| US 7,577,279 B2 | ||
| Identity verification apparatus and fingerprint image pickup method | ||
| Emiko Sano, Tokyo (Japan); Akihide Shiratsuki, Tokyo (Japan); Masahiro Shikai, Tokyo (Japan); and Hajime Nakajima, Tokyo (Japan) | ||
| Assigned to Mitsubishi Denki Kabushiki Kaisha, Tokyo (Japan) | ||
| Filed on Mar. 08, 2004, as Appl. No. 10/793,747. | ||
| Claims priority of application No. 2003-067767 (JP), filed on Mar. 13, 2003; and application No. 2004-029169 (JP), filed on Feb. 05, 2004. | ||
| Prior Publication US 2004/0179723 A1, Sep. 16, 2004 | ||
| Int. Cl. G06K 9/00 (2006.01); G06K 9/40 (2006.01) | ||
| U.S. Cl. 382—124 [382/260] | 10 Claims |
| 1. A fingerprint formation method comprising:
passing light through an object including a fingerprint surface having projections and depressions to form a pattern of light
including dark portions corresponding to the projections and bright portions corresponding to the depressions due to light
transmittance of internal tissues proximate the fingerprint surface;
forming an image of the pattern of light in a focal plane located, when forming the image, within the object and spaced from
at least part of the fingerprint surface;
generating a fingerprint image from the pattern of light, the fingerprint image including dark portions corresponding to the
projections and bright portions corresponding to the depressions;
smoothing the fingerprint image to produce a smoothed image; and
generating a difference image by arithmetically determining differences between the fingerprint image and the smoothed image
to remove blood vessel images from the fingerprint image.
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