提出一种有效的单帧闭合条纹解调方法, 该方法采用傅里叶变换、带通滤波器和傅里叶逆变换估得初始相位, 然后通过图像分割、相位符号校正和Zernike多项式拟合得到高准确度相位分布.用图像分割和相位符号校正解决了相位符号不确定性, 用Zernike多项式拟合抑制了分割线附近的局部相位误差.数值分析了残余相位误差与干涉图参量(如倾斜量、离家量和随机噪音)之间的定性关系, 结果表明: 该方法所得相位与ZYGO 移相干涉仪测试结果吻合较好, 残余相位误差小于参考值的1/10, 验证了该方法的有效性.

An effective demodulation of single closed interferogram was proposed. The initial phase of the closed interferogram was estimated by using of Fourier transform, band pass filtering and inverse Fourier transform. Then the phase was obtained accurately by image segmentation, sign correction and Zernike polynomial fitting. Image segmentation and sign correction solve the problem of phase ambiguity, and Zernike polynomial fitting reduces the local phase error near the segmentation line . The qualitative relation between the residual phase error and the parameters of interferogram were analyzed by simulation, such as tilt, defocus and noise. Experimental result shows that the extracted phase by the proposed method is in good agreement with that tested by the ZYGO phase-shift interferometer and the residual phase error is less than one tenth of the reference phase. Numerical simulation demonstrates the effectiveness of this method.