ShiftGCN++

The implementation for "Extremely Lightweight Skeleton-Based Action Recognition with ShiftGCN++" (TIP2021). ShiftGCN++ further boosts the efficiency of ShiftGCN, which achieves comparable performance with 6× less FLOPs and 2× practical speedup.

Prerequisite

• PyTorch 0.4.1
• Cuda 9.0
• g++ 5.4.0

Compile cuda extensions

cd ./model/Temporal_shift
bash run.sh

Data Preparation

• Download the raw data of NTU-RGBD and NTU-RGBD120. Put NTU-RGBD data under the directory ./data/nturgbd_raw. Put NTU-RGBD120 data under the directory ./data/nturgbd120_raw.

• For NTU-RGBD, preprocess data with python data_gen/ntu_gendata.py. For NTU-RGBD120, preprocess data with python data_gen/ntu120_gendata.py.

• Generate the bone data with python data_gen/gen_bone_data.py.

• Generate the motion data with python data_gen/gen_motion_data.py.

Training & Testing

• NTU X-view

  python main.py --config ./config/nturgbd-cross-view/train_joint.yaml

  python main.py --config ./config/nturgbd-cross-view/train_bone.yaml

  python main.py --config ./config/nturgbd-cross-view/train_joint_motion.yaml

  python main.py --config ./config/nturgbd-cross-view/train_bone_motion.yaml

• NTU X-sub

  python main.py --config ./config/nturgbd-cross-subject/train_joint.yaml

  python main.py --config ./config/nturgbd-cross-subject/train_bone.yaml

  python main.py --config ./config/nturgbd-cross-subject/train_joint_motion.yaml

  python main.py --config ./config/nturgbd-cross-subject/train_bone_motion.yaml

• For NTU-RGBD dataset, we provide trained teacher models for knowledge distillation in ./teacher_models.

• For NTU120-RGBD dataset, change the dataset path in config files, and change num_class in config files from 60 to 120. You need to train teacher models before train ShiftGCN++ on NTU120-RGBD.

Multi-stream ensemble

To ensemble the results of 4 streams. Change models name in ensemble.py depending on your experiment setting. Then run python ensemble.py.

Trained models

We release several trained models:

Model	Dataset	Setting	Top1(%)
./save_models/ntu_ShiftGCN-plus_joint_xview.pt	NTU-RGBD	X-view	94.8
./save_models/ntu_ShiftGCN-plus_bone_xview.pt	NTU-RGBD	X-view	94.7
./save_models/ntu_ShiftGCN-plus_joint_xsub.pt	NTU-RGBD	X-sub	87.9
./save_models/ntu_ShiftGCN-plus_bone_xsub.pt	NTU-RGBD	X-sub	88.3

Citation

If you find this model useful for your research, please use the following BibTeX entry.

@article{cheng2021extremely,
title={Extremely Lightweight Skeleton-Based Action Recognition With ShiftGCN++},
author={Cheng, Ke and Zhang, Yifan and He, Xiangyu and Cheng, Jian and Lu, Hanqing},
journal={IEEE Transactions on Image Processing},
volume={30},
pages={7333--7348},
year={2021},
publisher={IEEE}
}