image manipulation with GIFT

image.go

@@ -0,0 +1,58 @@
+package main
+
+import (
+	"github.com/disintegration/gift"
+	"image"
+	"log"
+	"os"
+
+	_ "image/jpeg"
+	"image/png"
+)
+
+type Config struct {
+	Colorize [3]float32
+	Contrast int
+	Gamma    float64
+	Root     string
+}
+
+func loadImage(filename string) image.Image {
+	f, err := os.Open(filename)
+	if err != nil {
+		log.Fatalf("os.Open failed: %v", err)
+	}
+	defer f.Close()
+	img, _, err := image.Decode(f)
+	if err != nil {
+		log.Fatalf("image.Decode failed: %v", err)
+	}
+	return img
+}
+
+func saveImage(filename string, img image.Image) {
+	f, err := os.Create(filename)
+	if err != nil {
+		log.Fatalf("os.Create failed: %v", err)
+	}
+	defer f.Close()
+	err = png.Encode(f, img)
+	if err != nil {
+		log.Fatalf("png.Encode failed: %v", err)
+	}
+}
+
+func processImage(img image.Image, config Config) image.Image {
+
+	cArgs := config.Colorize
+	g := gift.New(
+		gift.Colorize(cArgs[0], cArgs[1], cArgs[2]),
+		gift.Contrast(float32(config.Contrast)),
+		gift.Gamma(float32(config.Gamma)),
+	)
+
+	dst := image.NewRGBA(g.Bounds(img.Bounds()))
+	g.Draw(dst, img)
+
+	return dst
+}