Video-Based Action Detection Using Multiple Wearable Cameras

This paper is focused on developing a new approach for video-based action detection where a set of temporally synchronized videos are taken by multiple wearable cameras from different and varying views and our goal is to accurately localize the starting and ending time of each instance of the actions of interest in such videos. Compared with traditional approaches based on fixed-camera videos, this new approach incorporates the visual attention of the camera wearers and allows for the action detection in a larger area, although it brings in new challenges such as unconstrained motion of cameras. In this approach, we leverage the multi-view information and the temporal synchronization of the input videos for more reliable action detection. Specifically, we detect and track the focal character in each video and conduct action recognition only for the focal character in each temporal sliding window. To more accurately localize the starting and ending time of actions, we develop a strategy that may merge temporally adjacent sliding windows when detecting durative actions, and non-maximally suppress temporally adjacent sliding windows when detecting momentary actions. Finally we propose a voting scheme to integrate the detection results from multiple videos for more accurate action detection. For the experiments, we collect a new dataset of multiple wearable-camera videos that reflect the complex scenarios in practice.