Parallel lossless compression of color-mapped images

The pseudo-distance technique (PDT) in lossless compression of color-mapped images has proved to be effective. We showed previously that by utilizing the PDT along with the Burrows-Wheeler transformation and an entropy coder, we obtained better compression gain than other well-known generic image compressors e.g. Portable Network Graphics (PNG). Most of these techniques have been designed as sequential image compression algorithms. In this paper, we propose a method for the PDT which allows to the parallelization of the PDT and reduces the compression time significantly.