Documentation

Overview

    Package jpeg implements a JPEG image decoder and encoder.

    JPEG is defined in ITU-T T.81: https://www.w3.org/Graphics/JPEG/itu-t81.pdf.

    Index

    Constants

    View Source
    const DefaultQuality = 75

      DefaultQuality is the default quality encoding parameter.

      Variables

      This section is empty.

      Functions

      func Decode

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

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

        func DecodeConfig

        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

          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.

            Types

            type FormatError

            type FormatError string

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

              func (FormatError) Error

              func (e FormatError) Error() string

              type Options

              type Options struct {
              	Quality int
              }

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

                type Reader

                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

                  type UnsupportedError string

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

                    func (UnsupportedError) Error

                    func (e UnsupportedError) Error() string