Accelerated augmented Lagrangian method for total variation minimization

The augmented Lagrangian method (TVAL3) (Li et al. in Comput Optim Appl 56(3):507–530, 2013), which combines an alternating direction technique with a nonmonotone line search to minimize the augmented Lagrangian function at each iteration, is a very efficient method for total variation image restoration. In this paper we present an accelerated augmented Lagrangian based on TVAL3 for total variation image restoration. It is widely accepted that the stepsize, is very crucial to the performance of numerical algorithms, especially for gradient-based methods. We design a new quadratic approximation model to generate an efficient approximately optimal stepsize, truncate it by the two well-known BB stepsizes and use the resulted approximately optimal stepsize to accelerate the augmented Lagrangian method. We establish the convergence of the proposed method under weaker condition. Numerical experiments show that the proposed method is very promising.