Henning Lorch

Fingerprint Distortion Measurement

A method for measuring deformations inside single fingerprint images is presented. State-of-the-art fingerprint recognition systems still use affine, to scale represented images. Therefore, image data from so-called sweep sensors is reconstructed to obtain conventional images. Measuring the deformation of fingerprint images facilitates other matching approaches not requiring the finger speed information, e.g. using directly concatenated slice images. Furthermore, fingerprint image compression can be realized by deleting similar content since the images can be reconstructed using deformation measurement.

Reconstruction-free matching for fingerprint sweep sensors

Many different types of silicon fingerprint sweep sensors presently enter the biometrics market. Since they provide small stripe image sequences instead of full fingerprint images, they require new matching algorithms. This paper presents a new one-stage, Viterbi-based matching approach which can be directly applied to the raw sweep sensor output. This is in contrary to the conventional two-stage approach where the stripe image sequences are combined to area images in a reconstruction step and subsequently fed into a recognition system appropriate for area images. Simulation results prove that the new algorithm is superior to the conventional two-stage system in terms of recognition performance and maximum allowed finger sweeping speed.