Huang M J, Sung Po-Chi
Department of Mechanical Engineering, National Chung Hsing University, Taichung, Taiwan.
Opt Express. 2010 Jan 18;18(2):1419-29. doi: 10.1364/OE.18.001419.
In this paper, a simple isoclinic phase map unwrapping method is proposed to retrieve map with ambiguities at photoelastic isotropic points. Regional phase unwrapping method is also utilized to enhance the retrieving efficiency after all phase inconsistencies have been fully detected and branch cutting works have been properly done to ensure blockings of all the paths which could cause incorrect integrations while involuntarily crossing them. The correctly retrieved isoclinic data are then fed into isochromatic formulation, and as a consequence an inconsistency free isochromatic phase map will be obtained. This map can be unwrapped by any simple and fast unwrapping algorithm accurately and effectively. Circular disk and ring under diametric compression samples are both applied for the verification of the proposed algorithm. The experimental results show the proposed algorithm can successfully solve the annoying problems occurred at photoelastic isotropic points with a processing time of roughly 2 seconds for a 420 x 420 pixels map by a general personal computer.
本文提出了一种简单的等倾线相位图展开方法，用于在光弹性各向同性点处恢复带有模糊性的相位图。在充分检测到所有相位不一致并正确进行分支切割操作以确保在无意中穿过可能导致错误积分的所有路径时对其进行阻塞之后，还利用区域相位展开方法来提高恢复效率。然后将正确恢复的等倾线数据输入到等色线公式中，从而得到无不一致的等色线相位图。该图可以通过任何简单快速的展开算法准确有效地展开。直径压缩试样下的圆盘和圆环均用于验证所提出的算法。实验结果表明，所提出的算法能够成功解决光弹性各向同性点处出现的棘手问题，对于一幅420×420像素的图像，使用普通个人计算机处理时间约为2秒。
