PATTERN VERIFICATION APPARATUS, PATTERN VERIFICATION METHOD, AND PROGRAM

• US 20100332487A1
• Filed: 01/13/2009
• Published: 12/30/2010
• Est. Priority Date: 02/19/2008
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Monden, Akira
• Granted Patent: US 8,340,370 B2
• Time in Patent Office: Days
• US Class Current: 707/758
• CPC Class Codes: G06V 40/1365 Matching; Classification

Abstract

When a false matching rate depends on data for evaluation, there is a possibility that the accuracy of pattern authentication could deteriorate in an actual operation. A pattern verification apparatus includes a correction value calculation unit that generates a plurality of unit area pairs by associating each of a plurality of unit areas generated by dividing a second pattern with each of a plurality of unit areas generated by dividing a first pattern according to a degree of similarity of a pattern, and calculates a correction value, which is suitable for matching or approximating unique feature values of the respective unit areas of the mutually associated unit areas, on the unit area pair basis; a difference value calculation unit that calculates a difference value indicating a difference between the correction values based on a comparison of the correction values between the unit area pairs that are positioned spatially adjacent to each other; and a verification evaluation value calculation unit that calculates a verification evaluation value according to a verification result between a condition indicating that patterns belong to mutually different categories and a plurality of difference values calculated by the difference value calculation unit.

Claims

1. A pattern verification apparatus comprising:

a correction value calculation unit that generates a plurality of unit area pairs by associating each of a plurality of unit areas generated by dividing a second pattern with each of a plurality of unit areas generated by dividing a first pattern according to a degree of similarity of a pattern, and calculates a correction value, which is suitable for matching or approximating unique feature values of the respective unit areas of the mutually associated unit areas, on the unit area pair basis;

a difference value calculation unit that calculates a difference value indicating a difference between the correction values based on a comparison of the correction values between the unit area pairs that are positioned spatially adjacent to each other; and

a verification evaluation value calculation unit that calculates a verification evaluation value according to a verification result between a condition indicating that patterns belong to mutually different categories and a plurality of difference values calculated by the difference value calculation unit.

2. The pattern verification apparatus according to claim 1, wherein each of the first and second patterns has a distribution in which the difference value between the feature values of mutually adjacent unit areas in a case where same categories are compared is stochastically smaller than a difference value in a case where different categories are compared.

3. The pattern verification apparatus according to claim 1, wherein the verification evaluation value calculation unit performs calculation in which the verification evaluation value does not change widely as a result of being affected by the difference value having a large absolute value.

4. The pattern verification apparatus according to claim 1, wherein the condition indicating that patterns belong to mutually different categories defines a state where random numbers are randomly arranged.

5. The pattern verification apparatus according to claim 1, further comprising a determination unit that determines a verification result based on a comparison between the verification evaluation value and a threshold.

6. The pattern verification apparatus according to claim 1, wherein

the first pattern is a pattern registered in advance in an internal or external storage medium, and

the second pattern is a pattern captured by an internal or external pattern acquisition device every time pattern comparison is performed.

7. The pattern verification apparatus according to claim 1, wherein the feature value is a value indicating a positional deviation of the second pattern with respect to the first pattern.

8. The pattern verification apparatus according to claim 7, wherein the correction value calculation unit performs at least first processing that performs alignment of the second pattern against the first pattern based on similarity between patterns, and second processing that performs alignment of the unit area of the first pattern against the unit area of the second pattern based on similarity between patterns.

9. The pattern verification apparatus according to claim 7, wherein a calculation method of the feature value is determined according to an aspect of a pattern that is to be verified.

10. A pattern verification method to perform verification of a pattern, comprising:

generating a plurality of unit area pairs by associating each of a plurality of unit areas generated by dividing a second pattern with each of a plurality of unit areas generated by dividing a first pattern according to a degree of similarity of a pattern, and calculates a correction value, which is suitable for matching or approximating unique feature values of the respective unit areas of the mutually associated unit areas, on the unit area pair basis;

a difference value calculation unit of the computer calculates calculating a difference value indicating a difference between the correction values based on a comparison of the correction values between the unit area pairs that are positioned spatially adjacent to each other; and

calculating a verification evaluation value according to a verification result between a condition indicating that patterns belong to mutually different categories and a plurality of difference values calculated by the difference value calculation unit.

11. The pattern verification apparatus according to claim 10, determining a verification result based on a comparison between the verification evaluation value and a threshold.

12. The pattern verification method according to claim 10, wherein each of the first and second patterns has a distribution in which the difference value between the feature values of the unit areas positioned mutually adjacent positions in a case where same categories are compared is stochastically smaller than a difference value in a case where different categories are compared.

13. The pattern verification method according to claim 10, said calculating for the verification evaluation value is performed such that the verification evaluation value does not change widely as a result of being affected by the difference value having a large absolute value.

14. The pattern verification method according to claim 10, wherein the condition indicating that patterns belong to mutually different categories defines a state where random numbers are randomly arranged.

15. A non-transitory computer readable medium storing a computer program that causes a computer to perform pattern matching, the computer program causing the computer to:

generate a plurality of unit area pairs by associating each of a plurality of unit areas generated by dividing a second pattern with each of a plurality of unit areas generated by dividing a first pattern according to a degree of similarity of a pattern, and calculates a correction value, which is suitable for matching or approximating unique feature values of the respective unit areas of the mutually associated unit areas, on the unit area pair basis;

calculate a difference value indicating a difference between the correction values based on a comparison of the correction values between the unit area pairs that are positioned spatially adjacent to each other; and

calculate a verification evaluation value according to a verification result between a condition indicating that patterns belong to mutually different categories and a plurality of difference values calculated by the difference value calculation unit.

16. The non-transitory computer readable medium according to claim 15, wherein each of the first and second patterns has a distribution in which the difference value between the feature values of the unit areas positioned mutually adjacent positions in a case where same categories are compared is stochastically smaller than a difference value in a case where different categories are compared.

17. The non-transitory computer readable medium according to claim 15, wherein the computer program further causes the computer to perform calculation in which the verification evaluation value does not change widely as a result of being affected by the difference value having a large absolute value.

18. The non-transitory computer readable medium according to claim 15, wherein the condition indicating that patterns belong to mutually different categories defines a state where random numbers are randomly arranged.