Publications
Photogrammetric Fingerprint Unwrapping 2007
Paar G.,
Maria del Pilar Caballo Perucha,
Bauer A.,
Nauschnegg B.
Photogrammetric Fingerprint Unwrapping 2007. 8th ISPRS Conference on Optical 3-D Measurement Techniques, Vol.II, , July 9-12, 2007, Zurich, Switzerland., 2007
abstract:
| Fingerprints are among the most important biometric cues for forensics, access control, health care, security and other authentication applications. Many fingerprint sensors acquire only a sub-region of the relevant part of the finger, in most cases the finger undergoes a deformation due to necessary touching of the sensor. Using a contactless strategy with more than one overlapping camera images for photogrammetric acquisition of the proximal phalanx (front-most finger segment) has a set of advantages and enables to perform objective fingerprint unwrapping for new and more robust fingerprint matching algorithms and further exploitation of the 3d surface of the finger. We report on a photogrammetric workflow for nail-to-nail fingerprint reconstruction for the purpose of virtual unwrapping. A calibrated sensor setup consisting of 5 cameras and dedicated illumination provides a data base with 4 stereo pairs of adjacent camera images. The finger silhouette images are used for carving a rough 3d finger model used as prediction for stereo-matching based refinement. The final proximal phalanx reconstruction consists of a principle finger axis and a digital surface grid containing perpendicular distances from the axis. For model texture a weighted combination of shading corrected images from the two closest cameras are used for each model grid pixel. Due to the knowledge about 3d position of each texture point the implementation of different unwrapping methods is possible. Further exploitation of the reconstruction will be more robust fingerprint detection methods, both by making use of the 3d data, and utilizing the comprehensive |
url: http://www.reference-global.com/doi/pdf/10.1515/JAG.2008.002