Method and apparatus for identifying an iris

• US 6,546,121 B1
• Filed: 03/05/1999
• Issued: 04/08/2003
• Est. Priority Date: 03/05/1998
• Status: Expired due to Fees

• Current Assignee: OKI Electric Industry Company Limited
• Original Assignee: OKI Electric Industry Company Limited
• Inventors: Oda, Takahiro
• Primary Examiner(s): Mehta, Bhavesh
• Assistant Examiner(s): CHAWAN, SHEELA C
• Application Number:
  US09/263,765
• Time in Patent Office: 1,495 Days
• Field of Search: 382/117, 382/115, 382/162, 382/181, 382/190, 382/195, 382/199, 382/203, 382/222, 382/232, 351/205, 351/206
• US Class Current: 382/117
• CPC Class Codes: G06V 40/18 Eye characteristics, e.g. of the iris

Abstract

The present invention is a method and an apparatus for identifying an iris that can compare new identification code with registered identification code regardless of the slant of the face of a person to be identified because the identification code produced using a standard line does not influence the slant of the face of the person. The apparatus provides a photographing part, a standard line deriving part, an iris extracting part, a code producing part, a code registering part, and a comparison part. The photographing part photographs an area including both eyes. The standard line deriving part calculates a standard line passing through the center of both eyes. The iris extracting part extracts an iris area on the standard line by luminance distribution. The code producing part divides the iris area into a plurality of pieces, calculates a luminance for each piece and codes the luminance distribution of the pieces on the basis of the standard line. The comparison part compares the identification code produced by the code producing part with the identification code registered by the code registering part.

Claims

1. A method for identifying an iris, comprising the steps of:

acquiring a part of a face including an image of both eyes;

calculating a standard line passing through centers of both eyes;

extracting an iris area on the standard line by luminance distribution;

dividing the iris area into a plurality of pieces;

calculating a luminance for each piece; and

coding the luminance distribution of the plurality of the pieces on the basis of a starting pattern on the standard line.

2. A method according to claim 1, wherein each piece is acquired by dividing the iris area based on circumference and radius.

3. A method according to claim 1, wherein two codes that are coded for the iris areas of both eyes are synthesized.

4. A method according to claim 1, further comprising the steps of calculating several points dividing an iris from a part other than the iris by the luminance distribution on two assisting standard lines lying at right angles to the standard line and passing through the center of each pupil, calculating at least one boundary standard line having a same slant as the standard line and passing through coordinates of at least one point, and extracting an iris core area based on a part of the iris surrounded by a dividing line between the iris and the pupil, a dividing line between a white of the eye and the iris, and the boundary standard line.

11. A method according to claim 1, wherein the luminance distribution of the plurality of the pieces is coded on the basis of the starting pattern and an ending pattern on the standard line.

5. An apparatus for identifying an iris, comprising:

a photographing part for photographing an area including both eyes;

a standard line deriving part for calculating a standard line passing through centers of both eyes;

an iris extracting part for extracting an iris area on the standard line by luminance distribution;

a code producing part for dividing the iris area into a plurality of pieces, calculating a luminance for each piece and coding the luminance distribution of the plurality of the pieces on the basis of a starting pattern on the standard line;

a code registering part for registering a first identification code produced by the code producing part; and

a comparison part for comparing a second identification code produced by the code producing part with the first identification code registered by the code registering part.

6. An apparatus according to claim 5, wherein the code producing part divides the iris area based on circumference and radius.

7. An apparatus according to claim 5, wherein the code producing part synthesizes two codes that are coded for the iris areas of both eyes.

8. An apparatus according to claim 5, further comprising a pre-processing part calculating several points dividing an iris from a part other than the iris by the luminance distribution on two assisting standard lines lying at right angles to the standard line and passing through the center of each pupil, calculating at least one boundary standard line having a same slant as the standard line and passing through coordinates of at least one point, and extracting an iris core area based on a part of the iris surrounded by a dividing line between the iris and the pupil, a dividing line between a white of the eye and the iris, and the boundary standard line.

9. An apparatus according to claim 5, wherein the photographing part further comprises a lighting unit irradiating infrared light toward both eyes.

12. An apparatus according to claim 5, wherein the luminance distribution of the plurality of the pieces is coded on the basis of the starting pattern and an ending pattern on the standard line.

10. An apparatus for changing data, comprising:

a photographing part for photographing an area including both eyes;

a standard line deriving part for calculating a standard line passing through centers of both eyes;

an iris extracting part for extracting an iris area on the standard line by luminance distribution;

a code producing part for dividing the iris area into a plurality of pieces, calculating a luminance for each piece and coding the luminance distribution of the plurality of the pieces on the basis of a starting pattern on the standard line to obtain a code; and

a changing part for changing the data by using the code produced by the code producing part in accordance with a predetermined function.

13. An apparatus according to claim 10, wherein the luminance distribution of the plurality of the pieces is coded on the basis of the starting pattern and an ending pattern on the standard line.