Distributed video coding for wireless video sensor networks: a review of the state-of-the-art architectures <s> Transform domain Wyner-Ziv (TDWZ) 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> Transform domain Wyner-Ziv (TDWZ) 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 pixel domain WZ codec has been extended from pixel-domain BIB001 to transform-domain BIB002 , which exploits spatial correlation within a given frame and temporal correlation among adjacent frames to achieve better rate-distortion performance as shown in Fig. 9 . The inclusion of DCT module makes TDWZ a more practical WZ codec, which encodes key and WZ frames using conventional intra-frame encoder, and WZ encoder, respectively. At decoder site, key frames are reconstructed via conventional inter-frame decoder, whereas decoding a WZ frame requires side information generated by the previously decoded key frames and WZ frames. In the following sub-sections, we will discuss only those modules of TDWZ which differ from those in the PDWZ codec architecture.