A Caratheodory-Fejer approach to robust multiframe tracking

A requirement common to most dynamic vision applications is the ability to track objects in a sequence of frames. This problem has been extensively studied in the past few years, leading to several techniques, such as unscented particle filter based trackers, that exploit a combination of the (assumed) target dynamics, empirically learned noise distributions and past position observations. While successful in many scenarios, these trackers remain fragile to occlusion and model uncertainty in the target dynamics. As we show in this paper, these difficulties can be addressed by modeling the dynamics of the target as an unknown operator that satisfies certain interpolation conditions. Results from interpolation theory can then be used to find this operator by solving a convex optimization problem. As illustrated with several examples, combining this operator with Kalman and UPF techniques leads to both robustness improvement and computational complexity reduction.