A new phase to height model in fringe projection profilometry by considering radial distortion of camera lens

Abstract

In fringe projection profilometry, the straight-shaped fringe patterns predefined in computer are projected onto the object surface and the distorted fringe patterns reflected from the surface are captured by camera. The phase information obtained by analysis of the modulated fringe pattern is converted to the height information by a certain phase to height model. Here, the accuracy of the height information is affected by the lens distortion. So it arises the problems to consider the lens distortion during capturing the fringe pattern and to use correct phase to height model. In this paper a phase to height model is proposed, which uses 9 coefficients, and a new method for removing the radial distortion of camera lens is suggested by ignoring the tangential distortion and approximating the total lens distortion model to a 5th-order equation. Simulation and experiment results demonstrate that the proposed method is available and effective in three-dimensional shape measurement.