An implementation of Go binding for LibJpeg (preferably libjpeg-turbo).
The core codes are picked from go-thumber and rewritten to compatible with image.Image interface.
import "github.com/pixiv/go-libjpeg"
func main() {
// Decoding JPEG into image.Image
io := os.Open("in.jpg")
img, err := jpeg.Decode(io, &jpeg.DecoderOptions{})
if err != nil {
log.Printf("Decode returns error: %v\n", err)
return
}
// Encode JPEG
f, err := os.Create("out.jpg")
if err != nil {
panic(err)
}
w := bufio.NewWriter(f)
if err := jpeg.Encode(w, img, &jpeg.EncoderOptions{Quality: 90}); err != nil {
log.Printf("Encode returns error: %v\n", err)
return
}
w.Flush()
f.Close()
}
See test code to read full features.
- Raw JPEG decoding in YCbCr color.
- Decoding with color conversion into RGB/RGBA (RGBA conversion is only supported with libjpeg-turbo).
- Scaled decoding.
- Encoding from some color models (YCbCr, RGB and RGBA).
$ go test -bench . -benchtime 10s
...
BenchmarkDecode 1000 26345730 ns/op
BenchmarkDecodeIntoRGB 500 30886383 ns/op
BenchmarkDecodeWithNativeJPEG 300 49815928 ns/op
...
With libjpeg-turbo:
BenchmarkDecode 2000 9557646 ns/op
BenchmarkDecodeIntoRGB 1000 12676414 ns/op
BenchmarkDecodeWithNativeJPEG 300 45836153 ns/op
go-libjpeg is about 1.9x faster than image/jpeg. With libjpeg-turbo, it can make more faster (about 4.8x faster than image/jpeg).
-
Go 1.3 (needed for cgo features)
-
libjpeg (preferably libjpeg-turbo)
DecodeIntoRGBA can only work if go-libjpeg is built with libjpeg-turbo. Because DecdeIntoRGBA uses
JCS_ALPHA_EXTENSIONS. You can use DecodeIntoRGB and convert to image.RGBA if can not use libjpeg-turbo.
Copyright (c) 2014 pixiv Inc. All rights reserved.
See LICENSE.