相位解包裹算法中基于调制度的新质量图

在移相法测量光学波面或物体形貌过程中,相位解包裹是条纹自动分析中的关键技术,而质量图对解包裹相位算法起着至关重要的作用。用计算机模拟干涉图获得相位导数偏差质量图,指出其在标识相位数据质量方面的不足,并根据调制度结合相位梯度构造出新的质量图(称之为调制度-相位梯度偏差质量图)来弥补此缺陷。再以新质量图数据为权值,采用加权最小二乘解包裹算法验证新质量图的可靠性。最后通过实验数据,比较新质量图和相位导数偏差质量图在解包裹相位算法中的作用,得到新质量图的解相结果均方根(RMS)值为2.652 rad,而相位导数偏差质量图的解相结果均方根值为5.151 rad,由此证明前者有更好的可靠性。

New Quality Map Based on Modulation for Phase Unwrapping Algorithm

In the phase-shifting interferometry, the phase unwrapping is a key technique of fringe pattern analysis; meanwhile, the quality map is crucial to phase unwrapping. At first, the disadvantage of the popular phase derivative variance quality map (PDVQM) is pointed out and then, based on the modulation of interferograms, a new quality map—modulation-phase gradient variance quality map (MPGVQM) is constructed. The new quality map can definitely identify the noises and phase jumping, and make up the disadvantage of the PDVQM. By use of experimental data, the new quality map and the popular one are compared and the unwrapping results are obtained. The root-mean-square (RMS) of unwrapping phase obtained by use of the new quality value is 2.652 rad and the other′s RMS is 5.151 rad. It proves that the new quality-map-guided least square phase-unwrapping method can successfully evade the residues and lead to the satisfactory phase unwrapping results. And it is more reliable and more robust than that by using PDVQM.