Rethinking phase height model of fringe projection profilometry: A geometry transformation viewpoint

The phase height model is developed in the phase measuring profilometry, while the geometry transformation model is proposed in the structured light method and the active stereovision. However the inner connection or coherence of them has not been clearly discussed. In this paper, the gap between them is bridged. The phase height model is reasoned from the geometry transformation model, which can be denoted as an explicit function of the geometry parameters. The reasoned phase height model is consistent with two traditional phase height models, whether the system is coplanar or non-coplanar optical axes. On the other hand, this generic phase height model explains the connection of two traditional phase height models. The simulation and experiments affirm that the reasoned model is valid and the proposed calibration method is feasible.