为了改善滤波效果, 提出了一种新的阈值选择方法。基于相位频谱系数的理论分析, 综合考虑条纹自身振幅对频谱幅度的放缩影响, 利用频谱系数最大值得到条纹振幅, 进而计算得到适用于散斑干涉条纹图的窗口傅里叶变换滤波阈值。经过模拟散斑干涉条纹图和实验所得真实条纹图验证可知, 该阈值选择方法能有效滤除高频噪声, 滤波效果较好。

We propose a new method for threshold selection to improve the filtering effect. Based on theoretical analyze of spectral coefficients of phase fields, considering the scaling effect of fringe amplitude on spectral amplitude, we obtain fringe amplitude by using maximal spectral coefficients. Then, a new threshold about windowed Fourier transform filter method for speckle pattern interferometry is calculated. Through the verification of simulated speckle fringe pattern and real fringe pattern, the new threshold selection method can effectively filter out high-frequency noise, which performs better in filtering.