Block boundary matching algorithm for generating side information in distributed video codec

Distributed video codec (DVC) has been developed to construct a simple encoder that utilizes information theory for distributed sources in the circumstance of mobile multimedia communication. In the DVC codec, an efficient algorithm to generate side information (SI) is one of the most important techniques to improve the coding performance. We propose a scheme to increase the quality of SI frame, where the proposed scheme consists of three steps. In the first step, SI frame is constructed by motion estimation and motion compensation in the DVC decoder. Then, in the second step, the blocks in the temporary SI frame are classified into reliable or unreliable ones. The unreliable blocks are updated by block boundary matching algorithm in the third step. Simulation results show that the proposed algorithm outperforms the conventional methods significantly. In addition, the proposed scheme can be combined with the conventional schemes generating SI frame to increase the coding performance of the DVC codec. 1 Introduction In the last few years, a variety of mobile multimedia devices have been developed and become popular. The end-users would like to capture various scenes and to send those through up-link channels. Usually, the capability of the mobile devices that the end-users have is constrained with low-power and low-CPU speed. In this circumstance, the conventional video codecs, such as MPEG-2, H.264/AVC, and MPEG-4, are not appropriate for the portable devices because those codecs need the high power to encode video sequences. Thus, demand for simple and low-power video encoder has been continuously increasing. Distributed video codec (DVC) is one of the solutions to encode video sequence with low complexity on the encoder side. The complexity of DVC encoder is significantly lower than those of the conventional encoders. DVC codec is regarded as an advanced codec that is appropriate for low power applications such as wireless surveillance, sensor network , and mobile camera phones. DVC had been developed based on Slepian–Wolf 1 and the Wyner–Ziv 2 theorems which had proved that two signals can be decoded with prediction on the decoder side after those signals have been encoded without prediction between them on the encoder side. A theoretical method for lossless coding with side information (SI) was performed in Ref. 1. This method is referred to as Slepian–Wolf coding and is used with a channel-coding scheme. Slepian–Wolf coding was extended to a lossy compression by Wyner and Ziv. 2,3 The Wyner–Ziv codec consists …