A technique for reducing complexity of recursive motion estimation algorithms

The recursive search motion estimation algorithm offers smooth and accurate motion vector fields. Computationally, the most expensive part of the motion estimator is the evaluation of the various motion vector candidates. Evaluation is performed by comparing blocks in two consecutive frames indicated by motion vector candidates. The paper addresses the issue of reducing the already extremely low number of motion vector evaluations. We apply preprocessing techniques to reduce the number of motion vector candidates from 7 to 5, i.e. 30%, without sacrificing quality. We exemplify the above findings through experimental results obtained using the 3D recursive search motion estimation algorithm. The required preprocessing overhead is negligible.