Minimum Mean Square Error Approach in Images Processing for Full-field Displacements and Deformation Measurements

摘要

A vision system is applied to full-field displacements and deformation measurements in solidmechanics. A speckle like pattern is preliminary formed on the surface under investigation. To determinedisplacements field of one speckle image with respect to a reference speckle image, sub-images, referred toZones Of Interest (ZOI) are considered. The field is obtained by matching a ZOI in the reference image with therespective ZOI in the moved image. Two image processing techniques are used for implementing the matchingprocedure: – cross correlation function and minimum mean square error (MMSE) of the ZOI intensity distribution.The two algorithms are compared and the influence of the ZOI size on the accuracy of measurements is studied.