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Autori principali: Riccio, Danilo, Ehrhardt, Matthias J., Benning, Martin
Natura: Preprint
Pubblicazione: 2022
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Accesso online:https://arxiv.org/abs/2206.13193
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author Riccio, Danilo
Ehrhardt, Matthias J.
Benning, Martin
author_facet Riccio, Danilo
Ehrhardt, Matthias J.
Benning, Martin
contents Variational regularization methods are commonly used to approximate solutions of inverse problems. In recent years, model-based variational regularization methods have often been replaced with data-driven ones such as the fields-of-expert model (Roth and Black, 2009). Training the parameters of such data-driven methods can be formulated as a bilevel optimization problem. In this paper, we compare the framework of bilevel learning for the training of data-driven variational regularization models with the novel framework of deep equilibrium models (Bai, Kolter, and Koltun, 2019) that has recently been introduced in the context of inverse problems (Gilton, Ongie, and Willett, 2021). We show that computing the lower-level optimization problem within the bilevel formulation with a fixed point iteration is a special case of the deep equilibrium framework. We compare both approaches computationally, with a variety of numerical examples for the inverse problems of denoising, inpainting and deconvolution.
format Preprint
id arxiv_https___arxiv_org_abs_2206_13193
institution arXiv
publishDate 2022
record_format arxiv
spellingShingle Regularization of Inverse Problems: Deep Equilibrium Models versus Bilevel Learning
Riccio, Danilo
Ehrhardt, Matthias J.
Benning, Martin
Optimization and Control
Variational regularization methods are commonly used to approximate solutions of inverse problems. In recent years, model-based variational regularization methods have often been replaced with data-driven ones such as the fields-of-expert model (Roth and Black, 2009). Training the parameters of such data-driven methods can be formulated as a bilevel optimization problem. In this paper, we compare the framework of bilevel learning for the training of data-driven variational regularization models with the novel framework of deep equilibrium models (Bai, Kolter, and Koltun, 2019) that has recently been introduced in the context of inverse problems (Gilton, Ongie, and Willett, 2021). We show that computing the lower-level optimization problem within the bilevel formulation with a fixed point iteration is a special case of the deep equilibrium framework. We compare both approaches computationally, with a variety of numerical examples for the inverse problems of denoising, inpainting and deconvolution.
title Regularization of Inverse Problems: Deep Equilibrium Models versus Bilevel Learning
topic Optimization and Control
url https://arxiv.org/abs/2206.13193