Multiple Technique Entropy Coding System And Method

Abstract

A system, method and computer program product having optimal matching to a known or measured probability distribution encodes data without the use of an excessively large lookup table. An encoder constructed according to the present invention uses two or more different encoding methods in combination. In one embodiment, Huffman coding by table lookup is combined with computational generation, such as by using an exponential Golomb equation. The most commonly occurring elements are looked up in a small Huffman table, while the remaining elements are coded with the equation. In another embodiment, data is encoded using two or more equations. In yet another embodiment, data is encoded using multiple tables in conjunction with one or more equations.

1 . A method of compressing data, comprising:
 entropy coding an incoming data stream using a combination of at least two coding techniques in parallel, each of the coding techniques processing a different part of the data stream.   
   
   
       2 . The method of  claim 1 , wherein the at least two coding techniques comprise a Huffman lookup table and a computational generation. 
   
   
       3 . The method of  claim 2 , wherein the computational generation is an exponential-Golomb type. 
   
   
       4 . The method of  claim 2 , wherein the incoming data stream comprises a series of symbols to be encoded, each symbol having a magnitude, and wherein symbols having a magnitude less than a fixed constant are coded by using the Huffman lookup table and symbols having a magnitude not less than the fixed constant are coded using the computational generation.