This is an implementation of TCPNet (NeurIPS 2021).

For video recognition task, a global representation summarizing the whole contents of the video snippets plays an important role for the final performance. However, existing video architectures usually generate it by using a simple, global average pooling (GAP) method, which has limited ability to capture complex dynamics of videos. For image recognition task, there exist evidences showing that covariance pooling has stronger representation ability than GAP. Unfortunately, such plain covariance pooling used in image recognition is an orderless representative, which cannot model spatio-temporal structure inherent in videos. Therefore, this paper proposes a Temporal-attentive Covariance Pooling (TCP), inserted at the end of deep architectures, to produce powerful video representations. Specifi- cally, our TCP first develops a temporal attention module to adaptively calibrate spatio-temporal features for the succeeding covariance pooling, approximatively producing attentive covariance representations. Then, a temporal covariance pooling performs temporal pooling of the attentive covariance representations to char- acterize both intra-frame correlations and inter-frame cross-correlations of the calibrated features. As such, the proposed TCP can capture complex temporal dynamics. Finally, a fast matrix power normalization is introduced to exploit geometry of covariance representations. Note that our TCP is model-agnostic and can be flexibly integrated into any video architectures, resulting in TCPNet for effective video recognition. The extensive experiments on six benchmarks (e.g., Kinetics, Something-Something V1 and Charades) using various video architectures show our TCPNet is clearly superior to its counterparts, while having strong generalization ability.

@article{gao2021temporal,
  title={Temporal-attentive Covariance Pooling Networks for Video Recognition},
  author={Gao, Zilin and Wang, Qilong and Zhang, Bingbing and Hu, Qinghua and Li, Peihua},
  journal={NeurIPS},
  year={2021}
}

pytorch v1.0+(for TCP_TSN); v1.0~1.4(for TCP+TEA)

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graphviz pip install graphviz

tensorboard pip install tensorboardX

tqdm pip install tqdm

scikit-learn conda install scikit-learn

matplotlib conda install -c conda-forge matplotlib

fvcore pip install 'git+https://github.com/facebookresearch/fvcore'

We provide a detailed dataset preparation guideline for Kinetics-400 and Mini-Kinetics-200. See Dataset preparation.

1. download the pretrained model and put it in pretrained_models/
2. execute the training script file e.g.: sh script/K400/train_TCP_TSN_8f_R50.sh
3. execute the inference script file e.g.: sh script/K400/test_TCP_TSN_R50_8f.sh

├── ops
|    ├── TCP
|    |   ├── TCP_module.py
|    |   ├── TCP_att_module.py
|    |   ├── TSA.py
|    |   └── TCA.py
|    ├ ...
├ ...

• We thank TSM for providing well-designed 2D action recognition toolbox.
• We also refer to some functions from iSQRT, TEA and Non-local.
• Mini-K200 dataset samplling strategy follows Mini_K200.
• We would like to thank Facebook for developing pytorch toolbox.

Thanks for their work!