作者:
Chen， Z.B.， Xu， J.F.， Zhou， P. and He， Y.
关键词:
H.264；
摘要:
This paper proposes a fast motion estimation algorithm for H.264. Considering the characteristics of multi prediction modes, multi reference frames in H.264, we propose a hybrid Unsymmetrical-cross Multi-Hexagon-grid Search algorithm to solve the contradiction of keeping video quality and decreasing computation complexity. We change the search order for utilizing the motion relationship between different modes and an unsymmetrical-cross search is used to give a more accurate initial search point. Then an uneven multi-hexagon-grid search strategy is performed to keep search from dropping into the local minimum. At last an extended hexagon based search is adopted to get fine motion vector. Different sequences from QCIF format to HD (High Definition) format with high motions are tested and our algorithm shows very good capability in keeping the rate distortion performance (largest distortion less than O.1dB) and a computation reduction of more than 7 times than Fast Full Search algorithm in H.264.
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