Provides a cgo binding of libwebp to process WebP image.
- gcc
- libwebp 1.1.0
Encode lossy
var opts *webp.EncodeOptions
//default options
opts, _ = webp.NewEncOptions()
//or init with preset
opts, _ = webp.NewEncOptionsByPreset(webp.PresetPicture, webp.LossyDefaultQuality)
var buf = bytes.NewBuffer(nil)
err = webp.Encode(buf, img, opts)
if err != nil {
panic(err)
}
ioutil.WriteFile("foo_lossy.webp", buf.Bytes(), os.ModePerm)Encode lossless
opts, _ := webp.NewEncOptions()
opts.SetupLosslessPreset(webp.LosslessDefaultLevel)
//or just
opts.Lossless = true
opts.Quality = webp.LosslessDefaultQuality
//set true if you want preserve RGB values under transparent area
opts.Exact = true
var buf = bytes.NewBuffer(nil)
err = webp.Encode(buf, img, opts)
if err != nil {
panic(err)
}
ioutil.WriteFile("foo_lossless.webp", buf.Bytes(), os.ModePerm)Decode
fin, _ := os.Open("foo.webp")
webpImg, err := webp.Decode(fin)
if err != nil {
panic(err)
}
fin.Seek(0, io.SeekStart)
//decode with options
decOpts := webp.NewDecOptions()
decOpts.ImageType = webp.TypeNRGBA //decode as image.NRGBA
webpImg, err = webp.DecodeEX(fin, decOpts)
if err != nil {
panic(err)
}Get and Set metadata chunk
iccp, err := webp.GetMetadata(webpData, webp.ICCP)
if err != nil {
newWebpData, err := webp.SetMetadata(webpdata2, webp.ICCP, iccp)
}