Unrolled denoising networks provably learn optimal Bayesian inference

Fuente: arXiv
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Main Authors: Karan, Aayush, Shah, Kulin, Chen, Sitan, Eldar, Yonina C.
Format: Preprint
Published: 2024
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author Karan, Aayush
Shah, Kulin
Chen, Sitan
Eldar, Yonina C.
author_facet Karan, Aayush
Shah, Kulin
Chen, Sitan
Eldar, Yonina C.
contents Much of Bayesian inference centers around the design of estimators for inverse problems which are optimal assuming the data comes from a known prior. But what do these optimality guarantees mean if the prior is unknown? In recent years, algorithm unrolling has emerged as deep learning's answer to this age-old question: design a neural network whose layers can in principle simulate iterations of inference algorithms and train on data generated by the unknown prior. Despite its empirical success, however, it has remained unclear whether this method can provably recover the performance of its optimal, prior-aware counterparts. In this work, we prove the first rigorous learning guarantees for neural networks based on unrolling approximate message passing (AMP). For compressed sensing, we prove that when trained on data drawn from a product prior, the layers of the network approximately converge to the same denoisers used in Bayes AMP. We also provide extensive numerical experiments for compressed sensing and rank-one matrix estimation demonstrating the advantages of our unrolled architecture - in addition to being able to obliviously adapt to general priors, it exhibits improvements over Bayes AMP in more general settings of low dimensions, non-Gaussian designs, and non-product priors.
format Preprint
id arxiv_https___arxiv_org_abs_2409_12947
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Unrolled denoising networks provably learn optimal Bayesian inference
Karan, Aayush
Shah, Kulin
Chen, Sitan
Eldar, Yonina C.
Machine Learning
Data Structures and Algorithms
Much of Bayesian inference centers around the design of estimators for inverse problems which are optimal assuming the data comes from a known prior. But what do these optimality guarantees mean if the prior is unknown? In recent years, algorithm unrolling has emerged as deep learning's answer to this age-old question: design a neural network whose layers can in principle simulate iterations of inference algorithms and train on data generated by the unknown prior. Despite its empirical success, however, it has remained unclear whether this method can provably recover the performance of its optimal, prior-aware counterparts. In this work, we prove the first rigorous learning guarantees for neural networks based on unrolling approximate message passing (AMP). For compressed sensing, we prove that when trained on data drawn from a product prior, the layers of the network approximately converge to the same denoisers used in Bayes AMP. We also provide extensive numerical experiments for compressed sensing and rank-one matrix estimation demonstrating the advantages of our unrolled architecture - in addition to being able to obliviously adapt to general priors, it exhibits improvements over Bayes AMP in more general settings of low dimensions, non-Gaussian designs, and non-product priors.
title Unrolled denoising networks provably learn optimal Bayesian inference
topic Machine Learning
Data Structures and Algorithms
url https://arxiv.org/abs/2409.12947