Fast search algorithm for integer pixel and sub-pixel in H.264
Peng Liu · Journal of Zhejiang University(Engineering Science) · 2008
Two new block-matching algorithms were proposed to speed up motion estimation,which were respectively used in integer pixel search and sub-pixel search.A modified diamond search(MDS) algorithm adopts the search pattern which needs less searching points according to the best searching points' sum of absolute difference(SAD) distribution in spatial domain.The MDS algorithm concludes a layered search strategy in which the 2nd level search reduces the searching points on the base of the 1st level searching result.A sub-pixel diamond point search(SPDPS) algorithm utilizes the statistics of attributes in object's motion and the best searching point's SAD distribution in spatial domain.The SPDPS algorithm also adopts a two-level layered search strategy.Simulation showed that without degrading the picture quality and compression ratio,the MDS algorithm averagely reduced the number of integer pixel searching points by about 22% compared with the diamond search algorithm,and the SPDPS algorithm averagely reduced the number of sub-pixel searching points by about 17% compared with the subpixel full search.The two algorithms together averagely reduced the number of searching points in motion estimation by about 21%.