DRYer

tools/utils/images/formats.go

@@ -0,0 +1,44 @@
+// License: GPLv3 Copyright: 2022, Kovid Goyal, <kovid at kovidgoyal.net>
+
+package images
+
+import (
+	"fmt"
+	"image"
+	"image/gif"
+	"image/jpeg"
+	"image/png"
+	"io"
+
+	"golang.org/x/image/bmp"
+	"golang.org/x/image/tiff"
+	_ "golang.org/x/image/webp"
+)
+
+var _ = fmt.Print
+
+var DecodableImageTypes = map[string]bool{
+	"image/jpeg": true, "image/png": true, "image/bmp": true, "image/tiff": true, "image/webp": true, "image/gif": true,
+}
+
+var EncodableImageTypes = map[string]bool{
+	"image/jpeg": true, "image/png": true, "image/bmp": true, "image/tiff": true, "image/gif": true,
+}
+
+func Encode(output io.Writer, img image.Image, format_mime string) (err error) {
+	switch format_mime {
+	case "image/png":
+		return png.Encode(output, img)
+	case "image/jpeg":
+		return jpeg.Encode(output, img, nil)
+	case "image/bmp":
+		return bmp.Encode(output, img)
+	case "image/gif":
+		return gif.Encode(output, img, nil)
+	case "image/tiff":
+		return tiff.Encode(output, img, nil)
+	}
+	err = fmt.Errorf("Unsupported output image MIME type %s", format_mime)
+	return
+
+}