A new set of signal processing algorithms in laser speckle metrology

Non-contacting methods for strain and displacement measurement are now well established, although not in very wide spread use in material science applications. Besides other methods, laser speckle pattern shift techniques can be successfully used for strain and displacement measurements. Using such a technique, one is confronted with the problem of calculating speckle pattern shift values from a time series of images. In this paper, we present a new set of algorithms based on minimum-mean-square error and maximum likelihood principles suitable for this task. We show their application in two different strain and displacement measurement set-ups.