Pre-calibration-free 3D shape measurement method based on fringe projection.

This paper presents a pre-calibration-free 3D shape measurement method based on fringe projection. Unlike ordinary methods, it performs calibration and 3D shape measurement concurrently. The captured phase-coded fringe images are utilized to obtain homogenous control points from two camera viewpoints, and the rough 3D structure of these points can be retrieved. Further, a constrained non-linear least-squares optimization model is established to determine the in situ geometry of the optical components, and then, the 3D scene is reconstructed. This method provides an accurate 3D shape measurement capability even during disturbance of the optical geometry. Moreover, not requiring a preliminary calibration process makes the system ultra-flexible. The performance of this method was verified by experiments.