[HTML][HTML] Functional penalised basis pursuit on spheres

M Simeoni - Applied and Computational Harmonic Analysis, 2021 - Elsevier
In this paper, we propose a unified theoretical and practical spherical approximation
framework for functional inverse problems on the hypersphere S d− 1. More specifically, we …

Functional inverse problems on spheres: Theory, algorithms and applications

MMJA Simeoni - 2020 - infoscience.epfl.ch
Many scientific inquiries in natural sciences involve approximating a spherical field-namely
a scalar quantity defined over a continuum of directions-from generalised samples of the …

Sparse image reconstruction on the sphere: a general approach with uncertainty quantification

MA Price, L Pratley, JD McEwen - arXiv preprint arXiv:2105.04935, 2021 - arxiv.org
Inverse problems defined naturally on the sphere are becoming increasingly of interest. In
this article we provide a general framework for evaluation of inverse problems on the …

Solving continuous-domain problems exactly with multiresolution b-splines

T Debarre, J Fageot, H Gupta… - ICASSP 2019-2019 IEEE …, 2019 - ieeexplore.ieee.org
We propose a discretization method for continuous-domain linear inverse problems with
multiple-order total-variation (TV) regularization. It is based on a recent result that proves …

[HTML][HTML] Tensor-free proximal methods for lifted bilinear/quadratic inverse problems with applications to phase retrieval

R Beinert, K Bredies - Foundations of Computational Mathematics, 2021 - Springer
We propose and study a class of novel algorithms that aim at solving bilinear and quadratic
inverse problems. Using a convex relaxation based on tensorial lifting, and applying first …

[PDF][PDF] Faces and extreme points of convex sets for the resolution of inverse problems

V Duval - 2022 - theses.hal.science
Trying to identify the state of a physical system from the knowledge of a few indirect
measurements is an ubiquitous problem in applied sciences known as inverse problem …

The regularized orthogonal functional matching pursuit for ill-posed inverse problems

V Michel, R Telschow - SIAM Journal on Numerical Analysis, 2016 - SIAM
We propose a novel algorithm to solve a general class of linear ill-posed inverse problems.
For our numerical tests, we consider ill-posed problems on the sphere as they appear in the …

Regularization of inverse problems via box constrained minimization

P Hungerländer, B Kaltenbacher, F Rendl - arXiv preprint arXiv …, 2018 - arxiv.org
In the present paper we consider minimization based formulations of inverse problems
$(x,\Phi)\in\mbox {argmin}\{\mathcal {J}(x,\Phi; y)\colon (x,\Phi)\in M_ {ad}(y)\} $ for the …

First order methods beyond convexity and Lipschitz gradient continuity with applications to quadratic inverse problems

J Bolte, S Sabach, M Teboulle, Y Vaisbourd - SIAM Journal on Optimization, 2018 - SIAM
We focus on nonconvex and nonsmooth minimization problems with a composite objective,
where the differentiable part of the objective is freed from the usual and restrictive global …

On the complexity of Mumford–Shah-type regularization, viewed as a relaxed sparsity constraint

B Alexeev, R Ward - IEEE transactions on image processing, 2010 - ieeexplore.ieee.org
We show that inverse problems with a truncated quadratic regularization are NP-hard in
general to solve or even approximate up to an additive error. This stands in contrast to the …