Abstract

.We study an energy functional for computing optical flow that combines three assumptions: a brightness constancy assumption, a gradient constancy assumption, and a discontinuity-preserving spatio-temporal smoothness constraint.Inordertoallowforlargedisplacements,linearisationsinthetwodata termsarestrictlyavoided.Wepresentaconsistentnumericalschemebasedontwo nestedfixedpointiterations.Byprovingthatthisschemeimplementsacoarse-tofinewarpingstrategy,wegiveatheoreticalfoundationforwarpingwhichhasbeen used on a mainly experimental basis so far. Our evaluation demonstrates that the novel method gives significantly smaller angular errors than previous techniques for optical flow estimation.We show that it is fairly insensitive to parameter variations, and we demonstrate its excellent robustness under noise