func Decode(r io.Reader) (image.Image, error)
Decode reads a PNG image from r and returns it as an image.Image. The type of Image returned depends on the PNG contents.
func DecodeConfig(r io.Reader) (image.Config, error)
DecodeConfig returns the color model and dimensions of a PNG image without decoding the entire image.
func Encode(w io.Writer, m image.Image) error
Encode writes the Image m to w in PNG format. Any Image may be encoded, but images that are not image.NRGBA might be encoded lossily.
type CompressionLevel int
const (
DefaultCompression CompressionLevel = 0
NoCompression CompressionLevel = -1
BestSpeed CompressionLevel = -2
BestCompression CompressionLevel = -3
)
type Encoder struct {
CompressionLevel CompressionLevel
}
Encoder configures encoding PNG images.
func (enc *Encoder) Encode(w io.Writer, m image.Image) error
Encode writes the Image m to w in PNG format.
type FormatError string
A FormatError reports that the input is not a valid PNG.
func (e FormatError) Error() string
type UnsupportedError string
An UnsupportedError reports that the input uses a valid but unimplemented PNG feature.
func (e UnsupportedError) Error() string