comparison src/IMGmanip.go @ 0:de451fa0c9cd

golang repository.
author pyon@macmini
date Sat, 01 Oct 2016 11:16:31 +0900
parents
children 9072560fc0f2
comparison
equal deleted inserted replaced
-1:000000000000 0:de451fa0c9cd
1 /* Image Manipulator - ver 0.2 ( Last Change: 2016-08-21 Sun 09:51:52.) */
2 package main
3
4 import(
5 "errors"
6 "flag"
7 "fmt"
8 "image"
9 "image/jpeg"
10 "image/png"
11 "io"
12 "os"
13 "strings"
14 "strconv"
15 )
16
17 func main() {
18 ver := "0.2"
19
20 // arguments
21 kind := flag.String( "t", "", "file type : jpeg / png" )
22 resize := flag.String( "s", "", "new size : 600x800 / 320x0 / ..." )
23 crop := flag.String( "c", "", "crop size : 300x200+10+35" )
24 angle := flag.Uint( "r", 0, "rotate : 90 / 180 / 270" )
25
26 flag.Parse()
27 if flag.NFlag() == 0 {
28 fmt.Fprintf( os.Stderr, "\n=== Image-Manipulator - version %s ===", ver )
29 fmt.Fprintf( os.Stderr, "\n$ imgmanip [option parameter] < infile > outfile\n" )
30 flag.PrintDefaults()
31 os.Exit( 1 )
32 }
33
34 // convert
35 if *kind != "" {
36 err := Convert( os.Stdin, os.Stdout, *kind ); if err != nil {
37 fmt.Fprintf( os.Stderr, "%s: %v\n", *kind, err )
38 os.Exit( 1 )
39 }
40 return
41 }
42
43 // resize
44 if *resize != "" {
45 err := Resize( os.Stdin, os.Stdout, *resize ); if err != nil {
46 fmt.Fprintf( os.Stderr, "resize: %v\n", err )
47 os.Exit( 1 )
48 }
49 return
50 }
51
52 // crop
53 if *crop != "" {
54 err := Crop( os.Stdin, os.Stdout, *crop ); if err != nil {
55 fmt.Fprintf( os.Stderr, "crop: %v\n", err )
56 os.Exit( 1 )
57 }
58 return
59 }
60
61 // rotate
62 if *angle != 0 {
63 err := Rotate( os.Stdin, os.Stdout, *angle ); if err != nil {
64 fmt.Fprintf( os.Stderr, "rotate: %v\n", err )
65 os.Exit( 1 )
66 }
67 return
68 }
69 }
70
71 func Convert( in io.Reader, out io.Writer, kind string ) error {
72
73 img, _, err := image.Decode( in ); if err != nil {
74 return err
75 }
76
77 switch kind {
78 case "jpeg":
79 return jpeg.Encode( out, img, &jpeg.Options{ Quality: 100 } )
80 case "png":
81 return png.Encode( out, img )
82 }
83
84 return errors.New( "image-type is not supported")
85 }
86
87 func Resize( in io.Reader, out io.Writer, size string ) error {
88
89 img, kind, err := image.Decode( in ); if err != nil {
90 return err
91 }
92 srcW := img.Bounds().Max.X
93 srcH := img.Bounds().Max.Y
94
95 wh := strings.Split( size, "x" )
96 w, err := strconv.Atoi( wh[0] ); if err != nil || w < 0 {
97 return errors.New( "invalid width" )
98 }
99 h, err := strconv.Atoi( wh[1] ); if err != nil || h < 0 {
100 return errors.New( "invalid height" )
101 }
102 if w == 0 && h == 0 {
103 return errors.New( "invalid size" )
104 }
105 if w == 0 {
106 w = h * srcW / srcH
107 }
108 if h == 0 {
109 h = w * srcH / srcW
110 }
111
112 dst := image.NewNRGBA( image.Rect( 0, 0, w, h ) )
113 for x := 0; x < w; x++ {
114 for y := 0; y < h; y++ {
115 dst.Set( x, y, img.At( x * srcW / w, y * srcH / h ) )
116 }
117 }
118
119 switch kind {
120 case "jpeg":
121 return jpeg.Encode( out, dst, &jpeg.Options{ Quality: 100 } )
122 case "png":
123 return png.Encode( out, dst )
124 }
125
126 return errors.New( "image-type is not supported")
127 }
128
129 func Crop( in io.Reader, out io.Writer, geo string ) error {
130
131 img, kind, err := image.Decode( in ); if err != nil {
132 return err
133 }
134 srcW := img.Bounds().Max.X
135 srcH := img.Bounds().Max.Y
136
137 buf := strings.Split( geo, "x" )
138 w, err := strconv.Atoi( buf[0] ); if err != nil || w < 0 || w > srcW {
139 return errors.New( "invalid width" )
140 }
141 buf = strings.Split( buf[1], "+" )
142 h, err := strconv.Atoi( buf[0] ); if err != nil || h < 0 || h > srcH {
143 return errors.New( "invalid height" )
144 }
145 x0, err := strconv.Atoi( buf[1] ); if err != nil || x0 < 0 {
146 return errors.New( "invalid x" )
147 }
148 y0, err := strconv.Atoi( buf[2] ); if err != nil || y0 < 0 {
149 return errors.New( "invalid y" )
150 }
151
152 var dst *image.NRGBA
153
154 dst = image.NewNRGBA( image.Rect( 0, 0, w, h ) )
155 for x := 0; x < x0 + w; x++ {
156 for y := 0; y < y0 + h; y++ {
157 dst.Set( x, y, img.At( x0 + x, y0 + y ) )
158 }
159 }
160
161 switch kind {
162 case "jpeg":
163 return jpeg.Encode( out, dst, &jpeg.Options{ Quality: 100 } )
164 case "png":
165 return png.Encode( out, dst )
166 }
167
168 return errors.New( "image-type is not supported")
169 }
170
171 func Rotate( in io.Reader, out io.Writer, angle uint ) error {
172
173 img, kind, err := image.Decode( in ); if err != nil {
174 return err
175 }
176 srcW := img.Bounds().Max.X
177 srcH := img.Bounds().Max.Y
178
179 var dst *image.NRGBA
180 switch angle {
181 case 90:
182 dst = image.NewNRGBA( image.Rect( 0, 0, srcH, srcW ) )
183 for x := 0; x < srcH; x++ {
184 for y := 0; y < srcW; y++ {
185 dst.Set( x, y, img.At( y, srcH - x ) )
186 }
187 }
188 case 180:
189 dst = image.NewNRGBA( image.Rect( 0, 0, srcW, srcH ) )
190 for x := 0; x < srcW; x++ {
191 for y := 0; y < srcH; y++ {
192 dst.Set( x, y, img.At( srcW - x, srcH - y ) )
193 }
194 }
195 case 270:
196 dst = image.NewNRGBA( image.Rect( 0, 0, srcH, srcW ) )
197 for x := 0; x < srcH; x++ {
198 for y := 0; y < srcW; y++ {
199 dst.Set( x, y, img.At( y, x ) )
200 }
201 }
202 default:
203 return errors.New( "bad angle" )
204 }
205
206 switch kind {
207 case "jpeg":
208 return jpeg.Encode( out, dst, &jpeg.Options{ Quality: 100 } )
209 case "png":
210 return png.Encode( out, dst )
211 }
212
213 return errors.New( "image-type is not supported")
214 }
215