Document Type

Conference Proceeding

Conference

Annual Review of Progress in Quantitative Nondestructive Evaluation

Publication Version

Published Version

Publication Date

2015

Journal or Book Title

AIP Conference Proceedings

Volume

1650

First Page

1707

Last Page

1716

DOI

10.1063/1.4914792

Conference Title

41st Annual Review of Progress in Quantitative Nondestructive Evaluation

Conference Date

July 20-25, 2014

City

Boise, ID

Abstract

We develop a sparse image reconstruction method for polychromatic computed tomography(CT) measurements under the blind scenario where the material of the inspected object and the incident energy spectrum are unknown. To obtain a parsimonious measurement model parameterization, we first rewrite the measurement equation using our mass-attenuation parameterization, which has the Laplace integral form. The unknown mass-attenuationspectrum is expanded into basis functions using a B-spline basis of order one. We develop a block coordinate-descent algorithm for constrained minimization of a penalized negative log-likelihood function, where constraints and penalty terms ensure nonnegativity of the spline coefficients and sparsity of the density map image in the wavelet domain. This algorithm alternates between a Nesterov’s proximal-gradient step for estimating the density map image and an active-set step for estimating the incident spectrum parameters. Numerical simulations demonstrate the performance of the proposed scheme.

Comments

The following article appeared in AIP Conference Proceedings 1650 (2015): 1707, doi:10.1063/1.4914792 and may be found at http://scitation.aip.org/content/aip/proceeding/aipcp/10.1063/1.4914792.

Rights

Copyright 2015 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics.

Copyright Owner

AIP Publishing LLC

Language

en

File Format

application/pdf

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