ { 31 | for x := b.Min.X; x < b.Max.X; x++ { 32 | src.SetRGBA(x, y, color.RGBA{ 33 | R: oc.src[i], 34 | G: oc.src[i], 35 | B: oc.src[i], 36 | A: oc.src[i], 37 | }) 38 | i++ 39 | } 40 | } 41 | return src 42 | } 43 | 44 | func (oc *transformOneColorTest) newDst() *image.RGBA { 45 | return image.NewRGBA(image.Rect(0, 0, oc.dstWidth, oc.dstHeight)) 46 | } 47 | 48 | func checkTransformTest(t *testing.T, oc *transformOneColorTest, dst *image.RGBA) bool { 49 | for ch := 0; ch < 4; ch++ { 50 | i := 0 51 | res := make([]byte, len(oc.res)) 52 | for y := 0; y < oc.dstHeight; y++ { 53 | for x := 0; x < oc.dstWidth; x++ { 54 | off := (y-dst.Rect.Min.Y)*dst.Stride + (x-dst.Rect.Min.X)*4 55 | res[i] = dst.Pix[off+ch] 56 | i++ 57 | } 58 | } 59 | 60 | if !bytes.Equal(res, oc.res) { 61 | got := graphicstest.SprintBox(res, oc.dstWidth, oc.dstHeight) 62 | want := graphicstest.SprintBox(oc.res, oc.dstWidth, oc.dstHeight) 63 | t.Errorf("%s: ch=%d\n got\n%s\n want\n%s", oc.desc, ch, got, want) 64 | return false 65 | } 66 | } 67 | 68 | return true 69 | } 70 | -------------------------------------------------------------------------------- /graphics/thumbnail.go: -------------------------------------------------------------------------------- 1 | // Copyright 2011 The Graphics-Go Authors. All rights reserved. 2 | // Use of this source code is governed by a BSD-style 3 | // license that can be found in the LICENSE file. 4 | 5 | package graphics 6 | 7 | import ( 8 | "image" 9 | "image/draw" 10 | ) 11 | 12 | // Thumbnail scales and crops src so it fits in dst. 13 | func Thumbnail(dst draw.Image, src image.Image) error { 14 | // Scale down src in the dimension that is closer to dst. 15 | sb := src.Bounds() 16 | db := dst.Bounds() 17 | rx := float64(sb.Dx()) / float64(db.Dx()) 18 | ry := float64(sb.Dy()) / float64(db.Dy()) 19 | var b image.Rectangle 20 | if rx < ry { 21 | b = image.Rect(0, 0, db.Dx(), int(float64(sb.Dy())/rx)) 22 | } else { 23 | b = image.Rect(0, 0, int(float64(sb.Dx())/ry), db.Dy()) 24 | } 25 | 26 | buf := image.NewRGBA(b) 27 | if err := Scale(buf, src); err != nil { 28 | return err 29 | } 30 | 31 | // Crop. 32 | // TODO(crawshaw): improve on center-alignment. 33 | var pt image.Point 34 | if rx < ry { 35 | pt.Y = (b.Dy() - db.Dy()) / 2 36 | } else { 37 | pt.X = (b.Dx() - db.Dx()) / 2 38 | } 39 | draw.Draw(dst, db, buf, pt, draw.Src) 40 | return nil 41 | } 42 | -------------------------------------------------------------------------------- /graphics/thumbnail_test.go: -------------------------------------------------------------------------------- 1 | // Copyright 2011 The Graphics-Go Authors. All rights reserved. 2 | // Use of this source code is governed by a BSD-style 3 | // license that can be found in the LICENSE file. 4 | 5 | package graphics 6 | 7 | import ( 8 | "github.com/hunterhug/go_image/graphics/graphicstest" 9 | "image" 10 | "testing" 11 | 12 | _ "image/png" 13 | ) 14 | 15 | func TestThumbnailGopher(t *testing.T) { 16 | dst := image.NewRGBA(image.Rect(0, 0, 80, 80)) 17 | 18 | src, err := graphicstest.LoadImage("../testdata/gopher.png") 19 | if err != nil { 20 | t.Fatal(err) 21 | } 22 | if err := Thumbnail(dst, src); err != nil { 23 | t.Fatal(err) 24 | } 25 | cmp, err := graphicstest.LoadImage("../testdata/gopher-thumb-80x80.png") 26 | if err != nil { 27 | t.Fatal(err) 28 | } 29 | err = graphicstest.ImageWithinTolerance(dst, cmp, 0) 30 | if err != nil { 31 | t.Error(err) 32 | } 33 | } 34 | 35 | func TestThumbnailLongGopher(t *testing.T) { 36 | dst := image.NewRGBA(image.Rect(0, 0, 50, 150)) 37 | 38 | src, err := graphicstest.LoadImage("../testdata/gopher.png") 39 | if err != nil { 40 | t.Fatal(err) 41 | } 42 | if err := Thumbnail(dst, src); err != nil { 43 | t.Fatal(err) 44 | } 45 | cmp, err := graphicstest.LoadImage("../testdata/gopher-thumb-50x150.png") 46 | if err != nil { 47 | t.Fatal(err) 48 | } 49 | err = graphicstest.ImageWithinTolerance(dst, cmp, 0) 50 | if err != nil { 51 | t.Error(err) 52 | } 53 | } 54 | -------------------------------------------------------------------------------- /imageF2F.go: -------------------------------------------------------------------------------- 1 | package go_image 2 | 3 | import ( 4 | "bytes" 5 | //"errors" 6 | "github.com/hunterhug/go_image/graphics" 7 | "image" 8 | "image/jpeg" 9 | "image/png" 10 | "io" 11 | "io/ioutil" 12 | "os" 13 | "path/filepath" 14 | "runtime" 15 | "strings" 16 | ) 17 | 18 | //按宽度和高度进行比例缩放，输入和输出都是图片字节数组 19 | func ThumbnailB2B(InRaw []byte, width int, height int) (OutRaw []byte, err error) { 20 | src, filetype, err := LoadImage(bytes.NewReader(InRaw)) 21 | if err != nil { 22 | return 23 | } 24 | dst := image.NewRGBA(image.Rect(0, 0, width, height)) 25 | err = graphics.Thumbnail(dst, src) 26 | if err != nil { 27 | return 28 | } 29 | 30 | w := new(bytes.Buffer) 31 | err = SaveImage(dst, filetype, w) 32 | if err != nil { 33 | return 34 | } 35 | 36 | OutRaw = w.Bytes() 37 | return 38 | } 39 | 40 | // 按宽度和高度进行比例缩放，输入和输出都是文件 41 | func ThumbnailF2F(filename string, savepath string, width int, height int) (err error) { 42 | raw, err := ioutil.ReadFile(filename) 43 | if err != nil { 44 | return err 45 | } 46 | 47 | out, err := ThumbnailB2B(raw, width, height) 48 | if err != nil { 49 | return err 50 | } 51 | 52 | err = ioutil.WriteFile(savepath, out, 0777) 53 | if err != nil { 54 | return err 55 | } 56 | 57 | return 58 | } 59 | 60 | //按宽度进行比例缩放，输入和输出都是图片字节数组 61 | func ScaleB2B(InRaw []byte, width int) (OutRaw []byte, err error) { 62 | img, filetype, err := Scale(InRaw, width) 63 | if err != nil { 64 | return 65 | } 66 | 67 | buffer := new(bytes.Buffer) 68 | err = SaveImage(img, filetype, buffer) 69 | if err != nil { 70 | return 71 | } 72 | 73 | OutRaw = buffer.Bytes() 74 | return 75 | } 76 | 77 | //按宽度进行比例缩放，输入输出都是文件 78 | func ScaleF2F(filename string, savepath string, width int) (err error) { 79 | raw, err := ioutil.ReadFile(filename) 80 | if err != nil { 81 | return err 82 | } 83 | 84 | out, err := ScaleB2B(raw, width) 85 | if err != nil { 86 | return err 87 | } 88 | 89 | err = ioutil.WriteFile(savepath, out, 0777) 90 | if err != nil { 91 | return err 92 | } 93 | 94 | return 95 | } 96 | 97 | //图像文件的真正名字 98 | func RealImageName(filename string) (filerealname string, err error) { 99 | raw, err := ioutil.ReadFile(filename) 100 | if err != nil { 101 | return "", err 102 | } 103 | 104 | _, ext, err := LoadImage(bytes.NewReader(raw)) 105 | if err != nil { 106 | return 107 | } 108 | temp := strings.Split(filename, ".") 109 | if len(temp) < 2 { 110 | err = FileNameError 111 | } 112 | temp[len(temp)-1] = ext 113 | filerealname = strings.Join(temp, ".") 114 | return 115 | } 116 | 117 | //文件改名,如果force为假,且新的文件名已经存在,那么抛出错误 118 | func ChangeImageName(oldname string, newname string, force bool) (err error) { 119 | if !force { 120 | _, err = os.Open(newname) 121 | if err == nil { 122 | err = FileExistError 123 | return 124 | } 125 | } 126 | err = os.Rename(oldname, newname) 127 | return 128 | 129 | } 130 | 131 | // 获取调用者的当前文件DIR 132 | func CurDir() string { 133 | _, filename, _, _ := runtime.Caller(1) 134 | return filepath.Dir(filename) 135 | } 136 | 137 | // 根据文件名打开图片,并编码,返回编码对象和文件类型 138 | func LoadImage(r io.Reader) (img image.Image, filetype string, err error) { 139 | img, filetype, err = image.Decode(r) 140 | if err != nil { 141 | } 142 | return 143 | } 144 | 145 | // 将编码对象进行处理后返回字节数组 146 | func SaveImage(img *image.RGBA, filetype string, w io.Writer) (err error) { 147 | if filetype == "png" { 148 | err = png.Encode(w, img) 149 | } else if filetype == "jpeg" { 150 | err = jpeg.Encode(w, img, nil) 151 | } else { 152 | err = ExtNotSupportError 153 | } 154 | return 155 | } 156 | 157 | //对图片字节数组等比例变化,宽度为newdx,返回图像编码和文件类型 158 | func Scale(raw []byte, newdx int) (dst *image.RGBA, filetype string, err error) { 159 | src, filetype, err := LoadImage(bytes.NewReader(raw)) 160 | if err != nil { 161 | return 162 | } 163 | bound := src.Bounds() 164 | dx := bound.Dx() 165 | dy := bound.Dy() 166 | dst = image.NewRGBA(image.Rect(0, 0, newdx, newdx*dy/dx)) 167 | // 产生缩略图,等比例缩放 168 | err = graphics.Scale(dst, src) 169 | return 170 | } 171 | -------------------------------------------------------------------------------- /lib/codereview/codereview.cfg: -------------------------------------------------------------------------------- 1 | defaultcc: golang-dev@googlegroups.com 2 | -------------------------------------------------------------------------------- /testdata/gopher.png: -------------------------------------------------------------------------------- https://raw.githubusercontent.com/hunterhug/go_image/50c2408b96bfdbdef2267201993c641dd8c397fe/testdata/gopher.png -------------------------------------------------------------------------------- /testdata/gopher500.png: -------------------------------------------------------------------------------- https://raw.githubusercontent.com/hunterhug/go_image/50c2408b96bfdbdef2267201993c641dd8c397fe/testdata/gopher500.png -------------------------------------------------------------------------------- /testdata/gopher500_800.png: -------------------------------------------------------------------------------- https://raw.githubusercontent.com/hunterhug/go_image/50c2408b96bfdbdef2267201993c641dd8c397fe/testdata/gopher500_800.png --------------------------------------------------------------------------------