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Related papers: Tikhonov Regularization of Sphere-Valued Signals

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In this work, we propose a new criterion for choosing the regularization parameter in Tikhonov regularization when the noise is white Gaussian. The criterion minimizes a lower bound of the predictive risk, when both data norm and noise…

Numerical Analysis · Mathematics 2020-06-24 Federico Benvenuto , Bangti Jin

The Arnoldi-Tikhonov method is a well-established regularization technique for solving large-scale ill-posed linear inverse problems. This method leverages the Arnoldi decomposition to reduce computational complexity by projecting the…

Numerical Analysis · Mathematics 2025-06-02 Davide Bianchi , Marco Donatelli , Davide Furchì , Lothar Reichel

In this paper we consider the computation of approximate solutions for inverse problems in Hilbert spaces. In order to capture the special feature of solutions, non-smooth convex functions are introduced as penalty terms. By exploiting the…

Numerical Analysis · Mathematics 2015-06-18 Qinian Jin , Xiliang Lu

In this paper we present the Markov variation, a smoothness measure which offers a probabilistic interpretation of graph signal smoothness. This measure is then used to develop an optimization framework for graph signal interpolation. Our…

Signal Processing · Electrical Eng. & Systems 2020-01-29 Ayelet Heimowitz , Yonina C. Eldar

The problem of numerical differentiation can be thought of as an inverse problem by considering it as solving a Volterra equation. It is well known that such inverse integral problems are ill-posed and one requires regularization methods to…

Numerical Analysis · Mathematics 2020-04-15 Abinash Nayak

Many applications in science and engineering require the solution of large linear discrete ill-posed problems that are obtained by the discretization of a Fredholm integral equation of the first kind in several space-dimensions. The matrix…

Numerical Analysis · Mathematics 2017-05-19 Laura Dykes , Guangxin Huang , Silvia Noschese , Lothar Reichel

In this paper we provide a convergence analysis of some variational methods alternative to the classical Tikhonov regularization, namely Ivanov regularization (also called method of quasi solutions) with some versions of the discrepancy…

Numerical Analysis · Mathematics 2018-04-18 Barbara Kaltenbacher , Andrej Klassen

In this paper we consider convex Tikhonov regularisation for the solution of linear operator equations on Hilbert spaces. We show that standard fractional source conditions can be employed in order to derive convergence rates in terms of…

Optimization and Control · Mathematics 2020-02-24 Markus Grasmair

Tikhonov regularization is studied in the case of linear pseudodifferential operator as the forward map and additive white Gaussian noise as the measurement error. The measurement model for an unknown function $u(x)$ is \begin{eqnarray*}…

Analysis of PDEs · Mathematics 2016-06-03 Hanne Kekkonen , Matti Lassas , Samuli Siltanen

Finding a good regularization parameter for Tikhonov regularization problems is a though yet often asked question. One approach is to use leave-one-out cross-validation scores to indicate the goodness of fit. This utilizes only the noisy…

Numerical Analysis · Mathematics 2021-05-31 Felix Bartel , Ralf Hielscher , Daniel Potts

The present study investigates a linear-quadratic Dirichlet control problem governed by a non-coercive elliptic equation posed on a possibly non-convex polygonal domain. Tikhonov regularization is carried out in an energy seminorm. The…

Optimization and Control · Mathematics 2026-03-11 Thomas Apel , Mariano Mateos , Arnd Rösch

To solve convex optimization problems with a noisy gradient input, we analyze the global behavior of subgradient-like flows under stochastic errors. The objective function is composite, being equal to the sum of two convex functions, one…

Optimization and Control · Mathematics 2025-06-05 Rodrigo Maulen-Soto , Jalal Fadili , Hedy Attouch

Many problems in Science and Engineering give rise to linear integral equations of the first kind with a smooth kernel. Discretization of the integral operator yields a matrix, whose singular values cluster at the origin. We describe the…

Numerical Analysis · Mathematics 2022-04-13 Thomas Mach , Lothar Reichel , Marc Van Barel

We consider linear inverse problems that are formulated in the continuous domain. The object of recovery is a function that is assumed to minimize a convex objective functional. The solutions are constrained by imposing a continuous-domain…

Information Theory · Computer Science 2018-08-15 Harshit Gupta , Julien Fageot , Michael Unser

In this paper, we apply a new kind of smoothness concept, i.e. H\"older stability estimates for the determination of convergence rates of Tikhonov regularization for linear and non-linear inverse problems in Hilbert spaces. For linear…

Numerical Analysis · Mathematics 2020-11-05 Gaurav Mittal , Ankik Kumar Giri

We address the classical issue of appropriate choice of the regularization and discretization level for the Tikhonov regularization of an inverse problem with imperfectly measured data. We focus on the fact that the proper choice of the…

Numerical Analysis · Mathematics 2014-10-24 Vinicius Albani , Adriano De Cezaro , Jorge P. Zubelli

Depth maps captured with commodity sensors often require super-resolution to be used in applications. In this work we study a super-resolution approach based on a variational problem statement with Tikhonov regularization where the…

Computer Vision and Pattern Recognition · Computer Science 2021-12-22 Milena Gazdieva , Oleg Voynov , Alexey Artemov , Youyi Zheng , Luiz Velho , Evgeny Burnaev

In this paper, we study an explicit Tikhonov-regularized inertial gradient algorithm for smooth convex minimization with Lipschitz continuous gradient. The method is derived via an explicit time discretization of a damped inertial system…

Optimization and Control · Mathematics 2026-02-02 Samir Adly , Vinh Thanh Ho , Huu Nhan Nguyen

We consider the estimation of the regularization parameter for the simultaneous deblurring of multiple noisy images via Tikhonov regularization. We approach the problem in three ways. We first reduce the problem to a single-image deblurring…

Astrophysics · Physics 2009-11-10 R. Vio , P. Ma , W. Zhong , J. Nagy , L. Tenorio , W. Wamsteker

Conditional stability estimates require additional regularization for obtaining stable approximate solutions if the validity area of such estimates is not completely known. In this context, we consider ill-posed nonlinear inverse problems…

Numerical Analysis · Mathematics 2020-01-29 Frank Werner , Bernd Hofmann