An application of wavelet transform to speckle correlation measurement

When applying speckle correlation measurement to the study on the displacement and deformation of objects, a very strict position accuracy of the correlated peak is required, but the correlated peak acquired from speckle frequency-domain correlation is not sharp enough, thus affecting the measurement accuracy directly. In the paper, a wavelet preprocess method for the speckle image is presented. By this means, the speckle edge character is firstly extracted, and the correlation calculation is then performed, and the correlated peak is sharpened. The computer simulated result indicates that the correlated peak can be sharpened and enhanced; and the signal-to-noise ratio is also heightened.