基于概率密度函数的光源不稳定性校正

Illumination instability correction based on probability density function

在相位测量轮廓术中,当投影光源不稳定时,所产生的条纹图强度不均,将引起非线性相位误差。针对这一问题提出一种基于概率密度函数的条纹图像强度校正方法,通过计算不同强度系数组合的截断相位及其对应PDF曲线,将曲线STD最小值所对应的系数作为系统系数,进行图像灰度调整,从而减小强度不均带来的非线性误差。计算机仿真和实验均验证了该方法的有效性。

In the phase measurement profilometry,the intensity of fringe patterns will be uneven when the light source is unstable,which will induce nonlinear phase error.To solve this problem,a correction method for intensity of fringe patterns based on probability density function is proposed,and the coefficient corresponding to the minimum value of curve STD is used as the system coefficient to adjust the gray scale of the image by calculating the truncated phase of different intensity coefficient combinations and its corresponding PDF curve,so as to reduce the nonlinear error caused by uneven intensity.Computer simulations and experiments verify the effectiveness of this method.