# DiffusionClassifier

**Repository Path**: tan_fu_xiang/DiffusionClassifier

## Basic Information

- **Project Name**: DiffusionClassifier
- **Description**: No description available
- **Primary Language**: Unknown
- **License**: Not specified
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2025-10-10
- **Last Updated**: 2025-10-10

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

# Diffusion Classifier

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## Install

Please refer to:    [**BasicReadMe**](https://github.com/huanranchen/DiffusionClassifier/blob/main/Intro.md)


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## Model Checkpoints


### VP Diffusion implementation (not recommended)


There are two version of our implementation. One is based on VP-SDE proposed by Song et al. (2021). This version is not recommended, and has been depreciated. For this, you need to download:

- [CIFAR10 unconditional diffusion model for DiffPure](https://drive.google.com/file/d/1zfblaZd64Aye-FMpus85U5PLrpWKusO4/view). Put it into ./resources/checkpoints/DiffPure/32x32_diffusion.pth

- [CIFAR10 WideResNet-70-16-dropout](https://drive.google.com/drive/folders/1mQoH6WbnfItphYKehWVniZmq9iixRn8L?usp=sharing)(discriminative classifier used in DiffPure). Put it into ./resources/checkpoints/models/WideResNet_70_16_dropout.pt

- Conditional diffusion model for diffusion classifier: We will share our checkpoints soon. Now you can train it by yourself.      

- [ImageNet unconditional diffusion model for DiffPure](https://drive.google.com/file/d/1ZCWNdxL9siBhGKSJDXSwl89ncvwOjIQO/view?usp=drive_link). Put it into ./resources/checkpoints/DiffPure/256x256_diffusion_uncond.pt


### VE Diffusion implementation (not recommended)

Another is based on Karras et al. (2022), a.k.a. EDM. We strongly recommend you to use this implementation. For this, you need to download:

- [EDM checkpoints](https://drive.google.com/drive/folders/1mQoH6WbnfItphYKehWVniZmq9iixRn8L?usp=sharing). Put it into ./resources/checkpoints/models/EDM/               
- [CIFAR10 WideResNet-70-16-dropout](https://drive.google.com/drive/folders/1mQoH6WbnfItphYKehWVniZmq9iixRn8L?usp=sharing)(discriminative classifier used in DiffPure). Put it into ./resources/checkpoints/models/WideResNet_70_16_dropout.pt



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## Usage

### Demos

We provide some demos in the root. We believe it's very clear and you will know how to use DC/RDC/LM after playing with the example code. Hence, we didn't add more explanation in this README.

**LM.py**: Likelihood Maximization with WRN-70-2.

**DCTK.py**: Diffusion Classifier on CIFAR10.

**RDCN+TK.py**: Robust Diffusion Classifier on CIFAR10.

### Experiments

All experiments codes are in *'./experiments/'*.

**DiffAttack.py**:  Attack DiffPure.         

**DiffusionClassifierN+T**: Multihead diffusion with likelihood maximization.

**DiffusionClassifierTK**: Off-the-shelf diffusion.

**DiffusionClassifierN+TK**: Off-the-shelf diffusion with likelihood maximization.

**DiffusionAsClassifier**: Depreciated. Test robustness of diffusion classifier (VP-SDE) under AutoAttack+BPDA/Lagrange/DirectDifferentiate

**DiffusionMaximizer**: Likelihood maximizer. A new diffusion purification method we proposed. See Sec 3.4 in our paper for detail. Could be combined with discriminative classifier.

**DirectAttack**: Direct differentiate through likelihood maximization.

**ObfuscatedGradient**: Measure the cosine similarity between the gradient of diffusion classifier and DiffPure. See Sec 4.4 in our paper for detail.

**OptimalDiffusionClassifier**: See Sec 3.3 for detail.

**stadv**: Measure the robustness under STAdv attack.

**cifar100**: Experiment on cifar100





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## Citation
Please cite us:
```
@article{chen2023robust,
  title={Robust Classification via a Single Diffusion Model},
  author={Chen, Huanran and Dong, Yinpeng and Wang, Zhengyi and Yang, Xiao and Duan, Chengqi and Su, Hang and Zhu, Jun},
  journal={arXiv preprint arXiv:2305.15241},
  year={2023}
}
```

If you have any question, you can contact us by:  

Github issue.

Email: huanran_chen@outlook.com (Recommended), huanranchen@bit.edu.cn (Not recommended, this email will be banned 1 years later)