The clipping method is used to carry out the fast calculation of a correlation function of speckle intensity in several applications. Using this technique, the peak position of the cross-correlation function can be determined more accurately than that for the nonclipped one. There are several possible logical operations for calculating clipped speckle intensity. Several methods of the logical operation of the intensity clipping are studied to evaluate the accuracy of the peak detection of the clipped correlation function. Both the theoretical consideration and experimental results are given.