Two camera biometric imaging

• US 8,165,357 B2
• Filed: 09/10/2009
• Issued: 04/24/2012
• Est. Priority Date: 06/01/2004
• Status: Expired due to Fees

• Current Assignee: HID Global Corporation (Assa Abloy AB)
• Original Assignee: Lumidigm Incorporated (Assa Abloy AB)
• Inventors: Rowe, Robert K.
• Primary Examiner(s): STREGE, JOHN B
• Application Number:
  US12/557,406
• Publication Number:
  US 20100067748A1
• Time in Patent Office: 957 Days
• Field of Search: 382/124, 382/127, 340/5.53, 340/5.83, 356/71
• US Class Current: 382/127
• CPC Class Codes: G06V 10/143 Sensing or illuminating at different wavelengths
• CPC Class Codes: G06V 40/1324 by using geometrical optics, e.g. using prisms G06V40/1312 takes precedence
• CPC Class Codes: G06V 40/1394 using acquisition arrangements

Abstract

Methods and systems are provided for performing a biometric measurement on an individual. A purported skin site of the individual is illuminated under a plurality of distinct optical conditions during a single illumination session. Light scattered beneath a surface of the purported skin site is received separately for each of the plurality of distinct optical conditions. A multispectral image of the purported skin site is derived from the received light. A biometric function is performed with the derived multispectral image.

Claims

1. A biometric sensor comprising:

a platen adapted for placement of a purported skin site by an individual;

an illumination source configured to direct light toward the skin site;

a first imager configured to collect light scattered from an interface of the platen and the purported skin site at an angle less than a platen-skin site critical angle, wherein the platen-skin site critical angle is defined by an interface of the platen with an external environment in the vicinity of the purported skin site; and

a second imager configured to collect light scattered from an interface of the platen and the purported skin site at an angle greater than a platen-skin site critical angle.

2. The biometric sensor according to claim 1, wherein the illumination source comprises a single illumination source.

3. The biometric sensor according to claim 1, wherein the illumination source comprises a plurality of illumination sources.

4. The biometric sensor according to claim 3, wherein at least two of the illumination sources provide light at different illumination wavelengths.

5. The biometric sensor according to claim 1, wherein the illumination source is disposed to illuminate the skin site with light incident at an angle greater than the critical angle.

6. The biometric sensor according to claim 1, wherein the illumination source is disposed to illuminate the skin site with light incident at an angle less than the critical angle.

7. The biometric sensor according to claim 1, wherein the illumination source is a broadband illumination source.

8. The biometric sensor according to claim 1, wherein the illumination source is a monochromatic illumination source.

9. The biometric sensor according to claim 1 further comprising a controller interfaced with the illumination source, the first imager, and the second imager, the controller including:

instructions to derive an image of the purported skin site from light received by the first imager and the second imager after scattering from the purported skin site.

10. The biometric sensor according to claim 9 wherein the controller further includes:

instructions to create a multispectral image from light received at the first imager and the second imager; and

instructions to determine the identity of an individual from the multispectral image of the purported skin site.

11. The biometric sensor according to claim 9 further comprising a polarizer disposed within an optical path between the platen and the first imager.

12. The biometric sensor according to claim 1 wherein either or both of the first imager or the second imager comprises a color imager.

13. The biometric sensor according to claim 1 wherein either or both of the first imager or the second imager comprises a monochromatic imager.

14. A method comprising:

illuminating a purported skin site of an individual disposed relative to a platen;

receiving light scattered from an interface of the platen and the purported skin site at an angle less than a platen-skin site critical angle, wherein the platen-skin site critical angle is defined by an interface of the platen with an external environment in the vicinity of the purported skin site using a first imager;

receiving light scattered from an interface of the platen and the purported skin site at an angle greater than a platen-skin site critical angle using a second imager;

deriving an image of the skin site from the light received at the first imager and second imager; and

performing a biometric function from the images collected from the images.

15. The method according to claim 14, wherein performing a biometric function comprises determining the identity of an individual from the image.

16. A biometric sensor comprising:

a platen configured for placement of a skin site by an individual;

illumination means for directing light toward the skin site; and

first imaging means for deriving an image of the skin site from light scattered from an interface of the platen and the purported skin site at an angle less than a platen-skin site critical angle; and

second image means for deriving an image of the skin site from light scattered from an interface of the platen and the purported skin site at an angle greater than a platen-skin site critical angle, wherein the platen-skin site critical angle is defined by an interface of the platen with an external environment in the vicinity of the purported skin site.

17. The biometric sensor according to claim 16, wherein the illumination means comprises a plurality of illumination sources.

18. The biometric sensor according to claim 16, further comprising means for determining the identity of an individual from the image.