Method and Apparatus For Providing Strobed Image Capture

• US 20090232418A1
• Filed: 04/24/2009
• Published: 09/17/2009
• Est. Priority Date: 04/11/2005
• Status: Active Grant

• Current Assignee: Princeton Identity Inc.
• Original Assignee: Sarnoff Corporation (SRI International, Inc.)
• Inventors: Naroditsky, Oleg, Tinker, Michael, Lolacono, Dominick, Matey, James R., Zappia, Thomas
• Granted Patent: US 7,657,127 B2
• Time in Patent Office: Days
• US Class Current: 382/312
• CPC Class Codes: A61B 3/112 for measuring diameter of pupils
• CPC Class Codes: A61B 5/1171 based on the shapes or appearances of their bodies or parts thereof
• CPC Class Codes: G06V 10/141 Control of illumination
• CPC Class Codes: G06V 40/19 Sensors therefor

Abstract

A method and apparatus for strobed image capture includes stroboscopic illumination synchronized with one or more cameras to improve a signal to noise ratio, reduce motion blur and avoid object damage in sensor systems used to analyze illumination sensitive objects.

Claims

1. A method for providing strobed image capture, comprising:

controlling at least one strobed illumination source to limit an amount of radiation from the illumination source that is applied to an illumination sensitive object;

synchronizing at least one camera with the strobed illumination source; and

capturing at least one image of the illumination sensitive object with the at least one camera, the object being illuminated at least in part by a plurality of photons from the strobed illumination source.

2. The method of claim 1, wherein the illumination sensitive object is an iris.

3. The method of claim 2, wherein a subject having the iris is moving.

4. The method of claim 2 further comprising processing the at least one image to identify a subject.

5. The method of claim 2 further comprising processing the at least one image to provide pupillometry.

6. The method of claim 1 wherein the controlling step further comprises:

controlling a second illumination source that continuously illuminates the illumination sensitive object.

7. The method of claim 1 wherein the at least one image is a video stream.

8. The method of claim 2, wherein the at least one image of the iris is suitable for biometric purposes.

9. The method of claim 4 wherein the biometric purpose is at least one of iris recognition or pupillometry.

10. The method of claim 2, wherein a light intensity of the strobed illumination source is increased during a strobe, while an average irradiance of the strobed illumination source remains below a safety threshold.

11. The method of claim 10, wherein a processor controls the strobed illumination source and an eve finder provides a plurality of iris images.

12. A system for providing strobed image capture, comprising:

at least one camera

at least one illumination controller for synchronizing with the at least one camera at least one illumination source for illuminating an illumination sensitive object with a plurality of photons;

wherein the at least one captures at least one image of the illumination sensitive object at least in part from the plurality of photons reflected from the illumination sensitive object.

13. The system of claim 12, wherein the illumination sensitive object is an iris.

14. The system of claim 13, wherein a subject having the iris is moving.

15. The system of claim 13, wherein the at least one image is suitable for biometric purposes.

16. The system of claim 13, wherein a light intensity of the strobed illumination source is increased during a strobe, while an average irradiance of the strobed illumination source remains below a safety threshold.

17. The apparatus of claim 12 further comprising processing the at least one image to identify a subject.

18. The method of claim 13 further comprising processing the at least one image to provide pupillometry.

19. The method of claim 12 wherein the controlling step further comprises:

controlling a second illumination source that continuously illuminates the illumination sensitive object.

20. The method of claim 12 wherein the at least one image is a video stream.