Half-pixel Motion Estimation Bypass Based on a Linear Model

In hybrid video coding schemes, motion estimation at sub-pixel accuracy, such as 1/2 pixel and 1/4 pixel obviously possesses higher coding efficiency than that at integer-pixel accuracy only. However, it requires more computational overhead for additional processes such as interpolation and search on sub-pixels. We proposed a novel half-pixel motion estimation bypass algorithm based on a linear model. The key idea is to skip over blocks that do not benefit from half-pixel search, therefore we not only reduce the search points but also the interpolation process. Experimental results show that significant computation reduction is achieved while the degradation in video quality is negligible. The proposed algorithm is very suitable for scenarios where lowcomplexity computing is required, such as mobile video coding applications.