Fingerprint identification/verification system

• US 6,241,288 B1
• Filed: 08/03/1998
• Issued: 06/05/2001
• Est. Priority Date: 04/02/1998
• Status: Expired due to Term

• Current Assignee: Precise Biometrics AB (Precise Biometrics Incorporated)
• Original Assignee: Precise Biometrics AB (Precise Biometrics Incorporated)
• Inventors: Öbrink, Mårten, Fåhraeus, Christer, Wiebe, Linus, Bergenek, Jerker
• Primary Examiner(s): Wellington, A. L.
• Assistant Examiner(s): CARTER, MONICA SMITH
• Application Number:
  US09/128,442
• Time in Patent Office: 1,037 Days
• Field of Search: 283/67, 283/68, 283/69, 283/78, 382/116, 382/124, 396/15
• US Class Current: 283/67
• CPC Class Codes: A61B 5/1172 using fingerprinting
• CPC Class Codes: A61B 5/7257 using Fourier transforms
• 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 fingerprint identification/verification system using bitmaps of a stored fingerprint to correlate with a bitmap of an input fingerprint, wherein an accurate reference point is located and selected two-dimensional areas in the vicinity of the reference point of the input image of the fingerprint are correlated with stored fingerprint recognition information to determine if the input fingerprint image and the stored fingerprint recognition information are sufficiently similar to identify/verify the input fingerprint.

Claims

1. A fingerprint processing method comprising the steps of:

obtaining an image of a fingerprint comprising ridges and valleys;

searching the image to locate a reference point; and

selecting the reference point and a region in the vicinity of the reference point as a recognition template for the image, the region comprising a portion of the image.

2. The method of claim 1, wherein the obtaining step further comprises the steps of:

applying the fingerprint to a scanning device;

scanning the fingerprint to generate an image signal; and

storing the image signal as a digital image.

3. The method of claim 2, wherein the selecting step further comprises the steps of:

calculating a geographic center of the digital image; and

selecting the geographic center as the reference point.

4. The method of claim 1, wherein the searching step comprises the steps of:

selecting a starting point;

following along at least one ridge proximate the starting point to locate a ridge of a first type;

selecting adjacent ridges of the first type along a predetermined path to locate a ridge of a second type; and

selecting a point on a last located ridge of the first type as the reference point.

5. The method of claim 1, wherein the selecting step comprises the steps of:

selecting the region to include the reference point, the region having a size and a shape; and

storing the recognition template.

6. The method of claim 1, wherein the step of selecting the region includes the steps of:

identifying at least one feature in the image; and

selecting the region to include the at least one feature.

7. The method of claim 1, wherein the step of selecting the region includes the step of:

selecting the region to include a particular location relative to the reference point.

8. A computer program stored on a computer readable medium comprising the steps of claim 1.

9. A fingerprint processing method comprising the steps of:

applying the fingerprint to a scanning device;

scanning the fingerprint to generate an image signal;

storing the image signal as a digital image;

vectorizing the digital image;

selecting a starting sub-area in the vectorized image;

scanning from the starting sub-area along an orientation of each subsequent sub-area to locate a first sub-area having a horizontal orientation, the first sub-area included in a first horizontal structure;

scanning from the first sub-area across acceptable structures and along a path of acceptable sub-areas until an unacceptable sub-area is located;

selecting a center point of a last acceptable sub-area as the reference point; and

selecting the reference point and a region in the vicinity of the reference point as a recognition template for the image.

10. A computer program stored on a computer readable medium comprising the steps of claim 9.

11. A fingerprint processing method comprising the steps of:

applying the fingerprint to a scanning device;

scanning the fingerprint to generate an image signal;

storing the image signal as a digital image;

binarizing the digital image;

determining which row of the digital image has the greatest number of binary transitions;

determining which column of the digital image has the greatest number of binary transitions;

selecting a point in the image by following a path starting from a point in the image having the row and the column as coordinates; and

selecting the reference point and a region in the vicinity of the reference point as a recognition template for the image.

12. A computer program stored on a computer readable medium comprising the steps of claim 11.

13. A fingerprint processing method comprising the steps of:

obtaining an image of a fingerprint comprising ridges and valleys;

searching the image to locate a reference point;

selecting the reference point and a region in the vicinity of the reference point as part of a recognition template for the image;

selecting other regions, each of the other regions having a respective size and a respective shape, each such other region located with respect to the reference point according to relative location information;

selecting the other regions, and the respective relative location information for each respective other region as part of the recognition template for the image; and

storing the recognition template, the region and the other regions comprising respective portions of the image.

14. A computer program stored on a computer readable medium comprising the steps of claim 13.

15. A fingerprint processing method comprising the steps of:

obtaining an image of a fingerprint comprising ridges and valleys;

searching the image to locate a reference point;

selecting the reference point and a region in the vicinity of the reference point as part of a recognition template for the image;

selecting other regions, each of the other regions having a respective size and a respective shape, each such other region located with respect to the reference point according to relative location information;

selecting the other regions, and the respective relative location information for each respective other region as part of the recognition template for the image;

encrypting at least one of the region, the other regions, and the relative location information; and

storing the recognition template.

16. A fingerprint processing method comprising the steps of:

obtaining an image of a fingerprint comprising ridges and valleys;

searching the image to locate a reference point;

selecting the reference point and a region in the vicinity of the reference point as part of a recognition template for the image;

selecting other regions, each of the other regions having a respective size and a respective shape, each such other region located with respect to the reference point according to relative location information;

selecting the other regions, and the respective relative location information for each respective other region as part of the recognition template for the image;

compressing at least one of the region, the other regions, and the relative location information; and

storing the recognition template.

17. A fingerprint matching method comprising the steps of:

obtaining an image of a fingerprint comprising ridges and valleys;

searching the image to locate a reference point;

selecting the reference point and a region in the vicinity of the reference point, the region comprising a portion of the image;

selecting at least one recognition template, each recognition template comprising a template reference point and a template region, the template region comprising a portion of another image;

correlating at least a portion of the region with the template region to generate a correlation result; and

determining whether the correlation result exceeds a predetermined matching requirement.

18. The method of claim 17, further comprising the steps of:

obtaining from the recognition template, relative location information of at least one other template region;

selecting another region from the image utilizing the relative location information with respect to the template reference point;

correlating at least a portion of the another region with the other template region to generate a correlation result; and

determining whether the correlation result exceeds a predetermined matching requirement.

19. A computer program stored on a computer readable medium comprising the steps of claim 17.

20. A fingerprint processing method comprising the steps of:

obtaining sequential multiple images of a fingerprint comprising ridges and valleys; and

determining dynamics of the obtaining step by comparing the multiple images to each other.

21. A method according to claim 20 further comprising the step of:

determining from the dynamics if the fingerprint is real.

22. A computer program stored on a computer readable medium comprising the steps of claim 20.

23. A fingerprint information database organization method comprising the steps of:

obtaining, from each of a plurality of fingerprints, values associated with each of a number of fingerprint characteristics;

assigning each of the values to a respective coordinate, the coordinates defining a point in a dimensional space in which each fingerprint characteristic corresponds to at least one dimension of the dimensional space; and

associating information concerning each fingerprint with a respective point.

24. A method according to claim 23, further comprising the step of:

locating information concerning fingerprints based on proximity of points in the dimensional space.

25. The method of claim 23, wherein the characteristics are selected from the group consisting of:

a number of ridges crossing a certain line;

a ridge thickness;

or a number of transitions along a center line.

26. A computer program stored on a computer readable medium comprising the steps of claim 23.

27. A fingerprint processing device comprising:

a sensor for detecting a fingerprint and for generating an image signal corresponding to the fingerprint;

a processor for receiving the image signal and for identifying a reference point and a region in the vicinity of the reference point in an image formed from the image signal, the region comprising a portion of the image; and

a storage device for storing information concerning the reference point and the region.

28. A fingerprint processing device according to claim 27, wherein the device further comprises:

a correlator for comparing information received from the storage device and information concerning a corresponding region in the vicinity of a corresponding reference point of a second image.

29. A computer program stored on a computer readable medium comprising the steps of claim 27.

30. A storage template for a fingerprint processing system comprising:

a first region bitmap comprising a portion of an image of a fingerprint;

a reference point location;

outlying region bitmaps comprising respective portions of the image of the fingerprint; and

relative location information, the relative location information corresponding to the location of each of the outlying region bitmaps with respect to the reference point location.

31. A computer program stored on a computer readable medium comprising the steps of claim 30.