HYBRID VARIABLE LENGTH CODING FOR VIDEO COMPRESSION

摘要

A method for variable length coding an ordered series of digital signals, e.g., of quantized transform coefficients of a block of image data with a most likely-to-occur amplitude, e.g., O, and at least one other amplitude, e.g., 1, to form a set of codewords. The method includes establishing a breakpoint (301) along the ordering to define a first contiguous region and a second contiguous region, such that clusters of consecutive signals of any value other than the most likely-to-occur value occur mostly in the first contiguous region. The method includes encoding the signals in the first region using a first region encoding method (303) suitable for encoding clusters; and encoding the signals in the second region using a second region encoding method (305). The first region and second region encoding methods include variable length codes such that relatively short codewords are formed to represent relatively more likely-to-occur sequences.