Namespace: go.std.image.jpeg

v1.0

Contents

• Summary
• Index
• Constants
• Variables
• Functions, Macros, and Special Forms
• Types

Summary

Provides a low-level interface to the image/jpeg package.

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

• *FormatError
• *Options
• *UnsupportedError
• Decode
• DecodeConfig
• DefaultQuality
• Encode
• FormatError
• Options
• Reader
• UnsupportedError
• arrayOfFormatError
• arrayOfOptions
• arrayOfReader
• arrayOfUnsupportedError

Legend

Constant Variable Function Macro Special form Type GoVar Receiver/Method

Constants

Constants are variables with :const true in their metadata. Joker currently does not recognize them as special; as such, it allows redefining them or their values.

• DefaultQuality

  Int v1.0

  DefaultQuality is the default quality encoding parameter.
  

Variables

(None.)

Functions, Macros, and Special Forms

• Decode

  Function v1.0

  (Decode r)
  

  Decode reads a JPEG image from r and returns it as an image.Image.
  
  Go input arguments: (r io.Reader)
  
  Go returns: (image.Image, error)
  
  Joker input arguments: [^go.std.io/Reader r]
  
  Joker returns: [^go.std.image/Image, ^Error]

• DecodeConfig

  Function v1.0

  (DecodeConfig r)
  

  DecodeConfig returns the color model and dimensions of a JPEG image without
  decoding the entire image.
  
  Go input arguments: (r io.Reader)
  
  Go returns: (image.Config, error)
  
  Joker input arguments: [^go.std.io/Reader r]
  
  Joker returns: [^go.std.image/Config, ^Error]

• Encode

  Function v1.0

  (Encode w m o)
  

  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.
  
  Go input arguments: (w io.Writer, m image.Image, o *Options)
  
  Go returns: error
  
  Joker input arguments: [^go.std.io/Writer w, ^go.std.image/Image m, ^*Options o]
  
  Joker returns: ^Error

Types

• *FormatError

  Concrete Type v1.0

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

• *Options

  Concrete Type v1.0

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

• *UnsupportedError

  Concrete Type v1.0

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

• FormatError

  Concrete Type v1.0

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

• Error

  Receiver for FormatError v1.0

  ([])
  

• Options

  Concrete Type v1.0

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

• Reader

  Abstract Type v1.0

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

• Read

  Method for Reader v1.0

  ([p])
  

• ReadByte

  Method for Reader v1.0

  ([])
  

• UnsupportedError

  Concrete Type v1.0

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

• Error

  Receiver for UnsupportedError v1.0

  ([])
  

• arrayOfFormatError

  Concrete Type v1.0

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

• arrayOfOptions

  Concrete Type v1.0

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

• arrayOfReader

  Concrete Type v1.0

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

• arrayOfUnsupportedError

  Concrete Type v1.0

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