Biometric authentication device, authentication accuracy evaluation device and biometric authentication method

• US 8,374,401 B2
• Filed: 06/08/2010
• Issued: 02/12/2013
• Est. Priority Date: 06/11/2009
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Endoh, Toshio, Sugimura, Yuka
• Primary Examiner(s): Bali, Vikkram
• Application Number:
  US12/795,924
• Publication Number:
  US 20100316261A1
• Time in Patent Office: 980 Days
• Field of Search: None
• US Class Current: 382/115
• CPC Class Codes: G06V 10/758 Involving statistics of pixels or of feature values, e.g. histogram matching
• CPC Class Codes: G06V 40/1365 Matching; Classification
• CPC Class Codes: G06V 40/14 Vascular patterns

Abstract

A biometric authentication device includes a verification-image generation probability calculation unit for calculating a verification-image generation probability using a verification-image generation probability model, a change probability calculation unit for calculating a change probability of a set of a registration image and a verification image using a change probability model, a dissimilarity calculation unit for calculating the degree of dissimilarity on the basis of the verification-image generation probability and the change probability and an authentication unit for determining whether the verification image belongs to an authentication target by comparing the degree of dissimilarity with a predetermined authentication threshold.

Claims

1. A biometric authentication device, comprising:

a storage unit to store data indicating an initial-element generation probability of a blood vessel image, data indicating a branch probability of an element and data indicating a change coefficient or a change probability of the element, which are obtained by dividing a plurality of sets of a registration image and a verification image which indicate the blood vessel image of a living body into a plurality of respective elements;

a verification-image generation probability calculation unit to calculate an element generation probability of a focused-on element of a verification image to be authenticated, using the data indicating the generation probability of the initial element and the data indicating the branch probability which are stored in the storage unit and calculating a value obtained by multiplying the element generation probabilities of respective focused-on elements as a verification-image generation probability of the verification image to be authenticated;

a change probability calculation unit to calculate change probability of the change between the focused-on element of the verification image and the element of a registration image for a person to be authenticated, using the data indicating the change coefficient or the change probability which are stored in the storage unit and calculating a value obtained by multiplying the change probabilities of respective focused-on elements as a change probability of the verification image;

a dissimilarity or similarity calculation unit to calculate a degree of similarity or dissimilarity using the verification image generation probability and the change probability; and

an authentication unit to determine whether the verification image to be authenticated belongs to a registered person, in accordance with whether the degree of dissimilarity or similarity is more or less than a threshold.

2. The biometric authentication device according to claim 1, wherein

the verification-image generation probability calculation unit comprises

an initial-element generation probability calculation unit to calculate an initial-element generation probability of the verification image using the data indicating the generation probability of the initial element stored in the storage unit;

an element generation reference point determination unit to determine an element which becomes a generation reference point using a distance between the focused-on element of the verification image and an already-generated element;

an element generation probability calculation unit to calculate an element generation probability of the focused-on element using the data indicating the branch probability of the element stored in the storage unit; and

a multiplication unit to calculate a product of the initial-element generation probability and the element generation probabilities of respective elements as the verification-image generation probability data of the verification image to be authenticated.

3. The biometric authentication device according to claim 1, wherein

the change probability calculation unit comprises

an initial-element change probability calculation unit to calculate a distance between the initial element of the registration image and the focused-on element of the verification image, obtaining from the storage unit the data indicating the change coefficient or the change probability corresponding to the distance obtained by the calculation and calculating an initial-element change probability using the obtained data indicating the change coefficient or change probability and data indicating a generation probability of the initial element;

an element generation reference point determination unit to determine an element which becomes a generation reference point using a distance between the focused-on element and an already-generated element;

an element change probability calculation unit to calculate an element change probability of the focused-on element using the data indicating the branch probability of the element which is stored in the storage unit; and

a change probability calculation unit to calculate a product of the initial-element change probability and element change probabilities of respective focused-on elements as change probability of the registration image and the verification image to be authenticated.

4. The biometric authentication device according to claim 1, wherein

the storage unit stores initial-element generation evaluation value data as the data indicating an initial-element generation probability of the blood vessel image, stores element number evaluation value data as the data indicating the branch probability of the element and stores change coefficient data as the data indicating the change coefficient or the change probability of the verification image and the registration image and

the verification-image generation probability calculation unit comprises

an initial-element generation probability calculation unit to calculate initial-element generation probability of the verification image using the data indicating the initial-element generation probability stored in the storage unit;

an element generation reference point determination unit to determine an element which becomes a generation reference point using a distance between the focused-on element of the verification image and an already-generated element;

an element generation probability calculation unit for calculating element generation probability data of the focused-on element using the element number evaluation value data stored in the storage unit; and

a multiplication unit for calculating a product of the initial-element generation probability and the element generation probabilities of respective elements as the verification-image generation probability data of the verification image to be authenticated.

5. The biometric authentication device according to claim 4, wherein

the change probability calculation unit comprises

an initial-element change probability calculation unit to calculate a distance between an initial element of the registration image and the focused-on element of the verification image, to obtain from the storage unit the change coefficient data or the change probability corresponding to the calculated distance and to calculate an initial-element change probability using the obtained change coefficient data and the initial-element generation evaluation value data;

an element generation reference point determination unit to determine an element which becomes a generation reference point using a distance between the focused-on element and an already-generated element; and

an element change probability calculation unit to calculate an element change probability of the focused-on element using the generation element number evaluation value data stored in the storage unit.

6. The biometric authentication device according to claim 4, wherein

the element generation probability calculation unit comprises

an element number probability calculation unit to calculate a value obtained by dividing the element number evaluation value data of the corresponding focused-on element of the verification image by a sum of element number evaluation value data of branchable elements as element number probability data;

an element generation evaluation value calculation unit to calculate a n-th power of a distance between the focused-on element and an already-generated element as element generation evaluation value data; and

a multiplication unit to calculate a product of a value obtained by dividing the element generation evaluation value data of the focused-on element by a sum of the element generation evaluation value data of branchable elements and the element number probability data as the element generation probability.

7. The biometric authentication device according to claim 4, wherein

the change probability calculation unit comprises

an initial-element change probability calculation unit to calculate a distance between an initial element of the registration image and the focused-on element candidate of the verification image, to obtain from the storage unit the change coefficient data corresponding to the calculated distance and to calculate an initial-element change probability using the obtained change coefficient data and the initial-element generation evaluation value data;

an element change evaluation value calculation unit to calculate a n-th power of a distance between the focused-on element and an already-generated element as element generation evaluation value data, to obtain from the storage unit the change coefficient data corresponding to the distance and to calculate a product of the obtained change coefficient data and the element generation evaluation value as an element change evaluation value of the focused-on element;

an element change probability calculation unit to calculate an element change probability using a value obtained by dividing the element change evaluation value of the focused-on element by a sum of the element change evaluation values of branchable elements and an element number probability indicating a branch probability of the element obtained from the element number evaluation value; and

a multiplication unit to calculate a product of the initial-element change probability and the element change probabilities of respective elements as the change probability of the verification image.

8. A biometric authentication device, comprising:

a storage unit to store data indicating an initial-element generation probability of a blood vessel image, data indicating a branch probability of an element and data indicating a change coefficient or a change probability of the element, which is obtained by dividing a plurality of sets of a registration image and a verification image which indicate the blood vessel image of a living body into a plurality of respective elements;

a registration-image virtual generation unit to generate a registration-image by virtually generating a plurality of elements using the data indicating the initial-element generation probability and data indicating the branch probability of the element, which are stored in the storage unit;

a registration-image virtual generation probability calculation unit to calculate a registration-image virtual generation probability of the virtually generated registration image;

a registration-image generation probability calculation unit to calculate a registration-image generation probability of a registration image;

a first change probability calculation unit to calculate virtual change probabilities of the virtually generated registration image and the verification image;

a verification-image generation probability calculation unit to calculate a verification-image generation probability using the registration-image generation probability, the registration-image virtual generation probability and the virtual change probability;

a second change probability calculation unit to calculate a change probability of the registration image and the verification image to be authenticated;

a dissimilarity or similarity calculation unit to calculate a degree of similarity or dissimilarity using the verification-image generation probability and the change probability; and

an authentication unit to determine whether a verification image to be authenticated belongs to a registered person, in accordance with the degree of dissimilarity or similarity is more or less than a threshold.

9. The biometric authentication device according to claim 8, wherein

the storage unit stores initial-element generation evaluation value data as the data indicating the initial-element generation probability of the blood vessel image, stores element number evaluation value data as the data indicating the branch probability of the element and stores change coefficient data as the data indicating the change coefficient or the change probabilities of the element and

the registration-image virtual generation unit comprises

an initial-element virtual generation unit to virtually generate an initial element of the verification image using the initial-element generation evaluation value data stored in the storage unit;

an element virtual generation reference point determination unit to determine an element which becomes a generation reference point using a distance between the focused-on element of the verification image and an already-generated element; and

an element virtual generation unit to virtually generate an element using the element number evaluation value data stored in the storage unit.

10. The biometric authentication device according to claim 9, wherein

the initial-element virtual generation unit selects one from a plurality of initial elements with a probability proportional to the initial-element generation evaluation value data stored in the storage unit and virtually generates the initial element and

the element virtual generation unit comprises

an element number selection unit to select a number of generation elements with a probability proportional to the element number evaluation value data;

an element virtual generation evaluation value calculation unit to calculate element virtual generation evaluation value data of a set of element candidates of the selected number of generation elements; and

an element selection unit to select one from a plurality of element candidates with a probability proportional to the element virtual generation evaluation value data.

11. The biometric authentication device according to claim 9, wherein

the element virtual generation evaluation value calculation unit comprises

an evaluation value calculation unit to calculate a n-th power of a distance between the focused-on element and an already-generated element and to calculate the distance obtained by the calculation as element generation evaluation value data of the focused-on element;

an element virtual generation evaluation value calculation unit to calculate a distance between the focused-on element and an element of the verification image, to obtain from the storage unit change coefficient data corresponding to the obtained distance and to calculate an element virtual generation evaluation value data using the obtained change coefficient data and the element generation evaluation value data of the focused-on element; and

an element candidate-set element virtual generation evaluation value calculation unit to calculate a product of the element virtual generation evaluation value data of respective focused-on elements as element virtual generation evaluation value data of a set of element candidates.

12. An authentication accuracy evaluation device, comprising:

a storage unit to store data indicating an initial-element generation probability of a blood vessel image, data indicating a branch probability of an element and data indicating a change coefficient or a change probability of the element, which are obtained by dividing a plurality of sets of a registration image and a verification image which indicate the blood vessel image of a living body into a plurality of respective elements;

a registration-image virtual generation unit to virtually generate a plurality of registration images using the data indicating the initial-element generation probability and the data indicating the branch probability which are stored in the storage unit;

a verification-image virtual generation unit to virtually generate a plurality of verification images using the data indicating the initial-element generation probability, the data indicating the branch probability of an element and the data indicating the change coefficient or the change probability which are stored in the storage unit;

a verification-image generation probability calculation unit to calculate a generation probability of the verification image;

a change probability calculation unit to calculate change probability of the virtually generated registration image and the virtually generated verification image;

a dissimilarity or similarity calculation unit to calculate a degree of similarity or dissimilarity using the verification image generation probability and the change probability; and

an output unit to total a plurality of the degree of dissimilarity or similarity and to output data indicating authentication accuracy.

13. The authentication accuracy evaluation device according to claim 12, wherein

the storage unit stores initial-element generation evaluation value data as the data indicating the initial-element generation probability of the blood vessel image, stores element number evaluation value data as the data indicating the branch probability of an element and stores a change coefficient data of the element as the data indicating the change coefficient or the change probability of the element and

the registration-image virtual generation unit comprises

an initial-element virtual generation unit to select one from a plurality of initial-element candidates with a probability proportional to the initial-element generation evaluation value data stored in the storage unit and to virtually generate an initial element;

an element virtual generation reference point determination unit to determine an element which becomes a generation reference point using a distance between a focused-on element and an already-generated element;

an element virtual generation evaluation value calculation unit to select a number of generation elements with a probability proportional to the element number evaluation value data and to calculate an element virtual generation evaluation value of an element of the selected number of generation elements; and

an element virtual generation unit to select one from a plurality of element candidates with a probability proportional to the element virtual generation evaluation value data and to virtually generate an element.

14. The authentication accuracy evaluation device according to claim 13, wherein

the verification-image virtual generation unit comprises

an initial-element virtual generation unit to select one from a plurality of initial-element candidates with a probability proportional to a product of the initial-element generation evaluation value data and the change coefficient data stored in the storage unit and to virtually generate an initial element;

an element number selection unit to select one of numbers of generation elements from a plurality of numbers of generation elements with a probability proportional to the element number evaluation value data;

an element virtual generation evaluation value calculation unit to calculate an element virtual generation evaluation value of element candidate of the selected number of generation elements; and

an element virtual generation unit to select one from a plurality of element candidates with a probability proportional to the element virtual generation evaluation value and virtually generating an element.

15. A biometric authentication method, comprising:

storing data indicating an initial-element generation probability of a blood vessel image, data indicating a branch probability of an element and data indicating a change coefficient or a change probability of the element, which are obtained by dividing a plurality of sets of a registration image and a verification image which indicate the blood vessel image of a living body into a plurality of respective elements;

calculating an element generation probability of a focused-on element of a verification image to be authenticated, using the data indicating the generation probability of the initial element and the data indicating the branch probability which are stored in the storage unit and calculating a value obtained by multiplying the element generation probabilities of respective focused-on elements as a verification-image generation probability of the verification image to be authenticated;

calculating change probabilities of the focused-on element of the verification image and an element of a registration image of a person to be authenticated using the data indicating the change coefficient or the change probability which are stored in the storage unit and calculating a value obtained by multiplying the change probabilities of respective focused-on elements as a change probability of the verification image;

calculating a degree of similarity or dissimilarity using the verification image generation probability and the change probability; and

determining whether the verification image to be authenticated belongs to a registered person, in accordance with the degree of dissimilarity or similarity is more or less than a threshold.

16. The biometric authentication method according to claim 15, wherein

initial-element generation evaluation value data is stored as the data used to calculate a generation probability of an initial element, an element number evaluation value data is stored as the data indicating the branch probability of the element and change coefficient data is stored as the data indicating the change coefficient or change probability of the element and

calculation of the verification-image generation probability includes;

calculating a generation probability of the initial element of the verification image using the initial-element generation evaluation value data,

determining an element which becomes a generation reference point using a distance between the focused-on element of the verification image and already-generated elements,

calculating an element generation probability of the focused-on element using the element number evaluation value data stored in the storage unit and

calculating a product of the initial-element generation probability and the element generation probabilities of respective elements as the verification-image generation probability.

17. A biometric authentication method, comprising:

storing data indicating an initial-element generation probability of a blood vessel image, data indicating a branch probability of an element and data indicating a change coefficient or a change probability of the element, which are obtained by dividing a plurality of sets of a registration image and a verification image which indicate the blood vessel image of a living body into a plurality of respective elements;

virtually generating a registration image by virtually generating a plurality of elements using the data indicating the initial-element generation probability and the data indicating the branch probability of the element;

calculating a registration-image virtual generation probability of the virtual registration image,

calculating a registration-image generation probability of a registration image,

calculating a virtual change probability of the registration image and the virtual registration image;

calculating a verification-image generation probability using the registration-image generation probability, the registration-image virtual generation probability and the virtual change probability,

calculating a change probability of the registration image and the verification image to be authenticated;

calculating a degree of similarity or dissimilarity using the verification-image generation probability and the change probability; and

determining whether a verification image to be authenticated belongs to a registered person, in accordance with the degree of dissimilarity or similarity is more or less than a threshold.

18. An authentication accuracy evaluation method, comprising:

storing data indicating an initial-element generation probability of a blood vessel image, data indicating a branch probability of an element and data indicating a change coefficient or a change probability of the element, which are obtained by dividing a plurality of sets of a registration image and a verification image which indicate the blood vessel image of a living body into a plurality of respective elements;

virtually generating a plurality of registration images using the data indicating the generation probability of an initial element and the data indicating the branch probability which are stored in the storage unit;

virtually generating a plurality of verification images using the data indicating the generation probability of the initial element, the data indicating the branch probability of the element and the data indicating the change coefficient or the change probability, which are stored in the storage unit;

calculating a generation probability of a verification image;

calculating change probabilities of the virtually generated registration image and the virtually generated verification image;

calculating a degree of similarity or dissimilarity using the verification image generation probability and the change probability; and

totaling a plurality of the degree of dissimilarity or similarity and generating data indicating authentication accuracy.