Experimental implementation of visual cryptography based on time average moiré

Geometric moir is a classical in-plane whole-field non-destructive optical experimental technique based on analysis of visual patterns produced by superposition of two regular gratings that geometrically interfere. Two basic goals exist in moir pattern research. The first is the analysis of moir patterns. The task is to analyze and characterize the distribution of moir fringes in a moir pattern. Most of the research in moir pattern analysis deals with the interpretation of experimentally produced patterns of fringes and determination of displacements (or strains) at centerlines of appropriate moir fringes.