Preconditioned augmented Lagrangian method for mean curvature image deblurring

Autor: Shahbaz Ahmad, Faisal Fairag, Adel M. Al-Mahdi, Jamshaid ul Rahman
Jazyk: angličtina
Rok vydání: 2022
Předmět:
Zdroj: AIMS Mathematics, Vol 7, Iss 10, Pp 17989-18009 (2022)
Druh dokumentu: article
ISSN: 2473-6988
DOI: 10.3934/math.2022991?viewType=HTML
Popis: Image deblurring models with a mean curvature functional has been widely used to preserve edges and remove the staircase effect in the resulting images. However, the Euler-Lagrange equations of a mean curvature model can be used to solve fourth-order non-linear integro-differential equations. Furthermore, the discretization of fourth-order non-linear integro-differential equations produces an ill-conditioned system so that the numerical schemes like Krylov subspace methods (conjugate gradient etc.) have slow convergence. In this paper, we propose an augmented Lagrangian method for a mean curvature-based primal form of the image deblurring problem. A new circulant preconditioned matrix is introduced to overcome the problem of slow convergence when employing a conjugate gradient method inside of the augmented Lagrangian method. By using the proposed new preconditioner fast convergence has been observed in the numerical results. Moreover, a comparison with the existing numerical methods further reveal the effectiveness of the preconditioned augmented Lagrangian method.
Databáze: Directory of Open Access Journals