The process for reconstruction of present in raster form line structures

Line structures are used for person identification purposes. In order to gather a large number of such line structures in a data basis, their original reproductions are analysed and reconstructed by means of orthonormal basis functions. A preferred direction of the line structure is determined for each pixel. A quality criterion is used to evaluate the reliability of the analysed data. Singularities (SI) and minutiae (MI) are extracted and stored.