Successive refinement of side information frames in distributed video coding

In distributed video coding, generation of high-quality side information is required for reliable soft-input information for decoding each DCT band of a Wyner-Ziv (WZ) frame in the decoder, which in turn leads to a more efficient decoding. Consequently, less error-correcting bits need to be transmitted from the encoder to the decoder to decode the bitplanes of each DCT band, leading to a better compression efficiency and rate-distortion performance. In this paper, we investigate the problem of successive improvements in the quality of side information frames in distributed video coding in order to improve the rate-distortion performance. A new algorithm for the successive refinement of the side information is proposed to refine the initial side information frame using the additional information obtained after decoding the previous DCT bands of a WZ frame. As more information about the WZ frame becomes available after the decoding of each DCT band of the WZ frame, the corresponding side information frame is refined and then employed to decode the next DCT band of the WZ frame. Simulations are carried out demonstrating that the proposed algorithm for refinement of side information frame results in a considerable improvement in the RD performance of distributed video coding.