/
imagery.go
113 lines (94 loc) · 2.35 KB
/
imagery.go
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// Copyright 2013 Justin Wilson. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package imagery
import (
"bufio"
"bytes"
"errors"
"image"
"image/gif"
"image/jpeg"
"image/png"
"io/ioutil"
"os"
"path/filepath"
"code.google.com/p/graphics-go/graphics"
)
type ImgType int
const (
IMG_UNKNOWN ImgType = iota
IMG_PNG
IMG_JPEG
IMG_GIF
)
func Decode(path string) (image.Image, error) {
f, err := os.Open(path)
if err != nil {
//return nil, "", err
return nil, err
}
defer f.Close()
i, _, err := image.Decode(bufio.NewReader(f))
return i, err
}
func ResizeWidth(img image.Image, width int) (image.Image, error) {
s := img.Bounds().Size()
h := int((float32(width) / float32(s.X)) * float32(s.Y))
r := image.NewRGBA(image.Rect(0, 0, width, h))
if err := graphics.Scale(r, img); err != nil {
return nil, err
}
return r, nil
}
func WriteTo(t ImgType, m image.Image, path, filename string) error {
var buf bytes.Buffer
switch t {
default:
return errors.New("Invalid image type")
case IMG_PNG:
png.Encode(&buf, m)
case IMG_JPEG:
//jpeg.Encode(&buf, m, &jpeg.Options{Quality: 75})
jpeg.Encode(&buf, m, nil)
case IMG_GIF:
gif.Encode(&buf, m, nil)
}
return ioutil.WriteFile(filepath.Join(path, filename), buf.Bytes(), 0644)
}
func WriteToPng(img image.Image, path, filename string) error {
return WriteTo(IMG_PNG, img, path, filename)
}
func WriteToJpg(img image.Image, path, filename string) error {
return WriteTo(IMG_JPEG, img, path, filename)
}
func WriteToGif(img image.Image, path, filename string) error {
return WriteTo(IMG_GIF, img, path, filename)
}
func ConvertToJPG(path, filename string, deleteOrig bool) (image.Image, error) {
//img, _, err := Decode(fpath)
img, err := Decode(path)
if err != nil {
return img, err
} else if WriteToJpg(img, filepath.Dir(path), filename); err != nil {
return img, err
}
if deleteOrig {
os.Remove(path)
}
return img, nil
}
func ResizeWidthToJPG(path, filename string, deleteOrig bool, width int) (image.Image, error) {
img, err := Decode(path)
if err != nil {
return img, err
} else if img, err = ResizeWidth(img, width); err != nil {
return img, err
} else if err = WriteToJpg(img, filepath.Dir(path), filename); err != nil {
return img, err
}
if deleteOrig {
os.Remove(path)
}
return img, nil
}