Iris recognition method

• US 20080095411A1
• Filed: 11/22/2006
• Published: 04/24/2008
• Est. Priority Date: 09/29/2006
• Status: Active Grant

• Current Assignee: National Chiao Tung University (Government of The Republic of China)
• Original Assignee: National Chiao Tung University (Government of The Republic of China)
• Inventors: Huang, Chung-Lin, Lin, Jian-Liang, Che, Wei-Gang, Hwang, Wen-Liang
• Granted Patent: US 7,920,724 B2
• Time in Patent Office: Days
• US Class Current: 382/117
• CPC Class Codes: G06V 40/193 Preprocessing; Feature extraction

Abstract

The present invention disclose an iris recognition method, which utilizes a matching pursuit algorithm to simplify the extraction and reconstruction of iris features and reduce the memory space required by each iris feature vector without the penalty of recognition accuracy. The iris recognition method of the present invention comprises an iris-localization component and a pattern matching component. The iris-localization component locates the iris region via the color difference between different portions of the eyeball. The primary iris features are extracted from iris information and transformed into a sequence of iris feature vectors by a matching pursuit algorithm. Thus, the iris image can be represented by a sequence of atoms, and each atom contains base, amplitude and location. Then, the comparison between the feature vectors of two irises is performed to determine whether the two irises match.

Claims

1. An iris recognition method, comprising:

a step of locating an iris region, wherein said iris region is separated from an eye image and then transformed into a 2D rectangular image;

a step of iris feature extraction, wherein feature points are extracted from said 2D rectangular image and transformed into a sequence of vectors; and

a step of iris feature comparison, wherein said iris feature comparison is performed to estimate the similarity between said vectors of two irises and determine whether said two irises match.

2. The iris recognition method according to claim 1, wherein in said step of locating an iris region, the Hough Transform is used to obtain said iris region.

3. The iris recognition method according to claim 1, wherein in said step of locating an iris region, said iris region is transformed into said rectangular image via the polar coordinate system.

4. The iris recognition method according to claim 1, wherein in said step of iris feature extraction, a matching pursuit algorithm is used to transform the primary features of an iris image into a series of feature vectors.

5. The iris recognition method according to claim 4, wherein said feature vector further comprises a sequence of atoms.

6. The iris recognition method according to claim 5, wherein said atom contains the information of base, amplitude and location.

7. The iris recognition method according to claim 1, wherein in said step of iris feature comparison, the comparison between feature vectors of two irises is performed to determine whether said two irises match.

8. The iris recognition method according to claim 1, wherein in said step of iris feature comparison, an equation

9. The iris recognition method according to claim 4, wherein in said matching pursuit algorithm, four low pass filters are used in the vertical direction of said iris image.

10. The iris recognition method according to claim 4, wherein in said matching pursuit algorithm, Garbor filters are used in the horizontal direction of said iris image.

11. The iris recognition method according to claim 8, wherein the recognition accuracy can be adjusted via changing the value of the parameter n in said equation.