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
}
示例#2
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// 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
}
示例#3
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// 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
}