Intra Mode Decision Based on Spatio-Temporal Cues in Pixel Domain Wyner-ZIV Video Coding

Distributed source coding principles have been recently applied to video coding in order to achieve a flexible distribution of the complexity burden between the encoder and the decoder. In this paper we elaborate on a pixel based Wyner-Ziv video codec that shifts all the complexity of the motion estimation phase to the decoder, thus achieving light encoding. We observe that the correlation noise statistics describing the relationship between the frame to be encoded and the side information available at the decoder is not spatially stationary. For this reason we introduce a mode decision scheme either at the encoder or at the decoder in such a way that when the estimated correlation is weak we opt for intra coding on a block-by-block basis. Both spatial and temporal criteria are used to determine whether a block is better intra coded or not