Correlation image velocimetry: a spectral approach

A method, believed to be new, is introduced to evaluate displacement fields from the analysis of a deformed image compared with a reference image. In contrast to standard methods, which determine a piecewise constant displacement field, the present method gives direct access to spectral decomposition of the displacement field. A minimization procedure is derived and used twice: first, to determine an affine displacement field and, then, the spectral components of the residual displacement. Although the method is applicable to any space dimension, only cases dealing with one-dimensional signals are reported: First, a purely synthetic example is discussed to estimate the intrinsic performance of the method, and a second case deals with a profile extracted from a sample of compressed glass wool. (C) 2002 Optical Society of America.