Dynamic Speckle Contrast Imaging for Surface Defect Detection

Abstract

We propose to explore the dynamic speckle contrast imaging (DSCI) modality for non-contact surface defect detection. In this approach, the object under investigation is subjected to a continuous and monotonic loading. A number of speckle images are recorded during the continuous deformation of object surface. Speckle contrast analysis algorithm is applied to the stack of images which utilizes the fact that the variations on the object surface is reflected in significant changes in the speckle intensity variations. A simulation study was performed with the speckle images and with specklegrams recorded in the speckle interferometry and Shearographic setup. The results motivate the applicability of the DSCI technique in surface defect detection.