JP2009054052A - Face authentication device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a face authentication device for reducing a time required for authentication while suppressing false authentication. <P>SOLUTION: The device is provided with an image pickup part 1 for imaging a subject of authentication; a storage part 2 for storing registered images obtained by imaging faces of each registrant; and a control unit 3 for performing authentication operation by using subject images obtained by the image pickup part 1 and registered images stored in the storage part 2. The control unit 3 determines that the subject is registered when correlated value between any of the registered images and the subject image is equal to a prescribed authentication threshold or larger. Since the registrant is authenticated with any posture in a plurality of registered images, a time required for authentication can be reduced compared with when he or she is authenticated with only a posture of one registered image. Also, in comparison with the case when a similar effect is expected by reducing the authentication threshold, the false authentication can be suppressed. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a face authentication apparatus.

  Conventionally, the face portion of the subject is extracted from an image obtained by capturing the subject of authentication by a known technique (for example, see Patent Document 1), and the image of the extracted face portion is extracted from the face of the registrant registered in advance. There is provided a face authentication device that performs authentication by comparing with a partial image.

This type of face authentication device is used for security purposes such as unlocking an electric lock or permitting login only when the subject is authenticated as a registrant in combination with an electric lock or a personal computer. .
Japanese Patent Laid-Open No. 2007-80087

  In the conventional face authentication device, an image obtained by imaging an authentication target person is compared with one registered image for each registrant. Therefore, in order to be authenticated as the same person, a camera used for imaging And the conditions (hereinafter referred to as “posture”) such as the distance to the face and the orientation of the face must be made substantially the same as the posture at the time of capturing the registered image, and the registrant has the same posture as the registered image. It may take some time to get certified and take time to adjust to. If the conditions for determining the match between the person in the captured image and the person in the registered image are relaxed, the above problem will be alleviated, but the incidence of false authentication in which another person is authenticated as a registrant will increase. .

  The present invention has been made in view of the above reasons, and an object of the present invention is to provide a face authentication apparatus capable of reducing the time required for authentication while suppressing the occurrence of erroneous authentication.

  According to the first aspect of the present invention, an image pickup unit for picking up the target person and a plurality of registered images each picking up a face for each registrant are stored in association with identification information corresponding to the registrant on a one-to-one basis. A storage unit, and a control unit that performs an authentication operation for determining whether or not the subject imaged by the imaging unit is a registrant. A comparison operation for obtaining a target image from which the portion has been extracted from the imaging unit, calculating a correlation value between one of the registered images and the target image, and comparing the obtained correlation value with a predetermined authentication threshold is stored in the storage unit. A continuous comparison operation is sequentially performed for each registered image associated with at least one identification information among the stored registered images, and a correlation value with the target image is authenticated in all the registered images used in the continuous comparison operation. When below the threshold, A target image is obtained from the imaging unit, a continuous comparison operation is performed using the new target image as a target image, and a correlation value with the target image is obtained in any registered image by a comparison operation equal to or less than a predetermined limit number of times. When it is determined that the subject is a registrant when the authentication threshold is exceeded, but the comparison cannot be determined that the subject is a registrant even if the number of comparison operations reaches the limit number And a control unit that determines that the target person is not a registrant.

  According to the present invention, since the registrant is authenticated if the posture is one of a plurality of registered images, the authentication is required compared to the case where the registrant is authenticated only by the posture of one registered image. Time can be shortened. In addition, the occurrence of erroneous authentication can be suppressed as compared with a case where the same effect is to be obtained by lowering the authentication threshold.

  In the invention of claim 2, in the invention of claim 1, when the control unit authenticates the subject as a registrant, the control unit uses a target image used in the authentication process that satisfies a predetermined condition. The number of candidate images and the number of registered images associated with the identification information are stored in the storage unit as candidate images to be added to the registered image associated with the same identification information as the registered image at the time of authentication. Is compared with a predetermined limit number, and if the total is less than the limit number, the candidate image is added to the registered image associated with the identification information, and if the total exceeds the limit number, the identification information A candidate image is added to the registered image associated with the identification information after the associated registered image is deleted until the total becomes equal to or less than the limit number.

  According to the present invention, the registered image is updated using the candidate image, so that it is possible to cope with a registrant's movement habit and appearance change.

  According to a third aspect of the present invention, in the second aspect of the present invention, the control unit may be another registered image that is associated with the identification information and has a correlation value equal to or greater than a predetermined similarity threshold. It is characterized in that the registered images are deleted in order from the smallest number.

  According to the present invention, it is possible to leave a registered image in which there are many other similar registered images.

  According to a fourth aspect of the present invention, in the second aspect of the present invention, when the control unit deletes the registered image, the correlation value among the registered images associated with the identification information is not less than a predetermined similarity threshold. The operation of deleting one of the two registered images having the highest priority determined by a predetermined standard is repeated.

  According to the present invention, one of registered images that are very similar to each other is deleted, so that registered images with low similarity remain, that is, authentication in various postures is possible.

  According to a fifth aspect of the present invention, in the invention according to any one of the first to fourth aspects, the priority order is set for each registered image, and the control unit is determined based on a predetermined reference in the continuous comparison operation. It is characterized by being used for the comparison operation in order from the registered image having the highest priority.

  According to the present invention, the time required for authentication may be further shortened.

  The invention of claim 6 is characterized in that, in the invention of claim 4 or claim 5, the registered image having a lower average value of correlation values with other registered images has a lower priority.

  The invention of claim 7 is the invention of claim 4 or claim 5, further comprising a timekeeping unit that outputs the date and time, and the control unit stores the date and time output by the timekeeping unit when storing the registered image in the storage unit. The image is stored in the storage unit in association with the registered image, and the registered image having the older date and time associated with the storage unit has a lower priority.

  In the invention of claim 8, in the invention of claim 4 or claim 5, the storage unit stores the number of times of authentication, which is the number of times that each registered image is determined to match the target image in the comparison operation. Thus, the priority is lower for registered images with a smaller number of authentications.

  The invention of claim 9 is characterized in that, in the invention of claim 4 or claim 5, the priority is lowered as the registered image has a lower average value of correlation values with other registered images associated with the same identification information. And

  According to a tenth aspect of the present invention, in the second aspect of the present invention, there is provided a target image in which a distance from a target image immediately after the target person is authenticated as a registrant exceeds a predetermined identification threshold. When present, the target image before the target image is not a candidate image.

  According to the present invention, it is possible to prevent another person's image from being included in the registered image.

  The invention according to claim 11 is the invention according to claim 1, wherein the registration instructing unit to which an instruction for registration of a new registrant is input, and the control unit when the instruction for registration of the new registrant is input in the registration instructing unit. It is provided with an input requesting unit that requests a new registrant to perform the same operation as when it is controlled and authenticated by at least one of sound and image, and the control unit is requested after the input requesting unit makes a request. The registration image is obtained from the imaging unit at each of a plurality of predetermined timings.

  In the invention of claim 12, in the invention of claim 11, when the distance between two registered images obtained at successive timings exceeds a predetermined identification threshold, the older one of the two registered images All of the registered images before the registered image obtained after the request by the input request unit is discarded.

  According to the present invention, it is possible to prevent another person's image from being included in the registered image.

  According to the first aspect of the present invention, since the registrant is authenticated if the posture is one of a plurality of registered images, the registrant is authenticated only by the posture of one registered image. The time required for authentication can be shortened. In addition, the occurrence of erroneous authentication can be suppressed as compared with a case where the same effect is to be obtained by lowering the authentication threshold.

  According to the second aspect of the present invention, the registered image is updated using the candidate image selected from the target image, so that it is possible to cope with the habit of the registrant's movement and the change in appearance.

  According to the invention of claim 5, each registered image is set with a priority, and the control unit performs a comparison operation in order from a registered image having a high priority determined based on a predetermined reference in the continuous comparison operation. Therefore, the time required for authentication may be further shortened.

  According to the invention of claim 10, when there is a target image whose distance from the target image immediately after the target image exceeds a predetermined identification threshold, the target image before the target image is not a candidate image, and According to the invention, when the distance between two registered images obtained at successive timings exceeds a predetermined identification threshold, the registered image before the older registered image of the two registered images is used. In this case, all the registered images obtained after the request by the input request unit immediately before are discarded, so that it is possible to prevent the images of different persons from being included in the registered images.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  In the present embodiment, as shown in FIG. 1, an imaging unit 1 that captures an authentication target person M (see FIG. 2) and a plurality of registered images each capturing a face for each registrant are registered registrants. Whether the target person M is a registrant by comparing the storage unit 2 stored in association with the identification information corresponding one-to-one with the image captured by the imaging unit 1 and the image stored in the storage unit 2. And a control unit 3 that performs an authentication operation for determining whether or not. In the present embodiment, as shown in FIG. 2, the door D is juxtaposed, and the control unit 3 unlocks the electric lock (not shown) of the door D if it is determined that the subject M is a registrant. To do.

  The imaging unit 1 is a camera that uses a known imaging device such as a CCD (Charge Coupled Device) to generate an image expressed by digital data.

  In addition, the present embodiment includes an ID input unit 4 to which identification information (ID) is input, and the control unit 3 stores registered identification information (that is, associated registration images in the storage unit 2). When the identification information is input to the ID input unit 4, the authentication operation is started. The ID input unit 4 is configured by, for example, a card reader that reads identification information from a card having a magnetic band or an IC chip in which identification information is recorded, a keyboard that accepts an operation input for inputting an ID number as identification information, a touch panel, and the like. be able to.

  Furthermore, this embodiment is provided with the alerting | reporting part 5 which is controlled by the control part 3 and performs various alerting | reporting. As the notification unit 5, for example, a unit that has a speaker and performs notification by voice, or a unit that has a liquid crystal panel and performs notification by text can be used.

  When the identification information of the administrator is input to the ID input unit 4, the control unit 3 starts a registration operation for newly registering a registrant. That is, the ID input unit 4 is also a registration instruction unit in the claims. In the registration operation, first, the control unit 3 controls the notification unit 5 and requests a newly registered person (hereinafter referred to as “new registrant”) to input identification information to the ID input unit 4. Let Thereafter, the registration image is acquired from the image captured by the imaging unit 1 a plurality of times every predetermined time (for example, 100 milliseconds). Here, the storage unit 2 stores a reference face image that is used to determine the region of the target image that includes the region of the face of the subject person and is used for the determination operation, and the control unit 3 outputs the reference face image. A region where the correlation value with the reference face image is equal to or greater than a predetermined face determination threshold (that is, a region determined to include the head) is extracted as a registered image. The obtained plurality of registered images are stored in the storage unit 2 in association with the identification information input to the ID input unit 4. In addition, the control unit 3 stores the position of the region extracted as the registered image (that is, the position of the registered image) in the storage unit 2 every time the registered image is acquired, and the second and subsequent registered images. Is acquired, the distance between the region extracted as the registered image and the region extracted as the registered image immediately before (that is, the distance between the registered images and the moving distance of the head) is equal to or greater than the predetermined identification distance. If it is, it is determined that it is different from the person of the registered image obtained immediately before, and among the registered images obtained during the registration operation (that is, after the request by the input request unit is made immediately before), All registered images before the registered image obtained immediately before may be discarded. The identification distance is set to a distance that allows a person to move in an image captured by the imaging unit 1 within a time period from one imaging to the next imaging by the imaging unit 1. This prevents another person's image from being included in the registered image. Here, as the distance between the registered images and the distance between target images described later, for example, a distance between representative coordinates determined based on a predetermined standard for each region extracted as the registered image or the target image is used. be able to. As the representative coordinates, for example, the coordinates of the center of the area and the coordinates of the center of gravity of the area can be used, and if the area is rectangular, the coordinates of one corner of the area can be used.

  Next, the authentication operation of the control unit 3 will be described in detail with reference to the flowchart of FIG.

  When the identification information is input to the ID input unit 4 and the authentication operation is started (step S1), the control unit 3 first sets the comparison number Nc and the lap number Nr, which are parameters used for the authentication operation, to initial values 0. (Step S2). Next, the control part 3 extracts the target image used for authentication operation including the area | region of a subject's face from the image imaged by the imaging part 1 (step S3). Here, the region extracted as the target image from the image output by the imaging unit 1 in step S3 has a correlation value with the reference face image equal to or greater than the face determination threshold, similarly to the region extracted as the registered image in the registration operation. It is an area that becomes. Next, the control unit 3 reads one of the registered images associated with the identification information input to the ID input unit 4 from the storage unit 2 (step S4), and the target image extracted in step S3 and the step A comparison operation for comparing the correlation value with the registered image read in S4 with a predetermined authentication threshold is performed (step S5).

  When the correlation value between the target image and the registered image is less than the authentication threshold in step S5, that is, when the target person is not authenticated as a registrant, the control unit 3 sets 1 as the number of comparisons Nc. The number of registered images Np (number of registered images associated with the identification information in the storage unit 2 in this embodiment) and the number of comparisons Nc are added (step S6). Compare (step S7). If the number of comparisons Nc has not reached the number of registered images Np, the process returns to step S4 to read another registered image associated with the identification information and repeat the comparison operation. On the other hand, if the number of comparisons Nc has reached the number of registered images Np, that is, if the target image has already been compared with all of the registered images to be compared, the control unit 3 sets the number of comparisons Nc to an initial value of 0. In addition, 1 is added to the number of laps Nr (step S8), and the limited number of laps Nl that is a predetermined integer of 2 or more is compared with the number of laps Nr (step S9). If the number of laps Nr is less than the limit number of laps N1, the control unit 3 returns to step S3, obtains a new target image from the imaging unit 1, and again uses the new target image to perform steps S4 to S4. The continuous comparison operation in step S8 is performed. If the number of laps has reached the limit number of laps Nl in step S8, the control unit 3 determines that the subject M is not a registrant (step SS10), ends the authentication operation, and goes to the ID input unit 4. Return to the state of accepting the identification information (step S11). That is, the limited number of times Nl is multiplied by the registered pixel number Np to obtain the limited number of times in the claims.

  In step S5, when the correlation value between the registered image and the target image is equal to or greater than the authentication threshold, the control unit 3 determines (authenticates) that the target person M is a registrant (step S12). For example, a predetermined operation to be performed when the target person M is a registrant, such as unlocking the electric lock of the door D as described above, is performed, and the process proceeds to step 11 to end the authentication operation.

  Here, in the present embodiment, candidate images selected under a predetermined condition from the target images used in the authentication operation are stored in the storage unit 2 and held until the authentication operation ends. When it is determined in step S12 that the target person M is a registrant, the control unit 3 uses the candidate image stored in the storage unit 2 as the registrant authenticated in step S12 before proceeding to step 11. The registered image is updated so as to be added as a registered image associated with the identification number (step S13).

  The above operation for updating the registered image will be described in detail. As the candidate image, for example, a predetermined candidate threshold value that is smaller than the authentication threshold value and larger than the face determination threshold value is used, and a target image whose correlation value with the registered image is equal to or larger than the candidate threshold value is selected. The storage unit 2 stores the positions of all the target images, and the target image whose distance from the next target image is less than a predetermined identification distance is the same person as the next target image. A target image that is not recognized as the same person as the target image in step S12 is excluded from the candidate images as a target image that is recognized as being present. The identification distance is about a distance (a distance on an image captured by the image capturing unit 1) that a human can move within a time period from one image capturing by the image capturing unit 1 to the next image capturing. This prevents another person's image from being included in the registered image.

  Here, since the capacity of the storage unit 2 is limited, the candidate image cannot be continuously added to the registered image. Therefore, in the present embodiment, a predetermined limit number is set as the upper limit of the number of registered images associated with one piece of identification information, and the control unit 3 corresponds to the same identification information as the number of candidate images. If the total number of attached registered images (hereinafter referred to as “total number of images”) exceeds the limit number, the registered images are appropriately deleted before adding the candidate images to the registered images. .

  As a specific method for deleting a registered image when adding candidate images as described above, for example, the total images are sequentially displayed in order from a registered image with a small number of other registered images having a correlation value equal to or greater than a predetermined similarity threshold. There is a method of deleting until the number reaches the limit number. With this method, it is possible to leave a registered image in which there are many other similar registered images.

  Alternatively, for each registered image, the control unit 3 calculates a correlation value with another registered image and stores the correlation value in the storage unit 2, and the two registrations whose correlation values are equal to or higher than a predetermined similarity threshold and are the highest An operation of deleting one of the images having a lower priority determined according to a predetermined criterion as a registered image having the lowest priority at that time is performed by determining whether the total number of images is equal to or less than the limit number. May be repeated until there are no more registered image pairs whose correlation value is equal to or greater than the similarity threshold. With this method, one of registered images that are very similar to each other is deleted, so that registered images with low similarities remain, that is, authentication in various postures is possible.

  As a method for determining the priority order, for example, a method in which the priority order is increased as the number of times that the correlation value with the target image is greater than or equal to the authentication threshold in the authentication operation (hereinafter referred to as “authentication number”). Alternatively, there is a method in which the priority is higher as the date and time of registration image (hereinafter referred to as “registration date and time”) is newer. Information such as the number of authentications and registration date and time used for determining the priority order may be stored in the storage unit 2 in association with the registered image. In addition, when using the registration date and time, a time measuring unit (not shown) for outputting the date and time is required, but since this can be realized using a known technique, a detailed description thereof is omitted. Alternatively, the priority may be set higher as the average value of correlation values with other registered images (hereinafter referred to as “average correlation value”) is higher.

  For example, consider a case where registered images are image A to image E in the following table and the number of authentications is used to determine priority. In the following table, the numerical values in the columns having images A to E at the upper end indicate the correlation values between the left end image and the upper end image. The highest correlation value is a set of an image A and an image D having a correlation value of 0.83. The number of authentications for the image A is 10 while the number of authentications for the image D is 2. Since it is less, it is the image D that is deleted in this case. Further, when it is necessary to delete two or more images, the highest correlation value in the state where the image D is deleted is a set of the image A and the image C having a correlation value of 0.80. Since the image C is less in number, the image C is deleted next to the image D. In the above example, the similarity threshold is 0.80.

  Also, in the case of the above table, it is a case where a method of deleting from the registered images with a small number of other registered images having a correlation value equal to or higher than a predetermined similarity threshold in order until the total number of images reaches the limit number. Thus, when there are two registered images to be deleted and the similarity threshold is 0.80, other registered images having a correlation value of 0.80 or more exist in the images A to D. Since the number of other registered images is two for images A and D, but one for images B and C, the registered images to be deleted are images B and C.

  In each of the above examples, when there is no set of registered images in which the correlation value is equal to or greater than the similarity threshold even though the total number of images is larger than the limit number, for example, the registered images having the largest correlation value Delete the one with the lowest priority.

  Furthermore, the priority order may be used in the authentication operation. That is, the control unit 3 selects the registered images used in the comparison operation in order from the registered image having the highest priority. If this configuration is adopted, there is a possibility that the average time until the target person is determined to be a registrant is shortened.

  According to the above configuration, since the registrant is authenticated if the posture is one of a plurality of registered images, authentication is required compared to the case where the registrant is authenticated only by the posture of one registered image. Time can be shortened. In addition, the occurrence of erroneous authentication can be suppressed as compared with a case where the same effect is to be obtained by lowering the authentication threshold.

  Furthermore, since the registered image is updated using the target image used in the authentication operation, it is possible to cope with a change in appearance or appearance of the registrant.

  Instead of the so-called one-to-one collation as in the above embodiment, the ID input unit 4 may not be provided, and so-called one-to-N collation in which all registered images are used in the comparison operation. In this case, the registered image count Np is the total number of registered images stored in the storage unit 2, and the registered image to be deleted along with the update of the registered image is associated with the same identification information as the authenticated registered image. Registered image. Also, since there is nothing that determines the start or end of the authentication operation, the authentication operation loops from step S10 to step 1, and the authentication operation is performed every time a target image is obtained. Also, a registration instruction unit (not shown) for accepting an external instruction for starting the registration operation and input of registered identification information in order to determine the timing for starting the registration operation and the identification information to be newly registered. Is required. Furthermore, the operation that the notification unit 5 requests from the new registrant in the registration operation is, for example, an operation of walking from a predetermined position away from the imaging unit 1 to another predetermined position close to the imaging unit 1.

  Further, in the authentication operation, instead of counting the comparison number Nc and the lap number Nr as described above, the continuous comparison operation is continued for a predetermined authentication time from the start of the authentication operation, and the subject M May be determined not to be a registrant when it is determined that is not a registrant. In this case, the number obtained by dividing the authentication time by the time required for one comparison operation is the limit number in the claims.

It is a block diagram which shows embodiment of this invention. It is explanatory drawing which shows a usage form same as the above. It is a flowchart which shows operation | movement same as the above.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Imaging part 2 Storage part 3 Control part 4 ID input part 5 Notification part

Claims (12)

An imaging unit for imaging the target person;
For each registrant, a storage unit in which a plurality of registered images each capturing a face is stored in association with identification information corresponding to the registrant on a one-to-one basis;
A control unit that performs an authentication operation to determine whether or not the subject imaged by the imaging unit is a registrant,
In the authentication operation, the control unit obtains a target image obtained by extracting a face part from an image obtained by capturing the target person from the image capturing unit, calculates a correlation value between one of the registered images and the target image, and obtains the correlation In the continuous comparison operation, a comparison operation for comparing a value with a predetermined authentication threshold is performed sequentially for each registered image associated with at least one identification information among registered images stored in the storage unit. When the correlation value with the target image is less than the authentication threshold in all the registered images used, a new target image is obtained from the imaging unit, and a continuous comparison operation using the new target image as the target image is performed. When the correlation value with the target image is equal to or higher than the authentication threshold in any registered image in the comparison operation equal to or less than the predetermined limit number, the target person is determined to be a registered person, while the number of comparison operations is the limit number. Reached face authentication apparatus characterized by comprising a free and determining control unit in registrant the subject when the subject was not obtained a determination that the registrant in comparison operation be. When the control unit authenticates the target person as a registrant, the target image used in the authentication process is associated with the same identification information as the registration image at the time of authentication, which satisfies a predetermined condition. While storing in the storage unit as a candidate image to be added to the registered image,
Comparing the total number of candidate images and the number of registered images associated with the identification information with a predetermined limit number;
If the total is less than or equal to the limit number, add the candidate image to the registered image associated with the identification information,
If the total exceeds the limit number, the registration image associated with the identification information is deleted until the total is equal to or less than the limit number, and then the candidate image is added to the registration image associated with the identification information. The face authentication apparatus according to claim 1.   The control unit is configured to sequentially delete other registered images associated with the identification information and having a smaller number of other registered images whose correlation value is equal to or greater than a predetermined similarity threshold. The face authentication apparatus according to claim 2.   When deleting a registered image, the control unit selects a predetermined reference from among the two registered images having a correlation value equal to or higher than a predetermined similarity threshold among the registered images associated with the identification information. The face authentication apparatus according to claim 2, wherein the operation of deleting one of the lower priority orders determined in step 1 is repeated. Each registered image has its own priority,
5. The face authentication apparatus according to claim 1, wherein the control unit is used for the comparison operation in order from a registered image having a high priority determined based on a predetermined reference in the continuous comparison operation.   6. The face authentication apparatus according to claim 4, wherein the priority order is set lower for registered images having a lower average value of correlation values with other registered images. It has a timer that outputs the date and time,
When storing the registered image in the storage unit, the control unit stores the date and time output by the timing unit in the storage unit in association with the registered image,
6. The face authentication apparatus according to claim 4 or 5, wherein the priority order is lowered for a registered image having a date and time associated with each other in the storage unit. The storage unit stores, for each registered image, the number of times of authentication, which is the number of times that matching with the target image is determined in the comparison operation,
6. The face authentication apparatus according to claim 4, wherein the priority order is lowered for a registered image having a smaller number of authentications.   6. The face authentication apparatus according to claim 4 or 5, wherein the priority order is set lower for registered images having a lower average value of correlation values with other registered images associated with the same identification information.   If there is a target image whose distance from the target image immediately after the target image when the target person is authenticated as a registrant exceeds a predetermined identification threshold, the target image before the target image is a candidate image. The face authentication apparatus according to claim 2, wherein: A registration instructing unit for inputting a registration instruction of a new registrant;
Controlled by the control unit when an instruction to register a new registrant is input at the registration instruction unit, and requests the new registrant to perform the same operation as when receiving authentication by at least one of voice and image With an input requesting unit,
The face authentication apparatus according to claim 1, wherein the control unit obtains a registered image from each of the imaging units at a predetermined plurality of timings after the request by the input request unit is made.   If the distance between two registered images obtained at successive timings exceeds a predetermined identification threshold, an input request is made immediately before the registered image before the older one of the two registered images. 12. The face authentication apparatus according to claim 11, wherein all of the registered images obtained after the request by the unit is discarded.

Images