分段非均匀条纹生成方法及其在双频解相位中的应用

Generation method of piecewise-uneven fringes and its applications in two-frequency phase unwrapping

提出了一种描述图像像素和相位关系的分段函数,可以生成分段非均匀条纹,解决光栅测量系统倾斜投影时参考平面上条纹周期不均匀的问题。在利用双频解相位方法进行相位展开时,提出了一种条纹移动法,即将一种频率的条纹向右或向左移动π的整数倍,消除了投影双频分段非均匀条纹时得到相位展开结果的不连续性。对比其他非均匀条纹生成方法,分段非均匀条纹生成方法简单易行;双频分段非均匀条纹经过条纹移动后能够适用于双频解相位。对拱桥投影均匀条纹和分段非均匀条纹进行对比实验证明,投影分段非均匀条纹时测量精度得到了明显提高。

A novel method of generating piecewise-uneven fringes was proposed in order to get even fringes on the reference plane in oblique projection grating measuring system. The relationship between image pixels and phase was described by a piecewise function. To apply the fringes in double-frequency unwrapping, the method was further improved. Continuous unwrapping image series were obtained by left/ right phase shifting which is a multiple of π. Double-frequency piecewise-uneven fringes method can be used for double-frequency unwrapping. The applications in piecewise-uneven fringes generation shows simplicity and good performance than conventional solutions. Contrast tests on arch profilmetry were taken herein. The results indicate that the measurement precision of piecewise-uneven fringes can get effectively improved compared with the method of even fringes.