decode

Documentation

Overview

Package decode provides methods for decoding images.

Index

• func DecodeFromPath(ctx context.Context, path string) (image.Image, string, error)
• func RegisterDecoder(ctx context.Context, f InitializeDecoderFunc, schemes ...string) error
• type Decoder
  • func NewDecoder(ctx context.Context, uri string) (Decoder, error)
  • func NewGIFDecoder(ctx context.Context, uri string) (Decoder, error)
  • func NewJPEGDecoder(ctx context.Context, uri string) (Decoder, error)
  • func NewPNGDecoder(ctx context.Context, uri string) (Decoder, error)
• type GIFDecoder
  • func (e *GIFDecoder) Decode(ctx context.Context, r io.ReadSeeker) (image.Image, string, error)
• type InitializeDecoderFunc
• type JPEGDecoder
  • func (e *JPEGDecoder) Decode(ctx context.Context, r io.ReadSeeker) (image.Image, string, error)
• type PNGDecoder
  • func (e *PNGDecoder) Decode(ctx context.Context, r io.ReadSeeker) (image.Image, string, error)

Functions

func DecodeFromPath

func DecodeFromPath(ctx context.Context, path string) (image.Image, string, error)

func RegisterDecoder

func RegisterDecoder(ctx context.Context, f InitializeDecoderFunc, schemes ...string) error

RegisterDecoder registers 'scheme' as a key pointing to 'init_func' in an internal lookup table used to create new `Decoder` instances by the `NewDecoder` method.

Types

type Decoder

type Decoder interface {
	// Decode decodes an `io.ReaderSeeker` instance and returns an `image.Image` instance.
	Decode(context.Context, io.ReadSeeker) (image.Image, string, error)
}

func NewDecoder

func NewDecoder(ctx context.Context, uri string) (Decoder, error)

NewDecoder returns a new `Decoder` instance configured by 'uri'. The value of 'uri' is parsed as a `url.URL` and its scheme is used as the key for a corresponding `DecoderInitializationFunc` function used to instantiate the new `Decoder`. It is assumed that the scheme (and initialization function) have been registered by the `RegisterDecoder` method.

func NewGIFDecoder

func NewGIFDecoder(ctx context.Context, uri string) (Decoder, error)

NewGIFDecoder returns a new `GIFDecoder` instance. 'uri' in the form of:

/path/to/image.gif

func NewJPEGDecoder

func NewJPEGDecoder(ctx context.Context, uri string) (Decoder, error)

NewJPEGDecoder returns a new `JPEGDecoder` instance. 'uri' in the form of:

/path/to/image.jpg

func NewPNGDecoder

func NewPNGDecoder(ctx context.Context, uri string) (Decoder, error)

NewPNGDecoder returns a new `PNGDecoder` instance. 'uri' in the form of:

/path/to/image.png

type GIFDecoder

type GIFDecoder struct {
	Decoder
}

GIFDecoder is a struct that implements the `Decoder` interface for decoding GIF image.

func (*GIFDecoder) Decode

func (e *GIFDecoder) Decode(ctx context.Context, r io.ReadSeeker) (image.Image, string, error)

Decode will decode the body of 'r' in to an `image.Image` instance using the `image/gif` package.

type InitializeDecoderFunc

type InitializeDecoderFunc func(context.Context, string) (Decoder, error)

DecoderInitializationFunc is a function defined by individual decoder package and used to create an instance of that decoder.

type JPEGDecoder

type JPEGDecoder struct {
	Decoder
}

JPEGDecoder is a struct that implements the `Decoder` interface for decoding JPEG image.

func (*JPEGDecoder) Decode

func (e *JPEGDecoder) Decode(ctx context.Context, r io.ReadSeeker) (image.Image, string, error)

Decode will decode the body of 'r' in to an `image.Image` instance using the `image/jpeg` package.

type PNGDecoder

type PNGDecoder struct {
	Decoder
}

PNGDecoder is a struct that implements the `Decoder` interface for decoding PNG image.

func (*PNGDecoder) Decode

func (e *PNGDecoder) Decode(ctx context.Context, r io.ReadSeeker) (image.Image, string, error)

Decode will decode the body of 'r' in to an `image.Image` instance using the `image/png` package.