seaweedfs/go/images/resizing.go
2014-07-20 23:12:49 -07:00

42 lines
1 KiB
Go

package images
import (
"bytes"
"github.com/disintegration/imaging"
"image"
"image/gif"
"image/jpeg"
"image/png"
)
func Resized(ext string, data []byte, width, height int) (resized []byte, w int, h int) {
if width == 0 && height == 0 {
return data, 0, 0
}
if srcImage, _, err := image.Decode(bytes.NewReader(data)); err == nil {
bounds := srcImage.Bounds()
var dstImage *image.NRGBA
if bounds.Dx() > width && width != 0 || bounds.Dy() > height && height != 0 {
if width == height && bounds.Dx() != bounds.Dy() {
dstImage = imaging.Thumbnail(srcImage, width, height, imaging.Lanczos)
w, h = width, height
} else {
dstImage = imaging.Resize(srcImage, width, height, imaging.Lanczos)
}
} else {
return data, bounds.Dx(), bounds.Dy()
}
var buf bytes.Buffer
switch ext {
case ".png":
png.Encode(&buf, dstImage)
case ".jpg", ".jpeg":
jpeg.Encode(&buf, dstImage, nil)
case ".gif":
gif.Encode(&buf, dstImage, nil)
}
return buf.Bytes(), dstImage.Bounds().Dx(), dstImage.Bounds().Dy()
}
return data, 0, 0
}