Method and apparatus for determining reference points in a fingerprint

摘要

A method for determining reference points in a fingerprint image is used for determining similarity values using a determination of orientation patterns and a comparison with reference orientation patterns, in which the similarity values are compared with a first threshold value to determine whether a reference point is identified or not. Whorl, delta or core points are identified as core points. Both a linear and a nonlinear reference orientation pattern are used for core points. The orientation pattern for an image area is converted into a vector field for comparison with the reference orientation patterns. A scattering is computed from the spectral power density, which is determined for computation of orientation patterns, and severely distorted image areas are thereby eliminated from the determination of reference points.