Research on iterative decoupling algorithm in color fringe projection profilometry

An iterative decoupling algorithm (IDA) is proposed to improve the performance of a color fringe projection measurement system that suffers from the complicated color coupling effect. Firstly, we analyzed the effect of projection intensity and the measured object on color coupling, and the mechanism of coupling; then, get the coupling coefficients by three red, green, and blue uniform intensity images; finally, use the proposed IDA method to correct the captured color fringe pattern for phase recovery. The advantage of the IDA method is that only three uniform color images are needed to pre-calibrate the coupling coefficients and are therefore easy to implement, highly robust, and widely used. Simulation and experimental results present that the proposed algorithm can significantly reduce the interference of color coupling and then improve the measurement accuracy of the color-channel-based phase-shifting profilometry.