Object-guided motion estimation

Motion estimation in image sequences is classically addressed under one of the two following forms: estimation of optical flow (instantaneous apparent motion over the whole image) and visual tracking (estimation of the motion of a certain scene region over time). Major progresses have been recently achieved on both fronts, with robust and accurate techniques available for each problem. However, these problems are mostly studied as if they were independent, while they address in fact two faces of the same reality. This paper analyzes the benefits and consequences of combining tracking methods for estimation of per-object dense motion trajectories. We show experimentally that studying the global translation of an object will benefit the motion estimation accuracy of sample points inside the larger structure.