Very low bit-rate video compression using wavelets
Chiman Kwan, Baoxin Li, Roger Xu, Trac Duy Tran, Truong Q. Nguyen · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2001
A hybrid algorithm is proposed for very low bit-rate video compression. The algorithm uses a new wavelet based coder for Intraframe compression and DCT for Interframe compression. The wavelet coder technique known as OBTWC (Overlapped Block Transform Wavelet Coder) consists of three steps. First, a set of overlapped block transforms is used to transform the image data into 8 X 8 blocks in the frequency domain. Second, a mapping is then performed to convert the transformed image into a multiresolution representation that resembles the zero- tree wavelet transform. Third, the multiresolution representation is then coded by a conventional dyadic wavelet coder, which basically truncates the high frequency contents in a very efficient manner. Our proposed method essentially combines the advantages of both block transform and wavelet coding techniques while eliminating their respective weaknesses. Simulation results show that the coder achieves more than 300:1 compression ratio at a frame rate of 10 per second.