Extracting hierarchical spatial and temporal features for human action recognition

Human action recognition is a challenging computer vision task and many efforts have been made to improve the performance. Most previous work has concentrated on the hand-crafted features or spatial-temporal features learned from multiple contiguous frames. In this paper, we present a dual-channel model to decouple the spatial and temporal feature extraction. More specifically, we propose to capture the complementary static form information from single frame and dynamic motion information from multi-frame differences in two separate channels. In both channels we use two stacked classical subspace networks to learn hierarchical representations, which are subsequently fused for action recognition. Our model is trained and evaluated on three typical benchmarks: KTH, UCF and Hollywood2 datasets. The experimental results illustrate that our approach achieves comparable performances to the state-of-the-art methods. In addition, both feature analysis and control experiments are also carried out to demonstrate the effectiveness of the proposed approach for feature extraction and thereby action recognition.