Color quantization. Specifies color-quantization attributes for GIF output conversion.
quantize= *
type*[, *
dither*[, *
numColors*[, *
colorList*]]]
type |
{adaptive|web|mac} palette type Select ' web ' or ' mac ' to choose a predefined palette, or set to ' adaptive ' to calculate an optimal palette for the image. |
dither |
{diffuse|off} dithering options Select 'diffuse' for Floyd-Steinberg error diffusion or 'off' to disable dithering. |
numColors |
Number of output colors (integer) included in the ' adaptive ' palette. numColors must be from 2 through 256. |
colorList |
Comma-separated list of forced RGB colors in hex6 format. Lets you specify forced colors to be included in an ' adaptive ' palette. If the number of colors specified is less than numColors , additional colors are calculated based on the image content. Used only if fmt=gif or fmt=gif-alpha . Ignored otherwise. The colors specified with colorList must be RGB values in hex6 format (see color ); no other color specifiers are permitted. |
quantize=adaptive,diffuse,256
Generate a GIF thumbnail using the ’ web
’ palette and no dithering:
http://server/myRootId/myImageId?req=tmb&fmt=gif&quantize=web,off
Convert the image to a bi-tonal GIF with key-color transparency and force colors to black and white:
http://server/is/agm/myRootId/myImageId?fmt=gif-alpha&wid=100&quantize=adaptive,off,2,000000,ffffff