Fast sub-pixel inter-prediction - based on texture direction analysis (FSIP-BTDA) [video coding applications]
Motion estimation (ME) is a core part of modern video coding systems to exploit temporary redundancy in a video. Motion estimation is typically performed firstly with integer pixel accuracy and then at sub-pixel accuracy, which includes half-pixel and quarter-pixel accuracy. When sophisticated fast integer-pixel accuracy motion-search algorithms are used to decrease the number of search points for integer-pixel motion search, thus sub-pixel motion search became another important processing bottleneck in the encoding process. The conventional method is to search 8 half-pixel positions around the motion vector (MV) obtained from integer pixel motion search, then do motion search in the same way on 8 quarter-pixel positions around the MV obtained from half-pixel motion search, therefore totally 16 search points are needed. The proposed algorithm, fast sub-pixel inter-prediction - based on texture direction analysis (FSIP-BTDA), successfully optimizes the sub-pixel motion search on both half and quarter-pixel accuracy, and improves the processing speed with low PSNR penalty.