Personal authentication system, personal authentication method, and program

Abstract

This personal authentication system comprises a camera (260), and an information processing device (200) that executes personal authentication on the basis of a captured image of a subject captured by the camera (260). The information processing device (200) includes: a first processing unit (510) that, on the basis of a first captured image (251) of a subject who is continuously captured by the camera (260) and of whom the face orientation is changed from forward-facing to a direction different from forward-facing, determines movement of the face of the subject, and, on the basis of the first captured image (251) and a registered image (256), performs facial authentication of the subject; and a second processing unit (520) that performs facial authentication of the subject on the basis of a second captured image (252) of the subject captured by the camera (260) and the registered image (256).

Description

Personal authentication system, personal authentication method and program

[0001] The present invention relates to an authentication system, an authentication method, and a program.

[0002] Japanese Patent Application Laid-Open No. 2022-62533 (Patent Document 1) discloses an NC control panel equipped with functions for facial recognition of an operator and for managing the operator's body temperature.

[0003] Japanese Patent Application Laid-Open No. 2022-62533

[0004] As disclosed in the above-mentioned Patent Document 1, face recognition is used in various situations to authenticate the identity of a person (personal authentication). In such cases, it is required to perform the personal authentication of the person more accurately.

[0005] For example, in the case of machine tool maintenance, face recognition is performed on the worker performing the maintenance to authenticate the worker's identity. It is required that the worker's identity is authenticated accurately so that the maintenance of the machine tool is performed by someone with the appropriate knowledge and skills.

[0006] An object of the present invention is to provide an identity authentication system, an identity authentication method, and a program that can more accurately authenticate that a subject is the person in question.

[0007] An identity authentication system according to the present invention includes a camera for photographing a subject, and an information processing device that authenticates the identity of the subject based on images of the subject photographed by the camera. The information processing device includes a first processing unit that determines facial movement of the subject based on first photographed images of the subject changing the orientation of their face from facing forward to a direction different from facing forward, which are successively photographed by the camera, and performs face authentication of the subject based on the first photographed images and a pre-registered image of the subject, and a second processing unit that performs face authentication of the subject based on second photographed images of the subject photographed by the camera and the registered image.

[0008] An identity authentication method according to the present invention is a method for authenticating the identity of a subject based on photographed images of the subject, comprising the steps of: obtaining first photographed images by successively photographing the subject from the front as the subject changes the orientation of his or her face from the front to a direction different from the front; determining the subject's facial movement based on the first photographed images and performing face authentication of the subject based on the first photographed images and a pre-registered registered image of the subject; obtaining second photographed images by photographing the subject; and performing face authentication of the subject based on the second photographed images and the registered image.

[0009] A program according to the present invention is a program for an information processing device that authenticates the identity of a subject based on a captured image of the subject. The program causes the information processing device to execute the steps of: determining facial movement of the subject based on a first captured image of the subject changing the orientation of the face from a frontal direction to a direction different from the frontal direction; and performing face authentication of the subject based on the first captured image and a pre-registered registered image of the subject; and performing face authentication of the subject based on a second captured image of the subject and the registered image.

[0010] According to the present invention, it is possible to provide an individual authentication system, an individual authentication method, and a program that can more accurately authenticate that a subject is the individual in question.

[0011] Fig. 1 is a diagram schematically showing the relationship between an identity authentication system and a machine tool in an embodiment of the present invention. Fig. 2 is a functional block diagram showing an operator's PC and a face matching server at the time of spoofing detection. Fig. 3 is a diagram showing a display unit at the time of spoofing detection. Fig. 4 is a functional block diagram showing an operator's PC and a face matching server at the time of identity verification. Fig. 5 is a diagram showing a display unit at the time of identity verification. Fig. 6 is a flowchart showing steps of spoofing detection. Fig. 7 is a flowchart showing steps of identity verification.

[0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to the accompanying drawings, in which the same or equivalent components are designated by the same reference numerals.

[0013] Fig. 1 is a diagram schematically showing the relationship between an identity authentication system and a machine tool according to an embodiment of the present invention. Referring to Fig. 1, an operator performing maintenance on machine tool 600 carries operator PC 200. Once the operator's identity is authenticated, the operator can communicate maintenance information relating to various states of machine tool 600 between operator PC 200 and an operation panel 610 of machine tool 600. In this embodiment, a case will be described in which the identity authentication system, identity authentication method, and program of the present invention are applied to the identity authentication of an operator (corresponding to the subject in the present invention) performing maintenance on machine tool 600.

[0014] Identity authentication system 100 in this embodiment has worker PC 200, camera 260, identity authentication management server 300, and face matching server 400. Worker PC 200 (camera 260), identity authentication management server 300, and face matching server 400 communicate with each other via a network such as a wireless LAN.

[0015] The worker PC 200 corresponds to the information processing device of the present invention. Each component of the worker PC 200 is realized by hardware including computing units such as a CPU (Central Processing Unit) and various computer processors, storage devices such as memory and storage, and wired or wireless communication lines connecting these, as well as software stored in the storage devices that supplies processing instructions to the computing units. The computer programs may be configured by device drivers, an operating system, various application programs located at higher levels than these, or libraries that provide common functions to these programs.

[0016] The worker PC 200 performs authentication (personal authentication) to verify that the worker is the correct person based on an image of the worker captured by the camera 260 .

[0017] The main functions of the worker PC 200 are spoofing detection and worker identity verification. Spoofing detection detects spoofing using photographs. Worker identity verification confirms the identity of the worker using facial recognition. The worker PC 200 goes through the steps of spoofing detection and worker identity verification, and finally verifies that the worker is the person in question.

[0018] The worker PC 200 is a mobile computer that can be carried by the worker. The worker PC 200 has a display unit 210 and an operation unit 220. The display unit 210 is composed of a liquid crystal display, an organic EL display, or other display device. The display unit 210 can display images of the worker captured by a camera 260, etc. The operation unit 220 accepts various operations by the worker.

[0019] Camera 260 is configured to be able to capture an image of the worker. Camera 260 is provided in worker PC 200. Camera 260 is configured to be able to capture an image of the face of the worker operating operation unit 220 of worker PC 200. Note that in the present invention, the camera may be provided separately from the information processing device.

[0020] The personal authentication management server 300 is installed by the administrator of the personal authentication system 100. The personal authentication management server 300 is installed, for example, in the premises of the manufacturer of the machine tool 600.

[0021] The main function of the identity authentication management server 300 is to manage information related to the identity authentication of workers. The identity authentication management server 300 registers facial photographs of workers, verifies the facial photographs of workers before and after registration, monitors the identity reliability calculated during the identity authentication process (described later), and stores various information related to the identity authentication of workers in a database.

[0022] More specifically, the personal authentication management server 300 stores a registered image 256 of the worker. The registered image 256 of the worker is a facial photograph of the worker provided by the worker, which is registered in the database of the personal authentication management server 300 by the administrator of the personal authentication system 100. The personal authentication management server 300 stores a plurality of registered images 256 corresponding to one worker. The plurality of registered images 256 includes a registered image in which the worker's face is facing forward. The plurality of registered images 256 may further include a registered image in which the worker's face is facing in a direction other than forward.

[0023] The personal authentication management server 300 transmits the registered image 256 of the worker stored in its database to the face matching server 400. The face matching server 400 extracts facial features, which are quantified versions of features such as the position of the eyes, the shape of the nose, and the size of the mouth, from the registered image 256. The face matching server 400 stores the facial features of the worker extracted from the registered image 256.

[0024] Threshold information is further stored in the identity authentication management server 300. The threshold information includes a threshold t of the face angle used for spoofing detection, and a first threshold Ta and a second threshold Tb of identity reliability used for spoofing detection and identity verification, respectively.

[0025] When the worker operates the operation unit 220, the worker PC 200 accepts the worker's user ID and password. If the accepted password matches the password registered for the user ID, the worker PC 200 transmits the user ID to the identity authentication management server 300. The identity authentication management server 300 transmits identity information 561 corresponding to the user ID to the worker PC 200. The identity information 561 includes at least the above-mentioned threshold information.

[0026] Fig. 2 is a functional block diagram showing the worker PC and the face matching server when spoofing is detected, and Fig. 3 is a diagram showing the display unit when spoofing is detected.

[0027] 1 to 3, worker PC 200 has first processing unit 510. First processing unit 510 performs processing for detecting impersonation.

[0028] The first processing unit 510 determines the movement of the worker's face based on the first captured image 251 of the worker changing the direction of his face from the front to a direction different from the front, which is continuously captured by the camera 260, and performs facial authentication of the worker based on the first captured image 251 and a registered image 256 of the worker that has been registered in advance.

[0029] More specifically, first processing unit 510 has a display control unit 531. Display control unit 531 controls display unit 210. When spoofing is detected, display control unit 531 controls display unit 210 so that first display screen 210A is displayed.

[0030] As shown in FIG. 3 , the first display screen 210A has a first instruction image section 216A. The first instruction image section 216A displays instructions for the worker when impersonation is detected. The first instruction image section 216A includes a first comment section 218A and a first illustration section 217A. The first comment section 218A displays a comment instructing the worker to change their face orientation from a front-to-front direction to a direction different from the front. The first comment section 218A displays a comment such as "Please slowly turn in the following direction: right (hold this position for a few seconds)." The first illustration section 217A displays an illustration instructing the worker to change their face orientation from a front-to-front direction to a direction different from the front. The first illustration section 217A displays an illustration of a face and an arrow instructing the worker to turn right.

[0031] In the first instruction image section 216A, any of the left, right, up, and down directions is randomly indicated as a direction different from the front. The direction different from the front indicated in the first instruction image section 216A is not particularly limited, and may be, for example, a direction oblique to the up, down, left, and right directions.

[0032] The first display screen 210A further includes a caution comment section 212. The caution comment section 212 displays cautions for the worker when impersonation is detected. For example, the caution comment section 212 displays cautions such as "Please remove the following: mask, sunglasses, and safety goggles," "Avoid strong lighting (including backlighting)," and "Do not cover your eyes or mouth."

[0033] As shown in FIG. 2 , the first processing unit 510 further includes a camera control unit 532. The camera control unit 532 controls the camera 260. When impersonation is detected, the camera control unit 532 controls the camera 260 to continuously capture images of the worker who changes the orientation of their face from the front to a direction different from the front. The interval between captures by the camera control unit 532 is, for example, 500 msec per image. By capturing images using the camera 260, a first captured image 251 of the worker who changes the orientation of their face from the front to a direction different from the front is obtained.

[0034] The worker PC 200 further includes a transmission unit 230. The transmission unit 230 transmits the first captured image 251 to the face matching server 400 via the network.

[0035] 3, the first display screen 210A further includes a first captured image section 211A. The first captured image section 211A continuously displays first captured images 251 captured by a camera 260.

[0036] 1 and 2, face matching server 400 is installed by a cloud service provider. The main functions of face matching server 400 are to calculate the angle of the worker's face based on the captured image and to calculate the identity reliability by matching the facial feature values ​​extracted from the captured image with the facial feature values ​​extracted from the registered image.

[0037] Face matching server 400 has angle calculation unit 410. When spoofing is detected, angle calculation unit 410 acquires first captured image 251 from worker PC 200. Angle calculation unit 410 calculates the angle of the worker's face in first captured image 251 (the angle of the face when facing a direction different from the front, with the face facing forward being set as a reference angle of 0°).

[0038] For example, the angle calculation unit 410 recognizes the facial contour and feature points such as the eyebrows, eyes, nose, and mouth, and calculates the angle of the worker's face in the first captured image 251 by verifying changes in the position of the feature points relative to the recognized contour.

[0039] The face matching server 400 further includes a reliability calculation unit 420 and a feature amount storage unit 430. The feature amount storage unit 430 stores the facial feature amounts of the worker extracted from the registered image 256 from the personal authentication management server 300.

[0040] When impersonation is detected, the reliability calculation unit 420 acquires the first captured image 251 from the worker PC 200 and reads out facial features of the worker from the feature storage unit 430. The reliability calculation unit 420 compares the facial features extracted from the first captured image 251 of the worker facing a direction other than the front with the facial features read out from the feature storage unit 430 to calculate the reliability (identity reliability) that the face of the worker in the first captured image 251 is the face of the worker in the registered image 256. When the identity reliability is 1, the worker in the first captured image 251 is most likely to be the worker in the registered image 256, and when the identity reliability is 0, the worker in the first captured image 251 is least likely to be the worker in the registered image 256.

[0041] More specifically, the reliability calculation unit 420 extracts facial features of the worker from the first captured image 251, performs face matching by comparing the facial features of the worker with the facial features read from the feature storage unit 430, and calculates the identity reliability (corresponding to the degree of agreement between the facial features extracted from the first captured image 251 and the facial features read from the feature storage unit 430). The face matching is not limited to this, and may be performed by directly matching images with each other, or by a matching method that applies machine learning or the like. Furthermore, without using the face matching server 400 on the cloud, for example, the worker PC 200 may be provided with the functions performed by the face matching server 400.

[0042] The face angle and identity reliability of the worker calculated by face matching server 400 are transmitted to worker PC 200. Worker PC 200 further includes receiving unit 240. Receiving unit 240 receives the face angle and identity reliability of the worker from face matching server 400.

[0043] The worker PC 200 further includes a storage unit 560. The storage unit 560 stores personal information 561 from the personal authentication management server 300. The storage unit 560 also stores a program for causing the worker PC 200 to perform personal authentication of the worker.

[0044] First processing unit 510 further includes a movement determination unit 533. Movement determination unit 533 acquires the face angle of the worker from face matching server 400 and reads face angle threshold t from storage unit 560. Movement determination unit 533 compares the face angle of the worker from face matching server 400 with face angle threshold t, and determines that the worker has moved if the face angle is equal to or greater than threshold t. As an example, threshold t is 30°.

[0045] First processing unit 510 further includes a first face authentication determination unit 534. When movement determination unit 533 determines that the worker is moving, first face authentication determination unit 534 acquires the identity reliability from face matching server 400 and reads out a first threshold Ta of identity reliability at the time of impersonation detection from storage unit 560. First face authentication determination unit 534 compares the identity reliability from face matching server 400 with the first threshold Ta of identity reliability at the time of impersonation detection, and affirms face authentication of the worker when the identity reliability is equal to or greater than first threshold Ta.

[0046] When the first face authentication determination unit 534 affirmatively recognizes the face of the worker, the impersonation detection step is completed and the process moves to the identity confirmation step.

[0047] Fig. 4 is a functional block diagram showing the worker's PC and the face matching server during identity verification, and Fig. 5 is a diagram showing the display unit during identity verification.

[0048] 4 and 5, worker PC 200 has second processing unit 520. Second processing unit 520 performs processing for verifying the identity of the worker.

[0049] The second processing unit 520 performs face authentication of the worker based on the facial feature amount extracted from the second captured image 252 of the worker captured by the camera 260 and the registered image 256 .

[0050] More specifically, the second processing unit 520 has a display control unit 531. The display control unit 531 controls the display unit 210 so that the second display screen 210B is displayed when the identity of the worker is confirmed.

[0051] As shown in FIG. 5 , the second display screen 210B has a second instruction image section 216B and a warning comment section 212. The second instruction image section 216B displays instructions for the worker during identity verification. The second instruction image section 216B includes a second comment section 218B and a second illustration section 217B. The second comment section 218B displays a comment instructing the worker to return their face to the front. The second comment section 218B displays a comment such as "Please slowly look in the following direction: Front (move as far as both eyes can see)." The second illustration section 217B displays an illustration instructing the worker to return their face to the front. The second illustration section 217B displays an illustration of a face facing forward. The warning comment section 212 is the same as the warning comment section 212 on the first display screen 210A.

[0052] 4, the second processing unit 520 further includes a camera control unit 532. The camera control unit 532 controls the camera 260 to capture an image of the worker when verifying the worker's identity. The image captured by the camera 260 is a second captured image 252 of the worker facing forward.

[0053] The transmitting unit 230 transmits the second captured image 252 to the face matching server 400 via the network.

[0054] 5, the second display screen 210B further includes a second captured image section 211B. The second captured image section 211B displays a second captured image 252 captured by the camera 260.

[0055] 4 , when verifying the identity of a worker, the reliability calculation unit 420 acquires the second captured image 252 from the worker PC 200 and reads out the facial features of the worker extracted from the registered image 256 from the feature storage unit 430. The reliability calculation unit 420 compares the facial features extracted from the second captured image 252 with the facial features read out from the feature storage unit 430 to calculate the reliability (identity reliability) that the face of the worker in the second captured image 252 is the face of the worker in the registered image 256.

[0056] The identity reliability calculated by face matching server 400 is transmitted to worker PC 200. Receiving unit 240 receives the identity reliability from face matching server 400.

[0057] Second processing unit 520 further includes second face authentication determination unit 535. Second face authentication determination unit 535 acquires the identity reliability from face matching server 400 and reads a second threshold Tb of identity reliability at the time of identity verification from storage unit 560. Second face authentication determination unit 535 compares the identity reliability from face matching server 400 with the second threshold Tb of identity reliability at the time of identity verification, and affirms face authentication of the worker when the identity reliability is equal to or greater than second threshold Tb.

[0058] The second threshold Tb of the reliability of the identity verification is greater than the first threshold Ta of the reliability of the identity verification when detecting impersonation. For example, the first threshold Ta is 0.5 and the second threshold Tb is 0.8.

[0059] The identity verification step is completed when second face authentication determination unit 535 affirms the face authentication of the worker. Operator PC 200 finally authenticates that the worker is the actual worker. This enables communication of maintenance information for machine tool 600 between operator PC 200 and operation panel 610 of machine tool 600.

[0060] 6 is a flowchart showing steps of spoofing detection. Referring to FIGS. 1 to 3 and 6, worker PC 200 accepts an ID code and a password (S101).

[0061] In this step, if the received password matches the password registered for the user ID, the worker PC 200 sends the user ID to the identity authentication management server 300. The identity authentication management server 300 sends identity information 561 corresponding to the user ID to the worker PC 200.

[0062] Next, the worker PC 200 acquires the personal information 561 (S102). In this step, the storage unit 560 stores the personal information 561 from the personal authentication management server 300.

[0063] Next, the worker PC 200 (display control unit 531) displays the first display screen 210A on the display unit 210. In this step, the worker receives the instruction displayed in the first instruction image area 216A and changes the orientation of his or her face from facing forward to a direction different from facing forward.

[0064] Next, the worker PC 200 (camera control unit 532) captures an image of the worker as he or she changes the orientation of his or her face from facing forward to a direction different from facing forward. The worker PC 200 (transmission unit 230) transmits the obtained first captured image 251 to the face matching server 400 (S104).

[0065] The face matching server 400 (angle calculation unit 410 ) calculates the angle of the worker's face in the first captured image 251 from the worker PC 200 .

[0066] Next, worker PC 200 (receiving unit 240) receives the face angle calculated by face matching server 400 (S105). Next, worker PC 200 (movement determining unit 533) compares the face angle of the worker calculated by face matching server 400 with face angle threshold t stored in storage unit 560, and determines whether the face angle is equal to or greater than threshold t (S106).

[0067] If it is determined in step S106 that the face angle is less than the threshold value t, the process returns to step S104.

[0068] If it is determined in step S106 that the face angle is equal to or greater than the threshold value t, the face matching server 400 (reliability calculation unit 420) calculates the reliability (identity reliability) that the face of the worker in the first captured image 251 is the face of the worker himself / herself in the registered image 256.

[0069] Next, worker PC 200 (receiving unit 240) receives the identity reliability calculated by face matching server 400 (S107). Next, worker PC 200 (first face authentication determination unit 534) compares the identity reliability calculated by face matching server 400 with a first threshold Ta of identity reliability at the time of impersonation detection, and determines whether the identity reliability is equal to or greater than first threshold Ta (S108).

[0070] If it is determined in step S108 that the identity reliability is less than the first threshold Ta, the worker PC 200 determines whether a certain time has elapsed since the start of the impersonation detection step (S109).

[0071] If it is determined in step S109 that the certain time has not elapsed, the process returns to step S104. If it is determined in step S109 that the certain time has elapsed, the process returns to step S103, and the worker PC 200 (display control unit 531) displays a comment indicating that approval is not permitted on the first display screen 210A.

[0072] If it is determined in step S108 that the authenticity is equal to or greater than the first threshold value Ta, the spoofing detection step is completed.

[0073] 7 is a flowchart showing steps of identity verification. Referring to FIGS. 1, 4 to 5, and 7, worker PC 200 (display control unit 531) displays second display screen 210B on display unit 210 (S111). In this step, the worker receives the instruction displayed in second instruction image section 216B and returns the orientation of his or her face from a direction different from the front to the front.

[0074] Next, the worker PC 200 (camera control unit 532) captures an image of the worker, and the worker PC 200 (transmission unit 230) transmits the obtained second captured image 252 to the face matching server 400 (S112).

[0075] The face matching server 400 (reliability calculation unit 420) calculates the reliability (identity reliability) that the face of the worker in the second captured image 252 is the face of the worker in the registered image 256.

[0076] Next, the worker PC 200 (receiving unit 240) receives the identity reliability calculated by the face matching server 400 (S113). Next, the worker PC 200 (second face authentication determination unit 535) compares the identity reliability calculated by the face matching server 400 with a second threshold Tb of identity reliability at the time of identity verification, and determines whether the identity reliability is equal to or greater than the second threshold Tb (S114).

[0077] If it is determined in step S114 that the identity reliability is less than the second threshold value Tb, the worker PC 200 determines whether a certain time has elapsed since the start of the identity verification step (S115).

[0078] If it is determined in step S115 that the certain time has not elapsed, the process returns to step S112. If it is determined in step S115 that the certain time has elapsed, the process returns to step S111, and the worker PC 200 (display control unit 531) displays a comment indicating that approval is not permitted on the second display screen 210B.

[0079] If it is determined in step S114 that the identity reliability is equal to or greater than the second threshold Tb, the identity verification step is completed. The worker PC 200 finally authenticates that the worker is the identity of the worker.

[0080] The order of the spoofing detection step and the identity verification step described above may be reversed.

[0081] The configurations of the personal authentication system, personal authentication method, and program according to the embodiment of the present invention explained above will now be summarized.

[0082] The personal authentication system 100 of this embodiment includes a camera 260 for capturing an image of a worker as a subject, and a worker PC 200 as an information processing device that authenticates the identity of the worker based on the image of the worker captured by the camera 260. The worker PC 200 includes a first processing unit 510 that determines the movement of the worker's face based on first captured images 251 of the worker changing the orientation of his or her face from the front to a direction different from the front, which are continuously captured by the camera 260, and that performs face authentication of the worker based on the first captured images 251 and a registered image 256 of the worker that has been registered in advance, and a second processing unit 520 that performs face authentication of the worker based on a second captured image 252 of the worker captured by the camera 260 and the registered image 256.

[0083] The personal authentication method in this embodiment is a method for authenticating the identity of a worker based on a captured image of the worker as a subject. The personal authentication method includes a step (S104) of obtaining a first captured image 251 by continuously capturing images of the worker from the front as he or she changes the direction of his or her face from the front to a direction different from the front, a step (S106, S108) of determining the movement of the worker's face based on the first captured image 251 and performing face authentication of the worker based on the first captured image 251 and a registered image 256 of the worker that has been registered in advance, a step (S112) of obtaining a second captured image 252 by capturing an image of the worker, and a step (S114) of performing face authentication of the worker based on the second captured image 252 and the registered image 256.

[0084] The program in this embodiment is a program for worker PC 200 as an information processing device that authenticates the identity of a worker as a subject based on a captured image of the worker. The program causes worker PC 200 to execute steps (S106, S108) of determining the movement of the worker's face based on first captured image 251 of the worker changing the direction of his or her face from the front to a direction different from the front, and performing face authentication of the worker based on first captured image 251 and a registered image 256 of the worker that has been registered in advance, and a step (S114) of performing face authentication of the worker based on second captured image 252 of the worker and registered image 256.

[0085] The program may be recorded on a computer-readable storage medium, which may be a non-transitory computer-readable storage medium.

[0086] With this configuration, by determining the facial movement of the worker based on the first photographed image 251 of the worker changing the orientation of his / her face from the front to a direction different from the front, it is possible to confirm that the worker who is the subject of the first photographed image 251 is not a person impersonating someone else. When this impersonation is detected, facial authentication of the worker is performed based on the first photographed image 251 and a pre-registered registered image 256 of the worker, thereby confirming that the person performing the facial movement change is the actual person. Furthermore, facial authentication of the worker is performed based on the second photographed image 252 of the worker facing forward and the registered image 256, thereby confirming that the actual person is the actual worker. As described above, the identity of the worker can be accurately authenticated.

[0087] Furthermore, the second threshold Tb used for face authentication during identity verification is larger than the first threshold Ta used for face authentication during spoofing detection. With this configuration, a lower first threshold Ta is used for face authentication using the first captured image 251 facing a direction other than the front during spoofing detection, while a higher second threshold Tb is used for face authentication using the second captured image 252 during identity verification, thereby enabling more accurate identity authentication.

[0088] Furthermore, when spoofing is detected, first processing unit 510 displays the direction in which the worker turns his or her face on display unit 210. With this configuration, the display on display unit 210 prompts the worker to turn his or her face, thereby enabling the steps of spoofing detection to proceed smoothly.

[0089] In the present embodiment, the personal authentication system, personal authentication method, and program of the present invention have been described as being applied to the personal authentication of workers performing maintenance on machine tool 600, but the present invention is not limited to this. The present invention can be applied to, for example, personal authentication associated with unlocking various doors, or personal authentication associated with releasing access to a computer.

[0090] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims.

[0091] 100 Personal authentication system, 200 Worker PC, 210 Display unit, 210A First display screen, 210B Second display screen, 211A First captured image section, 211B Second captured image section, 212 Warning comment section, 216A First instruction image section, 216B Second instruction image section, 217A First illustration section, 217B Second illustration section, 218A First comment section, 218B Second comment section, 220 Operation unit, 230 Transmission unit, 240 Reception unit, 251 First captured image, 252 Second captured image, 256 Registered image, 260 Camera, 300 Personal authentication management server, 400 Face matching server, 410 Angle calculation unit, 420 Reliability calculation unit, 430 Feature amount storage unit, 510 First processing unit, 520 Second processing unit, 531 Display control unit, 532 Camera control unit, 533 movement determination unit, 534 first face authentication determination unit, 535 second face authentication determination unit, 560 storage unit, 561 personal information, 600 machine tool, 610 operation panel, 620 recording medium, Ta first threshold, Tb second threshold, t threshold.

Claims

1. An identity authentication system comprising: a camera for photographing a subject; and an information processing device that authenticates the identity of the subject based on images of the subject photographed by the camera, wherein the information processing device comprises: a first processing unit that determines the facial movement of the subject based on first images of the subject changing the orientation of their face from facing forward to a direction different from facing forward, which are successively photographed by the camera, and performs facial authentication of the subject based on the first photographed image and a registered image of the subject that has been registered in advance; and a second processing unit that performs facial authentication of the subject based on a second photographed image of the subject photographed by the camera and the registered image.

2. The identity authentication system of claim 1, wherein the first processing unit affirms facial authentication of the subject when the reliability that the subject in the first captured image is the same as the subject in the registered image is equal to or greater than a first threshold, and the second processing unit affirms facial authentication of the subject when the reliability that the subject in the second captured image is the same as the subject in the registered image is equal to or greater than a second threshold that is greater than the first threshold.

3. An identity authentication system as described in claim 1 or 2, further comprising a display unit capable of displaying the subject photographed by the camera, wherein the first processing unit causes the display unit to display the direction in which the subject changes the orientation of their face.

4. A method of personal authentication that authenticates the identity of a subject based on photographed images of the subject, comprising the steps of: obtaining a first photographed image by continuously photographing the subject from the front as he or she changes the orientation of his or her face from a frontal direction to a direction different from the frontal direction; determining the movement of the subject's face based on the first photographed image, and performing facial authentication of the subject based on the first photographed image and a registered image of the subject that has been registered in advance; obtaining a second photographed image by photographing the subject; and performing facial authentication of the subject based on the second photographed image and the registered image.

5. A program for an information processing device that authenticates the identity of a subject based on a photographed image of the subject, the program causing the information processing device to perform the following steps: determining the movement of the subject's face based on a first photographed image of the subject changing the orientation of their face from facing forward to a direction different from facing forward, and performing facial authentication of the subject based on the first photographed image and a registered image of the subject that has been registered in advance; and performing facial authentication of the subject based on a second photographed image of the subject and the registered image.

Images