3D information acquired by the correlation of projected fringe patterns

This paper presents a new method that acquires the height information automatically in projected fringe patterns for 3D profile. The principle is to project the gratings on reference plane and object surface to be measured respectively, and then record them by a CCD camera. Through comparing these two images with digital image correlation method, the offset of the fringe that modulated by the object surface can be obtained. Further the 3D profile or deformation will be inferred. In this new method, an important characteristic is that the principle and processing are only need one fringe pattern on object surface, so it can be well used in real time and dynamic measurement. Another advantage is no need of the complex unwrapping process. At last, this paper shows the experiment results and compared them with phase shifting method.