Subband coding algorithms for video applications: videophone to HDTV-conferencing

Various subband coding schemes are developed for high compression video coding applications. These schemes are based on two distinct interframe subband models. Both models are compared and show that they perform equally under certain conditions. The first model, which is relatively less complex but operates at full speed, was considered for video conferencing applications at lower rates. The second model, however, due to its generic structure which operates at a reduced speed, was found to be suitable for high quality video applications. As a result, a CCITT compatible video coding scheme for HDTV conferencing is developed. For the best performance, the higher frequency bands were coded with a combination of interframe differential pulse code modulation (DPCM) and direct PCM