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.