A robust scheme for the identification of centerlines of moire fringes from optical experimental images

A robust scheme for the identification of centerlines of moire fringes from optical experimental images is proposed in this paper. The proposed computational algorithm comprises three basic steps: the thresholding of the experimental image, thinning of the projected grating based on morphological and mid-point detection rules and, finally, the reconstruction of the map of continuous curves from the binary matrix of pixels representing fringe centerlines. The first steps can be considered as adaptations of standard image processing techniques, while the identification and the reconstruction of continuous curves is the original contribution specifically developed for optical projection moire images. The functionality of such an approach is demonstrated for a demanding optical experimental image.