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Bibliographic Details
Main Authors: Skuratovs, Nikolajs, Davies, Michael
Format: Preprint
Published: 2021
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Online Access:https://arxiv.org/abs/2105.07086
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author Skuratovs, Nikolajs
Davies, Michael
author_facet Skuratovs, Nikolajs
Davies, Michael
contents Many modern imaging applications can be modeled as compressed sensing linear inverse problems. When the measurement operator involved in the inverse problem is sufficiently random, denoising Scalable Message Passing (SMP) algorithms have a potential to demonstrate high efficiency in recovering compressed data. One of the key components enabling SMP to achieve fast convergence, stability and predictable dynamics is the Onsager correction that must be updated at each iteration of the algorithm. This correction involves the denoiser's divergence that is traditionally estimated via the Black-Box Monte Carlo (BB-MC) method \cite{MC-divergence}. While the BB-MC method demonstrates satisfying accuracy of estimation, it requires executing the denoiser additional times at each iteration and might lead to a substantial increase in computational cost of the SMP algorithms. In this work we develop two Large System Limit models of the Onsager correction for denoisers operating within SMP algorithms and use these models to propose two practical classes of divergence estimators that require no additional executions of the denoiser and demonstrate similar or superior correction compared to the BB-MC method.
format Preprint
id arxiv_https___arxiv_org_abs_2105_07086
institution arXiv
publishDate 2021
record_format arxiv
spellingShingle Divergence Estimation in Message Passing algorithms
Skuratovs, Nikolajs
Davies, Michael
Information Theory
Many modern imaging applications can be modeled as compressed sensing linear inverse problems. When the measurement operator involved in the inverse problem is sufficiently random, denoising Scalable Message Passing (SMP) algorithms have a potential to demonstrate high efficiency in recovering compressed data. One of the key components enabling SMP to achieve fast convergence, stability and predictable dynamics is the Onsager correction that must be updated at each iteration of the algorithm. This correction involves the denoiser's divergence that is traditionally estimated via the Black-Box Monte Carlo (BB-MC) method \cite{MC-divergence}. While the BB-MC method demonstrates satisfying accuracy of estimation, it requires executing the denoiser additional times at each iteration and might lead to a substantial increase in computational cost of the SMP algorithms. In this work we develop two Large System Limit models of the Onsager correction for denoisers operating within SMP algorithms and use these models to propose two practical classes of divergence estimators that require no additional executions of the denoiser and demonstrate similar or superior correction compared to the BB-MC method.
title Divergence Estimation in Message Passing algorithms
topic Information Theory
url https://arxiv.org/abs/2105.07086