A new reconstruction method based on fringe projection of three-dimensional measuring system

This paper presents a new reconstruction method of three-dimensional measuring system, with the simple calibration process, whole-field calibration and fast reconstruction. First, we project a sinusoidal fringe pattern on the surface of the calibration target within the scope of a calibrated field. At the same time, camera captures fringe images on the planar target. Then, we extract image coordinates and absolute phase values of the feature point of planar target, and obtain camera parameters and world coordinates by using image coordinates. Next, we use fitting polynomials to match the spatial relationships among image coordinates, absolute phases and world coordinates from planar target, solve the parameters from fitting equations. Finally, we solve the absolute phase values of object's surface in phase shifting and gray coding techniques, substitute it into fitting equations and reconstruct 3D shape of object's surface. The experimental results show that this reconstruction method is simple, with high precision. Most of all, the calibration target can be placed arbitrarily within entire calibrated fields in the calibration procedure.