Method Image.WebP.encode()

Method encode

string encode(Image.Image image, mapping(string:int|float|Image.Image)|void options)

Description

Encode an image using the WebP format.

The image to encode has to be at most 16384 pixels in any direction.

Commonly used options:

"alpha" : Image.Image	If present, the alpha channel for the image will be the green component of this image. Has to be the same size as the image
"preset" : int	Initialization for the encoding options. One of PRESET_DEFAULT, PRESET_PICTURE, PRESET_PHOTO PRESET_DRAWING, PRESET_ICON and PRESET_TEXT
"lossless" : bool	If set, do lossless encoding.
"quality" : float	Between 0 and 99. If quality is 100+, lossless encoding with quality 70 will be used.

Additionally these advanced options are also supported:

"image_hint" : int	One of HINT_DEFAULT, HINT_PICTURE, HINT_PHOTO and HINT_GRAPH. Only used in lossless mode
"target_size" : int	If non zero, sets the desired filesize, in bytes. Takes precedence over quality.
"target_PSNR" : int	if non-zero, specifies the minimal distortion to try to achieve. Takes precedence over target_size.
"segments" : int(1..4)	maximum number of segments to use.
"sns_strength" : int(0..100)	Spatial Noise Shaping. 0=off, 100=maximum.
"filter_strength" : int(0..100)	0=off
"filter_sharpness" : int(3bit)	0=off
"filter_type" : bool	For the type, 0=simple, 1=strong.
autofilter : bool	If true, automatically adjust the filter strengths
"alpha_compression" : bool	Select alpha channel encoding format. Currently supported are 0: No alpha and 1: WebP lossless
"alpha_filtering" : int(0..2)	Select alpha filtering method. 0: none, 1: fast, 2: best. Default if 1.
"alpha_quality" : int(0..100)	Select the base image quality for the alpha channel.
"pass" : int(1..10)	The number of entropy analysis passes. Defaults to 1.
"show_compressed" : bool
"preprocessing" : bool	If true, do preprocessing (segment-smooth)
"partitions" : int(2bit)	log2(number of token partitions). Default is set to 0 for easier progressive decoding.
"partition_limit" : int(0..100)	quality degradation allowed to fit the 512k limit on prediction modes coding (0: no degradation, 100: maximum possible degradation).
"emulate_jpeg_size" : bool	If true, try to map the quality setting to generate similar sizes when compared to jpeg.
"thread_level" : int	The maximum number of extra threads to use. Defaults to 0
"low_memory" : bool	Decrease memory usage at the cost of encoding speed

Returns

Always returns the encoded image as a string or throws an error.