投影条纹相移法中图像饱和误差抑制算法研究

Study of the Phase-recovering Algorithm for Saturated Fringe Patterns in the Projection Grating Phase-shifting Profilometry

针对投影条纹相移法三维形貌测量中的图像饱和误差进行了深入研究,分析了基于条纹相移技术的图像饱和误差抑制算法的适用范围,推导了基于六步相移的饱和误差抑制算法公式.理论分析表明,相移条纹图的帧数越多,饱和误差抑制算法的适用范围越广.并通过数值模拟和实验进行了验证,基于六步相移的饱和误差抑制算法可以更加有效地抑制图像饱和引起的相位误差.

The phase error caused by intensity saturation in the projection grating phase-shifting profilometry is studied. The applicability ranges of phase-recovering algorithms corresponding to different intensity saturation coefficients of N frame phase-shifting technique are studied. The formula of the phase-recovering algorithm corresponding to seven-frame phase-shifting method is deduced. The theoretical analysis indicates that the applicability range of the phase-recovering algorithm will be extended with the increasing of phase-shifting steps. Finally, some Simulative and experimental results are presented to prove the availability of the phase recovering algorithm. The phase error caused by the image intensity saturation can be effectively decreased by the phase-recovering algorithm based on seven-step phase-shifting technique.