Training-free Diffusion Model Alignment with Sampling Demons

Fuente: arXiv
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Auteurs principaux: Yeh, Po-Hung, Lee, Kuang-Huei, Chen, Jun-Cheng
Format: Preprint
Publié: 2024
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author Yeh, Po-Hung
Lee, Kuang-Huei
Chen, Jun-Cheng
author_facet Yeh, Po-Hung
Lee, Kuang-Huei
Chen, Jun-Cheng
contents 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.
format Preprint
id arxiv_https___arxiv_org_abs_2410_05760
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Training-free Diffusion Model Alignment with Sampling Demons
Yeh, Po-Hung
Lee, Kuang-Huei
Chen, Jun-Cheng
Computer Vision and Pattern Recognition
Artificial Intelligence
Machine Learning
Optimization and Control
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.
title Training-free Diffusion Model Alignment with Sampling Demons
topic Computer Vision and Pattern Recognition
Artificial Intelligence
Machine Learning
Optimization and Control
url https://arxiv.org/abs/2410.05760