Fingerprint matching device, fingerprint matching method, and program

• US 20040161135A1
• Filed: 11/21/2003
• Published: 08/19/2004
• Est. Priority Date: 03/12/2002
• Status: Abandoned Application

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Iida, Ryosuke, Ueki, Chihiro, Tsurube, Tomoyuki, Sano, Misa, Shiina, Sachiko, Ide, Chie, Nishizawa, Masato, Matsuyama, Yoshiyuki
• Application Number:
  US10/478,409
• Publication Number:
  US 20040161135A1
• Time in Patent Office: Days
• US Class Current: 382/124
• CPC Class Codes: G06V 40/1365 Matching; Classification

Abstract

A fingerprint ID device includes input means for receiving a fingerprint image, center detecting means for detecting a center point of a fingerprint from the fingerprint image, area extracting means for extracting a given area, which surrounds the center point, as a center image of the fingerprint, and checking means for checking the center image against fingerprint images registered in advance. This structure allows checking a fingerprint by using the center image which includes a large number of characteristics. Thus even if the finger deviates from a right position, the fingerprint can be identified with accuracy, and at the same time, a memory capacity of the device can be substantially reduced.

Claims

1. A fingerprint ID device comprising:

input means for receiving a fingerprint image;

center detecting means for detecting a center point of a fingerprint from the fingerprint image;

area extracting means for extracting a given area, which surrounds the center point, as a center image of the fingerprint; and

checking means for checking the center image against fingerprint images registered in advance.

2. The fingerprint ID device of claim 1, wherein said center detecting means including:

ridge-direction detecting means for detecting a ridge direction of the fingerprint image;

horizontal distribution calculating means for calculating a horizontal distribution of the ridge direction;

vertical distribution calculating means for calculating a vertical distribution of the ridge direction; and

center-point determining means for determining a center point of the fingerprint based on the horizontal distribution and the vertical distribution of the ridge direction.

3. The fingerprint ID device of claim 1, wherein said center detecting means including:

ridge-direction detecting means for detecting a ridge direction of the fingerprint image;

intensity projection calculating means for calculating an intensity projection of the fingerprint image;

area detecting means for detecting a fingerprint area based on the intensity projection;

horizontal distribution calculating means for calculating a horizontal distribution of the ridge direction within the fingerprint area;

vertical distribution calculating means for calculating a vertical distribution of the ridge direction within the fingerprint area; and

center-point determining means for determining a center point of the fingerprint based on the horizontal distribution and the vertical distribution of the ridge direction.

4. The fingerprint ID device of claim 1, wherein said area extracting means including:

cut-out area determining means for determining a cut-out area surrounding the center point of the fingerprint and having a given width and a given height; and

area cutting means for cutting the center image of the fingerprint out from the fingerprint image according to the cut-out area.

5. The fingerprint ID device of claim 1, wherein said area extracting means including:

fingertip detecting means for detecting a position of a fingertip from the fingerprint image;

cut-out area determining means for determining a cut-out area which has the position of the fingertip as an upper end, a position vertically downward at a given distance from the center point of the fingerprint, and a given width on both sides of the center point of the fingerprint; and

area cutting means for cutting the center image of the fingerprint out from the fingerprint image according to the cut-out area.

6. The fingerprint ID device of claim 1 further comprising:

display means for displaying a sign which prompts to re-enter a fingerprint when said center detecting means cannot detect the center point of the fingerprint.

7. A method of identifying a fingerprint, the method comprising the steps of:

receiving a fingerprint image;

detecting a center point of a fingerprint from the fingerprint image;

extracting a given area, which surrounds the center point, as a center image of the fingerprint; and

checking the center image against fingerprint images registered in advance.

8. The method of identifying a fingerprint of claim 7, wherein the step of detecting includes the steps of:

detecting a ridge direction of the fingerprint image;

calculating a horizontal distribution and a vertical distribution of the ridge direction; and

determining a center point of the fingerprint based on the horizontal distribution and the vertical distribution of the ridge direction.

9. The method of identifying a fingerprint of claim 7, wherein the step of detecting includes the steps of:

calculating a intensity projected from the fingerprint image;

detecting a fingerprint area based on the projected intensity;

detecting a ridge direction of the fingerprint image;

calculating a horizontal distribution and a vertical distribution of the ridge direction within the fingerprint area; and

determining a center point of the fingerprint based on the horizontal distribution and the vertical distribution of the ridge direction.

10. The method of identifying a fingerprint of claim 7, wherein the step of extracting carries out cutting an image, which has a given width and a given height with reference to the center point of the fingerprint, out from the fingerprint image as the center image of the fingerprint.

11. The method of identifying a fingerprint of claim 7, wherein the step of extracting includes the steps of:

detecting a position of a fingertip from the fingerprint image;

determining a cut-out area which has the position of the fingertip as an upper end, a position vertically downward at a given distance from the center point of the fingerprint, and a given width on both sides of the center point of the fingerprint; and

cutting the center image of the fingerprint out from the fingerprint image according to the cut-out area.

12. The method of identifying a fingerprint of claim 7 further comprising the step of:

displaying a sign which prompts to re-enter a fingerprint when the center point of the fingerprint cannot be detected.

13. A program executed by a computer, the program including the steps of:

receiving a fingerprint image;

detecting a center point of a fingerprint from the fingerprint image;

extracting a given area, which surrounds the center point, as a center image of the fingerprint; and

checking the center image against fingerprint images registered in advance.

14. The program of claim 13, wherein the step of detecting includes the steps of:

detecting a ridge direction of the fingerprint image;

calculating a horizontal distribution and a vertical distribution of the ridge direction; and

determining a center point of the fingerprint based on the horizontal distribution and the vertical distribution of the ridge direction.

15. The program of claim 13, wherein the step of detecting includes the steps of:

detecting a ridge direction of the fingerprint image;

calculating an intensity projection from the fingerprint image;

detecting a fingerprint area based on the intensity projection;

calculating a horizontal distribution and a vertical distribution of the ridge direction within the fingerprint area; and

determining a center point of the fingerprint based on the horizontal distribution and the vertical distribution of the ridge direction.

16. The program of claim 13, wherein the step of extracting carries out cutting an image, which has a given width and a given height with reference to the center point of the fingerprint, out from the fingerprint image as the center image of the fingerprint.

17. The program of claim 13, wherein the step of extracting includes the steps of:

detecting a position of a fingertip from the fingerprint image;

determining a cut-out area which has the position of the fingertip as an upper end, a position vertically downward at a given distance from the center point of the fingerprint, and a given width on both sides of the center point of the fingerprint; and

cutting the center image of the fingerprint out from the fingerprint image according to the cut-out area.

18. The program of claim 13 further including the step of displaying a sign which prompts to re-enter a fingerprint when the center point of the fingerprint cannot be detected.