Biometric imaging system and method

• US 20030142856A1
• Filed: 01/16/2003
• Published: 07/31/2003
• Est. Priority Date: 01/17/2002
• Status: Active Grant

• Current Assignee: HID Global Corporation (Assa Abloy AB)
• Original Assignee: Cross Match Technologies Incorporated (Assa Abloy AB)
• Inventors: McClurg, George W., Carver, John F., Scott, Walter G., Zyzdryn, Gregory
• Granted Patent: US 7,203,344 B2
• Time in Patent Office: Days
• US Class Current: 382/124
• 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 comprising:

(a) scanning a print image;

(b) processing the scanned image;

(c) separating the processed image into individual fingerprint images;

(d) comparing the print image to a previously scanned print image;

(e) quality classifying the separated images;

(f) indicating a quality classification of the print image based on the quality classifying step; and

(g) determining whether the print image is of a good quality.

2. The method of claim 1, further comprising:

determining how many print images have been scanned, wherein when the print image is a first image scanned, the method repeats steps (a)-(c) and the determining step before performing steps (d)-(g).

3. The method of claim 1, further comprising:

determining how many print images have been scanned, wherein when the print image is not the first image scanned, the method continues onto steps (d)-(g).

4. The method of claim 1, wherein the processing step (b) comprises:

(b1) filtering the print image;

(b2) binarizing the filtered image;

(b3) detecting a fingerprint area based on the binarized image;

(b4) detecting a fingerprint shape based on the binarized image; and

(b5) determining whether the fingerprint area and shape are acceptable.

5. The method of claim 4, wherein when the determining step (b5) determines the fingerprint area and shape are acceptable, then the method continues onto step (c).

6. The method of claim 4, wherein when the determining step (b5) determines the fingerprint area and shape are unacceptable, then the method returns to the scanning step (a).

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

(h) determining whether the print images is based on a left or a right hand.

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

(h1) determining whether the print image data represents at least one finger that is positioned at a diagonal with respect to a section of a platen.

9. The method of claim 8, wherein when the determining step (h1) determines the finger is at a diagonal, the method further comprises:

(h2a) determining whether the diagonal is greater than 90°

.

10. The method of claim 9, wherein when the determining step (h2a) determines the diagonal is greater than 90°

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

11. The method of claim 9, wherein when the determining step (h2a) determines the diagonal is less than 90°

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

12. The method of claim 8, wherein when the determining step (h1) determines the finger is not at a diagonal, the method further comprises:

(h2b) determining whether a longest finger is on a right side of a finger guide.

13. The method of claim 12, wherein when the determining step (h2b) determines the longest finger is on the right side of the finger guide, an output indicates the print image is from a left hand.

14. The method of claim 12, wherein when the determining step (h2b) determines the longest finger is on a left side of the finger guide, an output indicates the print image is from a right hand.

15. The method of claim 1, wherein when the determining step (g) 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 period is unexpired, the method returns to the scanning step (a).

18. The method of claim 4, wherein the determining step (b5) compares previous acceptable images to the binarized image to determine acceptability.

19. A method comprising:

(a) scanning a print image;

(b) filtering the print image;

(c) binarizing the filtered image;

(d) detecting a fingerprint area based on the binarized image;

(e) detecting a fingerprint shape based on the binairized image; and

(f) determining whether the fingerprint area and shape are acceptable.

20. The method of claim 19, wherein when the determining step (f) determines the fingerprint area and shape are acceptable, then the method further comprises:

(g) separating the print image into individual fingers.

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

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

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

(a) scanning a print image of at least one finger placed on a platen; and

(b) determining whether the scanned print image includes data representative of at least one finger positioned at a diagonal relative to a section of the platen.

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

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

.

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

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

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

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

27. The method of claim 23, wherein when the determining step (f) 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.

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 print 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 print image is from a right hand.

30. A system comprising:

means for scanning a print image;

means for processing the scanned image;

means for separating the processed image into individual fingerprint images;

means for comparing the print image to a previously scanned print image;

means for quality classifying the separated images;

means for indicating a quality classification of the print image based on the means for quality classifying; and

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

31. The system of claim 30, further comprising:

means for determining how many print images have been scanned.

32. The system of claim 30, wherein the means for processing comprises:

means for filtering the print image;

means for binarizing the filtered image;

means for detecting a fingerprint area based on the binarized image;

means for detecting a fingerprint shape based on the binarized image; and

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

33. The system of claim 30, further comprising:

means for determining whether the print images is based on 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 scanned print image includes data representative of at least one finger positioned at a diagonal relative to a section of the platen.

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

36. A system comprising:

means for scanning a print image;

means for filtering the print image;

means for binarizing the filtered image;

means for detecting a fingerprint area based on the binarized image;

means for detecting a fingerprint shape based on the binairized image; and

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

37. The system of claim 36, further comprising means for separating the print image into individual fingers.

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

means for scanning a print image of at least one finger placed on a platen; and

means for determining whether the at least on finger is from a left of right hand.

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.

40. The system of claim 38, wherein the means for determining comprises means for determining whether the scanned print image includes data 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 finger or thumb;

a scanner that scans the finger or thumb on the platen;

a processor that processes the scanned image;

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

a comparator that compares the print image to a previously scanned print image;

a classifier that classifies the separated images;

an output device that indicates a classification of the print image based on the classifier; and

an image quality determining device that determines whether the print image is of a good quality.

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

a filter that filters the scanned image; and

a binarizor that binarizes the filtered image.

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

an area determining device that determines an area of the scanned image based on the binarized image.

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

a shape determining device that determines a shape of the scanned image based on the binarized image.

45. The system of claim 41, further comprising a hand determination device that determines which had was scanned on the platen.