An efficient spectral minimization of the Dai-Yuan method with application to image reconstruction

In this paper, a spectral Dai and Yuan conjugate gradient (CG) method is proposed based on the generalized conjugacy condition for large-scale unconstrained optimization, in which the spectral parameter is motivated by some interesting theoretical features of quadratic convergence associated with the Newton method. Accordingly, utilizing the strong Wolfe line search to yield the step-length, the search direction of the proposed spectral method is sufficiently descending and converges globally. By applying some standard Euclidean optimization test functions, numerical results reports show the advantage of the method over some modified Dai and Yuan CG schemes in literature. In addition, the method also shows some reliable results, when applied to solve an image reconstruction model.