Full-Field Displacement Measurement Image Correlation Minimum Mean Square Error of Intensity Distribution Physical Sciences and Engineering
Institute of Information Theories and Applications FOI ITHEA
A vision system is applied to full-field displacements and deformation measurements in solid
mechanics. A speckle like pattern is preliminary formed on the surface under investigation. To determine
displacements field of one speckle image with respect to a reference speckle image, sub-images, referred to
Zones Of Interest (ZOI) are considered. The field is obtained by matching a ZOI in the reference image with the
respective ZOI in the moved image. Two image processing techniques are used for implementing the matching
procedure: – 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.