Red-green bicolor photoelasticity using a single-color image

Abstract

Conventional RGB or tricolor photoelasticity processes the intensity information of the red, green, and blue color planes to demodulate the photoelastic fringe orders (or isochromatics). We explore the possibility of isochromatic demodulation using the intensity data of only the red and green color planes drawn from a single-color image. This would help in avoiding the uncertainties caused due to the blue color plane in RGB photoelasticity. Moreover, a new procedure is proposed for isochromatic demodulation using a synthetically generated look-up table (LUT) to address the tint and intensity variations between the calibration and analysis images. The proposed method has been validated and extended to analyze live models and stress frozen slices. The results show that the proposed bicolor technique has the potential for demodulating higher fringe orders using generic white light sources with acceptable accuracy. Moreover, the bicolor algorithm consumes 13% less computational time than the tricolor algorithm.