一种改进的两步时域相位去包裹算法

An improved two-step temporal phase unwrapping algorithm

针对时域相位去包裹方法在三维形貌测量时存在采集图像幅数多、数据量大和处理时间长等问题,提出了一种改进的两步时域相位去包裹算法。首先,增加中间灵敏度投影条纹,将不同灵敏度光栅条纹投射到待测物体表面,由CCD相机采集;再通过不同灵敏度级联,得到最终灵敏度系数G值较大的去包裹相位数据。推导了两步时域相位去包裹算法的初始相位条件。并进行了实际测量。结果表明,本文方法可实现高灵敏度三维形貌测量,测量结果精度更高。

Servin et al proposed a 2-step temporal phase unwrapping algorithm,which only needs 2extreme phase-maps to achieve exactly the same results as the standard temporal unwrapping method.But this method also has some problems.In order to optimize the range of sensitivity coefficient Gand improve the measurement accuracy,an improved temporal phase unwrapping algorithm is proposed in this paper,which is an extension of Servin′s method.First,we add an intermediate sensitivity fringe pattern,project the fringe patterns with different sensitivities onto the object surface,and then collect the deformed fringe patterns with a CCD camera.Then we obtain the unwrapped phase with larger sensitivity coefficient Gby cascading the sensitivity coefficients.We derive the initial phase conditions of the 2-step temporal phase unwrapping algorithm.Finally,the experimental evaluation is conducted to prove the validity of the proposed method.The results are compared with those of the method in Ref.[21].The experimental results show that this method can achieve high sensitivity,and the results are more accurate.