Spectral approach to displacement evaluation from image analysis

A new approach to determine the displacement field between a reference and a deformed image is introduced. The method is based on a spectral decomposition of the displacement field which is determined through a multi-scale approach. The method is tested here on an artificial example by using computer-generated images devoid of boundary effects (i.e., periodic boundary conditions are used in the image texture and displacement field). The performance of the proposed algorithm allows for the determination of the prescribed displacement field up to machine precision, for a strain field whose trace extends from -50% to 40% with a root-mean-square average of 15%, within sub-minute runs on a standard PC.