Modeling and identification of group motion via compound evaluation of positional and directional cues

This paper addresses the problem of identification of pedestrian groups in crowded environments. To that end, positional and directional relations are modeled accounting for different environmental features and group configurations. Subsequently, a pair of simultaneously observed pedestrians is identified to belong to the same group or not utilizing these models in a parallel manner, which defines a compound hypothesis testing scheme. In case of ambiguities, local and global indicators of group relation are employed in quantifying the reliabilities of the two individual decisions. The contribution of this study lies in the improvement in positional and directional relation models to adjust to different environments and group configurations, description of compound evaluation, as well as resolution of ambiguities proposing uncertainty measures based on local and global indicators of group relation.