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.