Recent Developments in Context-Based Predictive Techniques for Lossless Image Compression

In this paper we describe some recent developments that have taken place in context-based predictive coding, in response to the JPEG/JBIG committee's recent call for proposals for a new international standard on lossless compression of continuous-tone images. We describe the different prediction techniques that were proposed and give a performance comparison. We describe the notion of context-based bias cancellation, which represents one of the key ideas that was proposed and incorporated in the final standard. We also describe the different error modelling and entropy coding techniques that were proposed for encoding prediction errors, the most important development here being an ingeniously simple and effective technique for adaptive Golomb-Rice coding. We conclude with a short discussion on avenues for future research.