Decode reads a JPEG image from r and returns it as an image.Image.

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

Encode writes the Image m to w in JPEG 4:2:0 baseline format with the given options.

DefaultQuality is the default quality encoding parameter.

Options are the encoding parameters.

If the passed in io.Reader does not also have ReadByte, then Decode will introduce its own buffering.

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

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