Title

A Generalized l1 Greedy Algorithm for Image Reconstruction in CT

Document Type

Article

Publication Date

2013

Publication Title

Applied Mathematics and Computations

DOI

10.1016/j.amc.2012.11.052

Abstract

The sparse vector solutions for an underdetermined system of linear equations Ax=b have many applications in signal recovery and image reconstruction in tomography. Under certain conditions, the sparsest solution can be found by solving a constrained l1 minimization problem: min||x||1 subject toAx=b. Recently, the reweighted l1 minimization and l1 greedy algorithm have been introduced to improve the convergence of the l1 minimization problem. As an extension, a generalized l1 greedy algorithm for computerized tomography (CT) is proposed in this paper. It is implemented as a generalized total variation minimization for images with sparse gradients in CT. Numerical experiments are also given to illustrate the advantage of the new algorithm.