Three fringe photoelasticity ‐ use of colour image processing hardware to automate ordering of isochromatics

Abstract

AbstractThe early application of digital image processing (DIP) technique to automate photoelastic analysis is based on black and white (B & W) image processing systems. The various methodologies reported can be traced to rely upon one or several features of a B &W DIP system. With the advancements in computer technology, nowadays colour image processing systems are available at affordable prices. A systematic study has been carried out on how to use the red green blue (RGB) value recorded using a colour image processing system for determining fringe orders up to 3 in a fringe field. The study has revealed that instead of directly using RGB values corresponding to a dark field image, if the difference of RGB values between bright anddarkfield images is used, the number of noise points is less. Experiments have been carried out for several arbitrary lines in a circular disk under diametral compression and the results are found to be good.