Correcting phase distortion of phase shifting method

We propose a method of correcting phase distortion which is caused when measuring any objects by phase shifting method with an ordinary projector. We have measured some objects with the projector which is commercially available [1]. In this paper, we try to improve the precision with the proposing method. The method calculates differences between the idealized phase and observed, and then feeding back the error to the observed phase. By using this method, the precision could be made better by 47%.