Apparatus and method for determining sequencing of fingers in images to a two-finger scanner of fingerprint images

• US 20110157346A1
• Filed: 11/12/2010
• Published: 06/30/2011
• Est. Priority Date: 11/11/2009
• Status: Active Grant

• Current Assignee: HID Global Corporation (Assa Abloy AB)
• Original Assignee: Cross Match Technologies Incorporated (Assa Abloy AB)
• Inventors: Zyzdryn, Grzegorz, Raguin, Daniel H.
• Granted Patent: US 9,280,695 B2
• Time in Patent Office: Days
• US Class Current: 348/77
• CPC Class Codes: G06V 40/1324 by using geometrical optics, e.g. using prisms G06V40/1312 takes precedence
• CPC Class Codes: G06V 40/1347 Preprocessing; Feature extraction

Abstract

An apparatus (10) for capturing fingerprint images having a platen (21) sized for at most two fingers of a hand, and an imaging system for enabling capture of fingerprint images presented to the platen (21), in which images of two different finger pairs are captured for each hand of a subject when presented to the platen. At least one processor (27) which determines for each of the images captured a difference in height of at least one characteristic of the fingers in the image. Using said difference in height of the fingers in each of the images, the processor (27) verifies that the correct sequence of specific ones of finger pair was provided by the subject to the platen when images were captured. Fingerprint images acquired from the images may be stored in an electronic record along with thumb prints and subject information, and optionally the height differences for the images.

Claims

1. An apparatus for capturing images of fingerprints comprising:

a platen sized for at most two fingers of a hand of a subject;

an imaging system for capturing images of two different finger pairs of each hand of a subject when presented to said platen; and

at least one processor which determines in each of the images a difference in height of at least one characteristic of fingers in the image, and verifies that specific ones of finger pairs was presented by the subject to the platen after one or more said images were captured using said difference in height determined for said one or more said images.

2. The apparatus according to claim 1 wherein for each of said images said at least one processor uses the difference in height associated with the image as being indicative of the sequence each finger of the finger pair in the image was situated when presented to the platen for imaging by the imaging system.

3. The apparatus according to claim 1 wherein said at least one processor uses the difference in height determined for two of the images each associated with different finger pairs of the same hand as being indicative of the sequence the finger pairs of said two of the images were each presented to the platen for imaging by the imaging system.

4. The apparatus according to claim 1 wherein said at least one processor uses the difference in height determined for two of the images each associated with corresponding ones of finger pairs of a different hand of the subject as being indicative of the sequence the finger pairs of said two of the images were each presented to the platen for imaging by the imaging system by being approximately the same in absolute magnitude.

5. The apparatus according to claim 1 wherein said at least one processor acquires fingerprint images for each of said images and verifies that no two fingerprint images are from the same finger of the subject.

6. The apparatus according to claim 1 wherein said imaging system utilizes said a least one processor.

7. The apparatus according to claim 1 wherein said processor determines said difference in the height of each of said images by determining the direction of at least one of said fingers in the image, and said difference in height is the difference in the relative position of the ends of the fingers in the image along said direction.

8. The apparatus according to claim 7 wherein said processor determines the direction of least one of said fingers in accordance with a linear direction of image elements representing of one of said fingers, or approximately perpendicular to a linear direction associated with image elements representing a crease in said at least one of said fingers.

9. The apparatus according to claim 1 wherein said processor determines said difference in the height of each of said images by determining direction and angle of rotation of at least one of said fingers in the image with respect to one of two axes associated with the image and rotates the image or points associated with the image in accordance with said angle of rotation to align the fingers in the image along said direction with one of said two axis of the image, and said difference in height is the difference in the relative position of the ends of the fingers in the image along said aligned one of said two axis of the image.

10. The apparatus according to claim 9 wherein said processor determines the direction of least one of said fingers in accordance with a linear direction of image elements representing of one of said fingers, or approximately perpendicular to a linear direction associated with image elements representing a crease in said at least one of said fingers.

11. The apparatus according to claim 1 further comprising memory, wherein said at least one processor acquires fingerprint images from each of said images and stores said fingerprint images in an electronic record for the subject in said memory.

12. The apparatus according to claim 1 further comprising memory, wherein said at least one processor stores the difference in height of said least one characteristic of fingers for each of the said images in said memory.

13. The apparatus according to claim 1 wherein for each of the images said characteristic is the highest point of each of the fingers of the image.

14. The apparatus according to claim 1 wherein for each of the images said characteristic is a corresponding crease of each of the fingers in the image.

15. The apparatus according to claim 14 wherein said corresponding crease is the crease closest to the tip of each of the fingers.

16. The apparatus according to claim 1 wherein for each of the images said characteristic is the distance from the highest point to the crease closest to the highest point of each of the fingers of the image

17. The apparatus according to claim 1 further comprising means for limiting the amount of rotation of fingers when presented to the platen to enable the fingers to extend in a direction at least approximate with one of axes of images captured by the imaging system.

18. A system for capturing fingerprint images comprising:

means for enabling capture of fingerprint images presented to a platen sized for at most two fingers of a hand, in which two images of two different finger pairs are captured for each hand of a subject; and

means for processing images captured to determine one or more characteristic of fingers in the images as to whether the fingers captured in each of the images correspond to specific ones of the fingers when presented to the platen.

19. The system according to claim 18 wherein said one or more characteristics is one or more of highest point of each of the fingers of the image, or in accordance with the location of a crease of each of the fingers in the image.

20. A method for capturing images of fingerprints upon a platen sized for at most two fingers of a hand of a subject comprising the steps of:

capturing images of two different finger pairs of each hand of a subject when presented to a platen; and

determining in each of the images a difference in height of at least one characteristic of fingers in the image;

verifying that specific ones of finger pairs was presented by the subject to the platen after one or more said images were captured using said difference in height determined for said one or more said images.

21. The method according to claim 20 wherein for each of the images said characteristic is one or more of highest point of each of the fingers of the image, or in accordance with the location of a crease of each of the fingers in the image.

22. A method for capturing fingerprint images of a subject on a finger print scanner having a platen comprising:

(a) prompting a subject to place one specific pair of fingers from one hand on a platen of a finger printer scanner;

(b) capturing an image of fingers presented on the platen after said prompting step is carried out;

(c) determining a difference in height of at least one characteristic of the fingers in the image; and

(d) determining whether the difference in height is consistent with a presentation of the two specific pair of fingers prompted for.

23. The method according to claim 22 wherein said difference in height presents a first difference in height, and said method further comprising the step of:

(e) prompting the subject to place a different one of said specific pair of fingers from said one hand on the platen of the finger print scanner;

(f) repeating said step (b) after said step (e) is carried out;

(g) determining a difference in height of the fingers in the image captured from step (f) to provide a second difference in height; and

(h) determining whether the difference between the first height difference and the second height difference is consistent with a presentation of said one of two pair of specific fingers and said different one of said two pairs of specific fingers when each was prompted for.

24. The method according to claim 23 further comprising the steps of:

(i) repeating steps (a) through (g) for a different one of the hand of the subject;

(j) determining whether the difference between the first height difference of said one of said hand is approximately the same as the first height difference of said different one of said hand; and

(k) determining whether the difference between the second height difference of said one of said hand is approximately the same as the second height difference of said different one of said hand.

25. The method according to claim 24 further comprising the step of:

storing fingerprints from said images in an electronic record.