Research On LVQ Based Distributed Source Coding

The conventional video coding, such as MPEG and H.26x international standards, use motion estimation and motion compensation to exploit statistics correlations in the source coding. But the source encoding is very complex and is not suitable for high demand of ends that need low complexity. Distributed source coding with its simple encoding and robustness in transmission has received more and more attention. Although distributed source coding based on scalar quantization with its simple encoding has received aboard application and got excellent result. Its performance is no better than vector quantization. Lattice vector quantization is a special lattice vector quantization. Its encoding is simple and it does not need codebook. So it is very suitable for distributed video coding that demand low complexity encoding .This paper is mostly based on lattice vector quantization. We do some research on A₂, D₄, and Eg and use them on distributed source coding and get some valuable results as follows,① This paper applies the lattice vector quantization to the distributed source coding and has implemented the lattice vector quantization based on side information. The A₂ lattice based on side information include coarse lattice and fine lattice. Then it transfers the differences between them. At decoding end, it reconstructs the signal based on side information. But in this scheme, there is conflict of lattice volume between the coarse lattice and fine lattice. This paper does second reconstruction to solve the conflict. Finally, we apply it to the distributed video coding and get the better result than the scheme based on scalar quantization.②We implement the D₄ PLVQ codec and combined it with distributed source coding. Then we use the scheme to the video coding and get better results. Base on Shannon information theory, the larger the dimension is, the closer its coding performance to the rate distortion function. So the performance of lattice should be better than A₂-DSC performance. The experiment result proves its superiority.③we implement the E₈ PLVQ codec and combined it with distributed source coding in the same way as D₄ PLVQ. D₄ and E₈ are the good lattice respectively in their dimension. So it is the research focus of future. Although E₈ is more complex than D₄, E₈ has good performance in reducing correlation and compression. It is a good selection to use high complex lattice for high performance. This paper adopts the Construction -A to construct E₈ and use a method efficiency of 100% to do the index assignment, and proposes a new DVC scheme based on it.