Title
Improved Solution to the ℓ0 Regularized Optimization Problem via Dictionary-Reduced Initial Guess
Date Issued
27 August 2018
Access level
metadata only access
Resource Type
conference paper
Publisher(s)
Institute of Electrical and Electronics Engineers Inc.
Abstract
The ℓ0 regularized optimization (ℓ0-RO) problem is a nonconvex problem that is central to several applications such as sparse coding, dictionary learning, compressed sensing, etc. Iterative algorithms for ℓ0 - RO problem are only known to have local or subsequence convergence properties i.e. the solution is trapped in a saddle point or in an inferior local solution. Inspired by techniques used to improve the alternating optimization (AO) of nonconvex functions, we propose a simple yet effective two step iterative method to improve the solution to the ℓ0RO problem. Given an initial solution, we first find the vanilla solution to ℓ0RO via a descent method (in particular, Nesterov's accelerated gradient descent), to then estimate a new initial solution by using a scaled version of the dictionary involved in the ℓ0-RO problem, considering only a reduced number of its atoms. Our proposed algorithm is empirically demonstrated to have the best tradeoff between accuracy and computation time, when compared to state-of-the-art algorithms. Furthermore, due to its structure, our proposed algorithm can be directly apply to the convolutional formulation of ℓ0-RO.
Language
English
OCDE Knowledge area
Otras ingenierías y tecnologías
Scopus EID
2-s2.0-85053895347
ISBN
9781538609514
Source
2018 IEEE 13th Image, Video, and Multidimensional Signal Processing Workshop, IVMSP 2018 - Proceedings
Sponsor(s)
a†This research was supported by the “Programa Nacional de Innovación para la Competitividad y Productividad” (Innóvate Perú) Program.
Sources of information: Directorio de Producción Científica Scopus