提出一种利用二维快速傅里叶变换(FFT)经频率域匹配滤波实现数字相关运算以提取散斑图携带位移信息的频率域数字散斑相关方法。 该方法因采取快速傅里叶变换、 散斑限幅、 滤波器优化等措施而减弱了空间域相关方法中不利因素对相关波峰的影响, 提高了相关点定位的时效性和精确性。

An algorithm for the extraction of speckle displacement is presented. It performs the two-dimensional discrete cross-correlation of the sub-specklegrams from different specklegrams in the frequency domain and thus improves considerably the speed of a cross-correlation calculation. For more accurate measurements of the displacement field the level-limiting technique is introduced to reduce the noise, and to optimize the correlation filter for obtaining a narrower and higher correlation peak to provide the optimum estimate of the peak position.