Projection-based block matching motion estimation

This paper introduces a fast block-based motion estimation algorithm based on matching projections. The idea is simple: blocks cannot match well if their corresponding 1D projections do not match well. We can take advantage of this observation to translate the expensive 2D block matching problem to a simpler 1D matching one by quickly eliminating a majority of matching candidates. Our novel motion estimation algorithm offers computational scalability through a single parameter and global optimum can still be achieved. Moreover, an efficient implementation to compute projections and to buffer recyclable data is also presented. Experiments show that the proposed algorithm is several times faster than the exhaustive search algorithm with nearly identical prediction performance. With the proposed BME method, high-performance real-time all-software video encoding starts to become practical for reasonable video sizes.