Rate scalable video coding technology based on flexible block wavelet

Rate scalable video compression techniques are very attractive, because they are able to encode the video in embedded way that makes the decoding process more flexible to the bandwidth changes. Embedded wavelet coding technology plays an important role in this area. Traditional wavelet transforms are globally optimized. It is very efficient to code the natural images where sudden transitions rarely exist. On the other hand, video compression mostly deals with the differences between adjacent frames, also known as delta frames. Unfortunately, commonly used wavelet transforms are not so efficient on delta frame coding. In this paper, we are presenting a new wavelet coding technique—flexible block wavelet coding (FBWC). It is specially designed for delta frame compression. FBWC not only makes delta frame compression more efficient but also keeps the rate scalability and other scalabilities of wavelet-based scalable video compression techniques. Based on this new delta frame compression technique, we have implemented a highly efficient rate scalable video codec. Its overall performance surpasses the video codec based on set partitioning in hierarchical trees and is comparable to that of H263.