Improved hierarchial intra prediction based on adaptive interpolation filtering for lossless compression

Often the adaptive interpolation filter provides a more accurate interpolation technique in the formulation of the sub-pixel reference frame for motion estimation and compensation. Inspired by its possible advantages, we make use of the adaptive interpolation filter for efficient lossless intra prediction in H.264/AVC. Specifically, four subblocks are firstly formed by sampling pixels in one macroblock/block, and then a hierarchical intra prediction is performed on these subblocks. The first subblock is predicted based on the intra spatial prediction method in H.264/AVC, and subsequently it is encoded and reconstructed. The remaining three subblocks are then predicted based on adaptive interpolation filters by using the neighboring reconstructed samples. The residual block is encoded by rate optimization. Experimental results show that the proposed algorithm can improve the compression efficiency of lossless intra coding.