UMHexagonS algorithm for an MPEG Type-1 video encoder
Yun He · Harbin Gongcheng Daxue Xuebao/Journal of Harbin Engineering University · 2011
In order to reduce the search complexity,this paper presented a novel motion estimation algorithm based on the original UMHexagonS.Compared with the original algorithm,the proposed UMHexagonS utilized a novel starting point prediction model to compensate the constraints of limited reference pictures and prediction modes.In the meantime,the proposed method modified the type-2 threshold used in the original UMHexgonS,which would cause great efficiency loss due to its non-adaptive calculation.The modification involved the threshold correction based on spatial correlation of the neighbor motion costs.Experimental results show that the proposed method can accurately reach the best search point and adapt to textural features of different sequences.Compared with the full search strategy,the proposed algorithm saves more than 97% of the search time while limiting the average coding efficiency loss to 0.032 dB;compared with the original UMHexagonS,the algorithm has advantages in both coding efficiency and average motion search time.