Title
A block coordinate variable metric forward–backward algorithm
Abstract
A number of recent works have emphasized the prominent role played by the Kurdyka-Łojasiewicz inequality for proving the convergence of iterative algorithms solving possibly nonsmooth/nonconvex optimization problems. In this work, we consider the minimization of an objective function satisfying this property, which is a sum of two terms: (i) a differentiable, but not necessarily convex, function and (ii) a function that is not necessarily convex, nor necessarily differentiable. The latter function is expressed as a separable sum of functions of blocks of variables. Such an optimization problem can be addressed with the Forward–Backward algorithm which can be accelerated thanks to the use of variable metrics derived from the Majorize–Minimize principle. We propose to combine the latter acceleration technique with an alternating minimization strategy which relies upon a flexible update rule. We give conditions under which the sequence generated by the resulting Block Coordinate Variable Metric Forward–Backward algorithm converges to a critical point of the objective function. An application example to a nonconvex phase retrieval problem encountered in signal/image processing shows the efficiency of the proposed optimization method.
Year
DOI
Venue
2016
https://doi.org/10.1007/s10898-016-0405-9
Journal of Global Optimization
Keywords
Field
DocType
Nonconvex optimization,Nonsmooth optimization,Proximity operator,Majorize–Minimize algorithm,Block coordinate descent,Alternating minimization,Phase retrieval,Inverse problems,90C25,90C26,65K10,65F08,49M27,68U10,94A08,90C05
Convergence (routing),Mathematical optimization,Forward–backward algorithm,Separable space,Regular polygon,Differentiable function,Minification,Inverse problem,Optimization problem,Mathematics
Journal
Volume
Issue
ISSN
66
3
0925-5001
Citations 
PageRank 
References 
2
0.37
18
Authors
3
Name
Order
Citations
PageRank
Emilie Chouzenoux120226.37
Jean-Christophe Pesquet220.37
Audrey Repetti3766.84