Efficient motion vector prediction algorithm using pattern matching

The state-of-the-art median prediction scheme is widely used for predicting motion vectors (MVs) in recent video standards. By exploiting the spatial correlations among MVs, median prediction scheme predicts MV for current block from three neighboring blocks. When MV is obtained from motion estimation, MV difference (MVD) is calculated and then transmitted. This process for predicting MV and calculating MVD is known as MV coding process. For MV coding, the performance depends on how efficient both the spatial and the temporal correlations among MVs are being exploited. Median prediction scheme applies a sophisticated way including some special rules to exploit the spatial correlations, however the temporal correlations among successive MVs are not exploited. In this paper, a new algorithm named MV pattern matching (MV-PM) exploiting both the spatial and temporal correlations is proposed. Various kinds of experimental results show that the proposed MV-PM algorithm outperforms the median prediction and the other related prediction schemes.

► “Motion vector prediction” and ”motion vector coding” are distinguished.
► Two ways (explicit way and implicit way) of predicting motion vector are introduced.
► Idea “searching the best match” used in motion estimation is utilized for predicting motion vector.
► “Search the best match for motion vectors’ pattern” is combined with median prediction.
► Compared with median prediction the proposed combined method reduces averagely 0.89% of the bitrate.