A Geometric Perspective on Diffusion Models

Fuente: arXiv
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Main Authors: Chen, Defang, Zhou, Zhenyu, Mei, Jian-Ping, Shen, Chunhua, Chen, Chun, Wang, Can
Format: Preprint
Published: 2023
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_version_ 1866913476948000768
author Chen, Defang
Zhou, Zhenyu
Mei, Jian-Ping
Shen, Chunhua
Chen, Chun
Wang, Can
author_facet Chen, Defang
Zhou, Zhenyu
Mei, Jian-Ping
Shen, Chunhua
Chen, Chun
Wang, Can
contents Recent years have witnessed significant progress in developing effective training and fast sampling techniques for diffusion models. A remarkable advancement is the use of stochastic differential equations (SDEs) and their marginal-preserving ordinary differential equations (ODEs) to describe data perturbation and generative modeling in a unified framework. In this paper, we carefully inspect the ODE-based sampling of a popular variance-exploding SDE and reveal several intriguing structures of its sampling dynamics. We discover that the data distribution and the noise distribution are smoothly connected with a quasi-linear sampling trajectory and another implicit denoising trajectory that even converges faster. Meanwhile, the denoising trajectory governs the curvature of the corresponding sampling trajectory and its finite differences yield various second-order samplers used in practice. Furthermore, we establish a theoretical relationship between the optimal ODE-based sampling and the classic mean-shift (mode-seeking) algorithm, with which we can characterize the asymptotic behavior of diffusion models and identify the empirical score deviation. Code is available at \url{https://github.com/zju-pi/diff-sampler}.
format Preprint
id arxiv_https___arxiv_org_abs_2305_19947
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle A Geometric Perspective on Diffusion Models
Chen, Defang
Zhou, Zhenyu
Mei, Jian-Ping
Shen, Chunhua
Chen, Chun
Wang, Can
Computer Vision and Pattern Recognition
Machine Learning
Recent years have witnessed significant progress in developing effective training and fast sampling techniques for diffusion models. A remarkable advancement is the use of stochastic differential equations (SDEs) and their marginal-preserving ordinary differential equations (ODEs) to describe data perturbation and generative modeling in a unified framework. In this paper, we carefully inspect the ODE-based sampling of a popular variance-exploding SDE and reveal several intriguing structures of its sampling dynamics. We discover that the data distribution and the noise distribution are smoothly connected with a quasi-linear sampling trajectory and another implicit denoising trajectory that even converges faster. Meanwhile, the denoising trajectory governs the curvature of the corresponding sampling trajectory and its finite differences yield various second-order samplers used in practice. Furthermore, we establish a theoretical relationship between the optimal ODE-based sampling and the classic mean-shift (mode-seeking) algorithm, with which we can characterize the asymptotic behavior of diffusion models and identify the empirical score deviation. Code is available at \url{https://github.com/zju-pi/diff-sampler}.
title A Geometric Perspective on Diffusion Models
topic Computer Vision and Pattern Recognition
Machine Learning
url https://arxiv.org/abs/2305.19947