A New Entropy Coding Technique for Data Compression

We present a novel entropy coding technique that is based on recursive interleaving of variable-to-variable-length binary source codes. An entropy coder using this technique is a general purpose module that can be used in a wide variety of data compression algorithms. The encoding process is adaptable in that each bit to be encoded has an associated probability-of-zero estimate that may depend on previously encoded bits. This adaptability allows more efficient compression, and the technique has speed advantages over arithmetic coding, the state-of-theart adaptable entropy coding method. The technique can achieve arbitrarily small redundancy. Much variation is possible in the choice of component codes and in the interleaving structure, yielding coder designs of varying complexity and compression efficiency. We discuss coder design and performance estimation methods. We present practical encoding and decoding algorithms, as well as measured performance results.