JPH0433065A - Fingerprint collating device - Google Patents

Abstract

PURPOSE:To speedily identify an individual with high reliability without requiring a key or password by collating an input fingerprint picture and a registered fingerprint picture. CONSTITUTION:Means 10-13 are provided to sample the fingerprint picture of a finger and outputs it as a two-dimensional quantized picture data, and a file 20 is provided to store a feature list registering feature points extracted from the registered fingerprint in advance. Then, a means 18 is provided to confirm the existence of the feature points read on the quantized picture data after successively reading out the feature lists. Then, it is decided whether the number of confirmed feature points exceeds a decided threshold value or not. When it exceeds the threshold value, a collation processing is completed and when it does not exceed the threshold value, the processing is repeated. Thus, a high-reliability individual identifying device can be obtained with high operability regardless of the robbery or oblivion of the password.

Description

TECHNICAL FIELD The present invention relates to a fingerprint matching device, and more particularly to a fingerprint matching device that identifies a human fingerprint and a registered fingerprint by determining their identity based on their pattern characteristics.

Conventional technology Systems that use fingerprints to identify individuals have extremely high reliability due to the nature of fingerprints being "unique for everyone" and "unchanging throughout life." Automatic verification devices for fingerprints have already been proposed, and there are many techniques including those disclosed in Japanese Patent Application Laid-Open No. 59-778 and Japanese Patent Application Laid-Open No. 55-138174.

On the other hand, with the rapid progress of electronic engineering in recent years, there is an increasing need for vehicle theft prevention using computer technology and for personal identification of extremely limited people, such as locks on the doors of ordinary houses. It is being done.

Traditionally, this has been done using keys, PIN numbers, etc.
Its effectiveness is lost due to theft, loss, forgetting, etc., and therefore it must be said that its reliability is low.

Purpose of the Invention Therefore, the present invention has been made to solve the drawbacks of the prior art, and its purpose is to identify individuals using their fingerprints without using uncertain elements such as keys or PIN numbers. It is an object of the present invention to provide a fingerprint verification device that allows identification to be performed quickly and with high reliability.

Structure of the Invention According to the present invention, a fingerprint matching method compares an input fingerprint image and a registered fingerprint image and determines whether or not the input fingerprint image matches the registered fingerprint image based on the characteristics of these two fingerprint images. The device includes a means for collecting a fingerprint image of a finger placed on a transparent body and outputting it as two-dimensional quantized image data, and a means for collecting a fingerprint image of a finger placed on a transparent surface and outputting it as two-dimensional quantized image data, and the position, pattern direction, and neighboring minutiae of a minutiae extracted from the registered fingerprint. a file storing a feature list in which the number of ridges existing between the ridges is registered in advance; a means for sequentially reading the feature list to confirm the existence of the read feature points on the quantized image data; means for determining whether the number of feature points exceeds a predetermined threshold; and when it is determined that the number of feature points exceeds the threshold, determining that the two images match and terminating the matching process; There is obtained a fingerprint verification device characterized in that it includes means for instructing to repeat the above process for the next feature list stored in the file when it is determined that the threshold value is not exceeded.

Embodiments Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of the present invention. In FIG. 1, the present embodiment is a fingerprint matching device that determines whether pattern characteristics match an input fingerprint image and a registered fingerprint image. This device includes a fingerprint image input unit 10 that collects a fingerprint image of a placed fingerprint and converts it photoelectrically, and a photoelectric conversion signal that is
an A/D converter 11 that converts into dimensional quantized image data;
An image control unit 12 that detects the placement position of the collected image and then performs image collection, an image memory 13 that stores two-dimensional quantized image data, and feature points extracted from registered fingerprints (hereinafter referred to as minutiae). a file 20 that stores a manual list in which the position of the pattern (hereinafter referred to as "relation"), the pattern direction, and the number of ridges existing between neighboring feature points (hereinafter referred to as relation); and an output unit 19 that outputs the matching results and various messages; It includes a verification processing section 18 that sequentially performs verification between the image data in the image memory 13 and all mechanical lists stored in the file 21.

The collation processing unit 18 has an external interface 14 that inputs data from the image memory 13 and the file 20 and outputs it to the output unit 19, a working memory 17 that stores the manual list from the file 20, and a program that stores the program. It is composed of a memory 16 and a central processing unit 15 that is controlled by a program.

Regarding the fingerprint input unit 10, using optical boundary conditions due to light from a light source with respect to a finger placed on a transparent body,
ITV (Industrial Televis)
A device for inputting a photoelectrically converted image of a fingerprint pattern using a photographing device such as
There are devices described in No. 00 and Japanese Unexamined Patent Publication No. 54-85600, which can be used.

Next, the image input control unit 12 checks temporal changes in density of a plurality of pixels at predetermined positions in the captured image as needed, detects placement of a fingerprint, and determines whether the density value of the pixel is equal to or higher than a threshold value. Automatically collects fingerprint images when The two-dimensional quantized image thus obtained is stored in the image memory 13.

The collation processing unit 18 reads out manualists Ml, M2゜...Mn stored in the file 20 as shown in FIG. Performs matching processing with.

FIGS. 2(a) and 2(b) show the fingerprint pattern and manualist in this embodiment. Figure 2 (a), (b)
), the fingerprint features are located at the position of minutiae M (X,
Y), pattern direction D, neighboring minutiae m1. , m2.
m3. m4 and its relations rl, r2. r3. r
4 is expressed as a list for each minutiae M that exists in the fingerprint.

FIG. 4 shows an example in which the minutiae list is registered as a file, and Mi is a file in which all the minutiae of a certain person's fingerprints are registered together.

Detailed definitions of these mechanicalists and methods for extracting them are described in Japanese Patent Application Laid-open No. 138174/1982, so detailed explanation thereof will be omitted here.

The matching processing unit 18, as shown in FIG.
Processing is performed to accurately match the grayscale fingerprint image 30 stored in file 20 with the minutiae (for example, 31) and relation (for example, 32) in one or more minutialists stored in the file 20. if,
If a correspondence is found, it is considered a match; if not, it is considered a mismatch, and if the number of matches exceeds a threshold, the matching is completed. If the number of matches does not reach the threshold, the same matching process is repeated for all manualists Mi stored in the file 20, thereby identifying individuals for various purposes.

Regarding the minutiae detection and the regression detection used here, the methods described in detail in Japanese Patent Laid-Open No. 144289/1982 and Japanese Patent Laid-open No. 118488/1987 are used, respectively, and their details are omitted here. do.

Next, the verification processing procedure in this embodiment will be explained based on the processing flow diagram of FIG. In step 51, as described above, image input processing is performed by examining the temporal change in density of pixels at a predetermined position.

In step 52, the manualists in the file 20 are accessed one by one in the order in which they are stored as shown in FIG. 3 and stored in the working memory 17.

In step 53, matching processing is performed using the aforementioned minutiae detection and relation detection. Step 5
In step 4, if the number of feature points confirmed among the feature points in the manualist on the input fingerprint is equal to or greater than the threshold θ1, it is assumed that the input fingerprint and the registered fingerprint match, and the result is determined in step 55. Display.

At step 54, if the unconfirmed minutiae among the minutiae points in the manualist does not reach θl, it is determined that there is no match, and it is determined in step 56 whether or not the manualist remains in the file 20. If there are any remaining manualists, the process returns to step 52, accesses the next manualist, and repeats the matching process in step 53. If there are no remaining manualists, it is determined that there is no matching fingerprint, and the result of non-matching is displayed in step 55.

In this embodiment, the fingerprint image stored in the image memory 13 is a multivalued image, but a multivalued image that has been binarized using a known method is stored and then processed. However, the essence of the process remains unchanged.

As described in detail, according to the present invention, by comparing one or more registered fingers with a human fingerprint, it is possible to access a specific manualist using a password as in the past. Since this is not necessary, it is possible to obtain a highly reliable personal identification device that is easy to operate and does not involve theft or forgetting of the PIN number.

[Brief explanation of the drawing]

FIG. 1 is a system block diagram of an embodiment of the present invention, FIG. 2(a) is a diagram showing an outline of the minutiae, FIG. 2(b) is a diagram showing a list of the minutiae, and FIG. 3 is a file diagram. A diagram showing the state of the manualist stored in,
FIG. 4 is a diagram showing the state of comparison between the collected fingerprint and the registered fingerprint with the minutiae, and FIG. 5 is a flowchart showing the operation of the embodiment of the present invention. Explanation of symbols of main parts 10... Fingerprint image input section 11... A/D conversion section 12... Image input control section 13... Image memory 15 ... Central processing section 17 ... Working memory 18 ... Verification processing section 19 ... Output section 20 ... File

Claims (1)

[Claims] (1) A fingerprint matching device that compares an input fingerprint image and a registered fingerprint image and determines whether the input fingerprint image matches the registered fingerprint image based on the characteristics of these two fingerprint images, Means for collecting a fingerprint image of a finger placed on a facepiece and outputting it as two-dimensional quantized image data; the position and pattern direction of minutiae extracted from the registered fingerprint; and the ridges existing between neighboring minutiae points. a file storing a feature list in which the number of feature points is registered in advance; a means for sequentially reading out the feature list to confirm the existence of the read feature points on the quantized image data; means for determining whether or not a predetermined threshold has been exceeded; means for determining that the two images match when it is determined that the threshold has been exceeded and terminating the matching process; and means for instructing to repeat the above process for the next feature list stored in the file when it is determined.