1. A method for filtering digital images stored in palettized image format, comprising: (1) retrieving data from a digital image stored in palettized image format, wherein the digital image is represented by a pixel buffer having a plurality of pixels, each pixel having a value that references an index in a palette, the palette including a plurality of channel values, each channel value associated with one of a plurality of channels of the palette; (2) filtering data associated with a first channel of the palette to generate filtered data associated with said first channel of the palette; and (3) storing the filtered data and the plurality of pixels in a linked manner together with the palette, thereby forming a filtered image.