Detecting Invisible People

[ICCV 2021 Paper] [Website]

Tarasha Khurana, Achal Dave, Deva Ramanan

Introduction

This repository contains code for Detecting Invisible People. We extend the original DeepSORT algorithm to localize people even while they are completely occluded in a video. See the arXiv preprint for more information.

Dependencies

Create a conda environment with the given environment.yml file.

conda env create -f environment.yml

Preprocessing

The code expects the directory structure of your dataset in the MOT Challenge data format, which is approximately like the following:

MOT17/
-- train/
---- seq_01/
------ img1/
------ img1Depth/
------ gt/
------ det/
...
-- test/
---- seq_02/
------ img1/
------ img1Depth/
------ det/

The folder img1Depth stores the normalized disparity in .npy format. See Note. Originally, the paper runs the method on depth given by the MegaDepth depth estimator.

Given the above folder structure, generate the appearance features for your detections as described in the DeepSORT repository.

Running the method

The script run_forecast_filtering.sh will run the method with hyperparameters used in the paper. It will produce output .txt files in the MOT Challenge submission format. The bashscript has support for computing the metrics, but this has not been verified. Run the bashscript like the following:

bash run_forecast_filtering.sh experimentName

Note that in order to speed up code release, the dataset, preprocessed detections and output file paths are hardcoded in the files and will have to be manually changed.

Citing Detecting Invisible People

If you find this code useful in your research, please consider citing the following paper:

@inproceedings{khurana2021detecting,
  title={{Detecting Invisible People}},
  author={Khurana, Tarasha and Dave, Achal and Ramanan, Deva},
  booktitle={{IEEE/CVF International Conference on Computer Vision (ICCV)}},
  year={2021}
}

Warning

This is only the starter code that has not been cleaned for release. It currently only has verified support for running the method described in Detecting Invisible People, with the output tracks written in the MOT Challenge submission format. Although Top-k metric's code has been provided, this codebase does not guarantee support for the metric yet.

The hope is that you are able to benchmark this method for your CVPR 2022 submission and compute your own metrics on the method's output. If the method code does not work, please open an issue.

Note

Although it is easy to run any monocular depth estimator and store their output (usually given as disparity) in an .npy file, I have added a script in tools/demo_images.py which can save the .npy files for you. Note that this script should be run after setting up the MegaDepth codebase and copying this file to its root directory. I will likely also release my own depth maps for the MOT17 dataset over the Halloween weekend.

If you try to run the metrics, I have given my groundtruth JSON (as expected by pycocotools).