Holography and holographic pattern recognition for preservation and evaluation of cultural-historic sources

Abstract

In the study of ancient cultures, a major difficulty is the fact that available remains of historic and cultural value are often in the possession of different institutions and, therefore, are not directly accessible simultaneously. Even fragments of such objects are often stored at different places, which creates an additional obstacle to the task of their recombination. Moreover, they are endangered by natural or man-made destruction, and many of them are already in such a state, that information regarding the surface structure is hardly interpretable. Thus, techniques for high-resolution 3-D documentation and fine-structure analysis as well as feature enhancement and extraction are indispensable. Documentation by two-dimensional photography gives only a restricted impression of the threedimensional appearance of these objects and is insufficient for a detailed analysis of the spatial fine structure of the surface relief. Plaster casts from molds display the three-dimensional geometry of the object, but show restricted spatial resolution, besides the risk of destruction of fine structures during the molding process. In order to overcome these obstacles holographic techniques can be used because of