3D shape measurement based on structured light projection applying polynomial interpolation technique

Because of the intrinsic drawbacks of existing 3D measurement methods, which are based on structured light projection, they often need precise linear z stage or other precise devices involvement, and the projector's parameter or relative position between projector and camera needs to be calibrated; therefore, the system costs very high and the processing time is very long. In this paper, we present a 3D shape measurement method based on structured light projection applying polynomial interpolation technique. We have deduced that phase and depth coordinates meet a polynomial relation, and the relation is used to calibrate relative position between camera and projector. The proposed approach can realize 3D shape measurement without projector calibration, without system calibration, and without precise linear z stage to be used. The relative position between camera and projector can be arbitrary, and the only involved device is a plane board. Experiment results validated that the accuracy of the proposed approach is not lower than that of many previous methods, but our approach costs lower and can be set up more easily.