Accounting for quantization noise in online correlation noise estimation for Distributed Video Coding

Abstract

In Distributed Video Coding (DVC), compression is achieved by exploiting correlation between frames at the decoder, instead of at the encoder. More specifically, the decoder uses already decoded frames to generate side information Y for each Wyner-Ziv frame X, and corrects errors in Y using error correcting bits received from the encoder. For efficient use of these bits, the decoder needs information about the correlation between X available at the encoder and Y at the decoder. While several techniques for online estimation of correlation noise X - Y have been proposed, the quantization noise in Y has not been taken into account. As a solution, in this paper, we calculate the quantization noise of intra frames at the encoder and use this information at the decoder to improve the accuracy of the correlation noise estimation. Results indicate averageWyner-Ziv bit rate reductions up to 19.5% (Bjøntegaard delta) for coarse quantization.