Universal compression lossless code statistically built

A universal compression statistical code based on a hierarchical transform of an image is presented. The properties of the transform that make it valuable for lossless image compression are studied. Based on them, a unique Huffman code, valid for every hierarchical transform, is constructed. Performance of the proposed coding scheme has been tested on a complete collection of images including small objects, faces, groups, remote sensing, ... obtained in different conditions. Results show that, on the average, a nearly 2:1 lossless compression is achieved, still keeping low the necessary computing requirements of the approach.