Fingerprint image acquiring device, fingerprint authenticating apparatus, fingerprint image acquiring method, and fingerprint authenticating method

1. A fingerprint image acquiring device comprising:

a fingerprint image input unit to which fingerprint images are input consecutively;

an image correlating unit to correlate a plurality of fingerprint images input from the fingerprint image input unit, the image correlating unit matching the input fingerprint images in position;

a resolution enhancing determining unit to determine whether an area making resolution enhancing possible is present by detecting an area overlapping between fingerprint images as a result of image correlating and estimating similarity between the fingerprint images;

an image synthesizing unit to synthesize the fingerprint images based on a result of the position matching by the image correlating unit; and

a resolution enhancing unit to enhance a resolution of the area making resolution enhancing possible in the fingerprint image, wherein

a fingerprint image is generated by partially enhancing the fingerprint image input to the fingerprint image input unit in resolution.

2. The fingerprint image acquiring device of claim 1 , wherein

the resolution enhancing determining unit includes:

a feature quantity extracting unit to extract a feature quantity from a fingerprint image; and

a feature quantity comparing unit to compare extracted feature quantities between fingerprint images, and wherein

reproducibility is estimated based on a feature quantity extracted from a fingerprint image to determine whether resolution enhancing is possible.

3. The fingerprint image acquiring device of claim 2 , wherein

the feature quantity includes any one of a ridgeline shape (ridgeline pattern) and an end point and a branch point of a ridgeline (feature point).

4. The fingerprint image acquiring device of claim 1 , wherein

the resolution enhancing determining unit further includes an area dividing unit to divide an overlapping area into small areas, and wherein

reproducibility between fingerprint images is estimated for each small area to determine whether resolution enhancing is possible, and an area making resolution enhancing possible is enhanced in resolution.

5. The fingerprint image acquiring device of claim 4 , wherein

the area dividing unit includes:

a sensor information acquiring unit to acquire sensor information indicative of a fingerprint sensor used as the fingerprint image input unit; and

an area shape selecting unit to receive the sensor information from the sensor information acquiring unit to select an area shape for dividing the fingerprint image in accordance with the sensor information, and wherein

the fingerprint image is divided into area shapes according to the fingerprint sensor.

6. The fingerprint image acquiring device of claim 5 , wherein

the overlapping area is divided into block shapes when a sweep fingerprint sensor is used as the fingerprint image input unit.

7. The fingerprint image acquiring device of claim 5 , wherein

division is carried out using a given shape based on a position of a feature point as a reference when a flat fingerprint sensor is used as the fingerprint image input unit.

8. A fingerprint authenticating apparatus comprising:

a fingerprint image input unit to which fingerprint images are input consecutively;

an image correlating unit to match a plurality of fingerprint images in position;

a resolution enhancing determining unit to determine whether an area making resolution enhancing possible is present by detecting an area overlapping between fingerprint images as a result of image correlating and estimating similarity between the fingerprint images;

an image synthesizing unit to synthesize the fingerprint images based on a result of the position matching by the image correlating unit;

a resolution enhancing unit to enhance a resolution of the area making resolution enhancing possible in the fingerprint image;

a feature information generating unit to generate feature information from a fingerprint image enhanced in resolution by the resolution enhancing unit; and

a fingerprint verification unit to verify acquired feature information with pre-registered feature information.

9. A fingerprint authenticating apparatus having the fingerprint image acquiring device of claim 2 , comprising:

a feature information generating unit to generate feature information from a fingerprint image generated by the image synthesizing unit; and

a fingerprint verification unit to verify acquired feature information with pre-registered feature information.

10. The fingerprint authenticating apparatus of claim 8 , wherein

the feature information generating unit includes:

a feature quantity extracting unit to extract a plurality of types of feature quantities;

an image area acquiring unit to acquire an area of a high-resolution image from the fingerprint image enhanced in resolution by the resolution enhancing unit; and

a feature quantity extraction selecting unit to select a feature quantity based on the area that is acquired.

11. The fingerprint authenticating apparatus of claim 8 , wherein

information of an outline of a ridgeline is extracted as a feature quantity.

12. The fingerprint authenticating apparatus of claim 8 , wherein

a position of a sweat gland pore on a ridgeline is extracted as a feature quantity.

13. The fingerprint authenticating apparatus of claim 8 , wherein

the fingerprint verification unit includes:

a plurality of feature quantity comparing units to compare a plurality of types of feature quantities extracted from the fingerprint image;

a comparison selecting unit to select one of the feature quantity comparing units in accordance with a type of the feature quantity; and

a verification determining unit to verify the feature information with each other based on a comparison result given by the feature quantity comparing unit selected by the comparison selecting unit.

14. The fingerprint authenticating apparatus of claim 13 , comprising:

a resolution enhancing unit to generate a high-resolution image in an area of a given shape based on a feature point as a reference;

an image synthesizing unit to update information of a position of a feature point to information of the position of the feature point in a synthesized image every time partial images are synthesized, the image synthesizing unit correlating the feature point with a high-resolution image to store the correlated feature point and high-resolution image;

a feature information generating unit to extract either or both of information of an outline of a ridgeline and a position of a sweat gland pore from a high-resolution image, the feature information generating unit correlating the extracted information or position with a feature point to generate feature information; and

a fingerprint verification unit to verify feature points included in each piece of feature information with each other, the fingerprint verification unit further verifying feature points determined to be matching with each other in terms of either or both of information of an outline of a ridgeline and a position of a sweat gland pore and determining whether the feature points are matching to output a determination result corresponding to the number of matching feature points.

15. A fingerprint image acquiring method comprising:

consecutively taking in fingerprint images;

matching a plurality of fingerprint images in position;

determining whether an area making resolution enhancing possible is present by detecting an area overlapping between fingerprint images as a result of image correlating and estimating similarity between the fingerprint images;

synthesizing the fingerprint images based on a result of the position matching; and

enhancing a resolution of the area making resolution enhancing possible in the fingerprint image, wherein

a fingerprint image is generated by partially enhancing the consecutively input fingerprint images in resolution.

16. A fingerprint authenticating method comprising:

consecutively taking in fingerprint images;

matching a plurality of fingerprint images in position;

determining whether an area making resolution enhancing possible is present by detecting an area overlapping between fingerprint images as a result of image correlating and estimating similarity between the fingerprint images;

synthesizing the fingerprint images based on a result of the position matching;

enhancing a resolution of the area making resolution enhancing possible in the fingerprint image;

generating feature information from a synthesized image enhanced in resolution; and

verifying acquired feature information with pre-registered feature information.

17. A non-transitory computer-readable recording medium having recorded thereon a fingerprint image acquiring program to be executed by a computer, the program comprising:

consecutively taking in fingerprint images;

matching a plurality of fingerprint images in position;

determining whether an area making resolution enhancing possible is present by detecting an area overlapping between fingerprint images as a result of image correlating and estimating similarity between the fingerprint images;

synthesizing the fingerprint images matched in position based on a result of the position matching; and

enhancing a resolution of the area making resolution enhancing possible in the fingerprint image, wherein

a fingerprint image is generated by partially enhancing the fingerprint images consecutively input by the computer in resolution.

18. A non-transitory computer-readable recording medium having recorded thereon a fingerprint authenticating program to be executed by a computer, the program comprising:

consecutively taking in fingerprint images;

matching a plurality of fingerprint images in position;

determining whether an area making resolution enhancing possible is present by detecting an area overlapping between fingerprint images as a result of image correlating and estimating similarity between the fingerprint images;

synthesizing the fingerprint images matched in position based on a result of the position matching;

enhancing a resolution of the area making resolution enhancing possible in the fingerprint image;

generating feature information from a synthesized image enhanced in resolution; and

verifying acquired feature information with pre-registered feature information.

19. A fingerprint image acquiring device comprising:

a fingerprint image input unit to which fingerprint images are input consecutively; and

a processor, wherein

the processor executes a process including:

correlating a plurality of fingerprint images input from the fingerprint image input unit;

matching the input fingerprint images in position;

determining whether an area making resolution enhancing possible is present by detecting an area overlapping between fingerprint images as a result of image correlating and estimating similarity between the fingerprint images;

synthesizing the fingerprint images based on a result of the position matching; and

enhancing a resolution of the area making resolution enhancing possible in the fingerprint image, wherein

a fingerprint image is generated by partially enhancing the consecutively input fingerprint images in resolution.

20. A fingerprint authenticating apparatus comprising:

a fingerprint image input unit to which fingerprint images are input consecutively; and

a processor, wherein

the processor executes a process including:

matching the input fingerprint images in position;

determining whether an area making resolution enhancing possible is present by detecting an area overlapping between fingerprint images as a result of image correlating and estimating similarity between the fingerprint images;

synthesizing the fingerprint images based on a result of the position matching;

enhancing a resolution of the area making resolution enhancing possible in the fingerprint image;

generating feature information from a synthesized image enhanced in resolution; and

verifying acquired feature information with pre-registered feature information.