An iterative thresholding algorithm for linear inverse problems with a sparsity constraint

Fuente: arXiv
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Main Authors: Daubechies, Ingrid, Defrise, Michel, De Mol, Christine
Format: Preprint
Published: 2003
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author Daubechies, Ingrid
Defrise, Michel
De Mol, Christine
author_facet Daubechies, Ingrid
Defrise, Michel
De Mol, Christine
contents We consider linear inverse problems where the solution is assumed to have a sparse expansion on an arbitrary pre-assigned orthonormal basis. We prove that replacing the usual quadratic regularizing penalties by weighted l^p-penalties on the coefficients of such expansions, with 1 < or = p < or =2, still regularizes the problem. If p < 2, regularized solutions of such l^p-penalized problems will have sparser expansions, with respect to the basis under consideration. To compute the corresponding regularized solutions we propose an iterative algorithm that amounts to a Landweber iteration with thresholding (or nonlinear shrinkage) applied at each iteration step. We prove that this algorithm converges in norm. We also review some potential applications of this method.
format Preprint
id arxiv_https___arxiv_org_abs_math_0307152
institution arXiv
publishDate 2003
record_format arxiv
spellingShingle An iterative thresholding algorithm for linear inverse problems with a sparsity constraint
Daubechies, Ingrid
Defrise, Michel
De Mol, Christine
Functional Analysis
Numerical Analysis
We consider linear inverse problems where the solution is assumed to have a sparse expansion on an arbitrary pre-assigned orthonormal basis. We prove that replacing the usual quadratic regularizing penalties by weighted l^p-penalties on the coefficients of such expansions, with 1 < or = p < or =2, still regularizes the problem. If p < 2, regularized solutions of such l^p-penalized problems will have sparser expansions, with respect to the basis under consideration. To compute the corresponding regularized solutions we propose an iterative algorithm that amounts to a Landweber iteration with thresholding (or nonlinear shrinkage) applied at each iteration step. We prove that this algorithm converges in norm. We also review some potential applications of this method.
title An iterative thresholding algorithm for linear inverse problems with a sparsity constraint
topic Functional Analysis
Numerical Analysis
url https://arxiv.org/abs/math/0307152