func cutImage(img *image.NRGBA) []*image.NRGBA {
r := image.Rect(0, 0, 6, 11)
cuts := make([]*image.NRGBA, 10)
for i := 0; i < 10; i++ {
cuts[i] = img.SubImage(r).(*image.NRGBA)
r = r.Add(image.Pt(7, 0))
}
return cuts
}
func Resize(src io.Reader, c *CacheContext) (io.Reader, error) {
raw, err := ioutil.ReadAll(src)
if err != nil {
return nil, err
}
width := c.Width
data := bytes.NewReader(raw)
img, format, err := image.Decode(data)
if err != nil {
return nil, err
}
var resizedImage image.NRGBA
if c.Crop {
minDimension := int(math.Min(float64(img.Bounds().Size().X), float64(img.Bounds().Size().Y)))
if minDimension < c.Width || c.Width == 0 {
width = minDimension
}
resizedImage = *imaging.Fill(img, width, width, imaging.Center, imaging.Lanczos)
} else {
resizedImage = *imaging.Resize(img, width, 0, imaging.Lanczos)
}
buf := new(bytes.Buffer)
var imgFormat imaging.Format
switch format {
case "png":
imgFormat = imaging.PNG
case "jpeg":
imgFormat = imaging.JPEG
case "tiff":
imgFormat = imaging.TIFF
case "bmp":
imgFormat = imaging.BMP
default:
return nil, errors.New("unsupported image format")
}
err = imaging.Encode(buf, resizedImage.SubImage(resizedImage.Rect), imgFormat)
if err != nil {
return nil, err
}
return buf, err
}