Distributed video coding with trellis coded quantization

Abstract

In conventional video coding systems, the encoder performs predictive coding (motion estimation) to exploit the temporal similarity, which make its complexity much higher than that of the decoder. The Wyner-Ziv theory or Lossy Distributed Coding theory suggests that when frames are separately encoded but jointly decoded, similar coding efficiency could be achieved. Trellis coded quantization (TCQ) is a powerful quantization method which has already shown its power in distributed source coding area. Recently, some applicable Wyner-Ziv video coding systems have been proposed. In this paper, based on the PRISM system, TCQ is employed to improve the performance. In order to minimize the complexity increase, only 4-state trellis is used, and no codebook is trained or stored, and we also propose a method to solve the refinement problem. Some other changes are also made to further improve the performance. Experimental results indicate that though the simplest TCQ is used, gain is also achieved over scalar quantization1. © Springer-Verlag Berlin Heidelberg 2007.