EMPIRICAL CHARACTERIZATION OF WOOD SURFACES BY MEANS OF ITERATIVE AUTOCORRELATION OF LASER SPECKLE PATTERNS

A simple and inexpensive method for the qualitative characterization of wood surfaces is presented. It is based on the iterative autocorrelation of laser speckle patterns produced by diffuse laser illumination of the wood surfaces.The method exploits the high spatial frequency content of speckle images. A similar approach with raw conventional photographs taken with ordinary light would be very difficult. A few iterations of the algorithm are necessary, typically three or four, in order to visualize the most important periodic features of the surface. The processed patterns help in the study of surface parameters, to design new scattering models and to classify the wood species.