Saved in:
Bibliographic Details
Main Authors: Li, Henry, Pereira, Marcus
Format: Preprint
Published: 2024
Subjects:
Online Access:https://arxiv.org/abs/2412.16748
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866917876159479808
author Li, Henry
Pereira, Marcus
author_facet Li, Henry
Pereira, Marcus
contents Existing approaches to diffusion-based inverse problem solvers frame the signal recovery task as a probabilistic sampling episode, where the solution is drawn from the desired posterior distribution. This framework suffers from several critical drawbacks, including the intractability of the conditional likelihood function, strict dependence on the score network approximation, and poor $\mathbf{x}_0$ prediction quality. We demonstrate that these limitations can be sidestepped by reframing the generative process as a discrete optimal control episode. We derive a diffusion-based optimal controller inspired by the iterative Linear Quadratic Regulator (iLQR) algorithm. This framework is fully general and able to handle any differentiable forward measurement operator, including super-resolution, inpainting, Gaussian deblurring, nonlinear deblurring, and even highly nonlinear neural classifiers. Furthermore, we show that the idealized posterior sampling equation can be recovered as a special case of our algorithm. We then evaluate our method against a selection of neural inverse problem solvers, and establish a new baseline in image reconstruction with inverse problems.
format Preprint
id arxiv_https___arxiv_org_abs_2412_16748
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Solving Inverse Problems via Diffusion Optimal Control
Li, Henry
Pereira, Marcus
Machine Learning
Existing approaches to diffusion-based inverse problem solvers frame the signal recovery task as a probabilistic sampling episode, where the solution is drawn from the desired posterior distribution. This framework suffers from several critical drawbacks, including the intractability of the conditional likelihood function, strict dependence on the score network approximation, and poor $\mathbf{x}_0$ prediction quality. We demonstrate that these limitations can be sidestepped by reframing the generative process as a discrete optimal control episode. We derive a diffusion-based optimal controller inspired by the iterative Linear Quadratic Regulator (iLQR) algorithm. This framework is fully general and able to handle any differentiable forward measurement operator, including super-resolution, inpainting, Gaussian deblurring, nonlinear deblurring, and even highly nonlinear neural classifiers. Furthermore, we show that the idealized posterior sampling equation can be recovered as a special case of our algorithm. We then evaluate our method against a selection of neural inverse problem solvers, and establish a new baseline in image reconstruction with inverse problems.
title Solving Inverse Problems via Diffusion Optimal Control
topic Machine Learning
url https://arxiv.org/abs/2412.16748