tiff

Documentation

Overview

Package tiff implements a TIFF image decoder and encoder.

The TIFF specification is at http://partners.adobe.com/public/developer/en/tiff/TIFF6.pdf

Index

• func Decode(r io.Reader) (img image.Image, err error)
• func DecodeConfig(r io.Reader) (image.Config, error)
• func Encode(w io.Writer, m image.Image, opt *Options) error
• type CompressionType
• type FormatError
  • func (e FormatError) Error() string
• type Options
• type UnsupportedError
  • func (e UnsupportedError) Error() string

Functions

func Decode

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

Decode reads a TIFF image from r and returns it as an image.Image. The type of Image returned depends on the contents of the TIFF.

func DecodeConfig

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

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

func Encode

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

Encode writes the image m to w. opt determines the options used for encoding, such as the compression type. If opt is nil, an uncompressed image is written.

Types

type CompressionType

type CompressionType int

CompressionType describes the type of compression used in Options.

const (
	Uncompressed CompressionType = iota
	Deflate
	LZW
	CCITTGroup3
	CCITTGroup4
)

Constants for supported compression types.

type FormatError

type FormatError string

A FormatError reports that the input is not a valid TIFF image.

func (FormatError) Error

func (e FormatError) Error() string

type Options

type Options struct {
	// Compression is the type of compression used.
	Compression CompressionType
	// Predictor determines whether a differencing predictor is used;
	// if true, instead of each pixel's color, the color difference to the
	// preceding one is saved.  This improves the compression for certain
	// types of images and compressors. For example, it works well for
	// photos with Deflate compression.
	Predictor  bool
	Resolution uint
}

Options are the encoding parameters.

type UnsupportedError

type UnsupportedError string

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

func (UnsupportedError) Error

func (e UnsupportedError) Error() string