English

Multilevel Preconditioning Strategies for Convex Optimization Methods in Image Deblurring

Numerical Analysis 2026-07-12 v1

Abstract

Proximal gradient methods are widely used in imaging, and their speed of convergence can be accelerated by incorporating variable metrics and/or extrapolation steps. Recent works have shown that preconditioning strategies can significantly enhance this acceleration, in particular, for image deblurring problems. In parallel, a multilevel framework has been introduced to speed up inertial and inexact forward-backward schemes for image restoration problems. In this paper, we combine preconditioning and multilevel strategies to design a robust and consistent acceleration framework for both standard and inexact forward-backward schemes applied to regularized convex optimization problems. Numerical experiments in image deblurring confirm that our approach yields a substantial improvement in convergence speed compared to standard methods.

Cite

@article{arxiv.2607.10864,
  title  = {Multilevel Preconditioning Strategies for Convex Optimization Methods in Image Deblurring},
  author = {Stefano Aleotti and Claudia Binda and Marco Donatelli and Rolf Krause},
  journal= {arXiv preprint arXiv:2607.10864},
  year   = {2026}
}