Documentation
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Overview ¶
Package jpeg implements a JPEG image decoder and encoder.
JPEG is defined in ITU-T T.81: https://www.w3.org/Graphics/JPEG/itu-t81.pdf.
Index ¶
Constants ¶
const DefaultQuality = 75
DefaultQuality is the default quality encoding parameter.
Variables ¶
This section is empty.
Functions ¶
func Decode ¶
Decode reads a JPEG image from r. Different from the standard package, the decoded result will be received by the callback set by SetCallback().
func DecodeConfig ¶
DecodeConfig returns the color model and dimensions of a JPEG image without decoding the entire image.
func Encode ¶
Encode writes the Image m to w in JPEG 4:2:0 baseline format with the given options. Default parameters are used if a nil *Options is passed.
func SetCallback ¶
SetCallback registers the buffer and fn required for Callback. Callback can be called multiple times by calling Decode().
Types ¶
type Callback ¶
A portion of the image data consisting of data, x, y, w, and h is passed to Callback. The size of the whole image is passed as width and height. If the callback is not called, add the implementation to image/png.readImagePass.
type FormatError ¶
type FormatError string
A FormatError reports that the input is not a valid JPEG.
func (FormatError) Error ¶
func (e FormatError) Error() string
type Options ¶
type Options struct {
Quality int
}
Options are the encoding parameters. Quality ranges from 1 to 100 inclusive, higher is better.
type Reader
deprecated
type Reader interface {
io.ByteReader
io.Reader
}
Deprecated: Reader is not used by the image/jpeg package and should not be used by others. It is kept for compatibility.
type UnsupportedError ¶
type UnsupportedError string
An UnsupportedError reports that the input uses a valid but unimplemented JPEG feature.
func (UnsupportedError) Error ¶
func (e UnsupportedError) Error() string
Source Files