Three-dimensional reconstruction of fracture surfaces

An original method is presented to improve fracture surface characterization through an accurate three-dimensional (3-D) reconstruction. The method, based on digital image-processing techniques, was developed under the Khoros system. The reconstruction technique is based upon the stereoscopic principle to extract the surface local elevations from the stereo-pair images. The fractographs that compose the stereo pair are obtained by scanning electron microscopy from two points of view by tilting the object at two observation angles. The first step of image processing is the alignment of the two images. Next, an iterative processing based on the cross-correlation operation builds a very dependable high resolution elevation map of the fracture surface. Finally, the elevation map can be used to provide a 3-D perspective view of the surface by using various visualization tools. Also, profiles and horizontal sections are generated by sectioning the 3-D reconstructed surface.