PRINT MATCHING METHOD AND APPARATUS USING PSEUDO-RIDGES

• US 20080101662A1
• Filed: 10/31/2006
• Published: 05/01/2008
• Est. Priority Date: 10/31/2006
• Status: Abandoned Application

• Current Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: LUO, YING, LO, PETER Z.
• Application Number:
  US11/554,720
• Publication Number:
  US 20080101662A1
• Time in Patent Office: Days
• US Class Current: 382/124
• CPC Class Codes: G06V 40/1359 Extracting features related to ridge properties; Determining the fingerprint type, e.g. whorl or loop
• CPC Class Codes: G06V 40/1365 Matching; Classification

Abstract

A method for comparing a search print image comprising a first plurality of minutiae to a file print image comprising a second plurality of minutiae and the apparatus implementing the method is provided. The method includes the steps of: aligning the search and file print images; obtaining the first and second plurality of minutiae, a first plurality of pseudo-ridges generated from a first direction field of the search print image and a second plurality of pseudo-ridges generated from a second direction field of the file print image; for each aligning of the search and file print images, generating a pseudo-ridge score, and determining a minutiae matching score; and providing, based on the pseudo-ridge and minutiae matching scores, an output that indicates a level of similarity between the search and file print images.

Claims

1. A method for comparing a search print image comprising a first plurality of minutiae to a file print image comprising a second plurality of minutiae, the method comprising the steps of:

aligning the search and file print images based on at least one parameter;

obtaining the first and second plurality of minutiae, a first plurality of pseudo-ridges generated from a first direction field of the search print image and a second plurality of pseudo-ridges generated from a second direction field of the file print image;

for each aligning of the search and file print images,

comparing the first and second plurality of pseudo-ridges and generating a pseudo-ridge score, and

determining a set of mated minutiae between the first and second plurality of minutiae and a corresponding minutiae matching score; and

providing, based on the pseudo-ridge and minutiae matching scores, an output that indicates a level of similarity between the search and file print images.

2. The method of claim 1, wherein the search and file prints images are one of fingerprint images and palm print images.

3. The method of claim 1, wherein the output comprises at least one of a set of mated minutiae provided to a secondary matcher stage and a combined score based on the pseudo-ridge and minutiae matching scores that were determined.

4. The method of claim 3 further comprising the step of comparing each of the determined pseudo-ridge and minutiae matching scores to a corresponding threshold to generate the combined score.

5. The method of claim 4 further comprising the step of selecting a score from the determined pseudo-ridge and minutiae matching scores based on the step of comparing the scores to the corresponding thresholds, wherein the combined score comprises the selected score.

6. The method of claim 5, wherein the determined pseudo-ridge and minutiae matching scores comprises:

a first pseudo-ridge score and a first minutiae matching score determined from aligning the search and file print images based on the first and second plurality minutiae; and

a second pseudo-ridge score and a second minutiae matching score determined from aligning the search and file print images based on a first set of global features identified from the search print image and a second set of global features identified from the file print image; and

the combined score is selected from the four generated pseudo-ridge and minutiae matching scores.

7. The method of claim 3 further comprising the step of calculating the combined score based on a function of the determined pseudo-ridge and minutiae matching scores.

8. The method of claim 7, wherein the determined pseudo-ridge and minutiae matching scores comprises one pseudo ridge score and one minutiae matching score.

9. The method of claim 3, wherein a first set of mated minutiae and corresponding first minutiae matching score is determined from a first aligning of the search and file print images based on a first parameter and at least a second set of mated minutiae and corresponding second minutiae matching score is determined from a second aligning of the search and file print images based on a second different parameter, the method further comprising the step of:

selecting a larger of the first and the at least a second minutiae matching scores, wherein the set of mated minutiae provided to the secondary matching stage corresponds to the selected larger score.

10. The method of claim 9, wherein:

the first aligning is based on the first and second plurality minutiae; and

the second aligning is based on a first set of global features identified from the search print image and a second set of global features identified from the file print image.

11. The method of claim 1, wherein aligning the search and file print images based on at least one parameter comprises:

aligning the search and file print images based on the first and second plurality minutiae; and

aligning the search and file print images based on a first set of global features identified from the search print image and a second set of global features identified from the file print image.

12. The method of claim 11, wherein the first and second set of global features each comprise at least one of a core, a delta, an arch, a loop and a whorl.

13. The method of claim 11, wherein:

a first pseudo-ridge score and a first minutiae matching score is generated from the aligning based on the first and second plurality of minutiae;

a second pseudo-ridge score and a second minutiae matching score is generated from the aligning based on the first and second set of global features; and

the output is based on the four pseudo-ridge and minutiae matching scores.

14. Apparatus for comparing a search print image comprising a first plurality of minutiae to a file print image comprising a second plurality of minutiae, the apparatus comprising:

an interface receiving the search and file print images; and

a processing device coupled to the interface, the processing device,

aligning the search and file print images based on at least one parameter;

obtaining the first and second plurality of minutiae, a first plurality of pseudo-ridges generated from a first direction field of the search print image and a second plurality of pseudo-ridges generated from a second direction field of the file print image;

for each aligning of the search and file print images,

comparing the first and second plurality of pseudo-ridges and generating a pseudo-ridge score, and

determining a set of mated minutiae between the first and second plurality of minutiae and a corresponding minutiae matching score; and

providing, based on the pseudo-ridge and minutiae matching scores, an output that indicates a level of similarity between the search and file print images.

15. The apparatus of claim 14, wherein the apparatus is included in an Automatic Fingerprint Identification System (AFIS).

16. The apparatus of claim 14, wherein the processing device comprises at least one of:

a microprocessor executing code;

an Application Specific Integrated Circuit (ASIC), a field programmable gate array (FPGA) and a state machine.

17. A computer-readable storage element having computer readable code stored thereon for programming a computer to perform a method for comparing a search fingerprint image comprising a first plurality of minutiae to a file fingerprint image comprising a second plurality of minutiae, the method comprising the steps of:

aligning the search and file fingerprint images based on at least one parameter;

obtaining the first and second plurality of minutiae, a first plurality of pseudo-ridges generated from a direction field of the search fingerprint image and a second plurality of pseudo-ridges generated from a direction field of the file fingerprint image;

for each aligning of the search and file fingerprint images,

comparing the first and second plurality of pseudo-ridges and generating a pseudo-ridge score, and

determining a set of mated minutiae between the first and second plurality of minutiae and a corresponding minutiae matching score; and

providing, based on the pseudo-ridge and minutiae matching scores, an output that indicates a level of similarity between the search and file fingerprint images.

18. The computer-readable storage medium of claim 17, wherein the computer readable storage medium comprises at least one of a hard disk, a CD-ROM, an optical storage device and a magnetic storage device.