Toward Accurate Person-level Action Recognition in Videos of Crowded Scenes
This work addresses action recognition in crowded scenes, a domain-specific challenge with incremental improvements.
The paper tackled the problem of person-level action recognition in crowded video scenes by fully utilizing scene information and collecting new data, achieving an average 26.05 wf_mAP and ranking first in the ACM MM grand challenge 2020.
Detecting and recognizing human action in videos with crowded scenes is a challenging problem due to the complex environment and diversity events. Prior works always fail to deal with this problem in two aspects: (1) lacking utilizing information of the scenes; (2) lacking training data in the crowd and complex scenes. In this paper, we focus on improving spatio-temporal action recognition by fully-utilizing the information of scenes and collecting new data. A top-down strategy is used to overcome the limitations. Specifically, we adopt a strong human detector to detect the spatial location of each frame. We then apply action recognition models to learn the spatio-temporal information from video frames on both the HIE dataset and new data with diverse scenes from the internet, which can improve the generalization ability of our model. Besides, the scenes information is extracted by the semantic segmentation model to assistant the process. As a result, our method achieved an average 26.05 wf\_mAP (ranking 1st place in the ACM MM grand challenge 2020: Human in Events).