Application of pseudo-distance to lossless coding of color-mapped images

Palette images are widely used in many applications, including WWW which occupies an important role in Cloud Computing. Recently, it has been shown that better compression can be obtained when a Huffman coder is used after a color-mapped image is transformed with a pseudo-distance metric. Unlike most of the color-mapped image compression techniques, which require two passes, the pseudo-distance compression technique requires one pass and runs in linear time. In this work, we show that further compression gains can be achieved for color-mapped images when a structured arithmetic coder is used along with the pseudo-distance metric.