Proximal Thresholding Algorithm for Minimization over Orthonormal Bases

  • Authors:
  • Patrick L. Combettes;Jean-Christophe Pesquet

  • Affiliations:
  • -;-

  • Venue:
  • SIAM Journal on Optimization
  • Year:
  • 2007

Quantified Score

Hi-index 0.00

Visualization

Abstract

The notion of soft thresholding plays a central role in problems from various areas of applied mathematics, in which the ideal solution is known to possess a sparse decomposition in some orthonormal basis. Using convex-analytical tools, we extend this notion to that of proximal thresholding and investigate its properties, providing, in particular, several characterizations of such thresholders. We then propose a versatile convex variational formulation for optimization over orthonormal bases that covers a wide range of problems, and we establish the strong convergence of a proximal thresholding algorithm to solve it. Numerical applications to signal recovery are demonstrated.