Context-Adaptive Cross Hexagons-grid search

The properties of H.264/AVC motion estimation and the statistical characteristics of H.264/AVC motion vectors are analyzed, and a context-adaptive cross hexagons-grid search (CACH) is proposed in this paper. It makes use of the correlation among neighboring motion vectors, the intensities of motion. Based on the information, the algorithm adaptively changes the search strategy and select different shape cross in order to perform fast search for motion vector. It integrates the benefit of Hexagon search and UMHexagonS, and reaches a well balance between encoding speed and encoding efficiency.