Motion compensated refinement for low complexity pixel based distributed video coding
Distributed video coding (DVC) is a new coding paradigm that enables to exploit video statistics, partially or totally at the decoder. A particular case of DVC, Wyner-Ziv coding, deals with lossy source coding with side information at the decoder and allows a shift of complexity from the encoder to the decoder, theoretically without any penalty in the coding efficiency. The Wyner-Ziv solution here described encodes each video frame independently (intraframe coding), but decodes the same frame conditionally (interframe decoding). At the decoder, and compensation tools are responsible to obtain an accurate interpolation of the original frame using previously decoded (temporally adjacent) frames. This paper proposes a novel approach to improve the performance of pixel domain Wyner-Ziv video coding by using a motion compensated refinement of the decoded frame and use it as improved side information. More precisely, upon partial decoding of each frame, the decoder refines its motion trajectories in order to achieve a better reconstruction of the decoded frame.