Wavelet video coding with ladder structures and entropy-constrained quantization

Abstract

A subband decomposition using wavelet filters has become an effective basis for image compression. The use of a ladder structure for the subband filtering provides a fast implementation and allows the system to be useful at video rates. A system is proposed that provides good quality video for moderate motion, roughly common intermediate format-f 0-t (CIF-) sized images at bit rates under 500 kb/s, and for teleconferencing scenes at bit rates from 180 kb/s to below 128 kb/s (basic rate ISDN). The system uses subband coding, a modified version of H.261, and entropy-constrained quantization to achieve the desired bit rate and image quality.