Structural codebook design and address-dependent vector quantization

A structural codebook design algorithm is proposed in this paper, which is aimed at considerably reducing the computational burden during the coding process of vector quantization while having almost no extra storage cost. Kohonen's self-organizing feature map algorithm is improved as to tackle two problems in codebook design. Since the address of currently coded block is often the same as that of the previously coded neighboring blocks, especially in the flat regions, an address-dependent vector quantization (ADVQ) scheme is proposed to further reduce the bit rate and computational complexity. The simulation results show that the ADVQ scheme can achieve a bit-rate reduction of 37 percent for a typical image 'Lena' while the computational complexity is reduced by a factor of 20.