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.