Exploiting the error-correcting capabilities of low-density parity check codes in distributed video coding using optical flow

摘要

We consider Distributed Video Coding (DVC) in presence of communication errors. First, we present DVCside information generation based on a new method of optical flow driven frame interpolation, where a highlyoptimized TV-Lsup1/sup algorithm is used for the flow calculations and combine three flows. Thereafter methods forexploiting the error-correcting capabilities of the LDPCA code in DVC are investigated. The proposed frameinterpolation includes a symmetric flow constraint to the standard forward-backward frame interpolation scheme,which improves quality and handling of large motion. The three flows are combined in one solution. The proposedframe interpolation method consistently outperforms an overlapped block motion compensation scheme and aprevious TV-Lsup1/sup optical flow frame interpolation method with an average PSNR improvement of 1.3 dB and2.3 dB respectively. For a GOP size of 2, an average bitrate saving of more than 40% is achieved comparedto DISCOVER on Wyner-Ziv frames. In addition we also exploit and investigate the internal error-correctingcapabilities of the LDPCA code in order to make it more robust to errors. We investigate how to achieve thisgoal by only modifying the decoding. One of approaches is to use bit flipping; alternatively one can modify theparity check matrix of the LDPCA. Different schemes known from LDPC codes are considered and evaluated inthe LDPCA setting. Results show that the performance depend heavily on the type of channel used and on thequality of the Side Information.© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.