OOD Detection Framework

Code for our paper Confidence-based Out-of-Distribution Detection: A Comparative Study and Analysis which won the best paper award at the UNSURE 2021 workshop at MICCAI.

Berger, Christoph, Magdalini Paschali, Ben Glocker, and Konstantinos Kamnitsas. "Confidence-based Out-of-Distribution Detection: A Comparative Study and Analysis." arXiv preprint arXiv:2107.02568 (2021).

Intro

Implemented methods: * Maximum Class Probability * Deep Ensembles * ODIN * Mahalanobis Distance * Center Loss * Mahalanobis Ensemble * Monte Carlo Dropout * Monte Carlo Dropout Ensemble

Usage Instructions

Datasets

The code works with CIFAR10 vs SVHN and with CheXpert OOD detection tasks. CIFAR10 and SVHN are automatically downloaded via torchvision. For CheXpert, download CheXpert-v1.0-small and place the folder in datasets. The current default settings for CheXpert can be found in config\chexpert.py and are categorized in 2 settings we trained on (see table 2).

Requirements

This code was developed and tested on Python 3.8. Install all the required packages from requirements.txt. Both training and inference need a supported Nvidia GPU.

Training

Train new models using train_wrn_cifar10.py or train_wrn_chexpert.py. To adapt the default settings, edit the config files for the respective datasets. The defaults values yielded the best results in our training. You might have to adapt the batch size to fit the datasets on your GPU. We also made use of Weights and Biases for data logging, you can disable or enable that via a command line arg (--wandb).

Evaluation

Run eval_chexpert.py -h or eval_cifar10.py -h to see which methods you can run. You can also specify the exact IDs of pretrained models in the config to set which one the code loads.

Further Analysis and Files

Some of the jupyter notebooks used for plotting of figures or analysing the results in more depth are located in the notebooks directory. However, some of the code and contents are experimental and might not work as intended.

Reference Results

CIFAR10 vs SVHN

CheXpert

Repositories that helped assemble this collection of baselines

• WideResNet from https://github.com/meliketoy/wide-resnet.pytorch/blob/master/config.py
• Values from SVHN for normalization: https://deepobs.readthedocs.io/en/develop/_modules/deepobs/pytorch/datasets/svhn.html
• Mahalanobis: https://github.com/pokaxpoka/deepMahalanobisdetector
• ODIN: https://github.com/facebookresearch/odin
• DUQ: https://github.com/y0ast/deterministic-uncertainty-quantification

How to cite

Please cite as: Berger, Christoph, Magdalini Paschali, Ben Glocker, and Konstantinos Kamnitsas. "Confidence-based Out-of-Distribution Detection: A Comparative Study and Analysis." arXiv preprint arXiv:2107.02568 (2021). BibTeX: bibtex @article{berger2021confidence, title={Confidence-based Out-of-Distribution Detection: A Comparative Study and Analysis}, author={Berger, Christoph and Paschali, Magdalini and Glocker, Ben and Kamnitsas, Konstantinos}, journal={arXiv preprint arXiv:2107.02568}, year={2021} }