SECURITY IMPROVEMENTS FOR IRIS RECOGNITION SYSTEMS

• US 20130089241A1
• Filed: 10/05/2012
• Published: 04/11/2013
• Est. Priority Date: 10/07/2011
• Status: Active Grant

• Current Assignee: IrisGuard UK Limited
• Original Assignee: Irisguard Corporation
• Inventors: Malhas, Imad, Holland, Andrew, Renforth, Alan
• Granted Patent: US 9,008,375 B2
• Time in Patent Office: Days
• US Class Current: 382/117
• CPC Class Codes: G06V 10/145 Illumination specially adapted for pattern recognition, e.g. using gratings
• CPC Class Codes: G06V 40/18 Eye characteristics, e.g. of the iris
• CPC Class Codes: G06V 40/45 Detection of the body part being alive

Abstract

A method of verifying the authenticity of an eye provided for identification purposes in an iris recognition identification system is described. The method comprises: illuminating the eye using an illumination source to generate a specular reflection in a pupil and/or iris region of the eye, the specular reflection forming as a result of light emitted from the illumination source being reflected from the eye; capturing an image of the eye including the specular reflection; determining the position of the specular reflection formed in the pupil and/or iris region, from the captured image; and verifying the authenticity of the eye by comparing the determined position with an expected position for an authentic eye.

Claims

1. A method of verifying the authenticity of an eye provided for identification purposes in an iris recognition identification system, the method comprising:

illuminating the eye using an illumination source to generate a specular reflection in a pupil and/or iris region of the eye, the specular reflection forming as a result of light emitted from the illumination source being reflected from the eye;

capturing an image of the eye including the specular reflection;

determining the position of the specular reflection formed in the pupil and/or iris region, from the captured image; and

verifying the authenticity of the eye by comparing the determined position with an expected position for an authentic eye.

2. The method of claim 1, wherein

the illuminating step comprises varying the angle of incidence of the light incident on a cornea of the eye over time to vary the location of the specular reflection formed in the pupil and/or iris region of the eye over time;

the capturing step comprises capturing a sequence of image frames of the eye including the specular reflection;

the determining step comprises analysing each captured image frame to determine the position of the specular reflection formed in the pupil and/or iris region for each captured image frame; and

the verifying step comprises calculating an expected specular reflection position for each captured image frame in the sequence, and comparing the determined position with the expected position for each image frame.

3. The method of claim 1, wherein the verifying step comprises determining that the eye is authentic if the determined position is substantially coincident with the expected position of the specular reflection.

4. The method of claim 1, wherein the verifying step comprises determining that the eye is not authentic if the determined position is not substantially coincident with the expected position of the specular reflection.

5. The method of claim 1, wherein the expected position of the specular reflection is associated with a range of expected position values, and the verifying step comprises comparing the determined position with the range of expected position values.

6. The method of claim 5, wherein the verification step comprises determining that the eye is authentic if the determined position lies within the range of expected position values.

7. The method of claim 5, wherein the verification step comprises determining that the eye is not authentic if the determined position lies outside the range of expected position values.

8. The method of claim 2, wherein the varying step comprises varying the relative position of the active illumination source with respect to the eye.

9. The method of claim 8, wherein the illumination source comprises a plurality of different illumination sources, each illumination source being located at a different position with respect to the eye, and wherein varying step comprises varying the relative position of the active illumination source in time by activating one or more different illumination sources over time.

10. The method of claim 9, further comprising generating an activation sequence signal defining which one or more of the plurality of different illumination sources are to be activated, and the sequence in which they are to be activated in the illuminating step.

11. The method of claim 10, wherein the activation sequence signal comprises a randomly generated sequence of illumination source activation events.

12. The method of claim 2, wherein the capturing step comprises capturing the sequence of image frames at a rate of 30 frames per second.

13. The method of claim 2, wherein the capturing step comprises capturing the sequence of image frames at a rate of at least 20 frames per second.

14. The method of claim 1, wherein the verifying step comprises calculating a radial distance D of the expected specular reflection position, expressed with respect to the centre of the eye'"'"'s pupil, using the equation:

D=R sin θ

where R is the radius of curvature of the cornea of the illuminated eye, and θ

is the angle of incidence of light emitted from the activated illumination source incident on the cornea.

15. The method of claim 1, wherein the determining step comprises converting the captured image into a negative image, and identifying the specular reflection by identifying the darkest coloured pixels in the negative image.

16. The method of claim 1, wherein the determining step comprises identifying the iris and/or pupil in the captured image before determining the position of the specular reflection.

17. Apparatus for verifying the authenticity of an eye provided for identification purposes in an iris recognition identification system, the apparatus comprising:

an illumination source for illuminating the eye to generate a specular reflection in a pupil and/or iris region of the eye, the specular reflection forming as a result of light emitted from the illumination source being reflected from the eye;

activating means for activating the illumination source;

an image capture device arranged to capture an image of the eye including the specular reflection;

a processor arranged to determine a position of the specular reflection in the pupil and/or iris region from analysis of the captured image; and

verifying means arranged to verify the authenticity of the eye by comparing the determined position of the specular reflection with an expected position for the specular reflection of an authentic eye in the captured image.

18. The apparatus of claim 17, further comprising:

specularity position varying means for varying the position of the specular reflection, by varying the angle of incidence of the light emitted from the illumination source incident on the cornea of the eye.

19. The apparatus of claim 17, wherein the image capture device is arranged to capture a sequence of image frames of the eye, each frame comprising an image of the eye including the specular reflection.

20. The apparatus of claim 18, wherein the specularity position varying means comprises illumination source position varying means arranged to vary the relative position of the illumination source with respect to the eye to vary the position of the specular reflection in the pupil and/or iris region of the eye.

21. The apparatus of claim 18, comprising a plurality of different illumination sources, and wherein the position varying means is arranged to simultaneously activate one or more of the plurality of different illumination sources.

22. The apparatus of claim 17, further comprising:

image analysis means arranged to localise the pupil and the iris in one or more captured images of the eye.

23. The apparatus of claim 17, wherein the verifying means is arranged to return a positive verification result where the determined position is substantially coincident with the expected position.

24. The apparatus of claim 17, wherein the verifying means is arranged to return a positive verification result where the determined position lies within a range of expected positions.

25. The apparatus of claim 17, further comprising:

sequence signal generating means, arranged to generate an activation sequence signal for use by the activating means, the activation sequence specifying a sequence in which the illumination source is to be activated.

26. The apparatus of claim 25, wherein the activation sequence signal is a randomly generated sequence of illumination source activation events.

27. An apparatus for verifying the authenticity of an eye provided for identification purposes in an iris recognition identification system, the apparatus comprising:

an illumination source for illuminating the eye to generate a specular reflection in a pupil and/or iris region of the eye, the specular reflection forming as a result of light emitted from the illumination source being reflected from the eye;

an activation module for activating the illumination source;

an image capture device arranged to capture an image of the eye including the specular reflection;

a processor arranged to determine a position of the specular reflection in the pupil and/or iris region from analysis of the captured image; and

a verifying module arranged to verify the authenticity of the eye by comparing the determined position of the specular reflection with an expected position for the specular reflection of an authentic eye in the captured image.

28. A non transitory computer readable storage medium storing instructions thereon, the instructions executable by a processor and comprising:

illuminating the eye using an illumination source to generate a specular reflection in a pupil and/or iris region of the eye, the specular reflection forming as a result of light emitted from the illumination source being reflected from the eye;

capturing an image of the eye including the specular reflection;

determining the position of the specular reflection formed in the pupil and/or iris region, from the captured image; and

verifying the authenticity of the eye by comparing the determined position with an expected position for an authentic eye.

29. An apparatus for verifying the authenticity of an eye provided for identification purposes, the apparatus having one or more integrated circuits performing a method comprising:

illuminating the eye using an illumination source to generate a specular reflection in a pupil and/or iris region of the eye, the specular reflection forming as a result of light emitted from the illumination source being reflected from the eye;

capturing an image of the eye including the specular reflection;

determining the position of the specular reflection formed in the pupil and/or iris region, from the captured image; and

verifying the authenticity of the eye by comparing the determined position with an expected position for an authentic eye.