Restoration of ultrasonic NDE images

Author

Snyder, Wesley E. ; Hsiao, Meng-ling ; Campbell, John N.

Author_Institution

Dept. of Radiol., Bowman Gray Sch. of Med., Winston-Salem, NC, USA

Volume

40

Issue

2

fYear

1993

fDate

4/1/1993 12:00:00 AM

Firstpage

250

Lastpage

258

Abstract

The problem of determining the ultrasonic reflectivity function resulting from density changes in a material is posed as an image restoration problem. The received time-domain signal is modeled as resulting from convolution of the acoustic pulse with the reflectivity function with additive noise. A new deconvolution method is used to estimate the reflectivity function. The method operates by an iterative maximum-a-posteriori (MAP) optimization method that not only estimates the deconvolved function but incorporates the a prior knowledge that the material is relatively uniform, except for step discontinuities. Finally, an annealing algorithm is added that allows the optimization to avoid many local minima. Initial results, based on application of the method to synthetic signals and to real signals from a nondestructive evaluation sensor, are presented

Keywords

acoustic imaging; image reconstruction; time-domain analysis; acoustic pulse; additive noise; deconvolution method; density changes; image restoration problem; iterative maximum-a-posteriori optimisation; nondestructive evaluation sensor; synthetic signals; time-domain signal; ultrasonic NDE images; ultrasonic reflectivity function; Acoustic pulses; Additive noise; Convolution; Deconvolution; Image restoration; Iterative methods; Optimization methods; Reflectivity; Signal restoration; Time domain analysis;

fLanguage

English

Journal_Title

Industrial Electronics, IEEE Transactions on

Publisher

ieee

ISSN

0278-0046

Type

jour

DOI

10.1109/41.222647

Filename

222647