// Smart crop given image file & write it to io.Writer
func smartCrop(w io.Writer, r io.Reader, size []int) error {
img, mimetype, err := image.Decode(r)
if size == nil || err != nil {
io.Copy(w, r)
return nil
}
size = setMaxSize(fitToActualSize(&img, size))
crop, err := smartcrop.SmartCrop(&img, size[0], size[1])
if err != nil {
io.Copy(w, r)
return nil
}
croppedBuffer := image.NewRGBA(image.Rect(0, 0, crop.Width, crop.Height))
draw.Draw(
croppedBuffer,
croppedBuffer.Bounds(),
img,
image.Point{crop.X, crop.Y},
draw.Src,
)
dst := image.NewRGBA(image.Rect(0, 0, size[0], size[1]))
graphics.Scale(dst, croppedBuffer)
return writeByMimetype(w, dst, mimetype)
}
func getFillCrop(src image.Image, targetRatio float32) (smartcrop.Crop, error) {
srcWidth := src.Bounds().Size().X
srcHeight := src.Bounds().Size().Y
newWidth := srcWidth
newHeight := srcHeight
srcRatio := float32(srcWidth) / float32(srcHeight)
if srcRatio > targetRatio {
// width stays the same
newHeight = int(float32(srcWidth) / targetRatio)
}
if srcRatio < targetRatio {
// height stays the same
newWidth = int(float32(srcHeight) * targetRatio)
}
return smartcrop.SmartCrop(&src, newWidth, newHeight)
}