JPH1196358A - Processing method and device for collating fingerprint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To set a collation level corresponding to the state of a picked-up fingerprint image concerning a processing method and a device for collating fingerprint with which a registered fingerprint and the picked-up fingerprint image are collated. SOLUTION: The image of a fingerprint sealed on a sealing plane 1 is picked up by a camera 2 and binarized by an image processing part 3, a feature point is extracted by a feature point extracting part 4, the fingerprint registered in a register file 6 is collated with the picked-up fingerprint image by a fingerprint collating part 5, and the identity is confirmed from the coincidence of collation by a main control part 7. At such a time, concerning this method, the average number of times of sealing is found as the average value of how many times the fingerprint is sealed until the collation shows coincidence by an average sealing time calculating part 13, the average state index of the average value of a state index expressing the state of the picked-up fingerprint image is found by an average state index calculating part 14 and based on these results, a collation level setting part 15 sets the collation level at the fingerprint collating part 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a fingerprint collation processing method and a fingerprint collation device for performing identity verification by fingerprint collation. The fingerprint and the identification number (ID number) are registered in a registration file in advance, and at the time of fingerprint collation, the registered fingerprint is read out based on the input ID number, and the captured fingerprint obtained by imaging the imprint fingerprint is collated with the registered fingerprint. Perform identity verification by matching match,
It is possible to unlock the door and operate the apparatus, and there is a demand for a flexible fingerprint collation corresponding to a fingerprint state or the like.

[0002]

2. Description of the Related Art When a fingerprint is registered in a conventional fingerprint matching device, the registration is performed, for example, according to a flowchart shown in FIG. That is, it is determined whether or not a fingerprint is imprinted (E1).
In the case of fingerprint imprinting, the imprinted fingerprint is imaged by a camera, a multi-valued image signal from the camera is captured (E2), the multi-valued image signal is binarized (E3), and an Registration processing is performed by extracting feature points such as branch points and the like (E4). It is determined whether registration is successful based on whether a predetermined number of feature points have been extracted by the registration processing (E5), and a predetermined number of feature points are determined. Is successfully registered and registered as dictionary data in a registration file (E6). If a predetermined number of feature points cannot be extracted, registration is rejected and registration failure processing is performed (E7). The registration failure process includes, for example, redoing a fingerprint registration operation.

The collation between the imaged fingerprint and the registered fingerprint is performed according to, for example, a flowchart shown in FIG. That is, it is determined whether or not a fingerprint is imprinted (F1). In the case of fingerprint imprinting, the imprinted fingerprint is imaged by a camera, a multi-valued image signal from the camera is taken in (F2), and the multi-valued image signal is converted into a binary image. It quantizes (F3), performs a matching process (F4), determines whether or not the matching is successful (F5). If the number of matching matches between the characteristic points of the registered fingerprint and the captured fingerprint is equal to or greater than a predetermined number, If the matching is successful, the identity is confirmed (F6). If the number of matching matches between the feature points of the registered fingerprint and the feature points of the captured fingerprint is not equal to or greater than a predetermined number, matching failure is performed (F7). The collation failure processing includes, for example, redoing a fingerprint for fingerprint collation.

[0004]

A fingerprint has a pattern peculiar to an individual. Therefore, by registering this fingerprint, it is possible to verify the identity by comparing the registered fingerprint with the imprinted fingerprint. it can. However, fingerprints of the elderly and those who do frequent manual work can cause rough skin,
There is a problem that the captured fingerprint becomes unclear and it is difficult to extract feature points for fingerprint verification, and fingerprint registration failure or fingerprint verification failure due to blurring of the captured fingerprint after fingerprint registration frequently occurs.

[0005] Therefore, it is conceivable to set the collation level in fingerprint collation low to increase the fingerprint collation rate.
However, fingerprint collation is intended to improve security, and lowering the collation level in fingerprint collation generally has the problem of lowering security. SUMMARY OF THE INVENTION It is an object of the present invention to automatically set a matching level according to the state of a captured fingerprint, and to improve the matching rate without lowering security.

[0006]

According to the present invention, there is provided a fingerprint collation processing method comprising the steps of: (1) collating an imaged fingerprint obtained by imprinting an imprinted fingerprint with a registered fingerprint; The collation level is set based on the average number of impressions of the number of times of imprinting until matching and the average state index of the average value of the state indices based on the number of extracted feature points indicating the state of the imaged fingerprint. In addition, the method includes a step of collating the captured fingerprint with the registered fingerprint according to the collation level. Since the collation level can be set according to the state of the captured fingerprint, the fingerprint collation is maintained while maintaining the security as a whole. The rate can be improved.

(2) A first range including the average number of times of printing until the matching is reached, a second range including an average number of times of printing that is greater than the first range, A third range of the average number of times of printing is set to be larger than the range of 2, and when the average number of times of printing is within the first range and the present state index is higher than the average state index, that is, the imaging fingerprint is good. When the collation level is raised, the collation is performed when the average number of impressions is within the third range exceeding the second range and the current state index is lower than the average state index, that is, when the imaged fingerprint is not good. It includes a process of lowering the level and maintaining the collation level at the previous state in other states. The collation level can be automatically set according to the average number of times of stamping and the average state index.

And (3) obtaining a state index of the imaged fingerprint, and displaying the state index or a collation level set based on the state index. The state includes characteristic points extracted from the imaged fingerprint. The index and the collation level based on the index are displayed, and it is possible to recognize or register the progress of the degradation of the fingerprint state, change the finger for collation, or the like based on the displayed content.

Further, the fingerprint collating apparatus of the present invention controls (4) a registration file 6 for storing a registered fingerprint, a fingerprint collating unit 5 for collating an imaged fingerprint obtained by imaging an imprinted fingerprint with the registered fingerprint, and controls each unit. The fingerprint control device includes a main control unit 7, wherein the main control unit 7 counts the number of times of imprinting on the imprinted surface until a match between the imaged fingerprint and the registered fingerprint in the fingerprint verification unit 5 is obtained. A calculating unit 13 for calculating an average number of times of printing with the past multiple times of the number of times of imprinting; And a collation level setting unit 15 for setting a collation level between the captured fingerprint and the registered fingerprint in the fingerprint collation unit 5 based on the average number of times of impression and the average state index.

(5) The main control unit 7 has a means for obtaining a state index of the imaged fingerprint and displaying the state index or a collation level set based on the state index on the display unit 10. Let the person recognize the current fingerprint state.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an explanatory view of a main part of a fingerprint collating apparatus according to an embodiment of the present invention, wherein 1 is an impression surface, 2 is a camera, 3 is an image processing unit, 4 is a feature point extracting unit, 5 is a fingerprint collating unit, 6 is a registration file, 7 is a main control unit, 8 is a numeric keypad,
9 is an input processing unit, 10 is a display unit, 11 is a display control unit, 1
2 is a control output unit, 13 is an average number of times of stamping calculation unit, 14 is an average state index calculation unit, and 15 is a collation level setting unit.

The imprinting surface 1 is illuminated from below by a light source such as an incandescent lamp or a light emitting diode (not shown) to perform fingerprint imprinting on the upper surface.
An image is captured by a camera 2 such as a CD camera. This camera 2
Is input to an image processing unit 3, which performs processing such as binarization processing, and extracts a characteristic point of a fingerprint such as an end point or a branch point in a characteristic point extracting unit 4. Collation unit 5
Is registered in the registration file 6 under the control of the main control unit 7 during fingerprint registration.

A ten key 8 is used to input an ID number, a password, a fingerprint registration request, a fingerprint collation request, a fingerprint state display request, and the like. However, a specific key or the like is generally required at the time of fingerprint registration, and a fingerprint is usually stamped after inputting an ID number without particularly inputting a fingerprint collation request. Also, the main control unit 7 performs
Based on the ID number input via the input processing unit 9, control is performed to read a registered fingerprint from the registered file 6 and input the fingerprint to the fingerprint matching unit 5.

In the registration file 6, feature points such as the end points and branch points of the imprinted fingerprint are extracted, and are registered fingerprints along with the position information of the feature points. An ID number is added to facilitate the search. The configuration to register is common. In the present invention, including the average number of times of stamping calculated by the average number of times of stroke calculation unit 13 and the average state index calculated by the average state index calculation unit 14, together with the registered fingerprint or corresponding to the ID number. be able to. It is also possible to register a state index at the time of fingerprint registration.

The fingerprint collating section 5 sets the collation level from the collation level setting section 15 of the main control section 7 and collates the captured fingerprint with the registered fingerprint. For example, the feature points extracted from the captured fingerprint are used. And the collation level can be set as the number of matching feature points. This state index is input to the average state index calculation unit 14,
An average value is obtained for a predetermined number of times in the past. Further, the number of times the fingerprint is repeatedly stamped until the matching coincidence signal is input from the fingerprint matching unit 5 is counted, and the average number of times of stamping calculation unit 13 obtains an average value for a predetermined number of past times. The verification level setting unit 15 sets a verification level in the fingerprint verification unit 5 according to the average number of times of stamping and the average state index.

When the collation level set in the fingerprint collation unit 5 is increased, collation coincides when the number of matching feature points is large, and security can be enhanced. Conversely, when the collation level is lowered, collation coincides even if the number of matching feature points is small, and the collation rate when the fingerprint state is poor can be increased.

In the case of door opening / closing control, the main control section 7 sends an unlock signal for an electric lock of the door from the control output section 12 in accordance with the collation coincidence signal from the fingerprint collation section 5, and also controls the important devices. When the operation is enabled, the control output unit 12 sends a power-on control signal or the like that enables the operation.

The display section 10 is constituted by a liquid crystal display panel or the like, and the display content is controlled by the display control section 11 based on data from the main control section 7. For example, it is possible to display on the display unit 10 the input information obtained by operating the numeric keypad 9 and the quality of the pressing force of the fingerprint imprinting state on the embossing surface 1 or the collation result. In this case, the pressing force in the fingerprint printing is, for example, whether or not an image signal suitable for feature point extraction in the feature point extraction unit 4 is obtained in the image processing unit 3 or the average luminance of the image. Therefore, the display format can be set so that the optimum value of the pressing force can be obtained. In addition, it is also possible to display an instruction of an input operation, a display as to whether or not the input is proper, and a display as to whether or not the collation result is correct, by selecting a synthesized voice or a plurality of tone colors.

When a fingerprint status display request is made, the main controller 7
Controls the display unit 10 to display the above-described state index or collation level of the captured fingerprint. This allows the fingerprint collator to recognize his / her fingerprint state and perform fingerprint collation using, for example, a finger having a good state index among five fingers. An image processing unit 3, a feature point extracting unit 4, a fingerprint matching unit 5,
The functions of each unit can be realized by the processing functions of the microprocessor, including the main control unit 7, the input processing unit 9, the display control unit 11, and the like.

FIG. 2 is a flowchart of fingerprint registration according to the embodiment of the present invention.
1) If stamping is performed, a multi-valued image is captured (A
2) Perform binarization and registration processing (A3). That is, FIG.
The camera 2 captures a fingerprint imprinted on the embossing surface 1 by the camera 2, fetches the multi-valued image from the camera 2 in the image processing unit 3, binarizes the multi-valued image, A registration process for extracting feature points such as points is performed. In general, an ID number is input from the numeric keypad 8 before the step (A1), and although not shown in the present invention, an ID number can be input.

Then, it is determined whether or not the registration has passed (A
4) If the number of extracted feature points is equal to or more than a predetermined value, it is determined that the registration is successful. If the number does not reach the predetermined value, registration failure processing is performed (A8). That is, fingerprint imprinting or the like is performed again. If the registration is successful, obtain the state index (A
5). That is, as described above, the number of feature points can be used as a state index. Alternatively, an index representing the state of various types of imaged fingerprints, such as the luminance distribution of the imaged fingerprints, the number of detected fine lines due to scratches different from ridges and valleys of the imaged fingerprints, and the like can be used.

The main control unit 7 sets a collation level based on the state index of the captured fingerprint (A6), and registers the fingerprint including the feature point in the registration file 6 as dictionary data (A7).
In this case, the above-mentioned state index and collation level are registered.

FIG. 3 is a flowchart of the fingerprint collation according to the embodiment of the present invention.
1). Although not shown in the figure at the time of fingerprint collation, as in the case of fingerprint registration, an ID number is input from the numeric keypad 8 (see FIG. 1) and the fingerprint is stamped. With this fingerprint imprint, a multi-valued image is captured (B2), and a binarization and collation process is performed (B3). That is, the fingerprint imprinted on the embossing surface 1 in FIG. 1 is captured by the camera 2, the multi-valued image from the camera 2 is fetched by the image processing unit 3, the multi-valued image is binarized, and the feature point extraction unit 4 Is performed to extract feature points such as end points and branch points.

The collation level setting unit 1 of the main control unit 7
5, the collation level is set in the fingerprint collation unit 5, the collation between the registered fingerprint and the imaged fingerprint is performed, and the collation is passed (collation coincidence).
It is determined whether or not (B4). For example, when the number of coincidences of the feature points between the registered fingerprint and the captured fingerprint is equal to or lower than the matching level, the matching failure processing is performed (B8). That is, a re-input operation including a fingerprint imprinting operation or an ID number input is performed again.

If the number of coincidences of the characteristic points between the registered fingerprint and the imaged fingerprint exceeds the collation level (the number of collations), the collation is passed (collation coincidence), and the state index of the imaged fingerprint at that time is determined by the main control unit 7. Is input to the average state index calculation unit 14 to obtain an average value of the state indexes over N times in the past (B5). Also, the number of times of stamping until the verification is passed (matching of matching) is input from the image processing unit 3 or the like to the average number of times of stamping calculation unit 13 of the main control unit 7, and the average value of the number of times of stamping until the past N times of verification is passed (B6). Then, the next collation level is set based on the average state index and the average number of times of printing (B7).

FIG. 4 is a flowchart for setting a collation level according to the embodiment of the present invention.
5) and (B6), an average number of times of stamping and an average state index are obtained (C1), and then the step (B) in FIG.
Perform the process of 7). That is, the average number of times of stamping is determined (C2). The minimum value of the average number of times of stamping is 1, and the maximum value is the allowable number of times of stamping during fingerprint collation.

In this case, the case where the average number of times of printing is 1.00 is the first range, the case where the average number of times of printing is 1.00 to 1.75 is the second range, and the case where the average number of times of printing is 1.75 or more is the third range. When the number of times of stamping is within the first range, that is, when it is 1.00, the average state index is determined (C3). (C6).

When the average number of times of printing is in the third range of 1.75 or more, it is determined whether or not the average state index has increased (C
4) If it does not rise or falls, the level is lowered as the next verification level setting (C7). That is, since the average number of times of impression is large when the state of the imaged fingerprint is poor and the state index of this time is low,
Control is performed such that the matching level is reduced and the matching rate becomes a predetermined value.

The average number of times of printing is in the second range, namely, 1.
In the case of the range of 00 to 1.75, the level is maintained (C
5) If the average number of impressions is in the first range, that is, 1.00, and the average state index does not increase, the level is maintained (C5). If the average number of impressions is in the third range, that is, 1.75 or more, and the average state index increases, the level is maintained (C5).

Therefore, when the state of the imaged fingerprint is very good, the average number of times of stamping is 1.00, and the average state index increases, the collation level is increased to improve the security. Is very bad, the average number of times of printing is in the third range exceeding the second range, and if the average state index does not increase further, the matching level is lowered to improve the matching rate. be able to. Also, the collation level can be updated within the range by setting an upper limit and a lower limit. Further, the conditions of maintenance, up, and down may be other conditions than those shown in FIG. For example,
When the average number of times of printing is in the second range and the average state index increases, it is possible to increase the level and increase the conditions for increasing the collation level.

The above-mentioned first, second, and third ranges can be set in consideration of the security of the entire fingerprint collation device, the resolution of the captured fingerprint including the camera 2 and the image processing unit 3, and the like. The above-described change of the collation level can be performed from the collation level setting unit 15 of the main control unit 7 to the fingerprint collation unit 5 corresponding to the ID number. For example, the collation level setting unit 1
5, the next matching level corresponding to the ID number is obtained and stored from the average number of times of stamping and the average state index, and the matching level is read out based on the ID number input at the time of fingerprint matching. Can be set.

FIG. 5 is a flowchart of a fingerprint state determination display according to the embodiment of the present invention.
Enter the fingerprint status display request and the ID number from
The fingerprint is imprinted on the surface. In that case, it is determined whether or not fingerprint imprinting is performed (D1). If imprinting is performed, a multi-valued image is captured (D2), and binarization and registration processing is performed (D
3). That is, the fingerprint imprinted on the imprint surface 1 in FIG.
The image processing unit 3 captures a multi-valued image from the camera 2, binarizes the multi-valued image, and extracts a feature point such as an end point or a branch point by the feature point extraction unit 4. Do.

Then, it is determined whether or not the registration has passed (D
4) If the number of extracted feature points is equal to or more than a predetermined value, the registration is determined to be successful. If the number does not reach the predetermined value, the registration is determined to be unsuccessful and a rejection is displayed on the display unit 10 (D8). If the registration is successful, a state index is obtained (D5) as in step (A5) of FIG. For example, the number of extracted feature points can be used as a state index. Alternatively, an index representing the brightness distribution of the captured fingerprint or another state of the captured fingerprint can be used.

The collation level is determined based on the state index (D6), and the result of the determination is displayed on the display unit 10 (D6).
7). That is, it is possible to display whether or not the state is such that a pass of verification is obtained when a fingerprint is imprinted for fingerprint verification.
Further, the quality of the current state of the captured fingerprint can be displayed as compared with the state index at the time of fingerprint registration. Also, judging from the current fingerprint state, it is also possible to use a display content that calls attention to use another finger for fingerprint collation. Alternatively, it is also possible to set the display content to prompt re-registration of the fingerprint. Such a determination process can be performed in the main control unit 7 based on a database or the like not shown.

[0035]

As described above, according to the present invention, the collation level is determined on the basis of the average number of impressions of the number of impressions until the collation coincides and the average state index of the average value of the state index indicating the state of the imaged fingerprint. The collation between the captured fingerprint and the registered fingerprint is performed according to the collation level. If the state of the captured fingerprint is degraded, the collation level is reduced accordingly to prevent the collation rate from decreasing. In addition, when the state of the imaged fingerprint is good, there is an advantage that the collation level can be increased correspondingly to improve security. In addition, by using the state index of the imaged fingerprint, it is possible to display whether the current fingerprint state is good or not so as to recognize whether or not the fingerprint state can be used for fingerprint collation.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a main part of a fingerprint matching device according to an embodiment of the present invention.

FIG. 2 is a flowchart of fingerprint registration according to the embodiment of the present invention.

FIG. 3 is a flowchart of fingerprint collation according to the embodiment of the present invention.

FIG. 4 is a flowchart of a collation level setting according to the embodiment of the present invention.

FIG. 5 is a flowchart of a fingerprint state determination display according to the embodiment of the present invention.

FIG. 6 is a flowchart of a conventional fingerprint registration.

FIG. 7 is a flowchart of a conventional fingerprint collation.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Impression surface 2 Camera 3 Image processing part 4 Feature point extraction part 5 Fingerprint collation part 6 Registration file 7 Main control part 8 Numeric keypad 9 Input processing part 10 Display part 11 Display control part 12 Control output part 13 Average number of times of stamping calculation part 14 Average State index calculator 15 Collation level setting unit

Claims (5)

[Claims] In a fingerprint collation processing method, an imprinted fingerprint obtained by imaging an imprinted fingerprint is collated with a registered fingerprint, and when the collation does not match, the fingerprint is imprinted again. Setting a collation level based on the number of times and the average state index of the average value of the state index indicating the state of the captured fingerprint, and collating the captured fingerprint with the registered fingerprint according to the collation level. Fingerprint matching processing method. 2. A first range including the average number of times of imprinting of one time, a second range of an average number of times of imprinting greater than the first range, and a third range of an average number of times of imprinting greater than the second range. The comparison level is increased when the average number of times of printing is within the first range and the current state index is higher than the average state index, and the average number of times of printing is lower than the second number of times. When the current state index is lower than the average state index within a third range exceeding the range, the collation level is reduced, and in other states, the collation level is maintained at the previous state. 2. The fingerprint matching processing method according to claim 1, comprising a step. 3. The method according to claim 1, further comprising the step of obtaining a state index of the captured fingerprint and displaying the state index or a collation level set based on the state index.
The described fingerprint matching processing method. 4. A fingerprint matching device comprising: a registration file for storing a registered fingerprint; a fingerprint matching unit for matching an imaged fingerprint obtained by capturing an imprinted fingerprint with the registered fingerprint; and a main control unit for controlling each unit. The main control unit counts the number of times of stamping on the stamped surface until a match between the imaged fingerprint and the registered fingerprint in the fingerprint matching unit is obtained, and calculates the average value of the number of times of past stamping and the number of times of stamping. A calculating unit for the average number of times of stamping, a calculating unit for calculating the state index of the imaged fingerprint, and a calculating unit for an average state index of an average value of a plurality of past state indices, based on the average number of times of stamping and the average state index A fingerprint collation device comprising: a collation level setting unit for setting a collation level between an imaged fingerprint and a registered fingerprint in the fingerprint collation unit. 5. The apparatus according to claim 1, wherein the main control unit obtains a state index of the captured fingerprint and displays a state index or a collation level set based on the state index on a display unit. The fingerprint matching device according to claim 1, wherein