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Hauptverfasser: Alberti, Giovanni S., Felisi, Alessandro, Santacesaria, Matteo, Trapasso, S. Ivan
Format: Preprint
Veröffentlicht: 2023
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Online-Zugang:https://arxiv.org/abs/2302.03577
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author Alberti, Giovanni S.
Felisi, Alessandro
Santacesaria, Matteo
Trapasso, S. Ivan
author_facet Alberti, Giovanni S.
Felisi, Alessandro
Santacesaria, Matteo
Trapasso, S. Ivan
contents Compressed sensing allows for the recovery of sparse signals from few measurements, whose number is proportional to the sparsity of the unknown signal, up to logarithmic factors. The classical theory typically considers either random linear measurements or subsampled isometries and has found many applications, including accelerated magnetic resonance imaging, which is modeled by the subsampled Fourier transform. In this work, we develop a general theory of infinite-dimensional compressed sensing for abstract inverse problems, possibly ill-posed, involving an arbitrary forward operator. This is achieved by considering a generalized restricted isometry property, and a quasi-diagonalization property of the forward map. As a notable application, for the first time, we obtain rigorous recovery estimates for the sparse Radon transform (i.e., with a finite number of angles $θ_1,\dots,θ_m$), which models computed tomography, in both the parallel-beam and the fan-beam settings. In the case when the unknown signal is $s$-sparse with respect to an orthonormal basis of compactly supported wavelets, we prove stable recovery under the condition \[ m\gtrsim s, \] up to logarithmic factors.
format Preprint
id arxiv_https___arxiv_org_abs_2302_03577
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Compressed sensing for inverse problems and the sample complexity of the sparse Radon transform
Alberti, Giovanni S.
Felisi, Alessandro
Santacesaria, Matteo
Trapasso, S. Ivan
Functional Analysis
Information Theory
Optimization and Control
42C40, 44A12, 60B20, 94A20
Compressed sensing allows for the recovery of sparse signals from few measurements, whose number is proportional to the sparsity of the unknown signal, up to logarithmic factors. The classical theory typically considers either random linear measurements or subsampled isometries and has found many applications, including accelerated magnetic resonance imaging, which is modeled by the subsampled Fourier transform. In this work, we develop a general theory of infinite-dimensional compressed sensing for abstract inverse problems, possibly ill-posed, involving an arbitrary forward operator. This is achieved by considering a generalized restricted isometry property, and a quasi-diagonalization property of the forward map. As a notable application, for the first time, we obtain rigorous recovery estimates for the sparse Radon transform (i.e., with a finite number of angles $θ_1,\dots,θ_m$), which models computed tomography, in both the parallel-beam and the fan-beam settings. In the case when the unknown signal is $s$-sparse with respect to an orthonormal basis of compactly supported wavelets, we prove stable recovery under the condition \[ m\gtrsim s, \] up to logarithmic factors.
title Compressed sensing for inverse problems and the sample complexity of the sparse Radon transform
topic Functional Analysis
Information Theory
Optimization and Control
42C40, 44A12, 60B20, 94A20
url https://arxiv.org/abs/2302.03577