A projected gradient algorithm based on the augmented Lagrangian strategy for image restoration and texture extraction

摘要

Based on the augmented Lagrangian strategy, we construct a projected gradient algorithm for image restoration and texture extraction. The proposed algorithm is established on the basis of a mixed model which combines the Rudin–Osher–Fatemi (ROF) model with the Lysaker–Lundevold–Tai (LLT) model to reduce the staircase effect and blur phenomenons. The proof of the convergence of the proposed algorithm is provided. Moreover, we show that the dual methods based on convex analysis which have been proposed in some papers can be actually deduced from the augmented Lagrangian strategy. Some numerical examples are supplied to illustrate the efficiency of the proposed algorithm.