Iris authentication apparatus

• US 20070025598A1
• Filed: 07/28/2006
• Published: 02/01/2007
• Est. Priority Date: 07/29/2005
• Status: Active Grant

• Current Assignee: Azbil Corporation (Azbil BioVigilant Incorporated), National University Corporation Chiba University
• Original Assignee: Azbil Corporation (Azbil BioVigilant Incorporated)
• Inventors: Nakajima, Hiroshi, Kobayashi, Koji, Aoki, Takafumi, Katsumata, Atsushi, Miyazawa, Kazuyuki, Ito, Koichi
• Granted Patent: US 8,155,395 B2
• Time in Patent Office: Days
• US Class Current: 382/117
• CPC Class Codes: G06V 10/431 Frequency domain transformation; Autocorrelation
• CPC Class Codes: G06V 40/193 Preprocessing; Feature extraction

Abstract

An iris authentication apparatus includes an iris area extraction unit, registration pattern generating unit, collation pattern generating unit, and collation unit. The iris area extraction unit extracts iris areas from a sensed registration eyeball image and a sensed collation eyeball image. When the iris area extraction unit extracts an iris area from the registration eyeball image, the registration pattern generating unit generates a registration iris pattern image by performing polar coordinate transformation of an image in the extracted iris area. When the iris area extraction unit extracts an iris area from the collation eyeball image, the collation pattern generating unit generates a collation iris pattern image by performing polar coordinate transformation of an image in the extracted iris area. The collation unit collates the registration iris pattern image output from the registration pattern generating unit and the collation iris pattern image output from the collation pattern generating unit on the basis of a correlation therebetween.

Claims

1. An iris authentication apparatus comprising:

iris area extraction means for extracting iris areas from a sensed registration eyeball image and a sensed collation eyeball image;

registration pattern generating means for, when said iris area extraction means extracts an iris area from the registration eyeball image, generating a registration iris pattern image by performing polar coordinate transformation of an image in the extracted iris area;

collation pattern generating means for, when said iris area extraction means extracts an iris area from the collation eyeball image, generating a collation iris pattern image by performing polar coordinate transformation of an image in the extracted iris area; and

collation means for collating the registration iris pattern image output from said registration pattern generating means and the collation iris pattern image output from said collation pattern generating means on the basis of a correlation therebetween.

2. An apparatus according to claim 1, wherein said iris area extraction means comprises

inner area detection means for detecting a boundary between a pupil and iris of an eyeball image as an inner boundary of the iris by elliptic approximation,

outer area detection means for detecting a boundary between an iris and sclera of an eyeball image as an outer boundary of the iris by one of circular approximation and elliptic approximation, and

area extraction means for extracting, as an iris area, an area sandwiched between the inner boundary of the iris output from said inner area detection means and the outer boundary of the iris output from said outer area detection means.

3. An apparatus according to claim 2, wherein

said registration pattern generating means performs polar coordinate transformation of an image of an iris area extracted from a registration eyeball image with reference to a center of an inner boundary of an iris detected from the registration eyeball image, and

said collation pattern generating means performs polar coordinate transformation of an image of an iris area extracted from a collation eyeball image with reference to a center of an inner boundary of an iris detected from the collation eyeball image.

4. An apparatus according to claim 1, wherein said collation means comprises

rectangular area cutting means for cutting out not less than one rectangular area from a registration iris pattern image output from said registration pattern generating means and a collation iris pattern image output from said collation pattern generating means so as not to include any non-iris portion,

correlation value calculation means for obtaining a correlation value between rectangular areas common to the registration iris pattern image output from said registration pattern generating means and the collation iris pattern image output from said collation pattern generating means, and

collation determination means for collating the two images on the basis the correlation value output from said correlation value calculation means.