Biometric imaging system and method

• US 7,203,344 B2
• Filed: 01/16/2003
• Issued: 04/10/2007
• Est. Priority Date: 01/17/2002
• Status: Expired due to Term

• Current Assignee: HID Global Corporation (Assa Abloy AB)
• Original Assignee: Cross Match Technologies Incorporated (Assa Abloy AB)
• Inventors: McClurg, George W, Carver, John F, Zyzdryn, Gregory, Scott, Walter G
• Primary Examiner(s): Do; Anh Hong
• Application Number:
  US10/345,420
• Publication Number:
  US 20030142856A1
• Time in Patent Office: 1,545 Days
• Field of Search: 382/124, 382/125, 382/112, 382/116, 382/115, 293/46, 198/396, 358/1.14, 340/5.83
• US Class Current: 382/115
• CPC Class Codes: G06V 10/993 Evaluation of the quality of the acquired pattern
• CPC Class Codes: G06V 40/1324 by using geometrical optics, e.g. using prisms G06V40/1312 takes precedence
• CPC Class Codes: G06V 40/67 by interactive indications to the user

Abstract

A method and system of obtaining a ten-print plain impression fingerprint includes scanning a print image, processing the scanned image, separating the processed image into individual fingerprint images, and determining how many print images have been scanned. The method also includes comparing the print image to a previously scanned print image, quality classifying the separated images, indicating a quality classification of the print image based on the classifying step, and determining whether the print image is of a good quality. The system can include a ten-print scanner having a finger guide and a platen used to position four finger slaps onto the platen.

Claims

1. A method for capturing and quality classifying fingerprint images, the method comprising:

(a) scanning a plurality of fingers substantially simultaneously;

(b) capturing data representing a combined image of a corresponding plurality of fingerprints;

(c) using concentrations of black pixels arranged in oval-like shapes in the combined image to determine individual fingerprint areas and shapes;

(d) separating the combined image into individual fingerprint images;

(e) comparing each of the separated individual fingerprint images to a corresponding previously captured acceptable fingerprint image;

(f) quality classifying the separated individual fingerprint images as being either acceptable, possibly acceptable, or unacceptable according to the comparing step (e);

(g) indicating the quality classification of each of the individual fingerprint images based on the quality classifying step (f); and

(h) determining whether the processed combined image is of a good quality.

2. The method of claim 1, further comprising:

(d1) determining whether the combined image is a first image captured, wherein when the combined image is the first image captured, the method repeats steps (a)–

(d) and the determining step (d1) before performing steps (e)–

(g).

3. The method of claim 1, further comprising:

determining whether the combined image is a first image captured, wherein when the combined image is not the first image captured, the method continues onto steps (e)–

(g).

4. The method of claim 1, wherein step (c) comprises:

(c1) filtering the combined image;

(c2) binarizing the filtered combined image;

(c3) detecting the individual fingerprint areas based on the concentrations of the black pixels in the binarized combined image;

(c4) detecting the individual fingerprint shapes based on arrangements of the concentrated black pixels in oval-like shapes in the binarized combined image; and

(c5) determining whether the individual fingerprint areas and shapes are acceptable.

5. The method of claim 4, wherein when the determining step (c5) determines whether each of the individual fingerprint areas and shapes are acceptable, then the method continues onto step (d).

6. The method of claim 4, wherein when the determining step (c5) determines each of the individual fingerprint areas and shapes are unacceptable, then the method returns to the scanning step (a).

7. The method of claim 1, wherein when the determining step (h) determines the combined image is of the good quality, the method further comprises:

(i) determining whether the combined image is captured from a left or a right hand.

8. The method of claim 7, wherein the determining step (i) comprises:

(i1) determining whether the combined image represents at least one finger that is positioned at a diagonal with respect to a section of a platen included in a scanner.

9. The method of claim 8, wherein when the determining step (i1) determines the finger is at a diagonal, the method further comprises:

(i2a) determining whether the diagonal is at an angle greater than 90°

.

10. The method of claim 9, wherein when the determining step (i2a) determines the diagonal is at an angle greater than 90°

, an output indicates the combined image is from a right hand.

11. The method of claim 9, wherein when the determining step (i2a) determines the diagonal is at an angle less than 90°

, an output indicates the combined image is from a left hand.

12. The method of claim 8, wherein when the determining step (i1) determines the finger is not at a diagonal, the method further comprises:

(i2b) determining whether a longest finger is on a right side of a finger guide coupled to the platen.

13. The method of claim 12, wherein when the determining step (i2b) determines the longest finger is on the right side of the finger guide, an output indicates the combined image is from a left hand.

14. The method of claim 12, wherein when the determining step (i2b) determines the longest finger is on a left side of the finger guide, an output indicates the combined image is from a right hand.

15. The method of claim 1, wherein when the determining step (h) determines the image is of a bad quality, the method further comprises determining whether a predetermined time period has expired.

16. The method of claim 15, wherein when the predetermined time period has expired, an output is generated indicating that a user can switch to a manual mode.

17. The method of claim 15, wherein when the predetermined time period is unexpired, the method returns to the scanning step (a).

18. The method of claim 4, wherein the determining step (c5) compares previous acceptable images to the binarized image to determine acceptability.

19. A method for capturing and processing a fingerprint image, the method comprising:

(a) scanning one or more fingers;

(b) capturing data representing a corresponding fingerprint image;

(c) filtering the fingerprint image;

(d) binarizing the filtered fingerprint image;

(e) detecting a fingerprint area based on a concentration of black pixels in the binarized fingerprint image;

(f) detecting a fingerprint shape based on an arrangement of the concentrated black pixels in an oval-like shape in the binarized fingerprint image; and

(g) determining whether the detected fingerprint area and shape are of an acceptable quality.

20. The method of claim 19, wherein when the determining steps (e) and (f) detect a plurality of acceptable fingerprint areas and shapes in the binarized image, then the method further comprises:

(h) separating the binarized image into individual fingerprint images.

21. The method of claim 19, wherein when the determining step (g) determines the fingerprint area and shape are unacceptable, then the method returns to step (a).

22. The method of claim 19, wherein the determining step (g) compares previous acceptable images to the binarized fingerprint image to determine acceptability.

23. A method of processing fingerprints, the method comprising:

(a) scanning at least one finger placed on a platen of a scanner;

(b) capturing data representing a corresponding fingerprint image; and

(c) determining whether the fingerprint image includes data of an acceptable quality representative of at least one finger positioned at a diagonal relative to a section of the platen to thereby determine if the fingerprint image is from a left hand or a right hand based on detecting areas with concentrations of black pixels arranged in oval-like shapes in a binarized image.

24. The method of claim 23, wherein when the determining step (c) determines the finger is at a diagonal, the method further comprises:

(c1) determining whether the diagonal is at an angle greater than 90°

.

25. The method of claim 24, wherein when the determining step (c1) determines the diagonal is at an angle greater than 90°

, an output indicates the fingerprint image is from a right hand.

26. The method of claim 24, wherein when the determining step (c1) determines the diagonal is at an angle less than 90°

, an output indicates the fingerprint image is from a left hand.

27. The method of claim 23, wherein when the determining step (c) determines the image is not at a diagonal, the method further comprises:

(c2) determining whether a longest finger is on a right side of a finger guide coupled to the platen.

28. The method of claim 27, wherein when the determining step (c2) determines the longest finger is on the right side of the finger guide, an output indicates the fingerprint image is from a left hand.

29. The method of claim 27, wherein when the determining step (c2) determines the longest finger is on a left side of the finger guide, an output indicates the fingerprint image is from a right hand.

30. A system for capturing and quality classifying fingerprint images, the system comprising:

means for scanning a plurality of fingers substantially simultaneously;

means for capturing data representing a combined image of a corresponding plurality of fingerprints;

means for determining individual fingerprint areas and shapes based on concentrations of black pixels arranged in oval-like shapes in the combined image;

means for separating the combined image into individual fingerprint images;

means for comparing each of the separated individual fingerprint images to a corresponding previously obtained acceptable fingerprint image;

means for quality classifying the separated individual fingerprint images as being either acceptable, possibly acceptable, or unacceptable according to the comparison;

means for indicating a quality classification of each of the individual fingerprint images based on the means for quality classifying; and

means for determining whether the processed combined image is of a good quality.

31. The system of claim 30, further comprising:

means for determining how many of the combined images have been captured.

32. The system of claim 30, wherein the means for determining individual fingerprint areas and shapes comprises:

means for filtering the combined image of the plurality of fingerprints;

means for binarizing the filtered combined image;

means for detecting a fingerprint area based on the concentrations of black pixels in the binarized image;

means for detecting a fingerprint shape based on arrangements of the concentrated black pixels in oval-like shapes in the binarized image; and

means for determining whether the individual fingerprint areas and shapes are acceptable.

33. The system of claim 30, further comprising:

means for determining whether the combined image is captured from a left or a right hand.

34. The system of claim 33, wherein the means for determining left or right hand comprises means for determining whether the combined image includes an image representative of at least one finger positioned at a diagonal relative to a section of a platen included in a scanner.

35. The system of claim 33, wherein the means for determining left or right hand comprises means for determining whether a longest finger is on a right side or a left side of a finger guide coupled to the platen.

36. A system for capturing and processing data representative of a fingerprint image, the system comprising:

means for scanning one or more fingers;

means for capturing the data representing the fingerprint image;

means for filtering the fingerprint image;

means for binarizing the filtered fingerprint image;

means for detecting a fingerprint area based on a concentration of black pixels in the binarized fingerprint image;

means for detecting a fingerprint shape based on an arrangement of concentrated black pixels in oval-like shape in the binarized fingerprint image; and

means for determining whether the detected fingerprint area and shape are of acceptable quality.

37. The system of claim 36, further comprising means for separating the binarized fingerprint image into individual fingerprint images, if a plurality of acceptable fingerprint areas and shapes are detected.

38. A system for processing fingerprints, the system comprising:

means for scanning at least one finger placed on a platen;

means for generating data representative of a fingerprint image associated with the at least one finger; and

means for determining whether the at least one finger is from a left or a right hand, based on concentrations and arrangements of black pixels in a binarized fingerprint image.

39. The system of claim 38, wherein the means for determining comprises means for determining whether a longest finger is on a right side or a left side of a finger guide coupled to the platen.

40. The system of claim 38, wherein the means for determining comprises means for determining whether the captured fingerprint image includes an image representative of at least one finger positioned at a diagonal relative to a section of the platen.

41. A system, comprising:

a platen that receives a plurality of fingers or thumbs;

a scanner that substantially simultaneously scans the plurality of fingers or thumbs on the platen;

an image capturer that captures data representing a corresponding combined fingerprint image of the plurality of fingers or thumbs;

a processor that processes the combined fingerprint image;

a separator that separates the processed combined fingerprint image into individual fingerprint images;

a comparator that compares the captured fingerprint image to a previously obtained acceptable fingerprint image;

a classifier that classifies each of the separated individual fingerprint images as being either acceptable, possibly acceptable, or unacceptable according to results of the comparison;

an output device that indicates a classification of each of the individual fingerprint images based on the classifier; and

an image quality determining device that determines whether the captured combined fingerprint image is of a good quality.

42. The system of claim 41, wherein the processor comprises:

a filter that filters the combined fingerprint image; and

a binarizor that binarizes the filtered combined fingerprint image.

43. The system of claim 42, wherein the processor further comprises:

an area determining device that determines an area of each of the individual fingerprint image based on a concentration of black pixels in the binarized combined image.

44. The system of claim 42, wherein the processor further comprises:

a shape determining device that determines a shape of each of the individual fingerprint images based on an arrangement of concentrated black pixels in oval-like shape in the binarized combined image.

45. The system of claim 41, further comprising a hand determination device that determines which hand(s) the plurality of fingers or thumbs belongs to.