An improved nonlinear conjugate gradient method and its application to satellite image restoration

Bay, Atefe; Akbari, Zohreh

doi:10.22124/jmm.2026.30611.2744

An improved nonlinear conjugate gradient method and its application to satellite image restoration

Articles in Press

Document Type : Research Article

Authors

Atefe Bay ¹
Zohreh Akbari ²

¹ Department of Mathematics, Faculty of Mathematical Sciences, University of Mazandaran, Babolsar, Iran

² Department of Applied Mathematics, Faculty of Mathematical Sciences, University of Mazandran, Babolsar, Iran

10.22124/jmm.2026.30611.2744

Abstract

In this paper, an improved nonlinear conjugate gradient method is proposed for solving unconstrained optimization problems. Due to the high computational cost of Newton-type methods, conjugate gradient methods have emerged as efficient alternatives for large-scale problems. However, their performance heavily depends on the choice of search directions and algorithmic parameters. In the proposed method, a novel parameter and a modified search direction are introduced to ensure sufficient descent at each iteration. Global convergence of the method is established under standard assumptions. Numerical experiments on satellite image restoration demonstrate the superiority of the proposed method over the Polak–Ribiere–Polyak method in terms of noise reduction and image quality enhancement.

Keywords

Main Subjects