Title
Alternating Direction Method of Multipliers for a Class of Nonconvex and Nonsmooth Problems with Applications to Background/Foreground Extraction.
Abstract
In this paper, we study a general optimization model, which covers a large class of existing models for many applications in imaging sciences. To solve the resulting possibly nonconvex, nonsmooth and non-Lipschitz optimization problem, we adapt the alternating direction method of multipliers (ADMM) with a general dual step-size to solve a reformulation that contains three blocks of variables, and analyze its convergence. We show that for any dual step-size less than the golden ratio, there exists a computable threshold such that if the penalty parameter is chosen above such a threshold and the sequence thus generated by our ADMM is bounded, then the cluster point of the sequence gives a stationary point of the nonconvex optimization problem. We achieve this via apotential function specifically constructed for our ADMM. Moreover, we establish the global conver-gence of the whole sequence if, in addition, this special pot ential function is a Kurdyka-Lojasiewicz function. Furthermore, we present a simple strategy for initializing the algorithm to guarantee bound-edness of the sequence. Finally, we perform numerical experiments comparing our ADMM with the proximal alternating linearized minimization (PALM) proposed in [5] on the background/foreground extraction problem with real data. The numerical results show that our ADMM with a nontrivial dual step-size is efficient.
Year
DOI
Venue
2017
10.1137/15M1027528
SIAM JOURNAL ON IMAGING SCIENCES
Keywords
Field
DocType
nonsmooth and nonconex optimization,alternating dirtection method of multipliers,dual step-size,background/foreground extraction
Convergence (routing),Mathematical optimization,Existential quantification,Golden ratio,Stationary point,Minification,Initialization,Optimization problem,Mathematics,Bounded function
Journal
Volume
Issue
ISSN
10
1
1936-4954
Citations 
PageRank 
References 
21
0.64
30
Authors
3
Name
Order
Citations
PageRank
Lei Yang1433.05
Ting Kei Pong242723.18
Xiaojun Chen31298107.51