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

fmt= , color

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