JPH0321945B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a person verification method, and more particularly to a person verification method for identifying an individual using a fingerprint.

Prior Art Personal verification systems for identifying individuals are broadly divided into two types: access control and transaction control. In the former, when you want to enter a specific area, instead of using a key, you enter the personal identification number (ID number) given to each person using a keyboard or card, and check it with the ID number pre-registered at the center. This method checks the identity of an individual. The latter type of transaction management is used for commercial transactions by banks and so-called credit cards, and is a method in which file checks, updates, etc. are performed after confirming the identity of an individual using the same method as access control.

However, none of the above systems is perfect, and accidents such as unauthorized use have been occurring frequently, especially with the recent increase in credit transactions. Therefore, a more reliable and low-cost identity verification method is required.

Purpose of the Invention The purpose of the present invention is to provide an accurate, highly reliable, and low-cost identity verification method that is suitable for access control and transaction management systems.

Structure of the Invention The person verification method according to the present invention includes a conversion means that collects a fingerprint from a finger tip and converts it into image data, and a storage card that stores information indicating the minutiae of the fingerprint and the relationship between the minutiae points in advance. a card reading means for reading the stored information of the memory card when the card is read, and a collation means for checking and collating the information from the card reading means from the image data by the converting means, and the converting means and the card reading means are plural. The present invention is characterized in that the verification means is provided in one center device, and these terminal devices and the center device are connected by a communication line.

Embodiments Hereinafter, embodiments of the present invention will be described using the drawings.

FIG. 1 is a block diagram of an embodiment of the present invention.
It has a plurality of terminal devices 20.1 to 20.n and one center device 10, and each terminal is connected to the center by a communication line 16, respectively.

Each terminal includes a card reading device 15 that reads stored information when a storage card is input, a fingerprint input device 11 that collects a fingerprint by inserting the tip of a finger,
It is composed of an A/D (analog/digital) converter 12 and an image memory 13, and each part is connected with signal lines for transmitting and receiving various data as shown.

The fingerprint input device 11 generates a photoelectric conversion image of a fingerprint pattern using a light source and an imaging means such as an ITV, using the optical boundary conditions of the glass from the back side of a finger placed on a glass plate. . for example,
It is disclosed in Japanese Patent Application Laid-open No. 54-69300 and Japanese Patent Application Laid-open No. 54-85600, and these structures are used. Also,
The A/D converter 12 for quantizing the photoelectric conversion signal such as ITV and the image memory 13 may also be commonly known devices, so their details will be omitted.

The digital two-dimensional quantized image data thus obtained is stored in the memory 13, and
Characteristic points (end points, branch points) on the so-called manufactory card read by the card reader 15
and information regarding the relations between minutiae points are held in the working memory 103 within the matching processor 10. The fingerprint features are as shown in Figure 2a and b.
The position (X, Y) of the feature point M, the pattern direction D, and the relationships R1 to R4 with neighboring feature points are set as units.
This is a list representation of a plurality of minutiae points M in a fingerprint, and is recorded in advance on the magnificence card by an electromagnetic method or the like. Figure a
is an example of a fingerprint, and b in the same figure shows the concept of a list. Detailed definitions and extraction methods are described in Japanese Patent Application Laid-Open No. 138174/1983.

As shown in FIG.
This results in accurate correspondence between the fingerprint image 30 stored in the image memory 13 and the feature points (for example, 31) and relations (for example, 32) read out from the magistrate card. If the response is successful, it is a match, otherwise it is a mismatch, and management decisions can be made for various purposes.

The verification process to be performed by the verification processor 10 is as follows.

Referring to FIG. 4, a local pattern 41 on the image memory corresponding to the position of the minutiae 40 read out from the magnificence card is scanned perpendicularly to the minutiae direction with the minutiae position as the origin. 41
1,...412,413,414,415,41
6,...,417 and inspect the image data obtained according to this scanning, for example, 41 in Figure a.
2,413,...,416 are 422,42 in figure b
3,...,426. The feature points (endpoints in the example) 43 are discovered by matching the pattern edges associated with the dotted lines of each image data.
Furthermore, the feature direction is determined by averaging the matching angles of pattern edges. The feature points 43 and 40 thus discovered are held as candidate corresponding points based on their positional displacement and direction difference. Candidate corresponding points are obtained in the same manner for neighboring feature points that are related to this feature point by relations in the feature point list. Next, as shown in FIG. 5, the fingerprint pattern line 53 on the connecting line for the two neighboring minutiae points 51 and 52 is as shown in FIG.
Yi=3 is counted, and a check is performed against the list.

As described above, by sequentially inspecting the arrangement of feature points and the relations between neighboring feature points,
Fingerprint verification is performed.

The matching processor 10 can be configured exclusively for the above processing, but as described above, this matching processing is realized only by local linear scanning on the image memory, so as shown in FIG. , central processing unit 101, program memory 102, working memory 1
03, a general-purpose microprocessor configured with an external interface 104 may also be used.

As described above, using only the image data read out by linear scanning of the fingerprint pattern on the image, the identity of fingerprint minutiae and relations between minutiae points can be verified with high accuracy through simple microcomputer processing. As a result, the identity of the individual can be confirmed.

The image data sent from each terminal to the center is
In the case of flat fingerprint data, the amount of information is approximately 160K bytes, so if it is left as it is, communication line 1
An extremely high level of characteristics 6 is required. Therefore, if the A/D-converted fingerprint image data is compressed using a well-known data compression method such as a predictive encoding method and sent to the center, approximately 80K bytes of data will be enough to be sent. It's convenient. In this case, it goes without saying that it is necessary to add a data decompression function on the center side.

Effects of the Invention As described above, according to the present invention, since fingerprints are used for personal verification, it is an extremely reliable verification method, and a general-purpose microprocessor such as a microcomputer can be used. ,
It will be a small and low-cost system, and in particular will be a person-verification method that will replace the current cash card system for deposit and savings transactions.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of the present invention, FIG. 2 is a diagram defining fingerprint minutiae information, FIG. 3 is a diagram showing a fingerprint verification state, and FIG. 4 is a diagram showing an inspection of the fingerprint minutiae arrangement. FIG. 5 is a diagram illustrating the inspection of relations between feature points. Explanation of symbols of main parts: 10... Verification processor, 11... Fingerprint input device, 12... A/D conversion device, 15... Card reading device.

Claims (1)

[Scope of Claims] 1. Conversion means that collects a fingerprint from the tip of a finger and converts it into image data consisting of ridges, and the positions and directions of registered feature points such as end points and branch points of the ridges of the fingerprint, and the registered features. Card reading that reads the stored information of a memory card when a memory card that stores information indicating the relation between registered minutiae points including the number of ridges existing between a point and other registered minutiae points in the vicinity is input. and a position of the registered feature point obtained by local linear scanning in a scanning direction orthogonal to the feature point direction with the registered feature point in the storage card as the origin in the image data by the converting means. Using relation information between registered feature points including the position, direction, and number of ridges of the registered feature points, from local image data and neighboring local image data corresponding to the positions of other registered feature points in the vicinity thereof, respectively, a verification unit that performs a process of detecting a feature point and its neighboring feature points, and performs a process of matching the storage card with a fingerprint from the fingertip, and the conversion unit and card reading unit are connected to a plurality of terminal devices. The verification means is provided in one center device, and these terminal devices and the center device are connected by a communication line. 2. The principal according to claim 1, wherein the image data is compressed using a predetermined data compression method and sent from the terminal, and the center device is configured to decompress this compressed data. Matching method.