Systems and methods for capturing artifact free images

• US 8,965,064 B2
• Filed: 08/21/2012
• Issued: 02/24/2015
• Est. Priority Date: 08/22/2011
• Status: Active Grant

• Current Assignee: EyeLock LLC (VOXX International Corporation)
• Original Assignee: Eyelock Corporation (VOXX International Corporation)
• Inventors: Hanna, Keith J.
• Primary Examiner(s): Rahmjoo, Mike
• Application Number:
  US13/590,898
• Publication Number:
  US 20130051631A1
• Time in Patent Office: 917 Days
• Field of Search: 382/117, 382/275, 382/103, 382/274, 382/299, 651/208, 651/206
• US Class Current: 382/117
• CPC Class Codes: G06V 40/19 Sensors therefor
• CPC Class Codes: G06V 40/197 Matching; Classification

Abstract

The present disclosure is directed towards methods and systems for capturing artifact-free biometric images of an eye. The eye may be in motion and in the presence of partially-reflective eyewear. The method may include acquiring, by a first sensor, a first image of an eye while the eye is illuminated by a first illuminator. The first image may include a region of interest. The first sensor may be disposed at a fixed displacement from the first illuminator and a second sensor. The second sensor may acquire, within a predetermined period of time from the acquisition of the first image, a second image of the eye. The second image may include the region of interest. An image processor may determine if at least one of the first and second images include artifacts arising from one or both of the first illuminator and eyewear, within the region of interest.

Claims

1. A method of acquiring artifact-free biometric images of an eye in relative motion with a sensor, and in the presence of partially-reflective eyewear, the method comprising:

(a) acquiring, by a first sensor having a first optical axis, a first image of an eye while the eye is illuminated by a first illuminator, the first image including a region of interest, the first sensor disposed at a fixed displacement from the first illuminator and a second sensor disposed at a separation distance S from the first sensor and having a second optical axis;

(b) acquiring, by the second sensor within a predetermined period of time from the acquisition of the first image, a second image of the eye, the second image including the region of interest; and

(c) determining if at least one of the first and second images include artifacts arising from one or both of the first illuminator and eyewear, within the region of interest, wherein the first optical axis and the second optical axis converge at a distance D between the eye and a midpoint between the first sensor and the second sensor and the first sensor and the second sensor are substantially at or below an angle of arcTan(0.5*S/D) from a line connecting the eye and the midpoint between the first sensor and second sensor.

2. The method of claim 1, wherein (a) comprises acquiring, by the first sensor, the first image of the eye while illuminated by the first illuminator, the first sensor vertically displaced with respect to the second sensor.

3. The method of claim 1, wherein (b) comprises acquiring, by the second sensor simultaneous with the acquisition of the first image, the second image of the eye, the second image including the region of interest.

4. The method of claim 1, further comprising acquiring, by the first sensor, a third image of the eye while illuminated by a second illuminator, the second illuminator disposed at a predefined distance from the first illuminator.

5. The method of claim 1, further comprising acquiring, by the first sensor within a predetermined time from the acquisition of the first image, a third image of the eye while illuminated by a second illuminator, the second illuminator disposed at a vertical distance from the first illuminator.

6. The method of claim 5, further comprising acquiring, by the second sensor, a fourth image of the eye while illuminated by the second illuminator.

7. The method of claim 1, further comprising selecting, based on the determination, at least a portion of the region of interest, from one or both of the first and second images, for use in biometric verification.

8. The method of claim 7, further comprising combining the at least a portion of the region of interest selected, for biometric verification.

9. The method of claim 1, wherein (c) comprises determining if at least one of the first and second images include specular reflection off the eyewear within the region of interest, the specular reflection arising from the first illuminator.

10. The method of claim 1, wherein (c) comprises determining if at least one of the first and second images include at least one of:

obstruction from a non-lens portion of the eyewear, discontinuity in a lens of the eyewear, and distortion from a rim of the lens.

11. A system of acquiring artifact-free biometric images of an eye in relative motion with a sensor, and in the presence of partially-reflective eyewear, the system comprising:

a first illuminator;

a first sensor having a first optical axis and a second sensor disposed at a separation distance S and having a second optical axis, the first sensor acquiring a first image of an eye while illuminated by a first illuminator,

the first image including a region of interest, the first sensor disposed at a fixed displacement from the first illuminator and the second sensor,

the second sensor acquiring a second image of the eye within a predetermined period of time from the acquisition of the first image, the second image including the region of interest; and

an image processor determining if at least one of the first and second images include artifacts arising from one or both of the first illuminator and partially reflective eyewear, within the region of interest,

wherein (i) the first optical axis and the second optical axis converge at a distance D between the eye and a midpoint between the first sensor and the second sensor and (ii) the first sensor and the second sensor are substantially at or below an angle of arcTan(0.5*S/D) from a line connecting the eye and the midpoint between the first sensor and second sensor.

12. The system of claim 11, wherein the first sensor is vertically displaced with respect to the second sensor.

13. The system of claim 11, wherein the second sensor acquires, simultaneous with the acquisition of the first image, the second image of the eye.

14. The system of claim 11, wherein the first sensor acquires a third image of the eye while illuminated by a second illuminator, the second illuminator disposed at a predefined distance from the first illuminator.

15. The system of claim 11, further comprising a second illuminator, the first sensor acquiring, within a predetermined time from the acquisition of the first image, a third image of the eye while illuminated by the second illuminator, the second illuminator disposed at a vertical distance from the first illuminator.

16. The system of claim 15, wherein the second sensor acquires a fourth image of the eye while illuminated by the second illuminator.

17. The system of claim 11, wherein the image processor selects, based on the determination, at least a portion of the region of interest, from one or both of the first and second images, for use in biometric verification.

18. The system of claim 17, wherein the image processor combines the at least a portion of the region of interest selected, for biometric verification.

19. The system of claim 11, wherein the image processor determines if at least one of the first and second images include specular reflection off the eyewear within the region of interest, the specular reflection arising from the first illuminator.

20. The system of claim 11, wherein the image processor determines if at least one of the first and second images include at least one of:

obstruction from a non-lens portion of the eyewear, discontinuity in a lens of the eyewear, and distortion from a rim of the lens.