LOCAL ADAPTIVE PHASE CORRECTION ALGORITHM FOR 3D PROFILOMETRY SYSTEMS BASED ON PHASE SHIFTING METHOD

Abstract

It is very popular to reflect sinusoidal phase patterns to the surface with technique of demodulation of the phase information in order to get 3D surface depth with 2D images.The phase information that extracted with this method is wrapped; so it must be unwrapped.Even though the phase information is unwrapped; there will be some errors because of possibility of non-sinusoidal characteristics of phase patterns, surface discontinuities, low sample ratesand technical handicaps (poor calibration and hardware malfunctions etc).To deal with those errors resulting from the phase unwrapping process, there are some computationally expensive and complex methods have been presented.In this paper, a fast and low complexlocal adaptive phase correction algorithm forfour-step phase shifting methodis implemented especially for oral applications. The method is firstly validated by using synthetic data. After validation process, an optic test system is realized and a few experiments are performed by using real data. For optic system, a look-up table based calibration techniqueis also implemented for getting accurate surface phase information. Visual and quantitative simulation results are presented to show the performance of the method.