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quantize

Color quantization. Specifies color-quantization attributes for GIF output conversion.
quantize= * type *[, * dither *[, * numColors *[, * colorList *]]]
type
{adaptive|web|mac}
Specifies the palette type.
Set to adaptive to calculate an optimal palette for the image.
Set to web or mac to choose a pre-defined palette.
Note: The mac pallet type is only supported for GIF and PNG8 formats but not for GIF-Alpha and PNG8-Alpha formats.
dither
{diffuse|off}
Specifies the dithering options.
Set to diffuse for Floyd-Steinberg error diffusion
Set to off to disable dithering.
numColors
Number of output colors (2-256)
Specifies how many colors are included in the adaptive palette.
colorList
A comma-separated list of forced RGB colors in hex6 format
Lets you specify colors to include in an adaptive palette. If the number of colors specified is less than numColors , additional colors are calculated based on the image content.

Properties

Request attribute. Applies regardless of current layer setting. Used only if fmt=gif , fmt=gif-alpha , fmt=png8 , or fmt=png8-alpha . Ignored otherwise.
The colors specified with * colorList * must consist of RGB values in hex6 format (see [color](../../../../../is-api/http-ref/image-serving-api-ref/c-http-protocol-reference/c-command-reference/r-color-commandref.md#reference-b044954ec6184253b8831579466b4423) ) without ' 0x ' prefix. No other color specifiers are permitted. numColors must be between 2-256.

Default

quantize=adaptive,diffuse,256

Example

Generate a GIF thumbnail using the web palette and no dithering:
http:// * server */myRootId/myImageId?req=tmb&fmt=gif&quantize=web,off
Convert image to a bi-tonal GIF with key-color transparency and force colors to black and white:
http:// * server */myRootId/myImageId?fmt=gif-alpha&wid=100&quantize=adaptive,off,2,000000,ffffff

See also