Palettized image data for two or more images, represented by color lookup table (CLUT) indices, are mapped to an index space. Blended pixels are generated from the pixels in the index space using alpha blending. The blended pixels are mapped back to CLUT indices to generate palettized blended image data....http://www.google.fr/patents/USRE37476?utm_source=gb-gplus-shareBrevet USRE37476 - Alpha blending palettized image data
