English
Related papers

Related papers: Iterative regularization methods for a discrete in…

200 papers

We investigate the regularizing behavior of an iterative Krylov subspace method for the solution of linear inverse problems in precisions lower than double. Recent works have considered the projection of iterated Tikhonov methods using…

Numerical Analysis · Mathematics 2025-12-02 Chelsea Drum , James. G. Nagy , Lucas Onisk

In this paper we propose an iterative method using alternating direction method of multipliers (ADMM) strategy to solve linear inverse problems in Hilbert spaces with general convex penalty term. When the data is given exactly, we give a…

Numerical Analysis · Mathematics 2016-01-13 Yuling Jiao , Qinian Jin , Xiliang Lu , Weijie Wang

Magnetic resonance imaging (MRI) reconstruction is an active inverse problem which can be addressed by conventional compressed sensing (CS) MRI algorithms that exploit the sparse nature of MRI in an iterative optimization-based manner.…

Computer Vision and Pattern Recognition · Computer Science 2019-06-13 Yuxiang Dai , Peixian Zhuang

Magnetic Resonance Imaging can produce detailed images of the anatomy and physiology of the human body that can assist doctors in diagnosing and treating pathologies such as tumours. However, MRI suffers from very long acquisition times…

Image and Video Processing · Electrical Eng. & Systems 2022-03-30 George Yiasemis , Jan-Jakob Sonke , Clarisa Sánchez , Jonas Teuwen

In many modern imaging applications the desire to reconstruct high resolution images, coupled with the abundance of data from acquisition using ultra-fast detectors, have led to new challenges in image reconstruction. A main challenge is…

Numerical Analysis · Mathematics 2020-06-24 Julianne Chung , Matthias Chung , J. Tanner Slagel , Luis Tenorio

This dissertation is devoted to provide advanced nonconvex nonsmooth variational models of (Magnetic Resonance Image) MRI reconstruction, efficient learnable image reconstruction algorithms and parameter training algorithms that improve the…

Optimization and Control · Mathematics 2023-03-06 Wanyu Bian

In this paper we present a convergence rate analysis of inexact variants of several randomized iterative methods. Among the methods studied are: stochastic gradient descent, stochastic Newton, stochastic proximal point and stochastic…

Optimization and Control · Mathematics 2019-03-20 Nicolas Loizou , Peter Richtárik

Inverse problems are characterized by their inherent non-uniqueness and sensitivity with respect to data perturbations. Their stable solution requires the application of regularization methods including variational and iterative…

Numerical Analysis · Mathematics 2023-10-17 Aviv Gibali , Markus Haltmeier

In this paper, we discuss the construction, analysis and implementation of a novel iterative regularization scheme with general convex penalty term for nonlinear inverse problems in Banach spaces based on the homotopy perturbation…

Numerical Analysis · Mathematics 2018-01-10 Jing Wang , Wei Wang , Bo Han

This work is concerned with applying iterative image reconstruction, based on constrained total-variation minimization, to low-intensity X-ray CT systems that have a high sampling rate. Such systems pose a challenge for iterative image…

Medical Physics · Physics 2016-11-17 Emil Y. Sidky , Rick Chartrand , Yuval Duchin , Christer Ullberg , Xiaochuan Pan

We provide estimators for a large class of inverse problems, including nonlinear inverse problems. Using complexity regularization technics we provide adaptive estimators achieving the best rate over the collection of models.

Statistics Theory · Mathematics 2007-06-13 Jean Michel Loubes , Ludeña Carenne

In this paper we study the inverse Laplace transform. We first derive a new global logarithmic stability estimate that shows that the inversion is severely ill-posed. Then we propose a regularization method to compute the inverse Laplace…

Analysis of PDEs · Mathematics 2023-04-18 Pierre Maréchal , Faouzi Triki , Walter C. Simo Tao Lee

We deal with the solution of a generic linear inverse problem in the Hilbert space setting. The exact right hand side is unknown and only accessible through discretised measurements corrupted by white noise with unknown arbitrary…

Numerical Analysis · Mathematics 2023-02-14 Bastian Harrach , Tim Jahn , Roland Potthast

We consider a class of regularization methods for inverse problems where a coupled regularization is employed for the simultaneous reconstruction of data from multiple sources. Applications for such a setting can be found in multi-spectral…

Optimization and Control · Mathematics 2018-08-01 Martin Holler , Richard Huber , Florian Knoll

We propose an approach for super-resolution optical lithography which is based on the inverse of magnetic resonance imaging (MRI). The technique uses atomic coherence in an ensemble of spin systems whose final state population can be…

Quantum Physics · Physics 2015-05-19 Fahad AlGhannam , Philip Hemmer , Zeyang Liao , M. Suhail Zubairy

We consider the variational reconstruction framework for inverse problems and propose to learn a data-adaptive input-convex neural network (ICNN) as the regularization functional. The ICNN-based convex regularizer is trained adversarially…

This study examines, in the framework of variational regularization methods, a multi-penalty regularization approach which builds upon the Uniform PENalty (UPEN) method, previously proposed by the authors for Nuclear Magnetic Resonance…

Numerical Analysis · Mathematics 2025-02-20 Villiam Bortolotti , Germana Landi , Fabiana Zama

The standard approach for photoacoustic imaging with variable speed of sound is time reversal, which consists in solving a well-posed final-boundary value problem for the wave equation backwards in time. This paper investigates the…

Optimization and Control · Mathematics 2016-03-17 Zakaria Belhachmi , Thomas Glatz , Otmar Scherzer

This paper presents an uncalibrated deep neural network framework for the photometric stereo problem. For training models to solve the problem, existing neural network-based methods either require exact light directions or ground-truth…

Computer Vision and Pattern Recognition · Computer Science 2021-04-20 Berk Kaya , Suryansh Kumar , Carlos Oliveira , Vittorio Ferrari , Luc Van Gool

In this paper, we consider linear ill-posed problems in Hilbert spaces and their regularization via frame decompositions, which are generalizations of the singular-value decomposition. In particular, we prove convergence for a general class…

Numerical Analysis · Mathematics 2022-11-04 Simon Hubmer , Ronny Ramlau , Lukas Weissinger