Qiuhong Ke, Mohammed Bennamoun, Senjian An, Ferdous Sohel, Farid Boussaid
This paper presents a new method for 3D action recognition with skeleton sequences (i.e., 3D trajectories of human skeleton joints). The proposed method first transforms each skeleton sequence into three clips each consisting of several frames for spatial temporal feature learning using deep neural networks. Each clip is generated from one channel of the cylindrical coordinates of the skeleton sequence. Each frame of the generated clips represents the temporal information of the entire skeleton sequence, and incorporates one particular spatial relationship between the joints. The entire clips include multiple frames with different spatial relationships, which provide useful spatial structural information of the human skeleton. We propose to use deep convolutional neural networks to learn long-term temporal information of the skeleton sequence from the frames of the generated clips, and then use a Multi-Task Learning Network (MTLN) to jointly process all frames of the generated clips in parallel to incorporate spatial structural information for action recognition. Experimental results clearly show the effectiveness of the proposed new representation and feature learning method for 3D action recognition.
| Task | Dataset | Metric | Value | Model |
|---|---|---|---|---|
| Video | NTU RGB+D | Accuracy (CS) | 79.6 | Clips+CNN+MTLN |
| Video | NTU RGB+D | Accuracy (CV) | 84.8 | Clips+CNN+MTLN |
| Temporal Action Localization | NTU RGB+D | Accuracy (CS) | 79.6 | Clips+CNN+MTLN |
| Temporal Action Localization | NTU RGB+D | Accuracy (CV) | 84.8 | Clips+CNN+MTLN |
| Zero-Shot Learning | NTU RGB+D | Accuracy (CS) | 79.6 | Clips+CNN+MTLN |
| Zero-Shot Learning | NTU RGB+D | Accuracy (CV) | 84.8 | Clips+CNN+MTLN |
| Activity Recognition | NTU RGB+D | Accuracy (CS) | 79.6 | Clips+CNN+MTLN |
| Activity Recognition | NTU RGB+D | Accuracy (CV) | 84.8 | Clips+CNN+MTLN |
| Action Localization | NTU RGB+D | Accuracy (CS) | 79.6 | Clips+CNN+MTLN |
| Action Localization | NTU RGB+D | Accuracy (CV) | 84.8 | Clips+CNN+MTLN |
| Action Detection | NTU RGB+D | Accuracy (CS) | 79.6 | Clips+CNN+MTLN |
| Action Detection | NTU RGB+D | Accuracy (CV) | 84.8 | Clips+CNN+MTLN |
| 3D Action Recognition | NTU RGB+D | Accuracy (CS) | 79.6 | Clips+CNN+MTLN |
| 3D Action Recognition | NTU RGB+D | Accuracy (CV) | 84.8 | Clips+CNN+MTLN |
| Action Recognition | NTU RGB+D | Accuracy (CS) | 79.6 | Clips+CNN+MTLN |
| Action Recognition | NTU RGB+D | Accuracy (CV) | 84.8 | Clips+CNN+MTLN |