在快速傅里叶变换(FFT)方法处理单幅干涉图原理的基础上,提出一种基于样本块匹配的干涉图延拓方法,利用干涉图像的可信度和等照度线特征,来确定待填充块的优先权,然后在干涉图的已知区域寻找与待填充块最相似的样本块来进行填充。充分利用了干涉图的条纹特征,结合梯度变化方向有效地合成纹理信息,具有很好的延拓效果。最后将该干涉图延拓方法与傅里叶变换,合适的滤波函数和相位解包方法结合起来形成整套单幅干涉图处理方法。采用该单幅干涉图处理方法获得的波面峰谷值与Zygo移相干涉仪得到的平均相差不到λ/100,并且两种方法获得的波面均方根值平均相差不到λ/200。

Based on single interferogram analysis method using fast Fourier transform (FFT), an interferogram spreading method based on exemplar matching is proposed. By analyzing the confidence and isophote of interferogram, the priority that is assigned to each patch on the fill front are calculated. After the patch most similar to the patch on the fill front is found in the source region of the interferogram, the value of each pixel in the patch on the fill front is copied from its corresponding position in the most similar patch. This spreading algorithm takes full advantage of the fringe characteristics and the directions of isophotes to synthesize the structure and texture information of interferogram and achieves good spreading effect. The proposed spreading algorithm is combined with FFT, filtering and phase unwrapping together to from a single interferogram analysis method of high-accuracy. The differences between the wave surface peak-valley value obtained by the proposed single interferogram analysis method and Zygo interferometer is less than λ/100, and the difference between the wave surface root-mean-square value obtained by these two methods is less then λ/100.