Median trajectories using well-visited regions and shortest paths

For a set of "similar" trajectories, a median trajectory is a trajectory that is most like the trajectories in the set, but it need not be a trajectory from the set itself. A recent method composed a median from parts of the set of trajectories, using ideas from homotopy to decide which parts to use. That method has two drawbacks. Firstly, it requires a significant subset of the trajectories to be homotopic, and such a subset may not always exist. Secondly, it sometimes misses relevant parts of trajectories because homotopy does not characterize the shape of the trajectories in all situations. In this paper we present a new approach to overcome these two drawbacks, leading to majority medians. We give results from extensive experiments, which indicate that majority medians are indeed better than homotopic medians.