JP2964199B2 - Fingerprint matching method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fingerprint collation method for collating an inputted fingerprint with a registered fingerprint and identifying the person by collation matching. Means such as entering a personal identification number or reading a magnetic card are used for personal identification when entering a computer room or vault, or for personal identification when using a specific terminal device. If the number is complicated, it is difficult to memorize the number, and if it is simple, the number can be easily guessed and may be misused. Also, the magnetic card or the like may be lost or stolen. On the other hand, fingerprints are said to be unique to everyone and to be invariant for life, and are useful information for personal identification. Therefore, various means for personal identification by fingerprint collation have already been proposed. However, there is a case where there is a person whose fingerprint is unclear, and even if he / she is the person himself / herself, the matching match between the registered fingerprint and the input fingerprint cannot be obtained. Therefore, a simple remedy in such a case is demanded.

[0002]

2. Description of the Related Art As shown in FIG. 4, for example, a fingerprint collation apparatus has a fingerprint input unit 1, a fingerprint registration unit 2, a collation unit 3, and an ID number input unit 4, and one fingerprint input unit 1 is provided. The finger is placed on the reading unit, and the fingerprint is read by a television camera or the like comprising a CCD or the like. An ID number such as an employee number is input from an ID number input unit 4 including a numeric keypad, and a registered fingerprint is read from an area of the fingerprint registration unit 2 corresponding to the ID number and input to the collation unit 3. The collation unit 3 collates the input fingerprint with the registered fingerprint, and if the collation matches, the personal fingerprint is identified. If the number of registered fingerprints is small,
Fingerprint collation can be performed without inputting the D number.

FIG. 5 is an explanatory diagram of fingerprint registration and fingerprint collation. A screen read by the fingerprint input unit 1 is, for example, 51
This is a screen 5 composed of 2 × 512 pixels. In order to clarify the pattern of ridges and valleys of a fingerprint, ridge thinning processing is performed, and branch points and end points in the processing result are included. 16x
The feature points 7, 8, 9,... Of 16 pixels are extracted. Are registered in the fingerprint registration unit 2 along with the addresses of the feature points 7, 8, 9,... In the screen 5 and the pattern of the center window 6 is registered.

Accordingly, the fingerprint input at the time of fingerprint collation is also subjected to thinning processing, and a search is made in the direction of the arrow to determine whether or not the pattern of the read central window 6 of the screen 5 matches the pattern of the registered central window 6. Based on the coincidence of the center windows, the patterns of the feature points 7, 8, 9,... Are sequentially collated based on the coincidence. In this case, the matching threshold is set to 7, and the input fingerprint in which seven or more matching feature points out of the fifteen feature points are present is:
It is determined that the registered fingerprint matches with the registered fingerprint, and the user is identified.

[0005]

There is a fingerprint image having a low matching rate that does not match even if the fingerprint registered in the fingerprint registering section 2 and the fingerprint input by the fingerprint input section 1 during fingerprint matching do not match. . For example, in the case where the input fingerprint includes a flaw in the registered fingerprint due to an unclear person or an injured boundary line between the ridge and the valley of the fingerprint, even if the fingerprint input operation is performed a plurality of times, the matching match is obtained. May not be. In this case, it is conceivable to lower the matching threshold, but there is a security problem.

As a remedy for fingerprint collation having a low collation matching rate, a method of lowering the collation threshold value and combining other means such as a password, an ID card, and voice recognition can be considered. However, if the password is short, there is a high possibility that it will be stolen. If the password is long, it is difficult to memorize it. Also, the ID card has a problem of being lost or stolen, and it is necessary to carry it. There is a disadvantage that it is inconvenient. In the case where the voice is used as the auxiliary means for personal identification, there is a disadvantage that the voice recognition and the feature extracting means are complicated and expensive in order to accurately perform the personal identification. The present invention
An object of the present invention is to provide a rescue mode so that identification can be performed even when the matching rate is low.

[0007]

Fingerprint verification method of the present invention SUMMARY OF] is, referring to FIG. 1, the normal mode and repair mode
In the normal mode, a fingerprint of the first finger input by the fingerprint input unit and a plurality of fingers including the first finger in the fingerprint registration unit are provided .
Registration of fingerprints (1st finger to Mth finger) registered in a predetermined order
Matches based on the settings verification threshold at the matching portion of the first finger fingerprint of the fingerprint, the collation coincidence intended to determine the person identified
The rescue mode includes the first finger registered in the fingerprint registration unit by inputting fingerprints in a predetermined order for a plurality of fingers (first to Mth fingers) including the first finger. the fingerprint of a plurality of fingers (the thumb, second M finger) Te sequentially reading in a predetermined order, sequentially collated at the lower verification threshold than in set verification threshold to the normal mode to the matching unit based on the first finger In the case where all the fingerprints of a plurality of fingers (first finger to M-th finger) including the above match, the personal identification is determined.

[0008]

In the normal mode, the first mode input from the fingerprint input unit is used.
A fingerprint of a finger (a finger corresponding to an arbitrary registered fingerprint of the five fingers) and a fingerprint of a first finger registered in the fingerprint registration unit are collated in a collation unit. As a result, identification can be performed, but if only a fingerprint image with a low matching coincidence rate can be obtained, the mode shifts to the rescue mode. In the rescue mode, for example, assuming that the collation threshold in the normal mode is 7, collation is performed with a lower value, for example, 4 or less. In this case, the input fingerprint and the registered fingerprint are sequentially collated with respect to a plurality of fingers, and when all the fingerprints from the first finger to the M-th finger are collated and matched,
It is determined that the person is identified. In this case, even if the collation threshold is set low, fingerprint collation is performed on a plurality of fingers, so that the same security as in the normal mode can be maintained.

[0009]

FIG. 2 is a flowchart of a normal mode according to an embodiment of the present invention, and FIG. 3 is a flowchart of a rescue mode according to the embodiment of the present invention. Explaining with reference to the configuration of the fingerprint matching device shown in FIG. 4, a plurality of fingers, for example, a finger such as an index finger, a ring finger, and a little finger are registered for a person or a person who has a low fingerprint matching match rate. And in the normal mode, the ID
An ID number is input from the number input unit 4 (a), a registered fingerprint corresponding to the ID number is read from the fingerprint registration unit 2 (b), and input to the matching unit 3. Also in this case, when the number of registered fingerprints is small, fingerprint matching in the normal mode can be performed without inputting an ID number.

Then, a fingerprint is input by the fingerprint input unit 1 (c). In this case, when the fingerprint of the index finger is registered in the fingerprint registration unit 2, the fingerprint of the index finger is read and input. Then, the registered fingerprint is collated with the input fingerprint in the collating unit 3 (d). It is determined whether or not the collation matches (e), and in the case of the collation, the person is identified (f). As described with reference to FIG. 5, the registered fingerprint is compared with the input fingerprint by comparing a plurality of feature point patterns. For example, when the registered fingerprints are registered as 15 feature point patterns, the matching threshold is set to 7. , When there is a match for seven or more feature point patterns, it is determined that the registered fingerprint matches the input fingerprint.

In the case of collation mismatch, N + 1 is set to count the number of times of collation mismatch (g), and it is determined whether N ≧ 3 (h). If N ≧ 3, that is, if fingerprint collation has not been repeated three times, the process proceeds to step (c). If N ≧ 3, ie, if fingerprint collation has been repeated three times, the rescue mode (i) Move to In the step (h) for determining whether or not N ≧ 3, a value other than 3 can be set. Further, in the case where the collation does not match in step (e), it is possible to immediately shift to the rescue mode (i).

In the rescue mode, a rescue ID number is input (j) and J = 1 (k). In this case, the ID number input from the ID number input section 4 in the normal mode is
For example, if a six-digit number of “123456” is used, for example, “* 23456” can be used as the rescue ID number. Alternatively, a code indicating the rescue mode may be added to the ID number in the normal mode and input. Alternatively, it is also possible to automatically shift to the rescue mode when N ≧ 3 in step (h) of the normal mode.

Next, the fingerprint input of the J-th finger (J = 1, 2, 3,...) Is performed (1), and the registered fingerprint of the J-th finger (first time is the first finger) is compared with the input fingerprint. (M). The collation threshold in this case is set lower than the collation threshold in the normal mode, as described above. As a result, in the step (n) of determining whether or not there is a matching match, the matching match rate increases. Then, in the case of collation matching, J = J + 1 (o), and it is determined whether J ≧ M (p).

In the case of J ≧ M, since the fingerprint collation from the first finger to the M-th finger is identical, the person is identified (p). If J ≧ M is not satisfied, since the fingerprint collation up to the M-th finger has not been completed, the process proceeds to step (l). In this case, M = 3, that is, collation is sequentially performed for the three fingers. When the collation matches are obtained for the three fingers from the first finger to the third finger, the identification is determined as the identification. .

The arrangement order of the fingers is as follows: thumb, index finger, middle finger,
When the ring finger and the little finger are used , the above-mentioned J = 1 to J = 5 in this order.
Generally, for example, fingerprints are registered in the order of J = 1 = finger finger, J = 2 = little finger, J = 3 = ring finger,
By inputting fingerprints in the order of registration at the time of fingerprint collation, personal identification including the fingerprint collation order can also be performed. Similarly, the registration order for all fingerprints of the five fingers
And personal identification can be performed by collation matching.
That is, in the rescue mode, the settings in the normal mode
Using a matching threshold lower than the matching threshold,
If the fingerprint matches, the identity is determined.
Therefore, depending on the combination of the number of fingers and the matching threshold,
Identity can be maintained while maintaining security.

[0016]

As described above, according to the present invention, the fingerprint of the first finger input by the fingerprint input unit 1 , for example,
And a plurality of fingers (first finger to first finger) including the first finger in the fingerprint registration unit 2 .
M finger) in a predetermined order, for example, a finger finger, a little finger, a medicine
A first fingerprint of the finger in the registered fingerprint registered in the order of the finger at the collation unit 3 collates based on the settings match threshold, a normal mode is determined that the person identification in the case of collation coincidence, the normal mode
Rescue mode to shift to when the verification mismatch occurs
And And in this rescue mode
For a plurality of fingers (first finger to Mth finger) including the first finger
In a predetermined order, in the above example, the order of the index finger, little finger, ring finger
Input by fingerprint input unit 1 and register in fingerprint registration unit 2
Fingerprints of a plurality of fingers (first finger to Mth finger) including the extracted first finger
In a predetermined order, in the example described above, the order of the index finger, the little finger, and the ring finger
Read sequentially in the order, from the set collation threshold in normal mode
The collating unit 3 sequentially performs collation based on the low collation threshold, and
Fingerprints of multiple fingers (1st to Mth fingers) including fingers
If all match, the identity is determined.
You. Therefore, in general, the user is identified and identified in the normal mode.
Can be specified, but the impression finger at the time of fingerprint collation
If the crest includes blurring or damage due to injury, use the same finger
Is not matched even if it is repeatedly stamped
However, in the present invention, the mode shifts to the rescue mode and the collation threshold is lowered.
And fingerprints of a plurality of fingers including the first finger in a predetermined order.
The fingerprint collation is performed by sequentially inputting the
And the condition that all fingerprints match
Lowering the collation threshold by performing personal identification
Identification by avoiding security degradation due to
There are advantages.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating the principle of the present invention.

FIG. 2 is a flowchart of a normal mode according to the embodiment of the present invention.

FIG. 3 is a flowchart of a rescue mode according to the embodiment of the present invention.

FIG. 4 is an explanatory diagram of a main part of the fingerprint matching device.

FIG. 5 is an explanatory diagram of fingerprint registration and fingerprint collation.

Claims (1)

(57) [Claims] 1. A fingerprint of a first finger input by a fingerprint input unit and fingerprints of a plurality of fingers including the first finger in a fingerprint registration unit are specified.
A fingerprint of the first finger of the registered fingerprint registered in order to set verification threshold against based at the matching portion of the normal mode is determined to be by an original person identified by collation coincidence, and disagreement In the normal mode A rescue mode that shifts when a plurality of fingers including the first finger are used in the rescue mode.
Input a fingerprint by the fingerprint input unit in a predetermined order ,
And sequentially reading out fingerprints of a plurality of fingers including the first finger registered in the fingerprint registration unit in the predetermined order, and in the matching unit, a matching threshold lower than the set matching threshold in the normal mode. A fingerprint matching method based on a plurality of fingerprints including the first finger, and when all of the fingerprints of the plurality of fingers match, the personal identification is determined.