This chapter describes methods for coding images without loss; this means that, after compression, the input signal can be exactly reconstructed. It first reviews the motivations and requirements for lossless compression and justifies the use of variable length symbol encoding. It then focuses attention on two primary methods, Huffman coding and arithmetic coding. The algorithms, properties, and limitations of both methods are explored, together with some performance comparisons. A full example is provided based on the ubiquitous JPEG encoding standard and further details are provided by the way in which lossless coding methods are used in the HEVC and H.264/AVC standards, via CABAC and CAVLC. Examples are provided throughout.

David R. Bull

Papers

Lossless Compression Methods