Adaptive in-loop prediction refinement for video coding

Modern video compression codecs achieve high compression efficiency by exploiting the temporal and spatial redundancies present in video sequences. Although state of the art block based intra and inter prediction have been refined to better adapt to the content in the scene, they still exhibit limitations in fully extracting information from the decoded data. We propose the addition of an in-loop prediction refinement stage that is initialized with the conventional intra or inter predicted result and is capable of further reducing the spatial redundancies present in the sequence. By extracting additional information from the decoded neighborhood, the refinement stage is able to bring the prediction closer to the original data, thus improving compression efficiency. In this work, we study one possible method of refinement for the particular case of intra prediction. This uses sparse decomposition of blocks that overlap decoded neighboring blocks and the current predicted block in order to make prediction more coherent with already encoded data.