import "image/gif"
Package gif implements a GIF image decoder and encoder.
The GIF specification is at https://www.w3.org/Graphics/GIF/spec-gif89a.txt.
const (
DisposalNone = 0x01
DisposalBackground = 0x02
DisposalPrevious = 0x03
)
Disposal Methods.
func Decode(r io.Reader) (image.Image, error)
Decode reads a GIF image from r and returns the first embedded image as an image.Image.
func DecodeConfig(r io.Reader) (image.Config, error)
DecodeConfig returns the global color model and dimensions of a GIF image without decoding the entire image.
func Encode(w io.Writer, m image.Image, o *Options) error
Encode writes the Image m to w in GIF format.
func EncodeAll(w io.Writer, g *GIF) error
EncodeAll writes the images in g to w in GIF format with the given loop count and delay between frames.
type GIF struct {
Image []*image.Paletted // The successive images.
Delay []int // The successive delay times, one per frame, in 100ths of a second.
// LoopCount controls the number of times an animation will be
// restarted during display.
// A LoopCount of 0 means to loop forever.
// A LoopCount of -1 means to show each frame only once.
// Otherwise, the animation is looped LoopCount+1 times.
LoopCount int
// Disposal is the successive disposal methods, one per frame. For
// backwards compatibility, a nil Disposal is valid to pass to EncodeAll,
// and implies that each frame's disposal method is 0 (no disposal
// specified).
Disposal []byte
// Config is the global color table (palette), width and height. A nil or
// empty-color.Palette Config.ColorModel means that each frame has its own
// color table and there is no global color table. Each frame's bounds must
// be within the rectangle defined by the two points (0, 0) and
// (Config.Width, Config.Height).
//
// For backwards compatibility, a zero-valued Config is valid to pass to
// EncodeAll, and implies that the overall GIF's width and height equals
// the first frame's bounds' Rectangle.Max point.
Config image.Config
// BackgroundIndex is the background index in the global color table, for
// use with the DisposalBackground disposal method.
BackgroundIndex byte
}
GIF represents the possibly multiple images stored in a GIF file.
func DecodeAll(r io.Reader) (*GIF, error)
DecodeAll reads a GIF image from r and returns the sequential frames and timing information.
type Options struct {
// NumColors is the maximum number of colors used in the image.
// It ranges from 1 to 256.
NumColors int
// Quantizer is used to produce a palette with size NumColors.
// palette.Plan9 is used in place of a nil Quantizer.
Quantizer draw.Quantizer
// Drawer is used to convert the source image to the desired palette.
// draw.FloydSteinberg is used in place of a nil Drawer.
Drawer draw.Drawer
}
Options are the encoding parameters.