Calibration method for angular measurement of Moiré patterns based on template matching

A high-accuracy calibration method for angular measurement of deformed and curved Moir patterns, based on template matching algorithm, was presented. It was feasible and accurate method, based on Talbot interferometry and Moir deflectometry, to measure long focal-length lenses. Theoretical analysis indicated that the precision of this method was mainly influenced by the angle of Moir patterns. However, it was difficult to obtain high-accuracy angle of Moir patterns, since the Moir patterns derived from experiment were constantly deformed or curved. A method based on template matching algorithm, was demontrated to calibrate deformed and curved Moir patterns, thus their angle can be calculated fast and accurately in sub-pixel domain. Numerical analysis and simulation prove that the method mentioned above demonstrates high precision and stability, and experiment results show that the accuracy of the long focal lengths measurement is improved obviously.