Dealing with Multiple Motions in Optical Flow Estimation

In this paper, a new approach to optical flow estimation in presence of multiple motions is presented. Firstly, motions are segmented on the basis of a frequency-based approach that groups spatio-temporal filter responses with continuity in its motion (each group will define a motion pattern). Then, the gradient constraint is applied to the output of each filter so that multiple estimations of the velocity at the same location may be obtained. For each "motion pattern", the velocities at a given point are then combined using a probabilistic approach. The use of "motion patterns" allows multiple velocities to be represented, while the combination of estimations from di#erent filters helps reduce the aperture problem