Free Hunch: Denoiser Covariance Estimation for Diffusion Models Without Extra Costs

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Rissanen, Severi, Heinonen, Markus, Solin, Arno
Format: Preprint
Published: 2024
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866912288310558720
author Rissanen, Severi
Heinonen, Markus
Solin, Arno
author_facet Rissanen, Severi
Heinonen, Markus
Solin, Arno
contents The covariance for clean data given a noisy observation is an important quantity in many training-free guided generation methods for diffusion models. Current methods require heavy test-time computation, altering the standard diffusion training process or denoiser architecture, or making heavy approximations. We propose a new framework that sidesteps these issues by using covariance information that is available for free from training data and the curvature of the generative trajectory, which is linked to the covariance through the second-order Tweedie's formula. We integrate these sources of information using (i) a novel method to transfer covariance estimates across noise levels and (ii) low-rank updates in a given noise level. We validate the method on linear inverse problems, where it outperforms recent baselines, especially with fewer diffusion steps.
format Preprint
id arxiv_https___arxiv_org_abs_2410_11149
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Free Hunch: Denoiser Covariance Estimation for Diffusion Models Without Extra Costs
Rissanen, Severi
Heinonen, Markus
Solin, Arno
Machine Learning
The covariance for clean data given a noisy observation is an important quantity in many training-free guided generation methods for diffusion models. Current methods require heavy test-time computation, altering the standard diffusion training process or denoiser architecture, or making heavy approximations. We propose a new framework that sidesteps these issues by using covariance information that is available for free from training data and the curvature of the generative trajectory, which is linked to the covariance through the second-order Tweedie's formula. We integrate these sources of information using (i) a novel method to transfer covariance estimates across noise levels and (ii) low-rank updates in a given noise level. We validate the method on linear inverse problems, where it outperforms recent baselines, especially with fewer diffusion steps.
title Free Hunch: Denoiser Covariance Estimation for Diffusion Models Without Extra Costs
topic Machine Learning
url https://arxiv.org/abs/2410.11149