A modified conjugate gradient method is presented for solving unconstrained optimization problems, which possesses the following properties: (i) The sufficient descent property is satisfied without any line search; (ii) The search direction will be in a trust region automatically; (iii) The Zoutendi
A descent spectral conjugate gradient method for impulse noise removal
โ Scribed by Gaohang Yu; Jinhong Huang; Yi Zhou
- Publisher
- Elsevier Science
- Year
- 2010
- Tongue
- English
- Weight
- 887 KB
- Volume
- 23
- Category
- Article
- ISSN
- 0893-9659
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โฆ Synopsis
a b s t r a c t
In most applications, denoising image is fundamental to subsequent image processing operations. This paper proposes a spectral conjugate gradient (CG) method for impulse noise removal, which is based on a two-phase scheme. The noise candidates are first identified by the adaptive (center-weighted) median filter; then these noise candidates are restored by minimizing an edge-preserving regularization functional, which is accomplished by the proposed spectral CG method. A favorite property of the proposed method is that the search direction generated at each iteration is descent. Under strong Wolfe line search conditions, its global convergence result could be established. Numerical experiments are given to illustrate the efficiency of the spectral conjugate gradient method for impulse noise removal.
๐ SIMILAR VOLUMES
A new implementation of the conjugate gradient method is presented that economically overcomes the problem of severe numerical noise superimposed on an otherwise smooth underlying objective function of a constrained optimization problem. This is done by the use of a novel gradient-only line search t