image

Documentation

Overview

Package image provides a bridge to the Go "image" package.

Index

• func Decode(im *imageserver.Image) (image.Image, error)
• func RegisterEncoder(format string, enc Encoder)
• type ChangeProcessor
  • func (prc *ChangeProcessor) Change(params imageserver.Params) bool
• type Changer
• type Encoder
• type EncoderFunc
  • func (f EncoderFunc) Change(params imageserver.Params) bool
  • func (f EncoderFunc) Encode(w io.Writer, nim image.Image, params imageserver.Params) error
• type Handler
  • func (hdr *Handler) Handle(im *imageserver.Image, params imageserver.Params) (*imageserver.Image, error)
• type ListProcessor
  • func (prc ListProcessor) Change(params imageserver.Params) bool
  • func (prc ListProcessor) Process(nim image.Image, params imageserver.Params) (image.Image, error)
• type Processor
• type ProcessorFunc
  • func (f ProcessorFunc) Change(params imageserver.Params) bool
  • func (f ProcessorFunc) Process(nim image.Image, params imageserver.Params) (image.Image, error)
• type ProcessorProvider
  • func (prv *ProcessorProvider) Get(params imageserver.Params) (image.Image, error)
• type Provider
• type ProviderFunc
  • func (f ProviderFunc) Get(params imageserver.Params) (image.Image, error)
• type Server
  • func (srv *Server) Get(params imageserver.Params) (*imageserver.Image, error)

Functions

func Decode

func Decode(im *imageserver.Image) (image.Image, error)

Decode decodes a raw Image to a Go Image.

It returns an error if the decoded Image format does not match the raw Image format.

func RegisterEncoder

func RegisterEncoder(format string, enc Encoder)

RegisterEncoder registers an Encoder for a format.

Types

type ChangeProcessor

type ChangeProcessor struct {
	Processor
}

ChangeProcessor is a Processor implementation that alway return true for the Change method.

func (*ChangeProcessor) Change

func (prc *ChangeProcessor) Change(params imageserver.Params) bool

Change implements Processor.

type Changer

type Changer interface {
	Change(imageserver.Params) bool
}

Changer returns true if the Image could change for the given Params.

type Encoder

type Encoder interface {
	Encode(io.Writer, image.Image, imageserver.Params) error
	Changer
}

Encoder encodes an Image.

An Encoder must encode to only one specific format.

type EncoderFunc

type EncoderFunc func(io.Writer, image.Image, imageserver.Params) error

EncoderFunc is an Encoder func.

func (EncoderFunc) Change

func (f EncoderFunc) Change(params imageserver.Params) bool

Change implements Encoder.

func (EncoderFunc) Encode

func (f EncoderFunc) Encode(w io.Writer, nim image.Image, params imageserver.Params) error

Encode implements Encoder.

type Handler

type Handler struct {
	Processor Processor // Optional Processor
}

Handler is a imageserver.Handler implementation that uses Go "image" package.

It supports format conversion and processing. It uses the "format" param to determine which Encoder is used.

If there is nothing to do, Handler does not decode the Image or call the Processor.

func (*Handler) Handle

func (hdr *Handler) Handle(im *imageserver.Image, params imageserver.Params) (*imageserver.Image, error)

Handle implements imageserver.Handler.

type ListProcessor

type ListProcessor []Processor

ListProcessor is a Processor implementation that wrap a list of Processor.

func (ListProcessor) Change

func (prc ListProcessor) Change(params imageserver.Params) bool

Change implements Processor.

func (ListProcessor) Process

func (prc ListProcessor) Process(nim image.Image, params imageserver.Params) (image.Image, error)

Process implements Processor.

type Processor

type Processor interface {
	Process(image.Image, imageserver.Params) (image.Image, error)
	Changer
}

Processor processes a Go Image.

It can return the given Image, but should not modify it.

type ProcessorFunc

type ProcessorFunc func(image.Image, imageserver.Params) (image.Image, error)

ProcessorFunc is a Processor func.

func (ProcessorFunc) Change

func (f ProcessorFunc) Change(params imageserver.Params) bool

Change implements Processor.

func (ProcessorFunc) Process

func (f ProcessorFunc) Process(nim image.Image, params imageserver.Params) (image.Image, error)

Process implements Processor.

type ProcessorProvider

type ProcessorProvider struct {
	Provider
	Processor Processor
}

ProcessorProvider is a Provider implementation that processes the Image.

func (*ProcessorProvider) Get

func (prv *ProcessorProvider) Get(params imageserver.Params) (image.Image, error)

Get implements Provider.

type Provider

type Provider interface {
	Get(imageserver.Params) (image.Image, error)
}

Provider returns a Go Image.

type ProviderFunc

type ProviderFunc func(imageserver.Params) (image.Image, error)

ProviderFunc is a Provider func.

func (ProviderFunc) Get

func (f ProviderFunc) Get(params imageserver.Params) (image.Image, error)

Get implements Provider.

type Server

type Server struct {
	Provider      Provider
	DefaultFormat string
}

Server is a imageserver.Server implementation that gets the Image from a Provider.

It uses the "format" param or the DefaultFormat variable to determine which Encoder is used.

func (*Server) Get

func (srv *Server) Get(params imageserver.Params) (*imageserver.Image, error)

Get implements imageserver.Server.