Dynamics Based Trajectory Segmentation for UAV videos

A novel representation of vehicle trajectories is proposed for applications in trajectory analysis and activity detection. Specifically, a piecewise arc fitting based smoothing algorithm is proposed for denoising the trajectories. A dynamic program is used to find the optimal arc fit to a given trajectory. We motivate the usage of dynamic primitives to parametrize common vehicular activities, and propose a dynamics based trajectory segmentation algorithm. Each primitive is modeled using a second order Auto-Regressive model, and form useful descriptors for a given vehicular trajectory. We evaluate both our trajectory smoothing and dynamic trajectory segmentation algorithm on a real UAV video dataset, and show performance improvements which clearly motivate its wide applicability in a general trajectory analysis system.