Papers › Training-free Diffusion Model Alignment with Sampling Demons

Training-free Diffusion Model Alignment with Sampling Demons

8 Oct 2024arXiv:2410.05760archive 2025-07-28

Po-Hung Yeh, Kuang-Huei Lee, Jun-Cheng Chen

Aligning diffusion models with user preferences has been a key challenge. Existing methods for aligning diffusion models either require retraining or are limited to differentiable reward functions. To address these limitations, we propose a stochastic optimization approach, dubbed Demon, to guide the denoising process at inference time without backpropagation through reward functions or model retraining. Our approach works by controlling noise distribution in denoising steps to concentrate density on regions corresponding to high rewards through stochastic optimization. We provide comprehensive theoretical and empirical evidence to support and validate our approach, including experiments that use non-differentiable sources of rewards such as Visual-Language Model (VLM) APIs and human judgements. To the best of our knowledge, the proposed approach is the first inference-time, backpropagation-free preference alignment method for diffusion models. Our method can be easily integrated with existing diffusion models without further training. Our experiments show that the proposed approach significantly improves the average aesthetics scores for text-to-image generation. Implementation is available at https://github.com/aiiu-lab/DemonSampling.

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duplicate_condition aiiu-lab/DemonSampling/src/api.py official repository ran · our draft was wrong Apache-2.0 (permissive) · fc10568aaa87f46f · report
modified_partition aiiu-lab/DemonSampling/pipelines/vllm_generate.py official repository ran · our draft was wrong Apache-2.0 (permissive) · 1bd28f45e9886c68 · report
rm_reward aiiu-lab/DemonSampling/pipelines/qualitative_generate.py official repository unverified Apache-2.0 (permissive) · 5c2539b943620d67 · report

Tasks

DenoisingImage GenerationLanguage ModelingLanguage ModellingStochastic OptimizationText to Image GenerationText-to-Image Generation

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Methods

DemonDiffusion

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