Print analysis

• US 20050152586A1
• Filed: 02/10/2005
• Published: 07/14/2005
• Est. Priority Date: 01/13/2004
• Status: Abandoned Application

• Current Assignee: TRI-D Systems, Inc.
• Original Assignee: TRI-D Systems, Inc.
• Inventors: Shatford, Will
• Application Number:
  US11/054,801
• Publication Number:
  US 20050152586A1
• Time in Patent Office: Days
• US Class Current: 382/124
• CPC Class Codes: G06V 40/1376 Matching features related to ridge properties or fingerprint texture

Abstract

A method for print analysis comprising extracting a plurality of block segments from a subject print, detecting a ridge line in each of said plurality of block segments, assigning a first directional value to each of said plurality of block segments, said first directional value corresponding to an orientation position of said ridge line, comparing each of said first directional values with a corresponding second directional value of a template print to determine if a match exists between each sample from said subject print and a corresponding sample from said template print, and affirming verification of said subject print if the number of block segments from said subject print that are determined to match said template print exceeds a predetermined value.

Claims

1. A method for print analysis comprising:

extracting a plurality of block segments from a subject print;

detecting a ridge line in each of said plurality of block segments;

assigning a first directional value to each of said plurality of block segments, said first directional value corresponding to an orientation position of said ridge line;

comparing each said first directional value with a corresponding second directional value of a template print to determine if a match exists between each block segment from said subject print and a corresponding block segment from said template print; and

affirming verification of said subject print if the number of block segments from said subject print that are determined to match said template print exceeds a predetermined value.

2. The method as set forth in claim 1, wherein said extracting step comprises:

obtaining a print from a pad sensor; and

superimposing a grid on said print to divide said print into block segments.

3. The method as set forth in claim 1, wherein said detecting step comprises:

evaluating a plurality of pixels contained within a block segment using a bi-modal distribution; and

identifying a ridge line based on said evaluating step.

4. The method as set forth in claim 1, wherein said assigning step comprises:

assigning a value between 0 and 179 to said ridge line representative of an angle relative to horizontal.

5. The method as set forth in claim 1, wherein said extracting step comprises:

obtaining a snapshot from a swipe sensor; and

superimposing a grid on said snapshot to divide said print into block segments.

6. The method as set forth in claim 1, wherein said comparing step comprises:

comparing said first directional value for each block segment to said corresponding second directional value of said template; and

determining a match if said first directional value is within a predetermined tolerance of said second directional value.

7. The method as set forth in claim 1, wherein said affirming step comprises:

computing a ratio of matching block segments from said plurality of block segments to total block segments in said plurality of block segments; and

affirming verification when said ratio exceeds a pre-selected ratio.

8. The method as set forth in claim 1, further comprising:

obtaining a personal identification number from a user;

comparing said personal identification number to a stored personal identification number associated with said user; and

denying verification unless both (i) the number of block segments from said subject print that are determined to match said template print exceeds a predetermined value, and (ii) said personal identification number matches said stored person identification number.

9. The method as set forth in claim 1, further comprising:

entering an identifying card by a user; and

denying verification unless both (i) the number of block segments from said subject print that are determined to match said template print exceeds a predetermined value and (ii) said identifying card is recognized as being associated said user.

10. The method as set forth in claim 8, further comprising:

entering an identifying card by a user; and

denying verification unless both (i) the number of block segments from said subject print that are determined to match said template print exceeds a predetermined value and (ii) said identifying card is recognized as being associated with said user.

11. A system for print analysis comprising:

means for extracting a plurality of block segments from a subject print;

means for detecting a ridge line in each of said plurality of block segments;

means for assigning a first directional value to each of said plurality of block segments, said first directional value corresponding to an orientation position of said ridge line;

means for comparing each said first directional value with a corresponding second directional value of a template print to determine if a match exists between each sample from said subject print and a corresponding sample from said template print; and

means for affirming verification of said subject print if the number of block segments from said subject print that are determined to match said template print exceeds a predetermined value.

12. A computer program product comprising a computer useable medium having program logic stored thereon, wherein said program logic comprises machine readable code executable by a computer, wherein said machine readable code comprises instructions for:

extracting a plurality of block segments from a subject print;

detecting a ridge line in each of said plurality of block segments;

assigning a first directional value to each of said plurality of block segments, said first directional value corresponding to an orientation position of said ridge line;

comparing each said first directional value with a corresponding second directional value of a template print to determine if a match exists between each sample from said subject print and a corresponding sample from said template print; and

affirming verification of said subject print if the number of block segments from said subject print that are determined to match said template print exceeds a predetermined value.

13. The computer program product as set forth in claim 12, wherein the instructions for extracting comprise instructions for:

obtaining a print from a pad sensor; and

superimposing a grid on said print to divide said print into block segments.

14. The computer program product as set forth in claim 12, wherein the instructions for detecting comprise instructions for:

evaluating a plurality of pixels contained within a sample using a bi-modal distribution; and

identifying a ridge line based on said evaluating step.

15. The computer program product as set forth in claim 12, wherein the instructions for assigning comprise instructions for:

assigning a value between 0 and 179 to said ridge line representative of an angle relative to horizontal.

16. The computer program product as set forth in claim 12, wherein the instructions for extracting comprise instructions for:

obtaining a snapshot from a swipe sensor; and

superimposing a grid on said snapshot to divide said print into block segments.

17. The computer program product as set forth in claim 12 wherein the instructions for comparing comprise instructions for:

comparing said first directional value for each segment to said corresponding second directional value of said template; and

determining a match if said first directional value is within a predetermined tolerance of said second directional value.

18. The computer program product as set forth in claim 12, wherein the instructions for affirming comprise instructions for:

computing a ratio of matching block segments from said plurality of block segments to total block segments in said plurality of block segments; and

affirming verification when said ratio exceeds a pre-selected ratio.

19. The computer program product as set forth in claim 12, further comprising instructions for:

obtaining a personal identification number from a user;

comparing said personal identification number to a stored personal identification number associated with said user; and

denying verification unless both (i) the number of block segments from said subject print that are determined to match said template print exceeds a predetermined value, and (ii) said personal identification number matches said stored person identification number.

20. The computer program product as set forth in claim 12, further comprising instructions for:

entering an identifying card by a user; and

denying verification unless both the number of block segments from said subject print that are determined to match said template print exceeds a predetermined value and said identifying card is associated with said template print.