Calibration of imaging systems typically involves the use of specially designed objects with known properties, called calibration targets. Standard calibration targets are, in general, used for calibrating the imaging pathway of fingerprint readers. However, there is no standard method for evaluating fingerprint readers in the operational setting where variations in finger placement by the user are encountered. The goal of this research is to design 3D targets for repeatable operational evaluation of fingerprint readers. 2D calibration patterns with known characteristics (e.g. sinusoidal gratings of pre-specified orientation and frequency, synthetic fingerprints with known singular points and minutiae) are projected onto a generic 3D finger surface to create electronic 3D targets (see Fig. 1). A state-of-the-art 3D printer (Stratasys Objet350 Connex) is used to fabricate the 3D targets with material similar in hardness and elasticity to the human finger skin. Our experimental results show that the (i) fabricated 3D targets can be imaged using three different (500/1000 ppi) commercial optical fingerprint readers, (ii) salient features in the 2D calibration patterns are preserved during the synthesis and fabrication of 3D targets, and (iii) intra-class variability between multiple impressions of the 3D targets captured using the optical fingerprint readers does not degrade the recognition accuracy. We also conduct experiments to demonstrate that the fabricated 3D targets can be used for operational evaluation of optical fingerprint readers (see Fig. 2).
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| Fig. 1. Synthesizing a 3D target from a 2D calibration pattern and a 3D finger surface. |
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| Fig. 2. Evaluating an optical fingerprint reader using the designed and fabricated 3D targets. (a) The 3D target is worn on a finger, (b) the finger is repeatedly placed on the fingerprint reader platen, and (c)-(f) multiple 2D impressions (four shown here) of the 3D target are captured which are utilized for evaluation of the reader. |
Relevant Publication(s)
1. S. S. Arora, K. Cao, A. K. Jain and N. G. Paulter Jr., "3D Targets for Evaluating Fingerprint Readers", MSU Technical Report, MSU-CSE-15-3, February 23, 2015. [pdf]
2. S. S. Arora, K. Cao, A. K. Jain and N. G. Paulter Jr., "3D Fingerprint Phantoms", 22nd International Conference on Pattern Recognition (ICPR), Stockolm, Sweden, August 24-28, 2014. [pdf][video]
3. S. S. Arora, K. Cao, A. K. Jain and N. G. Paulter Jr., "3D Fingerprint Phantoms", MSU Technical Report, MSU-CSE-13-12, December 24, 2013. [pdf][video]
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