Sampling point path selection for fast intra mode prediction

The intra mode prediction via full search mode selection used in H.264/Advanced Video Coding (AVC) improves coding efficiency effectively, but at the cost of yielding higher computational complexity. In this paper a learning method for the distortion calculation in fast intra prediction mode selection for H.264/AVC is proposed, which uses partial distortion sums on a selected sub-optimal search path of sample locations in a given macroblock. Results show that only few of the sampling points are required to select at more than 90% accuracy the correct mode and therefore reducing the computational complexity with little impact on the coding efficiency. The resulting sub-optimal path is further compared to a baseline linear search path and an arbitrary search path, and it performs better for any number of samples selected when less than the full search.