Rate scalable video compression based on flexible block wavelet coding technique

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. We present 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 of wavelet based rate scalable video compression techniques, and other scalabilities as well. Based on this new delta frame compression technique, we implement a highly efficient rate scalable video codec. Its overall performance surpasses the video codec based on SPIHT and is comparable to that of H.263