Abstract:Due to the advantages of noncontact and high efficiency, the phase shift profile (PSP) method based on structured light has been widely applied. However, the pixel value of the fringe captured by the industrial camera is distorted due to the gamma effect. It may result in the error of the calculated phase value and reduce the accuracy of measurement. To solve this problem, the mathematical model of phase error is analyzed and studied further. Then, based on the improved model, the projection scheme of the fringe image is designed. The value of shifted phase of the original fringe is π/2, and the mean phase of the original fringe and the phaseshifted fringe is utilized as the final phase. In this way, the purpose of phase compensation can be achieved. Finally, the number of fringe projections is improved. Experimental results show that the proposed method does not need to calculate the distortion value γ. After compensation, the root mean square (RMS) phase error is decreased by 457%.