Optimal codebook design for a trellis-searched vector quantization
Seung Jun Lee, Yong C. Seo, ChoongWoong Lee · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1994
This paper proposes a new trellis-searched vector quantization scheme with an optimal codebook design algorithm. The proposed vector quantizer employs a conditional index encoder to efficiently exploit high interblock correlation, where each index is adaptively encoded using a different Huffman table which is selected according to the index of the previously decoded block. We also modify the Viterbit algorithm in order to find the optimal path through the trellis of indices. For an optimal codebook design an iterative descent method is used, which is very similar to that for ECVQ (entropy-constrained vector quantization) codebook design. Simulation results show that at the same bitrate the proposed method provides higher PSNR performances than the conventional ECVQ by 1.0 approximately 3.0 dB when applied to image coding.