Method for authenticating fingerprint and authentication apparatus using same

Patent metadata

Field	Value
Publication number	US-10262186-B2
Application number	US-201615205687-A
Country	US
Kind code	B2
Filing date	Jul 8, 2016
Priority date	Aug 13, 2015
Publication date	Apr 16, 2019
Grant date	Apr 16, 2019

Abstract

There is provided a method for authenticating a fingerprint. The method includes receiving an inputted fingerprint image; selecting a plurality of comparison target pixels from pixels in the inputted fingerprint image and selecting a plurality of comparison reference pixels from pixels in a pre-stored registered fingerprint image; and determining a similarity of an overlapping area where the inputted fingerprint image overlaps the registered fingerprint image whenever a matching arrangement of each of the comparison target pixels is made with respect to each of the comparison reference pixels. The method further includes, whenever it is determined that the overlapping area is similar, comparing the inputted fingerprint image and the registered fingerprint image within the overlapping area to calculate a correlation score with respect to the overlapping area and authenticating the inputted fingerprint image based on the calculated correlation score.

First claim

What is claimed is:

1. A method for authenticating a fingerprint, the method comprising:
receiving an inputted fingerprint image;
selecting a plurality of comparison target pixels arranged at a first interval from pixels in the inputted fingerprint image and selecting a plurality of comparison reference pixels arranged at a second interval from pixels in a pre-stored registered fingerprint image;
upon an occurrence of a matching arrangement in which each of the comparison target pixels is mapped onto each of the comparison reference pixels, overlapping a first region of the inputted fingerprint image and a second region of the registered fingerprint image for determining a similarity between the first region and the second region by comparing ridges of the first region and those of the second region, wherein the first region and the second region are within an overlapping area where the inputted fingerprint image overlaps the registered fingerprint image;
upon determination that the first region and the second region are similar to each other according to the similarity, calculating a correlation score with respect to the overlapping area by comparing the first region and the second region pixel by pixel; and
authenticating the inputted fingerprint image based on the calculated correlation score,
wherein the first region and the second region are respectively obtained from larger prior starting first region and larger prior starting second region, after a series of prior similarity matching and correlation score calculations.

2. The method of claim 1 , wherein said determining the similarity includes:
selecting adjacent pixels around each of the comparison target pixels used in the matching arrangement in the overlapping area; and
comparing at least one of brightness information of a ridge and a valley, ridge direction information, and ridge curvature information between the adjacent pixels in the inputted fingerprint image and pixels, corresponding to the adjacent pixels, in the registered fingerprint image, respectively, to determine the similarity.

3. The method of claim 1 , further comprising:
checking whether the similarity has been determined for all of the comparison target pixels and the comparison reference pixels;
checking whether the second interval of the comparison reference pixels is equal to a unit interval when it is checked that the similarity has been determined for all of the comparison target pixels and the comparison reference pixels; and
selecting, when it is checked that the second interval of the comparison reference pixels is greater than the unit interval, at least one candidate area for a fingerprint comparison having a new interval smaller than the second interval.

4. The method of claim 3 , wherein said selecting the at least one candidate area for the fingerprint comparison includes:
comparing the correlation score, obtained when it is determined that the first region and the second region are similar to each other, with a threshold;
selecting, as the candidate area, an area having the correlation score equal to or greater than the threshold in the registered fingerprint image; and
selecting the comparison reference pixels in the candidate area arranged at the new interval smaller than the second interval.

5. A non-transitory computer-readable storage medium including computer-executable instructions, which cause, when executed by a processor, the processor to perform the method for authenticating the fingerprint of claim 1 .

6. An apparatus for authenticating a fingerprint, the apparatus comprising:
an input unit configured to receive an inputted fingerprint image from a user to be authenticated;
a pixel selection unit configured to select a plurality of comparison target pixels arranged at a first interval from pixels in the inputted fingerprint image and a plurality of comparison reference pixels arranged at a second interval from pixels in a pre-stored registered fingerprint image;
a similarity determination unit configured to, upon an occurrence of a matching arrangement in which each of the comparison target pixels is mapped onto each of the comparison reference pixels, overlap a first region of the inputted fingerprint image and a second region of the registered fingerprint image to determine a similarity between the first region and the second region by comparing ridges of the first region and those of the second region, wherein the first region and the second region are within an overlapping area where the inputted fingerprint image overlaps the registered fingerprint image;
a correlation calculation unit configured to calculate a correlation score with respect to the overlapping area by comparing the first region and the second region pixel by pixel when the first region and the second region are determined to be similar to each other according to the similarity;
an authentication unit configured to authenticate the inputted fingerprint image based on the calculated correlation score; and
an output unit configured to output authentication information based on a result obtained by the authentication unit,
wherein the first region and the second region are respectively obtained from larger prior starting first region and larger prior starting second region, after a series of prior similarity matching and correlation score calculations.

7. The apparatus of claim 6 , wherein the similarity determination unit is configured to:
select adjacent pixels around each of the comparison target pixels used in the matching arrangement in the overlapping area;
compare at least one of brightness information of a ridge and a valley, ridge direction information, and ridge curvature information between the adjacent pixels in the inputted fingerprint image and pixels, corresponding to the adjacent pixels, in the registered fingerprint image, respectively, to determine the similarity.

8. The apparatus of claim 6 , further comprising:
a calculation check unit configured to check whether the similarity has been determined for all of the comparison target pixels and the comparison reference pixels;
an interval check unit configured to check whether the second interval of the comparison reference pixels is equal to a unit interval when it is checked that the similarity has been determined for all of the comparison target pixels and the comparison reference pixels; and
an area selection unit configured to select, when it is checked that the second interval of the comparison reference pixels is greater than the unit interval, at least one candidate area for a fingerprint comparison having a new interval smaller than the second interval.

9. The apparatus of claim 8 , wherein the area selection unit is configured to:
compare the correlation score obtained, when it is determined that the first region and the second region are similar to each other, with a threshold;
select, as the candidate area, an area having the correlation score equal to or greater than the threshold in the registered fingerprint image; and
select the comparison reference pixels in the candidate area arranged at the new interval smaller than the second interval.

Assignees

• Suprema Inc

Inventors

• Lee Kideok
• Shin Hochul
• Lee Hyeonchang
• Lee Jong Man
• Song Bong Seop
• Lee Jae Won

Classifications

• G06V10/7515

  Shifting the patterns to accommodate for positional errors · CPC title

• G06K9/001 Primary

  Physics · mapped topic

• G06K9/6203

  Physics · mapped topic

• G06V40/1376 Primary

  Matching features related to ridge properties or fingerprint texture · CPC title