Tensorflow implementation for 3DV 2017 conference paper "Adversarially Parameterized Optimization for 3D Human Pose Estimation".

@inproceedings{jack2017adversarially,
  title={Adversarially Parameterized Optimization for 3D Human Pose Estimation},
  author={Jack, Dominic and Maire, Frederic and Eriksson, Anders and Shirazi, Sareh},
  booktitle={3D Vision (3DV), 2017 Fifth International Conference on},
  year={2017},
  organization={IEEE}
}

Code used to generate results for the paper has been frozen and can be found in the 3dv2017 branch. Bug fixes and extensions will be applied to other branches.

Algorithm Overview

The premise of the paper is to train a GAN to simultaneously learn a parameterization of the feasible human pose space along with a feasibility loss function.

During inference, a standard off-the-shelf optimizer infers all poses from sequence almost-independently (the scale is shared between frames, which has no effect on the results (since errors are on the procruste-aligned inferences which optimize over scale) but makes the visualizations easier to interpret).

Repository Structure

Each GAN is identified by a gan_id. Hyperparameters defining the network structures and datasets from which they should be trained are specified in gan_params/gan_id.json. A couple (those with results highlighted in the paper) are provided, h3m_big, h3m_small and eva_big. Note that compared to typical neural networks, these are still tiny, so the difference in size should result in a negligible difference in training/inference time.

Similarly, each inference run is identified by an inference_id, the parameters of which are defined in inference_params/inference_id.json. including geometric transforms, visualizations and dataset reading

• gan: provides application-specific GANs based on specifications in gan_params
• serialization.py: i/o related functions for loading hyper-parameters/results

Scripts:

• train.py: Trains a GAN specified by a json file in gan_params
• gan_generator_vis.py: visualization script for a trained GAN generator
• interactive_gan_generator_vis.ipynb: interactive jupyter/ipython notebook for visualizing a trained GAN generator
• generate_inferences.py: Generates inferences based on parameters specified by a json file in inference_params
• h3m_report.py/eva_report.py: reporting scripts for generated inferences.
• vis_sequecne.py: visualization script for entire inferred sequence.

Usage

1. Setup the external repositories: * human_pose_util
2. Clone this repository and add the location and the parent directory(s) to your PYTHONPATH

cd path/to/parent_folder
git clone https://github.com/jackd/adversarially_parameterized_optimization.git
git clone https://github.com/jackd/human_pose_util.git
export PYTHONPATH=/path/to/parent_folder:$PYTHONPATH
cd adversarially_parameterized_optimization

3. Define a GAN model by creating a gan_params/gan_id.json file, or select one of the existing ones.
4. Setup the relevant dataset(s) or create your own as described in human_pose_util.
5. Train the GAN

python train.py gan_id --max_steps=1e7

Our experiments were conducted on an NVidia K620 Quadro GPU with 2GB memory. Training runs at ~600 batches per second with a batch size of 128. For 10 million steps (likely excessive) this takes around 4.5 hours.

View training progress and compare different runs using tensorboard:

tensorboard --logdir=models

6. (Optional) Check your generator is behaving well by running gan_generator_vis.py model_id or interactively by running interactive_gan_generator_vis.ipynb and modifying the model_id.
7. Define an inference specification by creating an inference_params/inference_id.json file, or select one of the defaults provided.
8. Generate inference

python generate_inferences.py inference_id

Sequence optimization runs at ~5-10fps (speed-up compared to 1fps reported in paper due to reimplementation efficiencies rather than different ideas).

This will save results in results.hdf5 in the inference_id group. 9. See the results! * h3m_report.py or eva_report.py depending on the dataset gives qualitative results

python report.py eval_id

* `vis_sequence.py` visualizes inferences

Note that results are quite unstable with respect to GAN training. You may get considerably different quantitative results than those published in the paper, though qualitative behaviour should be similar.

Serialization

To aid with experiments with different parameter sets, model/inference parameters are saved in json for ease of parsing and human readability. To allow for extensibility, human_pose_util maintains registers for different datasets and skeletons.

See the README for details on setting up/preprocessing of datasets or implementing your own.

The scripts in this project register some default h3m/eva datasets using register_defaults. While normally fast, some data conversion is performed the first time this function is run for each dataset and requires the original datasets be available with paths defined (see below). If you only wish to experiment with one dataset -- e.g. h3m -- modify the default argument values for register_defaults, e.g. def register_defaults(h3m=True, eva=False): (or the relevant function calls).

If you implement your own datasets/skeletons, either add their registrations to the default functions, or edit the relevant scripts to register them manually.

Datasets

See human_pose_util repository for instructions for setting up datasets.

Requirements

For training/inference:

• tensorflow 1.4
• numpy
• h5py For visualizations:
• matplotlib
• glumpy (install from source may reduce issues) For initial human 3.6m dataset transformations:
• spacepy (for initial human 3.6m dataset conversion to hdf5)

Development

This branch will be actively maintained, updated and extended. For code used to generate results for the publication, see the 3dv2017 branch.

Contact

Please report any issues/bugs. Feature requests in this repository will largely be ignored, but will be considered if made in independent repositories.

Email contact to discuss ideas/collaborations welcome: [email protected].