func procImage(fileName string) (string, error) {
reader, err := os.Open(fileName)
if err != nil {
fmt.Errorf("Failed to open image with error: %s\n", err)
return "", err
}
defer reader.Close()
src, _, err := image.Decode(reader)
if err != nil {
fmt.Errorf("Failed to decode image with error: %s\n", err)
return "", err
}
g := gift.New(
gift.Invert(),
)
dst := image.NewRGBA(g.Bounds(src.Bounds()))
g.Draw(dst, src)
var opt jpeg.Options
opt.Quality = 100
fileName = fileName + "_processed.jpg"
out, _ := os.Create(fileName)
err = jpeg.Encode(out, dst, &opt)
if err != nil {
fmt.Errorf("Failed to encode image with error: %s\n", err)
return "", err
}
return fileName, nil
}
// take an image and revert its rgb channels (255-channel)
func invert(img image.Image) image.Image {
g := gift.New(gift.Grayscale(),
gift.Invert())
dst := image.NewRGBA(g.Bounds(img.Bounds()))
g.Draw(dst, img)
return dst
}