func (handler *ImageUtilsHandler) Save(img image.Image, format string) ([]byte, error) {
// Based on github.com/disintegration/imaging/helpers.go Save()
var err error
writer := new(bytes.Buffer)
switch format {
case ".jpg", ".jpeg":
var rgba *image.RGBA
if nrgba, ok := img.(*image.NRGBA); ok {
if nrgba.Opaque() {
rgba = &image.RGBA{
Pix: nrgba.Pix,
Stride: nrgba.Stride,
Rect: nrgba.Rect,
}
}
}
if rgba != nil {
err = jpeg.Encode(writer, rgba, &jpeg.Options{Quality: 95})
} else {
err = jpeg.Encode(writer, img, &jpeg.Options{Quality: 95})
}
case ".png":
err = png.Encode(writer, img)
case ".tif", ".tiff":
err = tiff.Encode(writer, img, &tiff.Options{Compression: tiff.Deflate, Predictor: true})
case ".bmp":
err = bmp.Encode(writer, img)
default:
return nil, errors.New("Invalid image format")
}
return writer.Bytes(), err
}
// Save saves the image to file with the specified filename.
// The format is determined from the filename extension: "jpg" (or "jpeg"), "png", "tif" (or "tiff") and "bmp" are supported.
func Save(img image.Image, filename string) (err error) {
format := strings.ToLower(filepath.Ext(filename))
okay := false
for _, ext := range []string{".jpg", ".jpeg", ".png", ".tif", ".tiff", ".bmp"} {
if format == ext {
okay = true
break
}
}
if !okay {
return fmt.Errorf(`imaging: unsupported image format: "%s"`, format)
}
file, err := os.Create(filename)
if err != nil {
return
}
defer file.Close()
switch format {
case ".jpg", ".jpeg":
var rgba *image.RGBA
if nrgba, ok := img.(*image.NRGBA); ok {
if nrgba.Opaque() {
rgba = &image.RGBA{
Pix: nrgba.Pix,
Stride: nrgba.Stride,
Rect: nrgba.Rect,
}
}
}
if rgba != nil {
err = jpeg.Encode(file, rgba, &jpeg.Options{Quality: 95})
} else {
err = jpeg.Encode(file, img, &jpeg.Options{Quality: 95})
}
case ".png":
err = png.Encode(file, img)
case ".tif", ".tiff":
err = tiff.Encode(file, img, &tiff.Options{Compression: tiff.Deflate, Predictor: true})
case ".bmp":
err = bmp.Encode(file, img)
}
return
}
// Save saves the image to file with the specified filename.
// The format is determined from the filename extension: "jpg" (or "jpeg"), "png", "tif" (or "tiff"), "bmp", and "gif" are supported.
func Save(img image.Image, filename string) (err error) {
format := strings.ToLower(filepath.Ext(filename))
m, err := regexp.MatchString(`^\.(jpg|jpeg|png|tif|tiff|bmp|gif)$`, format)
if err != nil || !m {
err = fmt.Errorf(`imaging: unsupported image format: "%s"`, format)
return
}
file, err := os.Create(filename)
if err != nil {
return
}
defer file.Close()
switch format {
case ".jpg", ".jpeg":
var rgba *image.RGBA
if nrgba, ok := img.(*image.NRGBA); ok {
if nrgba.Opaque() {
rgba = &image.RGBA{
Pix: nrgba.Pix,
Stride: nrgba.Stride,
Rect: nrgba.Rect,
}
}
}
if rgba != nil {
err = jpeg.Encode(file, rgba, &jpeg.Options{Quality: 95})
} else {
err = jpeg.Encode(file, img, &jpeg.Options{Quality: 95})
}
case ".png":
err = png.Encode(file, img)
case ".tif", ".tiff":
err = tiff.Encode(file, img, &tiff.Options{Compression: tiff.Deflate, Predictor: true})
case ".bmp":
err = bmp.Encode(file, img)
case ".gif":
err = gif.Encode(file, img, &gif.Options{NumColors: 256}))
default:
err = fmt.Errorf(`imaging: unsupported image format: "%s"`, format)
}
return
}