Tracking deformable moving objects under severe occlusions

We propose a nonlinear model for tracking a slowly deforming and moving contour despite significant occlusions. The contour is represented implicitly, and its motion is described by the action of a finite-dimensional group; we estimate both the implicit representation of the contour (its shape) and its motion. Our contribution consists in defining a generative model that is not subject to arbitrary re-parameterization, choice of (non-unique) key points or control points, and allows enforcing a dynamical model of motion when it is available. Otherwise, our approach allows enforcing simple phenomenological models, for instance low acceleration or low jerk.