openpifpaf 0.9.0

PifPaf: Composite Fields for Human Pose Estimation

openpifpaf

We propose a new bottom-up method for multi-person 2D human pose estimation that is particularly well suited for urban mobility such as self-driving cars and delivery robots. The new method, PifPaf, uses a Part Intensity Field (PIF) to localize body parts and a Part Association Field (PAF) to associate body parts with each other to form full human poses. Our method outperforms previous methods at low resolution and in crowded, cluttered and occluded scenes thanks to (i) our new composite field PAF encoding fine-grained information and (ii) the choice of Laplace loss for regressions which incorporates a notion of uncertainty. Our architecture is based on a fully convolutional, single-shot, box-free design. We perform on par with the existing state-of-the-art bottom-up method on the standard COCO keypoint task and produce state-of-the-art results on a modified COCO keypoint task for the transportation domain.

@article{kreiss2019pifpaf,
  title={PifPaf: Composite Fields for Human Pose Estimation},
  author={Kreiss, Sven and Bertoni, Lorenzo and Alahi, Alexandre},
  journal={CVPR, arXiv preprint arXiv:1903.06593},
  year={2019}
}

arxiv.org/abs/1903.06593

Demo

Image credit: "Learning to surf" by fotologic which is licensed under CC-BY-2.0.
Created with: python3 -m openpifpaf.predict --show docs/coco/000000081988.jpg

For more demos, see the openpifpafwebdemo project and the openpifpaf.webcam command. There is also a Google Colab demo.

Install

Python 3 is required. Python 2 is not supported. Do not clone this repository and make sure there is no folder named openpifpaf in your current directory.

pip3 install openpifpaf

For a live demo, we recommend to try the openpifpafwebdemo project. Alternatively, openpifpaf.webcam provides a live demo as well. It requires OpenCV. To use a globally installed OpenCV from inside a virtual environment, create the virtualenv with the --system-site-packages option and verify that you can do import cv2.

For development of the openpifpaf source code itself, you need to clone this repository and then:

pip3 install numpy cython
pip3 install --editable '.[train,test]'

The last command installs the Python package in the current directory (signified by the dot) with the optional dependencies needed for training and testing.

Interfaces

• python3 -m openpifpaf.predict --help
• python3 -m openpifpaf.webcam --help
• python3 -m openpifpaf.train --help
• python3 -m openpifpaf.eval_coco --help
• python3 -m openpifpaf.logs --help

Example commands to try:

# live demo
MPLBACKEND=macosx python3 -m openpifpaf.webcam --scale 0.1 --source=0

# single image
python3 -m openpifpaf.predict my_image.jpg --show

Pre-trained Models

Performance metrics with version 0.9.0 on the COCO val set obtained with a GTX1080Ti:

Backbone	AP	APᴹ	APᴸ	t_{total} [ms]	t_{dec} [ms]
shufflenetv2x1	50.2	47.0	55.4	56	44
shufflenetv2x2	58.5	55.2	63.6	60	41
resnet50	63.3	60.7	67.8	79	38
resnext50	63.8	61.1	68.1	93	33
resnet101	66.5	63.1	71.9	100	35
resnet152	67.8	64.4	73.3	122	30

Pretrained model files are shared in this Google Drive which you can put into your outputs folder. The pretrained models are downloaded automatically when using the command line option --checkpoint backbonenameasintableabove.

To visualize logs:

python3 -m openpifpaf.logs \
  outputs/resnet50block5-pif-paf-edge401-190424-122009.pkl.log \
  outputs/resnet101block5-pif-paf-edge401-190412-151013.pkl.log \
  outputs/resnet152block5-pif-paf-edge401-190412-121848.pkl.log

Train

See datasets for setup instructions. See studies.ipynb for previous studies.

Train a model:

python3 -m openpifpaf.train \
  --lr=1e-3 \
  --momentum=0.95 \
  --epochs=75 \
  --lr-decay 60 70 \
  --batch-size=8 \
  --basenet=resnet50block5 \
  --head-quad=1 \
  --headnets pif paf \
  --square-edge=401 \
  --regression-loss=laplace \
  --lambdas 30 2 2 50 3 3 \
  --freeze-base=1

You can refine an existing model with the --checkpoint option.

To produce evaluations at every epoch, check the directory for new snapshots every 5 minutes:

while true; do \
  CUDA_VISIBLE_DEVICES=0 find outputs/ -name "resnet101block5-pif-paf-l1-190109-113346.pkl.epoch???" -exec \
    python3 -m openpifpaf.eval_coco --checkpoint {} -n 500 --long-edge=641 --skip-existing \; \
  ; \
  sleep 300; \
done

Person Skeletons

COCO / kinematic tree / dense:

Created with python3 -m openpifpaf.data.

Video

Processing a video frame by frame from video.avi to video.pose.mp4 using ffmpeg:

export VIDEO=video.avi  # change to your video file

mkdir ${VIDEO}.images
ffmpeg -i ${VIDEO} -qscale:v 2 -vf scale=641:-1 -f image2 ${VIDEO}.images/%05d.jpg
python3 -m openpifpaf.predict --checkpoint resnet152 ${VIDEO}.images/*.jpg
ffmpeg -framerate 24 -pattern_type glob -i ${VIDEO}.images/'*.jpg.skeleton.png' -vf scale=640:-1 -c:v libx264 -pix_fmt yuv420p ${VIDEO}.pose.mp4

In this process, ffmpeg scales the video to 641px which can be adjusted.

Documentation Pages

• datasets
• Google Colab demo
• studies.ipynb
• evaluation logs
• performance analysis
• history

Related Projects

• openpifpafwebdemo