Diffusion Classifier Guidance for Non-robust Classifiers
- Classifier guidance is intended to steer a diffusion process such that a given classifier reliably recognizes the generated data point as a certain class. However, most classifier guidance approaches are restricted to robust classifiers, which were specifically trained on the noise of the diffusion forward process. We extend classifier guidance to work with general, non-robust, classifiers that were trained without noise. We analyze the sensitivity of both non-robust and robust classifiers to noise of the diffusion process on the standard CelebA data set, the specialized SportBalls data set and the high-dimensional real-world CelebA-HQ data set. Our findings reveal that non-robust classifiers exhibit significant accuracy degradation under noisy conditions, leading to unstable guidance gradients. To mitigate these issues, we propose a method that utilizes one-step denoised image predictions and implements stabilization techniques inspired by stochastic optimization methods, such as exponential moving averages. Experimental results demonstrate that our approach improves the stability of classifier guidance while maintaining sample diversity and visual quality. This work contributes to advancing conditional sampling techniques in generative models, enabling a broader range of classifiers to be used as guidance classifiers
| Author: | Philipp Vaeth, Dibyanshu Kumar, Benjamin Paassen, Magda Gregorova |
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| DOI: | https://doi.org/10.1007/978-3-032-05981-9_13 |
| Parent Title (English): | Machine Learning and Knowledge Discovery in Databases - European Conference, ECML PKDD 2025, Porto, Portugal, September 15–19, 2025 |
| Publisher: | Springer |
| Document Type: | Conference Proceeding |
| Language: | English |
| Year of publication: | 2025 |
| Publishing Institution: | Technische Hochschule Würzburg-Schweinfurt |
| Release Date: | 2025/07/15 |
| Faculties and institutes: | Institute und Zentren / Center for Artificial Intelligence (CAIRO) |
| Licence (German): | Creative Commons - CC BY - Namensnennung 4.0 International |

