A quad-tree decomposition approach to cartoon image compression

A quad-tree decomposition approach is proposed for cartoon image compression in this work. The proposed algorithm achieves excellent coding performance by using a unique quad-tree decomposition and shape coding method along with a GIF like color indexing technique to efficiently encode large areas of the same color, which appear in a cartoon-type image commonly. To reduce complexity, the input image is partitioned into small blocks and the quad-tree decomposition is independently applied to each block instead of the entire image. The LZW entropy coding method can be performed as a post-processing step to further reduce the coded file size. It is demonstrated by experimental results that the proposed method outperforms several well-known lossless image compression techniques for cartoon images that contain 256 colors or less.