Method and device for capturing fingerprints with reliably high quality based on fingerprint scanners

摘要

A method and a device for capturing fingerprints with reliably high quality based on fingerprint scanners are disclosed. The invention finds a novel possibility for capturing fingerprints of sufficiently high quality in which comprehensible feedback information of the capture process is given in real time so that the user can undertake any needed corrections of finger placement without active guidance. This object is met according to the invention in that an image processing unit is arranged downstream of the capture unit and a two-dimensional display unit is associated with the capture unit. Depending on results of the fingerprints analyzed in the image processing unit, the two-dimensional display unit displays positive real-time depictions of the fingers placed on the capture surface from an image storage having a library comprising a plurality of animated finger position images for guiding the user in a simple manner.

主权项

1. A method of capturing fingerprints of sufficiently high quality based on fingerprint scanners comprising:
capturing fingerprints of fingers placed upon a capture surface as a sensor image; analyzing said sensor image for relevant objects to determine fingerprints with regard to their quantity and position on the capture surface by (1) searching prints of first phalanges of the fingers as dark pixel areas, (2) providing rectangles circumscribing the prints, and (3) determining a position of the prints by using a center of mass, surface area and orientation of the rectangles for purposes of comparing first phalanges prints with reference presets; comparing an actual position and an actual quantity of the fingers placed on the capture surface with the reference presets for position, quantity and type of fingerprints; accessing an image storage with a library comprising a plurality of animated images corresponding to a plurality of conditions of fingers placed on the capture surface and to the reference presets; selecting images or series of images out of the image storage which correspond to a deficient placement of fingers derived from image analysis for determining quantity and position of fingerprints and representing a positive finger depiction that shows the fingers as a back view seen by a person who placed the fingers on the capture surface; and displaying the selected positive finger depiction in the form of two-dimensional images on a display unit for animating the finger-placing person to remedy the deficient placement of fingers.