Atomic Group Actions Dataset

Understanding group activities is an essential step towards studying complex crowd behaviours in video. However, such research is often hampered by the lack of a formal definition of a group, as well as a dearth of datasets that concentrate specifically on Atomic Group Actions. We introduce the Atomic Group Actions Dataset, a set of 200 videos that concentrate on the atomic group actions of objects in video, namely the group-group actions of formation, dispersal, and movement of a group, as well as the group-person actions of person joining and person leaving a group. In addition, we make the full dataset (the videos, along with their associated tracks and ground truth) publicly available to the research community for free use and extension at