A computer-based image-processing system for automated analysis of holographic and shearographic fringes

Abstract

Holography and shearography are two laser-based techniques which enable accuratedirect measurement of displacement and strain fields, respectively, in components under load. These techniques have also been used for nondestructive evaluation of components; defects may be revealed and assessed from anomalies in the interference fringe patterns. This paper describes a personal-computer-based image-processing system developed for the analysis of holographic and shearographic fringe patterns. It will also be demonstrated that the system enables accurate dimensional measurements and also estimation of both the size and depth of debonds in laminated plates. © 1991 Elsevier Science Publishers B.V.