COMPUTERIZED IMAGE-PROCESSING FOR WHOLE-FIELD DETERMINATION OF ISOCLINICS AND ISOCHROMATICS

A new computerized method for the whole-field determination of isoclinic and isochromatic parameters in a stressed photoelastic model is presented. The intensity data obtained from the fringe pattern at three analyzer positions (0, 45, and 90 degrees) in a plane polariscope, are used for the computations. The relationships between the intensity values and the photoelastic parameters are derived using Stokes representation of polarized light. The experiments were carried out using a computer-based image-processing system. The accuracy achieved is assessed by comparing the theoretical and measured values. Accuracies of within +/- 3 degrees for isoclinics and +/- 0.05 fringe for isochromatics are shown to be possible.