NewDecoder returns a new `Decoder` instance configured by 'uri'.

NewGIFDecoder returns a new `GIFDecoder` instance.

NewJPEGDecoder returns a new `JPEGDecoder` instance.

NewPNGDecoder returns a new `PNGDecoder` instance.

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.

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

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

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

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