Optical pattern recognition system and method for verifying the authenticity of a person, product or thing

• US 5,485,312 A
• Filed: 09/14/1993
• Issued: 01/16/1996
• Est. Priority Date: 09/14/1993
• Status: Expired due to Fees

• Current Assignee: The United States of America As Represented By The Secretary of Agriculture
• Original Assignee: United States Of America As Represented By The Secretary Of The Air Force
• Inventors: Walkup, John F., Javidi, Bahram, Horner, Joseph L.
• Primary Examiner(s): Healy, Brian
• Application Number:
  US08/127,651
• Time in Patent Office: 854 Days
• Field of Search: 359/29, 359/559, 359/560, 359/561, 359/569, 382/31, 382/43, 356/71
• US Class Current: 359/561
• CPC Class Codes: G06V 10/895 the filter being related to phase processing, e.g. phase-only filters
• CPC Class Codes: G06V 10/92 using spatial domain filters, e.g. joint transform correlators
• CPC Class Codes: G06V 40/1365 Matching; Classification
• CPC Class Codes: G07C 9/37 using biometric data, e.g. fingerprints, iris scans or voice recognition

Abstract

A method of verifying the authenticity of an object is disclosed preferrably employing a joint transform coherent optical processor. An unreadable and hence non-counterfeitable phase mask is coupled to the object and the optical processor compares the phase mask with a reference phase mask having the same phase code thereon. The processor produces a correlation spot having an intensity which exceeds a given level if the phase mask is genuine. A highly secure ID or credit card also carries a fingerprint bonded to the phase mask, and the fingerprint on the card is compared to a reference fingerprint of the card holder for added security.

Claims

1. A method of verifying the authenticity of an object comprising the steps of:

(a) associating an object related phase mask having invisible phase encoding thereon with said object; and

(b) comparing said object related phase mask with a reference phase mask in a coherent optical processor, said reference phase mask having a high degree of phase correlation with respect to said object related phase mask.

2. The method of claim 1 wherein step (b) is carried out in a joint Fourier transform correlator.

3. The method of claim 1 wherein step (b) is carried out in a Fourier transform frequency plane correlator.

4. The method of claim 1 wherein step (a) is carried out by coupling said object related phase mask to said object.

5. Method of verifying the authenticity of an object comprising the steps of:

(a) coupling a phase mask to said object;

(b) providing a joint transform coherent optical correlator having an image input plane;

(c) inserting a first image of said phase mask having a given phase code and a second image of a reference phase mask having said given phase code into the image input plane of said joint transform coherent optical correlator;

(d) producing a correlation signal indicating the degree of match between the first and second image; and

(e) producing a positive verification signal in response to the production of a close match signal during the execution of step (d) .

6. Method of verifying the authenticity of an object comprising the steps of:

(a) coupling a phase mask to said object;

(b) providing a frequency plane Fourier transform optical correlator having an optical axis and a Fourier plane intersecting said optical axis;

(c) inserting an image of said phase mask having a given phase code into the input plane of said frequency plane correlator and inserting a matched phase mask spatial filter into the Fourier plane of said optical correlator;

(d) producing a correlation signal indicating the degree of match between the image of the phase mask and the spatial filter; and

(e) producing a positive verification signal in response to the production of a close match signal during the execution of step (d).

7. The method of claim 6 wherein said matched phase mask spatial filter is a phase-only filter.

8. The method of claim 6 further including the step of causing the matched filter to dither in two dimensions about said optical axis to eliminate any adverse effect due to misalignment of the center of the matched filter with respect to said optical axis.

9. A method of controlling access to a facility comprising the steps of:

(a) superposing a phase mask over a biometric signature reference pattern on an identification means of a person seeking access to said facility;

(b) comparing a currently produced biometric signature pattern of said person seeking access with said biometric signature reference pattern on said identification means; and

(c) upon the production of a positive match resulting from carrying out step (b), granting said person access to said facility.

10. The method of claim 9 wherein said phase mask is compared with a reference phase mask in a coherent optical correlator to verify the authenticity of the phase mask.

11. The method of claim 9 wherein said phase mask is bonded to said reference pattern by a bonding agent which destroys said phase mask upon an attempted separation of said phase mask from said reference pattern.

12. The method of claim 10 wherein said phase mask is bonded to said reference pattern by a bonding agent which destroys said phase mask upon an attempted separation of said phase mask from said reference pattern.

13. Method of verifying the authenticity of an object comprising the steps of:

(a) coupling a phase mask, having an invisible phase encoded pattern thereon, to said object;

(b) providing a joint transform coherent optical correlator having an image input portion;

(c) inserting a first image of said phase mask having a first particular phase code and a second image of a reference phase mask having a particular reference phase code that matches said first particular phase code into the input image portion of said joint transform coherent optical correlator; and

(d) inspecting the resulting interference pattern between the first image and the second image to verify the authenticity of the phase mask coupled to said object.

14. An authenticity verification method comprising the steps of:

(a) providing a planar identification member; and

(b) affixing a seal to said planar identification member for verifying the authenticity of said planar identification member, and seal comprising a light phase modulating phase mask having an invisible phase encoded pattern thereon.

15. A method of verifying the authenticity of an object comprising the steps of:

(a) providing a seal for verifying the authenticity of an object to which said seal is applied, said seal comprising a light phase modulating phase mask;

(b) coupling said seal to said object;

(c) illuminating said seal with coherent light to produce a first image;

(d) providing a second image consisting of a reference phase-only image having a phase matching the phase of said phase mask;

(e) comparing said first and second images; and

(f) generating a verification signal upon the production of a close match produced upon the execution of step (e).

16. Method of verifying the authenticity of a biometric signature and a phase mask positioned on a card comprising the steps of:

(a) positioning the card having the phase mask and the biometric signature of a cardholder thereon in an input portion of a joint transform correlator (JTC);

(b) inserting a reference phase mask phase matched with respect to said phase mask on the card into said input portion;

(c) recording the joint power spectrum (JPS) produced by Fourier transforming images of said phase mask and said reference phase mask;

(d) inverse Fourier transforming the JPS produced in accordance with step (c) and measuring the intensity of the resulting correlation spot to determine the authenticity of the phase mask on the card;

(e) inserting a biometric reference signature of the cardholder into said input portion of said JTC corresponding to the biometric signature on the card;

(f) recording the joint power spectrum (JPS) produced by Fourier transforming images of said biometric reference signature of the cardholder and the biometric signature on the card;

(g) inverse Fourier transforming the JPS produced in accordance with step (f) and measuring the intensity of the resulting correlation spot to determine the authenticity of the biometric signature on the card.

17. Apparatus for verifying the authenticity of an object having a phase mask coupled thereto comprising:

(a) means for inputting a coherent optical representation of said phase mask coupled to said object into a coherent optical processor, said coherent optical processor including comparator means for comparing said representation of said phase mask with a reference phase mask; and

(b) means for producing a positive authentication signal in response to a close phase match condition sensed by said comparator means.

18. The apparatus of claim 17 wherein said coherent optical processor is a joint Fourier transform correlator.

19. The apparatus of claim 17 wherein said coherent optical processor is a Fourier transform frequency plane correlator.

20. Method of verifying the authenticity of a representation of a biometric signature and a phase mask both coupled to an identification device comprising the steps of:

(a) converting said biometric signature into a first phase mask;

(b) bonding a second phase mask to said first phase mask to form a composite phase mask coupled to said identification device;

(c) utilizing a coherent optical correlator to compare said composite phase mask to a reference mask phase matched with said composite mask; and

(d) generating a positive authenticity verification signal in response to a close match condition produced in the execution of step (c).

21. Method of verifying the authenticity of a representation of a biometric signature coupled to an identification device comprising the steps of:

(a) converting a biometric signature of a holder of said identification device into a biometric signature phase mask;

(b) coupling said biometric signature phase mask to said identification device;

(c) utilizing a coherent optical correlator to compare said biometric signature phase mask produced in accordance with step (a) to a reference biometric signature phase mask phase matched with respect to said biometric signature phase mask; and

(d) generating a positive authenticity verification signal in response to a close match condition produced during the execution of step (c).

22. The method of claim 21 further including the step of bonding an additional phase mask to said biometric signature phase mask.

23. A method for verifying the authenticity of an object comprising coupling a seal to said object, said seal having a invisible phase encoded pattern thereon.