On Combining Fractional-Pixel Interpolation and Motion Estimation: A Cost-Effective Approach

The additional complexity of the adoption of fractional-pixel motion compensation technology arises from two aspects: fractional-pixel interpolation (FPI) and fractional-pixel motion estimation (FPME). Different from current fast algorithms, we use the internal link between FPME and FPI as a factor in considering optimization by integrally manipulating them rather than attempting to speed them up separately. In this paper, a refinement search order for FPME is proposed to satisfy the criteria of cost/performance efficiency. And then, some strategies, i.e., FPME skipping, early termination and search pattern pruning, are also given for reducing the number of search positions with negligible coding loss. We also propose a FPI algorithm to save redundant interpolation as well as reduce duplicate calculation. Experimental results show that our integrated algorithm significantly improves the overall speed of FPME and FPI. Compared with the FFPS+XFPI and CBFPS+XFPI, the proposed algorithm has already reduced the speed by a factor of 65% and 32%. Additionally, our FPI algorithm can be used to cooperate with any fast FPME algorithms to greatly reduce the computational time of FPI.