Verification apparatus, verification method and program
A verification apparatus includes: a detection section that detects some or all of junction points, endpoints and turning points of a physical trait of a body part on an input image as feature points, the physical trait being used for verification; and a search section that searches a registered image of the physical trait for a pattern that is the same as or similar to a pattern of the feature points in a center area of the image whose vertical center line is perpendicular to the direction of motion of the physical trait that horizontally moves on a surface on which the body part is put, the registered image being taken along a curved surface of the body part and the center area being between two lines each of which is a predetermined distance away from the center line in opposite directions.
1. A verification apparatus comprising:
an image pickup element configured to receive an input image;
a memory device configured to store a registered image;
a detection section that detects some or all of junction points, endpoints and turning points of a physical trait of a body part on the input image as feature points, the physical trait being used for verification;
a search section that searches the registered image of the physical trait for a pattern that is the same as or similar to a pattern of the feature points in a center area of the input image whose vertical center line is perpendicular to the direction of motion of the physical trait that horizontally moves on a surface on which the body part is put; and
the registered image including at least two images, each of the at least two images being taken along a curved surface of the body part and the center area being between two lines each of which is a predetermined distance away from the center line in opposite directions, the at least two images configured to be positioned on one another in accordance with positional difference data of each of the at least two images.
2. The verification apparatus according to claim 1 , further comprising
an embossment section that embosses the physical trait on an input image, wherein
the detection section detects the feature points from the embossed physical trait.
3. The verification apparatus according to claim 1 , further comprising:
an embossment section that embosses the physical trait on an input image; and
a pattern extraction section that extracts the embossed physical trait as a line-shaped pattern, wherein
the detection section detects the feature points from the line-shaped pattern.
4. The verification apparatus according to claim 1 , wherein
the distance is determined such that, if the body part's physical trait horizontally moves along the surface, a ratio of a distance that the physical trait has traveled from the center line to a distance that the physical trait has traveled from a line beyond the center line becomes less than one pixel.
5. The verification apparatus according to claim 1 , wherein
if the number of pixels of the width of an image to be clipped is equivalent to that of the width of a finger, the width of the center area is equivalent to one third of the number of pixels of the width of the image.
6. The verification apparatus according to claim 1 , further comprising:
a clipping section that uses, if the search section has found a pattern that is the same as or similar to a pattern of the feature points in the center area, the pattern to clip from the registered image a verification-target image to be compared with the input image;
a correction section that corrects the verification-target image such that a blood vessel line on end areas of the verification-target image becomes curved, the end areas surrounding a central area of the verification-target image; and
a calculation section that calculates a cross correlation value between the corrected verification-target image and the input image.
7. The verification apparatus according to claim 6 , wherein
the correction section corrects the verification-target image such that the end areas that backwardly incline at a predetermined angle to the center area of the verification-target image are projected on the same plane as the center area.
8. A verification method comprising:
a first step of detecting some or all of junction points, endpoints and turning points of a physical trait of a body part on an input image as feature points, the physical trait being used for verification;
a second step of searching a registered image of the physical trait for a pattern that is the same as or similar to a pattern of the feature points in a center area of the input image whose vertical center line is perpendicular to the direction of motion of the physical trait that horizontally moves on a surface on which the body part is put; and
the registered image including at least two images, each of the at least two images being taken along a curved surface of the body part and the center area being between two lines each of which is a predetermined distance away from the center line in opposite directions, the at least two images configured to be positioned on one another in accordance with positional difference data of each of the at least two images.
9. A non-transitory computer-readable storage medium storing a computer program which, when executed by a computer, performs a verification method, the method including:
a step of detecting some or all of junction points, endpoints and turning points of a physical trait of a body part on an input image as feature points, the physical trait being used for verification;
a step of searching a registered image of the physical trait for a pattern that is the same as or similar to a pattern of the feature points in a center area of the input image whose vertical center line is perpendicular to the direction of motion of the physical trait that horizontally moves on a surface on which the body part is put; and
the registered image including at least two images, each of the at least two images being taken along a curved surface of the body part and the center area being between two lines each of which is a predetermined distance away from the center line in opposite directions, the at least two images configured to be positioned on one another in accordance with positional difference data of each of the at least two images.
10. The verification apparatus according to claim 1 , further comprising a positional difference calculation section configured to calculate the positional difference data.
11. The verification apparatus according to claim 10 , wherein the positional difference calculation section calculates a positional difference between a current image of a physical trait of a body part and a previous image of a physical trait of a body part of each of the at least two images;
the current image not configured to be processed through a pattern extraction section, and the previous image configured to be processed through the pattern extraction section.