jpeg

package standard library

go1.25.5 Latest Latest Go to latest Published: Dec 2, 2025 License: BSD-3-Clause Imports: 6 Imported by: 18,148

Documentation ¶

Package jpeg implements a JPEG image decoder and encoder.

View Source

const DefaultQuality = 75

DefaultQuality is the default quality encoding parameter.

This section is empty.

func Decode(r io.Reader) (image.Image, error)

Decode reads a JPEG image from r and returns it as an image.Image.

func DecodeConfig(r io.Reader) (image.Config, error)

DecodeConfig returns the color model and dimensions of a JPEG image without decoding the entire image.

func Encode(w io.Writer, m image.Image, o *Options) error

Encode writes the Image m to w in JPEG 4:2:0 baseline format with the given options. Default parameters are used if a nil *Options is passed.

type FormatError string

A FormatError reports that the input is not a valid JPEG.

func (e FormatError) Error() string

type Options struct {
	Quality int
}

Options are the encoding parameters. Quality ranges from 1 to 100 inclusive, higher is better.

type Reader interface {
	io.ByteReader
	io.Reader
}

Deprecated: Reader is not used by the image/jpeg package and should not be used by others. It is kept for compatibility.

type UnsupportedError string

An UnsupportedError reports that the input uses a valid but unimplemented JPEG feature.

func (e UnsupportedError) Error() string