6D Rotation Representation for Unconstrained Head Pose Estimation (Pytorch)

Paper

Thorsten Hempel and Ahmed A. Abdelrahman and Ayoub Al-Hamadi, "6D Rotation Representation for Unconstrained Head Pose Estimation", submitted to ICIP 2022. [ResearchGate][Arxiv]

Abstract

In this paper, we present a method for unconstrained end-to-end head pose estimation. We address the problem of ambiguous rotation labels by introducing the rotation matrix formalism for our ground truth data and propose a continuous 6D rotation matrix representation for efficient and robust direct regression. This way, our method can learn the full rotation appearance which is contrary to previous approaches that restrict the pose prediction to a narrow-angle for satisfactory results. In addition, we propose a geodesic distance-based loss to penalize our network with respect to the manifold geometry. Experiments on the public AFLW2000 and BIWI datasets demonstrate that our proposed method significantly outperforms other state-of-the-art methods by up to 20%.

Trained on 300W-LP, Test on AFLW2000 and BIWI

	Full Range	Yaw	Pitch	Roll	MAE		Yaw	Pitch	Roll	MAE
HopeNet ( =2)	N	6.47	6.56	5.44	6.16		5.17	6.98	3.39	5.18
HopeNet ( =1)	N	6.92	6.64	5.67	6.41		4.81	6.61	3.27	4.90
FSA-Net	N	4.50	6.08	4.64	5.07		4.27	4.96	2.76	4.00
HPE	N	4.80	6.18	4.87	5.28		3.12	5.18	4.57	4.29
QuatNet	N	3.97	5.62	3.92	4.50		2.94	5.49	4.01	4.15
WHENet-V	N	4.44	5.75	4.31	4.83		3.60	4.10	2.73	3.48
WHENet	Y/N	5.11	6.24	4.92	5.42		3.99	4.39	3.06	3.81
TriNet	Y	4.04	5.77	4.20	4.67		4.11	4.76	3.05	3.97
FDN	N	3.78	5.61	3.88	4.42		4.52	4.70	2.56	3.93
6DRepNet	Y	3.63	4.91	3.37	3.97		3.24	4.48	2.68	3.47

BIWI 70/30

	Yaw	Pitch	Roll	MAE
HopeNet ( =1)	3.29	3.39	3.00	3.23
FSA-Net	2.89	4.29	3.60	3.60
TriNet	2.93	3.04	2.44	2.80
FDN	3.00	3.98	2.88	3.29
6DRepNet	2.69	2.92	2.36	2.66

Fine-tuned Models

Fine-tuned models can be download from here: https://drive.google.com/drive/folders/1V1pCV0BEW3mD-B9MogGrz_P91UhTtuE_?usp=sharing

Quick Start:

git clone https://github.com/thohemp/6DRepNet
cd 6DRepNet

Set up a virtual environment:

python3 -m venv venv
source venv/bin/activate
pip install -r requirements.txt  # Install required packages

In order to run the demo scripts you need to install the face detector

pip install git+https://github.com/elliottzheng/[email protected]

Camera Demo:

python demo.py  --snapshot 6DRepNet_300W_LP_AFLW2000.pth \
                --cam 0

Test/Train 3DRepNet

Preparing datasets

Download datasets:

• 300W-LP, AFLW2000 from here.

• BIWI (Biwi Kinect Head Pose Database) from here

Store them in the datasets directory.

For 300W-LP and AFLW2000 we need to create a filenamelist.

python create_filename_list.py --root_dir datasets/300W_LP

The BIWI datasets needs be preprocessed by a face detector to cut out the faces from the images. You can use the script provided here. For 7:3 splitting of the BIWI dataset you can use the equivalent script here. We set the cropped image size to 256.

Testing:

python test.py  --batch_size 64 \
                --dataset ALFW2000 \
                --data_dir datasets/AFLW2000 \
                --filename_list datasets/AFLW2000/files.txt \
                --snapshot output/snapshots/1.pth \
                --show_viz False 

Training

Download pre-trained RepVGG model 'RepVGG-B1g2-train.pth' from here and save it in the root directory.

python train.py --batch_size 64 \
                --num_epochs 30 \
                --lr 0.00001 \
                --dataset Pose_300W_LP \
                --data_dir datasets/300W_LP \
                --filename_list datasets/300W_LP/files.txt

Deploy models

For reparameterization the trained models into inference-models use the convert script.

python convert.py input-model.tar output-model.pth

Inference-models are loaded with the flag deploy=True.

model = SixDRepNet(backbone_name='RepVGG-B1g2',
                    backbone_file='',
                    deploy=True,
                    pretrained=False)

Citing

If you find our work useful, please cite the paper:

@misc{hempel20226d,
      title={6D Rotation Representation For Unconstrained Head Pose Estimation}, 
      author={Thorsten Hempel and Ahmed A. Abdelrahman and Ayoub Al-Hamadi},
      year={2022},
      eprint={2202.12555},
      archivePrefix={arXiv},
      primaryClass={cs.CV}
}