Granted Patent B2

US 12,394,244 · App. 18/809,541 · Granted Aug 19, 2025

Inventors: Kan Satou (Tokyo, JP); Yoshinori Suzuki (Tokyo, JP); Masanori Mizoguchi (Tokyo, JP); Masanori Hara (Tokyo, JP)

Assignee: NEC CORPORATION

G06V40/1376G06V40/1359

Abstract

Claims (45)

1. A fingerprint image information processing device comprising:

at least one memory storing instructions; and

at least one processor configured to execute the instructions to:

acquire image information indicating an image of a finger;

detect a directional singular point of a ridge line from the image; and

detect a singular region indicating damage of the finger, by determining whether a detection result of the directional singular point satisfies a condition of any of an arch-shaped pattern, a loop-shaped pattern, a spiral-shape pattern, and a variant-shaped pattern.

2. The fingerprint image information processing device according to claim 1 ,

wherein the at least one processor is configured to execute the instructions to:

acquire ridge line direction information corresponding to a portion included in the image;

find an evaluation value for each ridge line direction information, based on a correlation between each ridge line direction information, and a template of an abnormal ridge line direction that is preliminary held, the evaluation value indicating a degree of possession of an abnormal ridge line direction pattern; and

detect a portion corresponding to ridge line direction information for which the evaluation value is equal to or greater than a predetermined threshold value, as the singular region.

3. The fingerprint image information processing device according to claim 1 ,

wherein the at least one processor is configured to execute the instructions to:

acquire ridge line direction information corresponding to a portion included in the image;

obtain smoothed ridge line direction information by performing direction smoothing processing for each ridge line direction information, based on ridge line direction information corresponding to a region located around a region corresponding to the ridge line direction information; and

detect a region corresponding to the ridge line direction information in which a difference between the ridge line direction information and the smoothed ridge line direction information is greater than a predetermined threshold value, as the singular region.

4. The fingerprint image information processing device according to claim 1 ,

wherein the at least one processor is configured to execute the instructions to:

acquire ridge line direction information and ridge line pitch information corresponding to a region included in the image;

find an evaluation value based on the ridge line direction information and the ridge line pitch information, the evaluation value taking a greater value as a difference in ridge line directions and a difference in ridge line pitches become greater between adjacent regions in the image; and

in a case where the evaluation value is greater than a predetermined threshold value, detect that the adjacent regions are a singular region due to cutout work.

5. The fingerprint image information processing device according to claim 1 ,

wherein the at least one processor is configured to execute the instructions to:

collate image information corresponding to a region other than the detected singular region among the acquired image information, and image information registered in advance in association with identifying information for identifying an individual.

6. The fingerprint image information processing device according to claim 5 , wherein the at least one processor is configured to execute the instructions to:

when performing the collation processing, make at least either one of a positional deviation allowance and a mismatch allowance variable, the positional deviation allowance representing a degree to which positional deviation is allowed, and the mismatch allowance representing a degree to which a mismatch is allowed.

7. The fingerprint image information processing device according to claim 5 ,

wherein the at least one processor is configured to execute the instructions to:

repair damage of the image information corresponding to the singular region in the obtained image information; and

regard a region corresponding to the repaired image information as the region other than the singular region, and perform the collation.

8. The fingerprint image information processing device according to claim 7 , wherein the at least one processor is configured to execute the instructions to:

exclude an exclusion region defined based on, the singular region, from the image, to thereby repair the damage.

9. The fingerprint image information processing device according to claim 7 ,

wherein the at least one processor is configured to execute the instructions to:

find an evaluation value for each portion included in the image, based on a correlation between ridge line direction information and a template of an abnormal ridge line direction pattern that is preliminary held, the evaluation value representing a degree to which the ridge line direction information has an abnormal ridge line directional pattern;

extract a straight line component of the evaluation value in the image; and

repair the damage by mutually replacing images included in a first polygon and a second polygon defined based on the extracted straight line components.

10. A fingerprint image information processing method executed by a computer, the method comprising:

acquiring image information indicating an image of a finger;

detecting a directional singular point of a ridge line from the image; and

detecting a singular region indicating damage of the finger, by determining whether a detection result of the directional singular point satisfies a condition of any of an arch-shaped pattern, a loop-shaped pattern, a spiral-shaped pattern, and a variant-shaped pattern.

11. A non-transitory computer-readable recording medium storing a computer-executable program, the program comprising:

instructions for acquiring image information indicating an image of a finger;

instructions for detecting a directional singular point of a ridge line from the image; and

instructions for detecting a singular region indicating damage of the finger, by determining whether a detection result of the directional singular point satisfies a condition of any of an arch-shaped pattern, a loop-shaped pattern, a spiral-shaped pattern, and a variant-shaped pattern.

Priority Claims (1)

Continuity (4)

References Cited (57)