Wavelet transform based on digital speckle correlation method: principle and algorithm

A new digital speckle correlation method, the Wavelet Transform based DSCM (WTDSCM) is presented. By this method, the two images of an object before and after loading can be expanded into two series of sub-images according to their frequency band respectively by wavelet transform. Choosing the suitable sub- images pairs mainly contributed by signal speckles, and then inducing the DSCM to calculate the deformation of the object, the probability of mismatch caused by noise could be reduced and the precision of DSCM can be improved. The experimental calibration results indicate that the precision of the WTDSCM is higher than normal DSCM.