Saved in:
Bibliographic Details
Main Authors: Khalafi, Shervin, Hounie, Ignacio, Ding, Dongsheng, Ribeiro, Alejandro
Format: Preprint
Published: 2025
Subjects:
Online Access:https://arxiv.org/abs/2508.19104
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866911289120391168
author Khalafi, Shervin
Hounie, Ignacio
Ding, Dongsheng
Ribeiro, Alejandro
author_facet Khalafi, Shervin
Hounie, Ignacio
Ding, Dongsheng
Ribeiro, Alejandro
contents Diffusion models have become prevalent in generative modeling due to their ability to sample from complex distributions. To improve the quality of generated samples and their compliance with user requirements, two commonly used methods are: (i) Alignment, which involves finetuning a diffusion model to align it with a reward; and (ii) Composition, which combines several pretrained diffusion models together, each emphasizing a desirable attribute in the generated outputs. However, trade-offs often arise when optimizing for multiple rewards or combining multiple models, as they can often represent competing properties. Existing methods cannot guarantee that the resulting model faithfully generates samples with all the desired properties. To address this gap, we propose a constrained optimization framework that unifies alignment and composition of diffusion models by enforcing that the aligned model satisfies reward constraints and/or remains close to each pretrained model. We provide a theoretical characterization of the solutions to the constrained alignment and composition problems and develop a Lagrangian-based primal-dual training algorithm to approximate these solutions. Empirically, we demonstrate our proposed approach in image generation, applying it to alignment and composition, and show that our aligned or composed model satisfies constraints effectively. Our implementation can be found at: \href{https://github.com/shervinkhalafi/constrained_comp_align}{https://github.com/shervinkhalafi/constrained\_comp\_align}
format Preprint
id arxiv_https___arxiv_org_abs_2508_19104
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Composition and Alignment of Diffusion Models using Constrained Learning
Khalafi, Shervin
Hounie, Ignacio
Ding, Dongsheng
Ribeiro, Alejandro
Machine Learning
Image and Video Processing
Diffusion models have become prevalent in generative modeling due to their ability to sample from complex distributions. To improve the quality of generated samples and their compliance with user requirements, two commonly used methods are: (i) Alignment, which involves finetuning a diffusion model to align it with a reward; and (ii) Composition, which combines several pretrained diffusion models together, each emphasizing a desirable attribute in the generated outputs. However, trade-offs often arise when optimizing for multiple rewards or combining multiple models, as they can often represent competing properties. Existing methods cannot guarantee that the resulting model faithfully generates samples with all the desired properties. To address this gap, we propose a constrained optimization framework that unifies alignment and composition of diffusion models by enforcing that the aligned model satisfies reward constraints and/or remains close to each pretrained model. We provide a theoretical characterization of the solutions to the constrained alignment and composition problems and develop a Lagrangian-based primal-dual training algorithm to approximate these solutions. Empirically, we demonstrate our proposed approach in image generation, applying it to alignment and composition, and show that our aligned or composed model satisfies constraints effectively. Our implementation can be found at: \href{https://github.com/shervinkhalafi/constrained_comp_align}{https://github.com/shervinkhalafi/constrained\_comp\_align}
title Composition and Alignment of Diffusion Models using Constrained Learning
topic Machine Learning
Image and Video Processing
url https://arxiv.org/abs/2508.19104