Distributed video coding for wireless video sensor networks: a review of the state-of-the-art architectures <s> Pixel domain Wyner-Ziv (PDWZ) video coding architecture <s> In current interframe video compression systems, the encoder performs predictive coding to exploit the similarities of successive frames. The Wyner-Ziv theorem on source coding with side information available only at the decoder suggests that an asymmetric video codec, where individual frames are encoded separately, but decoded conditionally (given temporally adjacent frames) could achieve similar efficiency. We report the first results on a Wyner-Ziv coding scheme for motion video that uses intraframe encoding, but interframe decoding. <s> BIB001 </s> Distributed video coding for wireless video sensor networks: a review of the state-of-the-art architectures <s> Pixel domain Wyner-Ziv (PDWZ) video coding architecture <s> In current interframe video compression systems, the encoder performs predictive coding to exploit the similarities of successive frames. The Wyner-Ziv Theorem on source coding with side information available only at the decoder suggests that an asymmetric video codec, where individual frames are encoded separately, but decoded ::: conditionally (given temporally adjacent frames) could achieve similar efficiency. We propose a transformdomain Wyner-Ziv coding scheme for motion video that uses intraframe encoding, but interframe decoding. In this system, the transform coefficients of a Wyner-Ziv frame are encoded independently using a scalar quantizer and turbo coder. The decoder uses previously reconstructed frames to generate side information to conditionally decode the Wyner-Ziv frames. Simulation results show significant gains above DCT-based intraframe coding and improvements over the pixel-domain Wyner-Ziv video coder. <s> BIB002
The WZ architecture, also widely known as Stanford DVC architecture, was originally designed based on PDWZ BIB001 coding. In later years, it was enhanced to TDWZ BIB002 ). In pixel domain WZ codec, which relies on intra-frame encoding and inter-frame decoding, the video sequence is spilt into X and Y , which represents the sets of even, and odd frames, respectively. Intra-frame encoding is used to encode X, given that X does not have any knowledge of Y . The redundancy between successive frames is exploited to determine the side information (Y ) at decoder, which in turn employs Y to conditionally decode X. The architecture of PDWZ codec is shown in Fig. 8 . The following discusses the encoder and decoder modules of the PDWZ codec: