An inverse error compensation method for color-fringe pattern profilometry

Abstract

Color-fringe pattern profilometry is a widely used method for high-speed measuring 3D surface because the RGB (red, green and blue) channels provide more information. However, the nonlinear response of the digital projector usually causes periodical phase errors. In this paper, we analyze the nonlinear error in color-fringe pattern profilometry, and propose a multi-frequency fringe inverse error compensation method to reduce the phase error caused by the nonlinear response of the projector. The proposed method only needs to add one highest frequency RGB pattern, thus improving the measurement accuracy of color-fringe pattern profilometry. Different from other compensation methods, the proposed method does not need gamma calibration, the construction of a look-up-table of gamma values or many additional patterns, which are really time consuming. The experimental results demonstrated that the proposed method can effectively reduce the nonlinear effect of the projector and improve the measurement accuracy of color-fringe pattern profilometry.