Authentication control device, authentication system, authentication control method, and program

Abstract

The purpose of the present invention is to improve the technology disclosed in the prior art. An authentication control device according to the present disclosure comprises: a biological information acquisition unit that acquires, from an image captured by a camera that photographs an authentication subject, face information and iris information of the authentication subject as acquired face information and acquired iris information; a target specification unit that specifies, on the basis of the acquired face information, from registered iris information registered in advance, target iris information to be used as a collation target in iris authentication of the authentication subject; and an iris authentication control unit that controls iris authentication using the target iris information and the acquired iris information.

Description

Authentication control device, authentication system, authentication control method, and program

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

[0002] In recent years, technologies for verifying identity using biometric authentication have become widespread. For example, a technology is known in which biometric authentication is performed to verify the identity of a user when the user performs a financial transaction at an automatic teller machine (ATM) installed in a convenience store.

[0003] As a related technique, Patent Document 1 discloses an information processing device that can automatically manage login status by detecting the approach or departure of a user using a passive infrared sensor. The information processing device disclosed in Patent Document 1 performs user authentication processing by face authentication or iris authentication processing using an image captured by an infrared camera, and automatically performs login processing.

[0004] Japanese Patent Application Laid-Open No. 2019-215274

[0005] The purpose of this disclosure is to improve upon the techniques disclosed in the above-mentioned patent documents.

[0006] The authentication control device according to this disclosure comprises: a biometric information acquisition means for acquiring facial information and iris information of an authentication target as acquired facial information and acquired iris information, respectively, from an image captured by a camera that captures the authentication target; a target identification means for identifying target iris information to be used as a match target in iris authentication of the authentication target from pre-registered iris information based on the acquired facial information; and an iris authentication control means for controlling the iris authentication using the target iris information and the acquired iris information.

[0007] The authentication control device disclosed herein comprises: a biometric information acquisition means for acquiring facial information and iris information of a subject to be authenticated as acquired facial information and acquired iris information, respectively, based on a facial image and iris image of the subject to be authenticated; a facial authentication control means for controlling facial authentication using the acquired facial information and acquiring the result of the facial authentication; an iris authentication control means for controlling iris authentication using the acquired iris information and acquiring the result of the iris authentication; and an exposure control means for controlling the brightness of at least one of the facial image and the iris image acquired by the biometric information acquisition means, based on at least one of the relationship between the luminance of the facial image and the result of the facial authentication and the relationship between the luminance of the iris image and the result of the iris authentication.

[0008] The authentication system according to this disclosure comprises a camera that photographs an object to be authenticated; an authentication control device; and an authentication device, wherein the authentication control device comprises: a biometric information acquisition means that acquires facial information and iris information of the object to be authenticated as acquired facial information and acquired iris information, respectively, from an image photographed by the camera; a target identification means that identifies target iris information to be used as a matching target in iris authentication of the object to be authenticated from pre-registered iris information based on the acquired facial information; and an iris authentication control means that controls the iris authentication using the target iris information and the acquired iris information, and the authentication device performs biometric authentication of the object to be authenticated using the target iris information and the acquired iris information.

[0009] The authentication system according to this disclosure comprises a camera that photographs an object to be authenticated; an authentication control device; and an authentication device, wherein the authentication control device comprises: a biometric information acquisition means that acquires facial information and iris information of the object to be authenticated as acquired facial information and acquired iris information, respectively, based on the facial image and iris image of the object to be authenticated photographed by the camera; a facial authentication control means that controls facial authentication using the acquired facial information and acquires the result of the facial authentication; an iris authentication control means that controls iris authentication using the acquired iris information and acquires the result of the iris authentication; and an exposure control means that controls the brightness of at least one of the facial image and the iris image acquired by the biometric information acquisition means, based on at least one of the relationship between the luminance of the facial image and the result of the facial authentication and the relationship between the luminance of the iris image and the result of the iris authentication, and the authentication device performs the facial authentication and the iris authentication.

[0010] The authentication control method disclosed herein acquires facial information and iris information of an authentication target as acquired facial information and acquired iris information, respectively, from an image captured by a camera that captures the authentication target; identifies, based on the acquired facial information, target iris information to be used as a match target in iris authentication of the authentication target from pre-registered iris information; and controls the iris authentication using the target iris information and the acquired iris information.

[0011] The authentication control method disclosed herein acquires facial information and iris information of a subject to be authenticated as acquired facial information and acquired iris information, respectively, based on a facial image and iris image of the subject to be authenticated; controls facial authentication using the acquired facial information and acquires a result of the facial authentication; controls iris authentication using the acquired iris information and acquires a result of the iris authentication; and controls brightness of at least one of the acquired facial image and iris image based on at least one of the relationship between the brightness of the facial image and the result of the facial authentication and the relationship between the brightness of the iris image and the result of the iris authentication.

[0012] The program disclosed here causes a computer to execute an authentication control method, which acquires facial information and iris information of an authentication target as acquired facial information and acquired iris information, respectively, from an image captured by a camera that captures the authentication target; identifies, based on the acquired facial information, target iris information to be used as a match target in iris authentication of the authentication target from pre-registered iris information; and controls the iris authentication using the target iris information and the acquired iris information.

[0013] The program disclosed herein causes a computer to execute an authentication control method, which acquires facial information and iris information of a subject to be authenticated as acquired facial information and acquired iris information, respectively, based on a facial image and iris image of the subject to be authenticated; controls facial authentication using the acquired facial information and acquires a result of the facial authentication; controls iris authentication using the acquired iris information and acquires a result of the iris authentication; and controls brightness of at least one of the acquired facial image and iris image based on at least one of the relationship between the brightness of the facial image and the result of the facial authentication and the relationship between the brightness of the iris image and the result of the iris authentication.

[0014] FIG. 1 is a block diagram showing the configuration of an authentication control device according to the present disclosure. FIG. 2 is a flowchart showing processing performed by the authentication control device. FIG. 3 is a diagram showing the overall configuration of an authentication system according to the present disclosure. FIG. 4 is a block diagram showing the functional configuration of an authentication control device. FIG. 5 is a flowchart showing processing performed by the authentication control device. FIG. 6 is a block diagram showing the configuration of an authentication device. FIG. 7 is a flowchart showing the flow of biometric information registration processing. FIG. 8 is a flowchart showing the flow of authentication processing. FIG. 9 is a block diagram showing the configuration of an authentication control device according to the present disclosure. FIG. 10 is a flowchart showing processing performed by the authentication control device. FIG. 11 is a block diagram showing the functional configuration of an authentication control device. FIG. 12 is a flowchart showing processing performed by the authentication control device. FIG. 13 is a block diagram showing an example of the hardware configuration of a computer that realizes an authentication control device or the like.

[0015] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In each drawing, the same or corresponding elements are designated by the same reference numerals. For clarity of explanation, duplicated explanations will be omitted as necessary.

[0016] First Embodiment First, the problem to be solved in this disclosure will be specifically described. Assume that in the related technologies described above, a predetermined authentication device is used to perform multimodal authentication using multiple types of biometric information. The multiple types of biometric information are, for example, facial images and iris images. In multimodal authentication, when performing one-to-N (N is a positive integer) authentication for all authentication elements, the authentication device compares N pieces of pre-registered biometric information with biometric information acquired from the authentication target. Therefore, processing by the authentication device takes a time multiplied by the number of elements. Therefore, in an ATM or the like that performs a predetermined procedure depending on the authentication result of the authentication target, the authentication time may be long, potentially reducing the convenience of the authentication target. The authentication target may be, for example, an ATM user, but is not limited to this. The authentication target may be any person who is the subject of biometric authentication.

[0017] The authentication control device according to this disclosure solves the above problem. Specifically, the authentication control device according to this disclosure solves the above problem by identifying M pieces of biometric information (M is a positive integer) that are less than N pieces of biometric information in advance and performing one-to-M authentication using the identified biometric information.

[0018] 1 is a block diagram showing the configuration of an authentication control device 100 according to this disclosure. The authentication control device 100 includes a biometric information acquisition unit 101, an object identification unit 103, and an iris authentication control unit 104.

[0019] The biometric information acquisition unit 101 acquires facial information and iris information of the authentication target as acquired facial information and acquired iris information, respectively, from an image captured by a camera that captures the authentication target.The target identification unit 103 identifies target iris information to be used as a match target in iris authentication of the authentication target from pre-registered iris information based on the acquired facial information.The iris authentication control unit 104 controls iris authentication using the target iris information and acquired iris information.

[0020] The authentication control device 100 includes a processor, memory, and storage device (not shown). The storage device stores a computer program that implements the processes described in this disclosure. The processor can load the computer program from the storage device into the memory and execute the computer program. This allows the processor to realize the functions of a biometric information acquisition unit 101, an object identification unit 103, and an iris authentication control unit 104.

[0021] Alternatively, the biometric information acquisition unit 101, the object identification unit 103, and the iris authentication control unit 104 may each be realized by dedicated hardware. Furthermore, some or all of the components may be realized by a general-purpose or dedicated circuit, processor, etc., or a combination of these. These may be configured by a single chip, or by multiple chips connected via a bus. Some or all of the components may be realized by a combination of the above-mentioned circuits, etc., and a program.

[0022] (Processing of the authentication control device 100) The processing performed by the authentication control device 100 will be described with reference to Fig. 2. Fig. 2 is a flowchart showing the processing performed by the authentication control device 100.

[0023] First, the biometric information acquisition unit 101 acquires facial information and iris information of the authentication target from an image captured by a camera that captures the authentication target as acquired facial information and acquired iris information, respectively (S1). Next, the target identification unit 103 identifies target iris information from registered iris information based on the acquired facial information (S2). Then, the iris authentication control unit 104 controls iris authentication using the target iris information and acquired iris information (S3).

[0024] As described above, the authentication control device 100 according to this disclosure identifies target iris information from registered iris information based on acquired face information, and controls iris authentication using the target iris information and the acquired iris information. This enables the authentication control device 100 to reduce the processing load for iris authentication and improve the speed of iris authentication.

[0025] Second Embodiment Next, a description will be given of a second embodiment, which is a specific example of the first embodiment described above.

[0026] (Configuration of authentication system 5) Fig. 3 is a diagram showing the overall configuration of the authentication system 5 according to this disclosure. The authentication system 5 includes an authentication control device 1 and an authentication device 2. The authentication control device 1 and the authentication device 2 each include a communication unit (not shown) and communicate with each other via a network N. The network N is a wired or wireless communication line. For example, a wireless LAN (Local Area Network) or an internet line may be used as the network N. The type of communication is not limited.

[0027] The number of each component included in the authentication system 5 is not limited to that shown in the figure. For example, the authentication system 5 may include a plurality of authentication control devices 1 and a plurality of authentication devices 2.

[0028] (Overview of Authentication System 5) The authentication system 5 is a system that authenticates the authentication subject and performs desired processing of the authentication subject according to the authentication result. For example, the authentication control device 1 has a display unit (not shown) that displays operation buttons corresponding to predetermined processing on the display unit. The display unit may be a touch panel that accepts input from the authentication subject when touched by the authentication subject. The authentication subject can perform the desired processing by selecting the operation button corresponding to the desired processing by touching the display unit, for example.

[0029] When an operation button is selected by the authentication subject, the authentication control device 1 performs processing corresponding to the selected operation button. When a specific operation button, which is an operation button corresponding to a specific process requiring biometric authentication, is selected, the authentication control device 1 performs biometric authentication of the authentication subject and performs the desired process of the authentication subject according to the result of the biometric authentication.

[0030] The specific operation button is, for example, an operation button corresponding to a process that requires a higher level of security than operation buttons other than the specific operation button (hereinafter, sometimes referred to as "normal operation button"). Examples of the specific operation button include a "withdraw button" for withdrawing cash from the account to be authenticated, and a "transfer button" for transferring money to a transfer destination.

[0031] The normal operation buttons are, for example, operation buttons that correspond to processes that are not directly related to ATM transactions. Examples of normal operation buttons include a "transaction start button" for starting a transaction, a "language change button" for switching the display language, and a "help button" for referring to guidance on operation methods.

[0032] The normal operation buttons may also include operation buttons corresponding to transaction-related processes that do not require biometric authentication. For example, the normal operation buttons may include a "balance inquiry button" for making a balance inquiry, a "passbook entry button" for making entries in a passbook, etc.

[0033] When a specific operation button is selected, the authentication control device 1 acquires biometric information of the authentication target and controls biometric authentication using the acquired biometric information. The authentication control device 1 may acquire biometric information of the authentication target at a timing other than the timing when the specific operation button is selected. For example, when the authentication target approaches the authentication control device 1, the authentication control device 1 may acquire biometric information when the distance between the authentication target and the authentication control device 1 becomes less than a predetermined value.

[0034] The authentication control device 1 requests biometric authentication from the authentication device 2 by transmitting an authentication request including biometric information to the authentication device 2. The authentication device 2 performs biometric authentication in response to the request from the authentication control device 1 and transmits the result of the biometric authentication to the authentication control device 1.

[0035] In the following, an ATM capable of depositing and withdrawing cash in response to operations by the authentication target is used as an example of the authentication control device 1. The authentication control device 1 is not limited to this, and any device capable of performing various processes may be used. The authentication control device 1 may be, for example, a device that controls entry and exit to a specific space (e.g., an apartment building). The authentication control device 1 may be any device that is capable of performing desired processing by the authentication target.

[0036] The authentication control device 1 acquires biometric information used for biometric authentication of an authentication target at a predetermined timing. The biometric information of the authentication target is, for example, a face image and an iris image. For example, the authentication control device 1 uses a single near-infrared camera to capture an image of the face area of ​​the authentication target and acquires the face image and iris image as biometric information. The biometric information is not limited to the face image and iris image, but may also be feature amounts extracted from each of the face image and iris image. The feature amounts are information indicating biometric features unique to the authentication target.

[0037] In the following, an example of the authentication control device 1 is used in which multimodal authentication is possible using a face image and an iris image as biometric information, but the types of biometric information are not limited to these. Various types of information may be used as biometric information of the authentication target. For example, fingerprints, veins, palm prints, or retina may be used as biometric information. Furthermore, the authentication control device 1 is not limited to multimodal authentication, and may be configured to perform single-modal authentication using a single authentication method.

[0038] (Authentication control device 1) The authentication control device 1 will be described with reference to Fig. 4. Fig. 4 is a block diagram showing the functional configuration of the authentication control device 1. The authentication control device 1 is an example of the above-mentioned authentication control device 100. As shown in Fig. 4, the authentication control device 1 includes a biometric information acquisition unit 11, a face authentication control unit 12, an object identification unit 13, an iris authentication control unit 14, an update unit 15, an imaging control unit 16, an illumination control unit 17, a processing control unit 18, a camera C, and an illumination L.

[0039] The biometric information acquisition unit 11 is an example of the above-mentioned biometric information acquisition unit 101. The biometric information acquisition unit 11 acquires facial information and iris information of the authentication target as acquired facial information and acquired iris information, respectively, from an image captured by a camera C that captures the authentication target. The acquired facial information is information to be matched with pre-registered registered facial information in face authentication. The acquired iris information is information to be matched with pre-registered registered iris information in iris authentication.

[0040] The facial information of the authentication target may be a facial image of the authentication target, or may be a feature extracted from the facial image. The iris information of the authentication target may be an iris image of the authentication target, or may be a feature extracted from the iris image. Each feature is information indicating a biometric feature unique to the authentication target. In the following description, the facial information and iris information of the authentication target will be described as the facial image and iris image of the authentication target, respectively.

[0041] The biometric information acquisition unit 11 may acquire a face image and an iris image of the authentication target at different times or at the same time. For example, the biometric information acquisition unit 11 may acquire a face image at a first time and an iris image at a second time. Specifically, the biometric information acquisition unit 11 acquires a face image captured at a first time from the camera C, and an iris image captured at a second time from the camera C. This allows the biometric information acquisition unit 11 to acquire a face image and an iris image from two images captured at different times by the same camera C.

[0042] The biometric information acquisition unit 11 may also acquire biometric information corresponding to each of a plurality of authentication methods from a single image acquired by the camera C. For example, the biometric information acquisition unit 11 acquires a face image and an iris image from a single infrared image capturing a facial region of the authentication target. The infrared image is, for example, a near-infrared image.

[0043] For example, the biometric information acquisition unit 11 detects the face and eyes of the authentication target from one near-infrared image. The biometric information acquisition unit 11 extracts a face image and an iris image from the one near-infrared image based on the detected face and eyes. This allows the biometric information acquisition unit 11 to acquire a face image and an iris image captured at the same time. The biometric information acquisition unit 11 may extract a face image from the near-infrared image and then extract an iris image from the face image.

[0044] In multimodal authentication using a face image and an iris image, if the face image and the iris image are captured at different times, there is a possibility that the people included in each image are different. In such a case, there is a risk of the authentication target being swapped. Because the biometric information acquisition unit 11 can acquire face images and iris images captured at the same time, the authentication control device 1 can reduce the risk of the authentication target being swapped.

[0045] The biometric information acquisition unit 11 may acquire face information of multiple authentication targets from a single image. The biometric information acquisition unit 11 may also store the acquired biometric information in a storage unit (not shown) to accumulate the biometric information.

[0046] The face authentication control unit 12 controls face authentication of the authentication target using the acquired face information acquired by the biometric information acquisition unit 11. The face authentication control unit 12 may control face authentication using feature amounts of the authentication target extracted from the acquired face information.

[0047] The face authentication control unit 12 transmits a face authentication request including the acquired face information to the authentication device 2. The face authentication control unit 12 also receives the face authentication result from the authentication device 2. The face authentication control unit 12 outputs the authentication result to the processing control unit 18. The face authentication control unit 12 may output the authentication result to the iris authentication control unit 14, the photography control unit 16, and the lighting control unit 17. The face authentication control unit 12 may output the face authentication result to these units, including a face authentication score, which will be described later.

[0048] The target identification unit 13 is an example of the above-mentioned target identification unit 103. The target identification unit 13 identifies target iris information to be used as a match target in iris authentication of the authentication target from among pre-registered iris information based on the acquired face information.

[0049] The registered iris information is pre-registered as iris feature data 212 in the authentication storage unit 21 of the authentication device 2. A detailed configuration of the authentication device 2 will be described later. The target identification unit 13 identifies target iris information from the iris feature data 212. The iris feature data 212 includes registered iris information of multiple authentication targets. In the following, it is assumed that the iris feature data 212 includes N pieces of registered iris information.

[0050] The target identification unit 13 may identify the target iris information by requesting the authentication device 2 to identify the target iris information. For example, the target identification unit 13 requests the authentication device 2 to identify the target iris information by transmitting predetermined conditions for identifying the target iris information from among the registered iris information.

[0051] The target identification unit 13 identifies M pieces of registered iris information as target iris information from the N pieces of registered iris information in the iris feature data 212. N and M are positive integers. The relationship between N and M is expressed as N>M. N may be the total number of authentication targets registered in the iris feature data 212. M is a number smaller than N. M may be set in advance or may be changed as appropriate.

[0052] M may be set to a number that can reduce the processing load required to match the target iris information with the acquired iris information. M may also be set to a number that can increase the processing speed required to match the target iris information with the acquired iris information. M may be set to a number smaller than N to the extent that at least one of these conditions is satisfied. In this way, by setting M to be smaller than N, the target identification unit 13 can narrow down the target iris information used for iris authentication from N to M.

[0053] The target identification unit 13 may identify, as target iris information, registered iris information that satisfies predetermined conditions that can contribute to reducing the load of authentication processing and improving the processing speed.

[0054] For example, the target identification unit 13 acquires the result of face authentication from the face authentication control unit 12 and identifies the target iris information based on the acquired result of face authentication. The result of face authentication may include a face authentication score indicating the degree of match between pre-registered registered face information and the acquired face information. The registered face information is pre-registered as face feature data 211 in the authentication storage unit 21 of the authentication device 2. A detailed configuration of the authentication device 2 will be described later.

[0055] For example, the target identification unit 13 identifies registered iris information associated with registered face information having a face recognition score equal to or higher than a predetermined value as target iris information. The target identification unit 13 may determine whether the face recognition score of the registered face information is equal to or higher than a predetermined value using an identification threshold for identifying the target iris information. The identification threshold may be set lower than a face recognition threshold for authenticating an authentication target in face recognition.

[0056] Furthermore, the target identification unit 13 may identify, as the target iris information, registered iris information associated with registered face information having a face recognition score ranking equal to or higher than a predetermined rank. For example, the target identification unit 13 may identify, as the target iris information, registered iris information associated with registered face information having a high rank (e.g., 1st to 10th) in face recognition score.

[0057] Furthermore, the target identification unit 13 may identify target iris information directly from the acquired face information without using the face recognition score. Specifically, the target identification unit 13 divides the registered face information into groups (for example, 10 groups) based on the similarity between the registered face information, and registers the grouped face information. When the acquired face information is directly input to the target identification unit 13, the target identification unit 13 determines which group the input acquired face information falls into using the similarity between each of the 10 representative face information and the acquired face information, and identifies the target iris information. Note that the similarity calculation may use a general similarity calculation method such as cosine similarity depending on the form of the face information.

[0058] In an authentication device that uses multimodal authentication to verify the identity of an authentication target, multiple biometric authentication methods (e.g., facial authentication and iris authentication) are performed. Therefore, performing one-to-many authentication for all authentication factors requires a long processing time. In ATMs and other devices that perform a predetermined procedure depending on the authentication result of the authentication target, the authentication time is long, which may reduce the convenience of the authentication target. Therefore, it is necessary to authenticate the authentication target quickly.

[0059] In contrast, in the authentication control device 1 disclosed herein, the target identification unit 13 identifies M pieces of target iris information from N pieces of registered iris information based on the acquired face information. Specifically, the target identification unit 13 identifies the target iris information based on the result of face authentication performed before iris authentication. This allows the target identification unit 13 to accurately identify the target iris information to be used in iris authentication. Furthermore, the authentication control device 1 can first perform face authentication using N pieces of data for authentication targets located at a predetermined distance or more from the authentication control device 1, and then perform iris authentication using M pieces of data narrowed down based on the result of face authentication. In this way, the authentication control device 1 can perform multimodal authentication at high speed.

[0060] The iris authentication control unit 14 is an example of the iris authentication control unit 104 described above. The iris authentication control unit 14 controls iris authentication using the target iris information and the acquired iris information. For example, the iris authentication control unit 14 transmits an iris authentication request including information related to the target iris information and the acquired iris information to the authentication device 2. As a result, the authentication device 2 performs iris authentication using the target iris information and the acquired iris information. The iris authentication control unit 14 receives the result of iris authentication from the authentication device 2. The iris authentication control unit 14 outputs the authentication result to the processing control unit 18.

[0061] The iris authentication control unit 14 may control iris authentication using an iris image included in the image used for face authentication of the authentication target. The iris authentication control unit 14 transmits an iris authentication request including the face image and iris image acquired from one image in the biometric information acquisition unit 11 to the authentication device 2.

[0062] To realize an authentication control device 1 that supports multimodal authentication, sensors that acquire biometric information according to the authentication method are required, which tends to increase the installation costs of the authentication control device 1. The biometric information acquisition unit 11 can acquire biometric information corresponding to each of multiple authentication methods from a single image acquired by a single camera C. In this way, the authentication control device 1 can perform multimodal authentication using a single camera C.

[0063] The update unit 15 updates the registered face information of the authentication target. For example, when the authentication target has successfully passed iris authentication using the target iris information, the update unit 15 updates the registered face information based on the face authentication score of the face authentication performed to identify the target iris information. For example, when the face authentication score of the authentication target is less than a predetermined value, the update unit 15 updates the registered face information. The update unit 15 may use a predetermined threshold to determine whether to update the registered face information.

[0064] Furthermore, the update unit 15 may update the registered face information based on a quality score indicating the quality of the biometric information in addition to the face authentication score. The quality of the biometric information indicates whether the biometric information is in a state suitable for authentication. For example, the higher the quality of the biometric information, the more suitable the biometric information is for biometric authentication, and the lower the quality of the biometric information, the less suitable the biometric information is for biometric authentication. For example, an image (acquired face information) in which the face of the authentication target is blurred has a lower quality score than an image in which the face is not blurred.

[0065] For example, when the face recognition score of the authentication target is less than a predetermined value and the quality score of the acquired face information is equal to or greater than a predetermined value, the update unit 15 updates the registered face information. The update unit 15 may determine whether to update the registered face information using predetermined thresholds set for the face recognition score and the quality score, respectively.

[0066] Furthermore, the update unit 15 may update the registered face information when the ranking of the face recognition score of the authentication target is lower than a predetermined rank. For example, the update unit 15 compares the face recognition score for the registered face information of the authentication target with the face recognition scores for the registered face information of other authentication targets. The update unit 15 determines whether the ranking of the face recognition score for the registered face information of the authentication target is lower than a predetermined rank.

[0067] For example, suppose the target identification unit 13 identifies the registered iris information of ten authentication targets U1 to U10 as target iris information, one of which is the registered iris information of the authentication target U1. The update unit 15 acquires the face recognition scores of the registered face information of the authentication targets U1 to U10 in the face recognition performed to identify the target iris information. The update unit 15 compares the face recognition scores of the authentication targets U1 to U10 and identifies the ranking of the face recognition score of the authentication target U1. The update unit 15 updates the registered face information of the authentication target U1 if the ranking of the face recognition score of the authentication target U1 is below a predetermined rank (e.g., 8th place or lower). Note that the update unit 15 may update the registered face information taking into account the quality score of the acquired face information. For example, the update unit 15 updates the registered face information if the ranking of the face recognition score of the authentication target is below a predetermined rank and the quality score of the acquired face information is equal to or higher than a predetermined rank. In this way, when the acquired face information has a high quality score but a low ranking in face recognition score, the update unit 15 can update the registered face information. In this way, the update unit 15 does not register, for example, an image in which the face is blurred as registered face information.

[0068] The registered face information is pre-registered as face feature data 211 in the authentication storage unit 21 of the authentication device 2. The face feature data 211 is also associated with iris feature data 212, which is registered iris information. The update unit 15 updates the face feature data 211 when at least one of the following conditions is met: the face authentication score of the authentication target is less than a predetermined value, and the ranking of the face authentication score of the authentication target is less than a predetermined value. The update unit 15 may update the face feature data 211 using a face image acquired by the camera C, or may capture a face image for updating via the photography control unit 16. Alternatively, the update unit 15 may prompt the authentication target to re-register a face image.

[0069] If registered face information that has been registered for a predetermined period of time is used for face authentication, the accuracy of face authentication may decrease. Since the update unit 15 updates the registered face information based on the results of face authentication performed to identify the target iris information, the authentication control device 1 can perform face authentication using appropriate registered face information.

[0070] The photography control unit 16 controls photography by the camera C. For example, the photography control unit 16 causes the camera C to photograph a person who is within a predetermined distance from the authentication control device 1. The photography control unit 16 may control the camera C to photograph at predetermined time intervals. For example, the photography control unit 16 may control the camera C to constantly photograph the authentication target.

[0071] The lighting control unit 17 controls the lighting L. For example, the lighting control unit 17 controls the lighting L to illuminate the authentication target based on the timing at which the camera C captures the image of the authentication target. When there are multiple lighting units L, the lighting control unit 17 controls each of the multiple lighting units L.

[0072] The process control unit 18 controls a process corresponding to an operation button selected by the authentication subject according to the result of the biometric authentication. For example, the process control unit 18 controls a process corresponding to a selected specific operation button according to at least one of the result of the first biometric authentication and the result of the second biometric authentication. For example, the first biometric authentication is face authentication, and the second biometric authentication is iris authentication.

[0073] For example, suppose that successful face authentication is required for a withdrawal process, and successful face authentication and iris authentication are required for a transfer process. The process control unit 18 controls the process corresponding to the selected specific operation button according to the results of the face authentication and the iris authentication.

[0074] For example, when the "withdrawal button" is selected, the process control unit 18 performs the withdrawal process depending on whether the face authentication is successful. If the face authentication is successful, the process control unit 18 performs the withdrawal process. If the face authentication is unsuccessful, the process control unit 18 does not perform the withdrawal process.

[0075] Furthermore, when the "transfer button" is selected, the process control unit 18 controls the transfer process depending on whether the face authentication and iris authentication are successful. If the face authentication and iris authentication are successful, the process control unit 18 performs the transfer process. If at least one of the face authentication and the iris authentication fails, the process control unit 18 does not perform the transfer process.

[0076] In processes that require a high level of security, it is necessary to strictly authenticate the identity of the person to be authenticated by biometric authentication. The process control unit 18 controls processes such as transactions based on the results of biometric authentication required for each process, thereby reducing the possibility that a person other than the person to be authenticated may perform the process.

[0077] Camera C photographs people around the authentication control device 1. Camera C photographs people under the control of the photography control unit 16. For example, camera C photographs an authentication target who uses the authentication control device 1. Camera C is, for example, a near-infrared camera that photographs an authentication target using a near-infrared light source as a light source. Camera C may be configured to be able to photograph a facial image and iris image of the authentication target.

[0078] The lighting L is a lighting that irradiates light toward the authentication target, illuminating the authentication target. The lighting L illuminates the authentication target under the control of the lighting control unit 17. The lighting L is provided, for example, near the camera C. For example, the lighting L may be provided together with the camera C on the bezel of a display unit provided in the authentication control device 1. The lighting L may also be provided integrally with the camera C.

[0079] The authentication control device 1 may be equipped with multiple lights L. For example, the lights L may be provided on both sides of the camera C. This allows the multiple lights L to illuminate the authentication target from multiple directions, allowing the camera C to photograph the authentication target with appropriate brightness. For example, the authentication control device 1 may be equipped with a light that illuminates the left side of the authentication target's face and a light that illuminates the right side of the authentication target's face. The authentication control device 1 may be equipped with a light that illuminates the authentication target's left eye and a light that illuminates the authentication target's right eye.

[0080] (Processing of the Authentication Control Device 1) Next, the processing performed by the authentication control device 1 will be described with reference to Fig. 5. Fig. 5 is a flowchart showing the processing performed by the authentication control device 1.

[0081] First, the biometric information acquisition unit 11 acquires an infrared image (S11). The infrared image is, for example, a near-infrared image captured by a camera C. The biometric information acquisition unit 11 determines whether or not a face of the authentication target has been detected from the infrared image (S12). If it is determined that a face has not been detected (NO in S12), the process returns to step S11. If it is determined that a face has been detected (YES in S12), the biometric information acquisition unit 11 acquires face information from the infrared image (S13). The face information may be a face image or may be feature amounts extracted from the face image. The face information corresponds to the acquired face information described above.

[0082] Next, the face authentication control unit 12 controls one-to-N face authentication (S14). Specifically, the face authentication control unit 12 transmits a face authentication request including the acquired face information to the authentication device 2. The face authentication control unit 12 receives the result of face authentication from the authentication device 2. The result of face authentication includes a face authentication score indicating the degree of match between the registered face information and the acquired face information.

[0083] Next, the target identification unit 13 determines whether there is registered face information whose face recognition score satisfies a predetermined condition (S15). For example, the predetermined condition may include at least one of the face recognition score being equal to or higher than a predetermined value and the ranking of the face recognition score being equal to or higher than a predetermined value.

[0084] If it is determined that there is no registered face information whose face recognition score satisfies the predetermined condition (NO in S15), the process returns to step S11. If it is determined that there is registered face information whose face recognition score satisfies the predetermined condition (YES in S15), the target identification unit 13 identifies the target iris information (S16). Specifically, the target identification unit 13 identifies the registered iris information associated with the registered face information that satisfies the predetermined condition as the target iris information.

[0085] Next, the biometric information acquisition unit 11 acquires iris information (S17). The iris information may be an iris image or feature values ​​extracted from the iris image. The iris information corresponds to the acquired iris information described above. For example, the biometric information acquisition unit 11 acquires an iris image included in the infrared image acquired in step S11 as the acquired iris information. The biometric information acquisition unit 11 may acquire the iris information when a specific operation button is selected by the authentication target on the display unit of the authentication control device 1.

[0086] Next, the iris authentication control unit 14 controls 1-to-M (N>M) iris authentication (S18). Specifically, the iris authentication control unit 14 transmits an iris authentication request including the acquired iris information to the authentication device 2. The iris authentication control unit 14 receives the result of iris authentication from the authentication device 2. The result of iris authentication may include an iris authentication score indicating the degree of match between the registered iris information and the acquired iris information.

[0087] The authentication control device 1 determines whether the authentication target has been successfully authenticated (S19). The authentication control device 1 may determine whether the authentication has been successful based on at least one of the results of face authentication and iris authentication. For example, the authentication control device 1 may determine that the authentication has been successful when the face authentication score is equal to or greater than a predetermined face authentication threshold and the iris authentication score is equal to or greater than a predetermined iris authentication threshold. The authentication control device 1 may receive the determination result of whether the authentication target has been successfully authenticated from the authentication device 2.

[0088] If it is determined that the authentication has failed (NO in S19), the process returns to step S17. If it is determined that the authentication has succeeded (YES in S19), the update unit 15 determines whether the face recognition score is equal to or higher than a predetermined value and whether the rank of the face recognition score is equal to or higher than a predetermined value (S20). If it is determined that the face recognition score is equal to or higher than a predetermined value and the rank of the face recognition score is equal to or higher than a predetermined value (YES in S20), the process ends. If at least one of the face recognition score being lower than a predetermined value and the rank of the face recognition score being lower than a predetermined value is satisfied (NO in S20), the update unit 15 updates the registered face information of the authentication target (S21).

[0089] If it is determined in step S19 that the authentication is successful (YES in S19), the process control unit 18 may control a process corresponding to the specific operation button selected by the authentication subject.

[0090] (Authentication Device 2) Next, the authentication device 2 will be described. The authentication device 2 may be realized using any cloud computing system. For example, the authentication device 2 may be a cloud server constructed by any cloud service or the like.

[0091] 6 is a block diagram showing the configuration of the authentication device 2. The authentication device 2 performs biometric authentication of the person to be authenticated. The authentication device 2 receives an image related to the biometric information of the person to be authenticated from the authentication control device 1, and authenticates the person by extracting a predetermined feature image from the received image.

[0092] The authentication device 2 mainly comprises an authentication storage unit 21 , a detection unit 22 , a feature point extraction unit 23 , a registration unit 24 , and an authentication unit 25 .

[0093] The authentication storage unit 21 stores a person ID of a person registered in advance in association with characteristic data of the person.

[0094] The feature data includes facial feature data 211 and iris feature data 212. The facial feature data 211 includes facial features of a person who has been registered in advance. The iris feature data 212 includes iris features of a person who has been registered in advance.

[0095] The detection unit 22 detects feature areas included in a registration image for registering biometric information and outputs the feature areas to the feature point extraction unit 23. The feature point extraction unit 23 extracts feature points from the feature areas detected by the detection unit 22 and outputs data related to the feature points to the registration unit 24. The data related to the feature points is a collection of the extracted feature points.

[0096] When registering the feature data, the registration unit 24 issues a new person ID. The registration unit 24 associates the issued person ID with the feature data extracted from the registered image and registers them in the authentication storage unit 21. Specifically, the registration unit 24 associates the person ID with facial feature data 211 extracted from the registered image and iris feature data 212 extracted from the registered image and registers them in the authentication storage unit 21. In addition to these data, the registration unit 24 may also associate the registered image and register them in the authentication storage unit 21.

[0097] The authentication unit 25 compares feature data extracted from an image related to the biometric information of the authentication target with feature data stored in the authentication storage unit 21. If feature data matching the biometric information of the authentication target is present, the authentication unit 25 determines that authentication has been successful. On the other hand, if feature data matching the biometric information of the authentication target is not present, the authentication unit 25 determines that authentication has been unsuccessful. The authentication unit 25 may determine the success or failure of authentication for each of face authentication and iris authentication. The authentication unit 25 transmits information related to the success or failure of authentication to the authentication control device 1. Furthermore, if authentication is successful, the authentication unit 25 identifies a person ID associated with the successful feature data and transmits an authentication result including the identified person ID to the authentication control device 1.

[0098] (Processing of Authentication Device 2) Next, biometric information registration processing and authentication processing in the authentication device 2 will be described with reference to Fig. 7 and Fig. 8. Fig. 7 is a flowchart showing the flow of biometric information registration processing. Fig. 8 is a flowchart showing the flow of authentication processing. In the following, registration of a face image will be described as an example.

[0099] First, the flow of the biometric information registration process will be described with reference to Fig. 7. The authentication device 2 acquires a registration image of the authentication target (S31). The registration image is an image related to biometric information used for authentication in the authentication control device 1. For example, the authentication device 2 may receive a biometric information registration request including the registration image from the authentication control device 1 or a website for biometric information registration via the network N. In this case, the registration image is a facial image of the authentication target.

[0100] The authentication device 2 may acquire registration images corresponding to a plurality of authentication methods from a single image. For example, the authentication device 2 may acquire a face image and an iris image from a single image captured by a camera (not shown) and use these as registration images. This allows the authentication device 2 to acquire a face image and an iris image in a single capture, thereby reducing the time required for the biometric information registration process.

[0101] Next, the detection unit 22 detects a facial region of the authentication target included in the registration image (S32). Next, the feature point extraction unit 23 extracts feature points from the facial region detected in step S32 and outputs feature data to the registration unit 24 (S33). Finally, the registration unit 24 issues a person ID and associates the person ID with the feature data, and registers the person ID and the feature data in the authentication storage unit 21 (S34). The authentication device 2 may receive feature data from a terminal or the like owned by the authentication target, and register the feature data in the authentication storage unit 21, associating the feature data with the person ID.

[0102] Next, the flow of the authentication process will be described with reference to Fig. 8. First, the feature point extraction unit 23 acquires a facial image for authentication included in a biometric authentication request (S41). For example, the authentication device 2 receives the biometric authentication request from the authentication control device 1 via the network N and extracts feature data from the biometric image included in the biometric authentication request as in steps S31 to S33. Alternatively, the authentication device 2 may receive feature data from the authentication control device 1.

[0103] Next, the authentication unit 25 compares the acquired feature data with the feature data stored in the authentication storage unit 21 (S42). Here, the feature data is the facial feature data 211. If the feature data match, that is, if the degree of match of the feature data is equal to or greater than a predetermined value (YES in S43), the authentication unit 25 identifies the person ID of the person to be authenticated whose feature data matches (S44). Then, the authentication unit 25 returns a message to the authentication control device 1 indicating that facial authentication was successful and the identified person ID (S45). If no matching feature data exists (NO in S43), the authentication unit 25 returns a message to the authentication control device 1 indicating that facial authentication failed (S46).

[0104] In step S42, the authentication unit 25 does not need to attempt matching with all feature data in the authentication storage unit 21. For example, the authentication unit 25 may preferentially attempt matching with feature data registered during the period from the day the biometric authentication request was received to several days prior. This can improve the matching speed. Furthermore, if the preferential matching fails, it is preferable to perform matching with all remaining feature data.

[0105] The above describes the configuration of the authentication system 5. Note that the above-described configuration of the authentication system 5 is merely an example and may be modified as appropriate. For example, when some or all of the components of the authentication control device 1 and the authentication device 2 are realized by multiple information processing devices, circuits, etc., the multiple information processing devices, circuits, etc. may be centrally or decentralized. For example, the information processing devices, circuits, etc. may be realized as a client-server system, a cloud computing system, or the like, in a form in which each is connected via a communication network. For example, the functions of the authentication device 2 may be provided in a SaaS (Software as a Service) format.

[0106] For example, some of the functions of the authentication control device 1 may be executed by a device (e.g., the authentication device 2) other than the authentication control device 1. In the above description, the authentication control device 1 and the authentication device 2 are provided separately, but the authentication control device 1 may also have the functions of the authentication device 2.

[0107] As described above, the authentication system 5 according to this disclosure can improve upon the techniques disclosed in the above-mentioned patent documents.

[0108] <Embodiment 3> Next, embodiment 3 will be described. Embodiment 3 is a modification of the above-described embodiment 1. The following description will focus on differences from embodiment 1, and overlapping points will be omitted as appropriate.

[0109] 9 is a block diagram showing the configuration of the authentication control device 100a according to this disclosure. The authentication control device 100a includes a biometric information acquisition unit 101, a face authentication control unit 102, an iris authentication control unit 104, and an exposure control unit 109.

[0110] The biometric information acquisition unit 101 acquires facial information and iris information of the authentication target as acquired facial information and acquired iris information, respectively, based on the facial image and iris image of the authentication target. The facial authentication control unit 102 controls facial authentication using the acquired facial information and acquires the result of facial authentication. The iris authentication control unit 104 controls iris authentication using the acquired iris information and acquires the result of iris authentication.

[0111] The exposure control unit 109 controls the brightness of at least one of the face image and the iris image acquired by the biometric information acquisition unit 101 based on at least one of the relationship between the brightness of the face image and the result of face authentication and the relationship between the brightness of the iris image and the result of iris authentication.

[0112] 10 is a flowchart showing the processing performed by the authentication control device 100a. First, the biometric information acquisition unit 101 acquires face information and iris information of the authentication target as acquired face information and acquired iris information, respectively, based on the face image and iris image of the authentication target (S101). Next, the face authentication control unit 102 controls face authentication using the acquired face information and acquires the result of face authentication (S102).

[0113] Next, the iris authentication control unit 104 controls iris authentication using the acquired iris information and acquires the result of iris authentication (S103).Then, the exposure control unit 109 controls the brightness of at least one of the face image and the iris image acquired by the biometric information acquisition unit 101 based on at least one of the relationship between the luminance of the face image and the result of face authentication and the relationship between the luminance of the iris image and the result of iris authentication (S104).

[0114] In an authentication device that performs multimodal authentication using face images and iris images, the brightness of the images corresponding to each authentication element may be inappropriate for authentication. In the authentication control device 100a, the exposure control unit 109 controls the brightness of at least one of the acquired face images and iris images based on the relationship between the brightness of each image and the result of each authentication. In this way, the authentication control device 100a can acquire images appropriate for authentication.

[0115] <Fourth Embodiment> Next, a fourth embodiment will be described. The fourth embodiment is a specific example of the third embodiment described above. An authentication system 5a according to this disclosure includes an authentication control device 1a and an authentication device 2. The configuration of the authentication system 5a is generally similar to that of the authentication system 5 described above, and therefore a description thereof will be omitted. In addition, the following description will focus on differences from the second embodiment, and overlapping points will be omitted as appropriate.

[0116] The authentication control device 1a will be described with reference to Fig. 11. Fig. 11 is a block diagram showing the functional configuration of the authentication control device 1a. The authentication control device 1a is an example of the above-mentioned authentication control device 100a. The authentication control device 1a differs from the above-mentioned authentication control device 1 in that the photography control unit 16 and the illumination control unit 17 are shown as an exposure control unit 19, and in that the authentication control device 1a does not include the object identification unit 13 and the update unit 15. Note that the authentication control device 1a may be configured to include the object identification unit 13 and the update unit 15.

[0117] The biometric information acquisition unit 11 acquires facial information and iris information of the authentication target as acquired facial information and acquired iris information, respectively, based on the facial image and iris image of the authentication target. The biometric information acquisition unit 11 may also acquire a facial image of the authentication target approaching the authentication control device 1a as a first image, and after acquiring the first image, acquire a facial image of the authentication target as a second image. The biometric information acquisition unit 11 may also acquire multiple facial images of the authentication target from a single image captured by the camera C.

[0118] The face authentication control unit 12 controls face authentication using the acquired face information and acquires a face authentication result, which includes a face authentication score indicating the degree of match between pre-registered face information and the acquired face information.

[0119] The face authentication control unit 12 may compare the brightness of a predetermined range in each of the acquired face images of authentication targets, and control face authentication using a face image whose brightness is relatively suitable for authentication. A face image whose brightness is relatively suitable for authentication is, for example, a face image among the face images of authentication targets that has a brightness close to the average brightness of the face images registered in the authentication storage unit 21 of the authentication device 2. The predetermined range may be set in advance depending on the environment in which the authentication control device 1a is installed, or may be changed as appropriate. The brightness of the predetermined range may be expressed, for example, using a statistical value of the brightness values ​​within the predetermined range. The face authentication control unit 12 identifies an authentication target corresponding to a face image whose brightness value is relatively suitable for authentication, and controls face authentication of the authentication target.

[0120] In recent years, biometric authentication technology using a camera that captures multiple people within its field of view has been developed. When multiple authentication targets are included in an image captured by the camera, the authentication device may not be able to correctly identify the authentication targets due to lighting conditions. The face authentication control unit 12 controls the face authentication of the authentication targets based on a predetermined range of brightness in each of the acquired face images of the authentication targets. This allows the authentication control device 1a to properly perform face authentication of the authentication targets.

[0121] Furthermore, the face authentication control unit 12 controls face authentication using the first image when the eye distance in the first image acquired by the biometric information acquisition unit 11 is equal to or greater than a first threshold. In other words, when the authentication target approaches the authentication control device 1a, the face authentication control unit 12 controls face authentication using the first image.

[0122] The iris authentication control unit 14 controls iris authentication using the acquired iris information and acquires the result of iris authentication. The result of iris authentication includes an iris authentication score indicating the degree of match between pre-registered iris information and the acquired iris information.

[0123] Furthermore, when the eye distance in the second image acquired by the biometric information acquisition unit 11 is equal to or greater than a second threshold value that is greater than the first threshold value, the iris authentication control unit 14 controls iris authentication using the second image. In other words, when the subject comes closer to the authentication control device 1a than the location where the first image was taken, the iris authentication control unit 14 controls iris authentication using the second image.

[0124] In an authentication device that performs multimodal authentication using a face image and an iris image, the distance at which the face of the authentication target can be authenticated from a captured image (camera resolution) differs from the distance at which the iris of the authentication target can be authenticated. Specifically, the distance at which authentication can be performed using the iris is shorter than the distance at which authentication can be performed using the face. Considering the convenience of the authentication target, it is desirable to perform authentication in a short time. In the authentication control device 1a, the face authentication control unit 12 controls face authentication using the first image based on the eye-to-eye distance in the first image, and the iris authentication control unit 14 controls iris authentication using the second image based on the eye-to-eye distance in the second image. In this manner, the authentication control device 1a first performs face authentication and then iris authentication, thereby distributing the processing load and shortening the time required for authentication.

[0125] The exposure control unit 19 controls the brightness of at least one of the face image and the iris image acquired by the biometric information acquisition unit 11, based on at least one of the relationship between the luminance of the face image and the result of face authentication and the relationship between the luminance of the iris image and the result of iris authentication. The result of face authentication may include a face authentication score, and the result of iris authentication may include an iris authentication score.

[0126] The exposure control unit 19 includes the photography control unit 16 and the lighting control unit 17. The exposure control unit 19 performs auto exposure (AE) processing using at least one of the photography control unit 16 and the lighting control unit 17. In this way, the exposure control unit 19 controls the brightness of at least one of the face image and the iris image.

[0127] The iris image includes a left-eye image that is an iris image of the left eye of the authentication target, and a right-eye image that is an iris image of the right eye of the authentication target. If the brightness of at least one of the left-eye image and the right-eye image is outside a predetermined range, the exposure control unit 19 controls the brightness of the iris image acquired by the biometric information acquisition unit 11.

[0128] When performing iris authentication, if the ambient brightness is insufficient, the accuracy of iris authentication for either the left or right iris may decrease. If the brightness of the iris image is outside a predetermined range, the exposure control unit 19 controls the brightness of the iris image acquired by the biometric information acquisition unit 11. This allows the biometric information acquisition unit 11 to acquire an iris image with appropriate brightness.

[0129] The photographing control unit 16 controls the photographing of the camera C that photographs the authentication target. The photographing control unit 16 controls the brightness of at least one of the face image and the iris image acquired by the biometric information acquisition unit 11 by controlling the camera C. The photographing control unit 16 controls at least one of the exposure time and the analog gain of the camera C.

[0130] For example, the photographing control unit 16 controls the shutter speed of the camera C according to the ambient brightness. In this way, the photographing control unit 16 controls the exposure time. When the ambient brightness is equal to or higher than a predetermined level, the photographing control unit 16 increases the shutter speed to a speed equal to or higher than the predetermined level. The photographing control unit 16 may also use different shutter speeds when photographing a left eye image and a right eye image. For example, when sunlight is shining on the right half of the face, the photographing control unit 16 sets the shutter speed when photographing the right eye to a speed equal to or higher than the predetermined level, and sets the shutter speed when photographing the left eye to a speed lower than the predetermined level. The photographing control unit 16 may also lower the gain when photographing an eye that is brighter than the predetermined level.

[0131] Furthermore, the photographing control unit 16 may cause the camera C to photograph at least one of the right-eye image and the left-eye image again when the difference in luminance between the right-eye image and the left-eye image is equal to or greater than a predetermined value.

[0132] In addition, when the shooting control unit 16 causes camera C to re-shoot at least one of the right-eye image and the left-eye image, it may control the shooting for the right eye using an analog gain based on the brightness of the right-eye image, and control the shooting for the left eye using an analog gain based on the brightness of the left-eye image.

[0133] Depending on the shooting environment, the iris image of the authentication target may not be captured properly. For example, strong sunlight may hit the target from the side, resulting in different luminance values ​​for the left and right irises in the image. If the difference in luminance between the right-eye image and the left-eye image is greater than a predetermined value, the shooting control unit 16 causes the camera C to take another image. The shooting control unit 16 also controls the analog gain based on the luminance of these images. This allows the authentication control device 1a to perform iris authentication using an appropriate iris image.

[0134] The illumination control unit 17 controls the illumination intensity of the illumination L that illuminates the authentication target. For example, the illumination control unit 17 controls the illumination intensity based on the luminance of the right-eye image and the luminance of the left-eye image. For example, when the luminance of the image is equal to or greater than a predetermined value, the illumination control unit 17 does not illuminate the eye area corresponding to the image, and when the luminance of the image is less than the predetermined value, the illumination control unit 17 illuminates the eye area corresponding to the image.

[0135] The processing control unit 18, the camera C, and the lighting L are generally similar in configuration to those in the authentication control device 1, and therefore a description thereof will be omitted.

[0136] (Processing of the authentication control device 1a) Next, the processing performed by the authentication control device 1a will be described with reference to Fig. 12. Fig. 12 is a flowchart showing the processing performed by the authentication control device 1a.

[0137] First, the biometric information acquisition unit 11 acquires an infrared image (S51). The infrared image is, for example, a near-infrared image captured by a camera C. The biometric information acquisition unit 11 determines whether or not the face and iris of the authentication target have been detected from the infrared image (S52). If it is determined that the face or iris has not been detected (NO in S52), the process returns to step S51. If it is determined that the face and iris have been detected (YES in S52), the biometric information acquisition unit 11 acquires face information and iris information for each of the left and right eyes (S53).

[0138] Next, the face authentication control unit 12 and the iris authentication control unit 14 respectively control face authentication and iris authentication for each of the left and right eyes (S54). The face authentication control unit 12 may compare the brightness of each of the acquired face images to be authenticated within a predetermined range, and control face authentication using a face image whose brightness is relatively suitable for authentication. The iris authentication control unit 14 may control iris authentication using an iris image included in the infrared image used for face authentication.

[0139] Furthermore, if the eye distance in the first image is equal to or greater than a first threshold, the face authentication control unit 12 may control face authentication using the first image. In this case, if the eye distance in the second image is equal to or greater than a second threshold that is greater than the first threshold, the iris authentication control unit 14 may control iris authentication using the second image. The face authentication control unit 12 and the iris authentication control unit 14 each transmit an authentication request to the authentication device 2 and receive an authentication result from the authentication device 2.

[0140] Next, the authentication control device 1a determines whether the authentication target has been successfully authenticated based on the results of face authentication and iris authentication (S55). If it is determined that the authentication has been successful (YES in S55), the process ends.

[0141] If it is determined that the authentication has failed (NO in S55), the exposure control unit 19 determines whether or not there is a dark image that is not suitable for authentication (S56).If it is determined that there is no dark image that is not suitable for authentication (NO in S56), the process returns to step S51.

[0142] If it is determined that there is a dark image that is not suitable for authentication (YES in S56), the exposure control unit 19 controls the brightness of the image acquired by the biometric information acquisition unit 11 based on the brightness of the image and the result of the authentication (S57). For example, the exposure control unit 19 controls the brightness of the image based on at least one of the relationship between the brightness of the face image and the result of the face authentication and the relationship between the brightness of the iris image and the result of the iris authentication.

[0143] For example, the exposure control unit 19 may control brightness using at least one of the imaging control unit 16 and the illumination control unit 17. For example, the exposure control unit 19 controls the brightness of the iris image when the luminance of at least one of the left-eye image and the right-eye image is outside a predetermined range. The exposure control unit 19 may cause the camera C to re-capture at least one of the right-eye image and the left-eye image when the difference in luminance between the right-eye image and the left-eye image is equal to or greater than a predetermined value. When causing the camera C to re-capture at least one of the right-eye image and the left-eye image, the imaging control unit 16 may control right-eye imaging using an analog gain based on the luminance of the right-eye image, and control left-eye imaging using an analog gain based on the luminance of the left-eye image.

[0144] As described above, the authentication system 5a according to this disclosure can improve upon the techniques disclosed in the above-mentioned patent documents.

[0145] <Example of Hardware Configuration> Each functional component of the above-described authentication control device 1, authentication control device 1a, and authentication device 2 (hereinafter referred to as the "authentication control device 1, etc.") may be realized by hardware (e.g., a hardwired electronic circuit, etc.) that realizes each functional component, or may be realized by a combination of hardware and software (e.g., a combination of an electronic circuit and a program that controls it). Below, a case where each functional component of the authentication control device 1, etc. is realized by a combination of hardware and software will be further described.

[0146] 13 is a block diagram illustrating an example of the hardware configuration of a computer 900 that realizes the authentication control device 1, etc. The computer 900 may be a dedicated computer designed to realize the authentication control device 1, etc., or may be a general-purpose computer. The computer 900 may also be a portable computer such as a smartphone or tablet terminal.

[0147] For example, by installing a predetermined application on the computer 900, the computer 900 realizes each function of the authentication control device 1, etc. The application is configured by a program for realizing the functional components of the authentication control device 1, etc.

[0148] The computer 900 has a bus 902, a processor 904, a memory 906, a storage device 908, an input / output interface 910, and a network interface 912. The bus 902 is a data transmission path for the processor 904, the memory 906, the storage device 908, the input / output interface 910, and the network interface 912 to transmit and receive data to and from each other. However, the method of connecting the processor 904 and other components to each other is not limited to a bus connection.

[0149] The processor 904 is a variety of processors, such as a central processing unit (CPU), a graphics processing unit (GPU), a field-programmable gate array (FPGA), or a quantum processor (quantum computer control chip). The memory 906 is a main storage device realized using a random access memory (RAM) or the like. The storage device 908 is an auxiliary storage device realized using a hard disk, a solid state drive (SSD), a memory card, a read only memory (ROM), or the like.

[0150] The input / output interface 910 is an interface for connecting the computer 900 with input / output devices. For example, the input / output interface 910 is connected to an input device such as a keyboard and an output device such as a display device.

[0151] The network interface 912 is an interface for connecting the computer 900 to a network. This network may be a LAN (Local Area Network) or a WAN (Wide Area Network).

[0152] The storage device 908 stores programs (programs that realize the above-mentioned applications) that realize the various functional components of the authentication control device 1, etc. The processor 904 reads these programs into the memory 906 and executes them to realize the various functional components of the authentication control device 1, etc.

[0153] Each processor executes one or more programs containing instructions for causing a computer to perform an algorithm. The programs contain instructions (or software code) that, when loaded into a computer, cause the computer to perform one or more functions described in the embodiments. The programs may be stored on various types of non-transitory computer-readable media or tangible storage media. By way of example and not limitation, non-transitory computer-readable media or tangible storage media include RAM, ROM, flash memory, SSD or other memory technologies, CD-ROM, DVD (Digital Versatile Disc), Blu-ray® disk or other optical disk storage, magnetic cassette, magnetic tape, magnetic disk storage or other magnetic storage devices. The programs may also be transmitted over various types of transitory computer-readable media or communication media. By way of example and not limitation, transitory computer-readable media or communication media include electrical, optical, acoustic, or other forms of propagated signals.

[0154] Although this disclosure has been described above with reference to the embodiments, this disclosure is not limited to the above-described embodiments. Various modifications that can be understood by those skilled in the art can be made to the configuration and details of this disclosure within the scope of this disclosure. Furthermore, each embodiment can be combined with other embodiments as appropriate.

[0155] Each drawing is merely an example for describing one or more embodiments. Each drawing may not relate only to one particular embodiment, but may also relate to one or more other embodiments. As will be understood by those skilled in the art, various features or steps described with reference to any one drawing can be combined with features or steps shown in one or more other drawings to create, for example, an embodiment not explicitly shown or described. Not all features or steps shown in any one drawing are necessary to describe an exemplary embodiment, and some features or steps may be omitted. The order of steps described in any drawing may be changed as appropriate.

[0156] It should be noted that this disclosure is not limited to the above-described embodiments, and can be appropriately modified without departing from the spirit and scope of the present disclosure. In addition, the above-described embodiments can be combined in any manner.

[0157] Some or all of the above embodiments can be described as, but are not limited to, the following supplementary notes. (Supplementary Note 1) An authentication control device comprising: a biometric information acquisition means for acquiring facial information and iris information of an authentication target as acquired facial information and acquired iris information, respectively, from an image captured by a camera that captures the authentication target; a target identification means for identifying target iris information to be used as a match target in iris authentication of the authentication target from pre-registered iris information based on the acquired facial information; and an iris authentication control means for controlling the iris authentication using the target iris information and the acquired iris information. (Supplementary Note 2) An authentication control device according to Supplementary Note 1, further including a facial authentication control means for controlling facial authentication of the authentication target using the acquired facial information, wherein the target identification means identifies the target iris information based on a result of the facial authentication. (Supplementary Note 3) The authentication control device according to Supplementary Note 2, wherein the result of the face authentication includes a face authentication score indicating a degree of match between pre-registered registered face information and the acquired face information, and the target identification means identifies, as the target iris information, the registered iris information associated with the registered face information that satisfies at least one of the following: the face authentication score is equal to or higher than a predetermined value, and the ranking of the face authentication score is equal to or higher than a predetermined value. (Supplementary Note 4) The authentication control device according to Supplementary Note 2 or 3, further comprising: an update means for updating the registered face information of the authentication target, wherein the update means updates the registered face information of the authentication target when at least one of the following is satisfied: the face authentication score of the authentication target, which indicates a degree of match between the registered face information of the authentication target and the acquired face information, is lower than a predetermined value, and the ranking of the face authentication score of the authentication target is lower than a predetermined value.(Supplementary Note 5) An authentication control device comprising: a biometric information acquisition means that acquires facial information and iris information of a target to be authenticated as acquired facial information and acquired iris information based on a facial image and iris image of the target to be authenticated, a facial authentication control means that controls facial authentication using the acquired facial information and acquires a result of the facial authentication, an iris authentication control means that controls iris authentication using the acquired iris information and acquires the result of the iris authentication, and an exposure control means that controls brightness of at least one of the facial image and the iris image acquired by the biometric information acquisition means, based on at least one of a relationship between luminance of the facial image and the result of the facial authentication, and a relationship between luminance of the iris image and the result of the iris authentication. (Supplementary Note 6) The authentication control device according to Supplementary Note 5, wherein the exposure control means controls the brightness using at least one of an imaging control means that controls a camera that images the target to be authenticated, and an illumination control means that controls lighting that illuminates the target to be authenticated. (Supplementary Note 7) The authentication control device according to Supplementary Note 6, wherein the photography control means controls at least one of an exposure time and an analog gain of the camera, and the lighting control means controls the lighting intensity of the lighting. (Supplementary Note 8) The authentication control device according to any one of Supplementary Notes 5 to 7, wherein the iris image includes a left-eye image that is an iris image of the left eye of the authentication subject, and a right-eye image that is an iris image of the right eye of the authentication subject, and the exposure control means controls the brightness of the iris image acquired by the biometric information acquisition means when the luminance of at least one of the left-eye image and the right-eye image is outside a predetermined range. (Supplementary Note 9) The authentication control device according to Supplementary Note 6 or 7, wherein the iris image includes a left-eye image that is an iris image of the left eye of the authentication subject, and a right-eye image that is an iris image of the right eye of the authentication subject, and the photography control means causes the camera to re-photograph at least one of the right-eye image and the left-eye image when a difference in luminance between the right-eye image and the left-eye image is equal to or greater than a predetermined value. (Supplementary Note 10) The authentication control device described in Supplementary Note 9, wherein the photography control means, when causing the camera to re-photograph at least one of the right-eye image and the left-eye image, controls right-eye photography using an analog gain based on the luminance of the right-eye image, and controls left-eye photography using an analog gain based on the luminance of the left-eye image.(Supplementary Note 11) The authentication control device according to Supplementary Note 6 or 7, wherein the biometric information acquisition means acquires a plurality of facial images of the authentication target from a single image captured by the camera, and the facial authentication control means compares a predetermined range of brightness in each of the acquired facial images of the authentication target, and controls the facial authentication using a facial image whose brightness is relatively suitable for authentication. (Supplementary Note 12) The authentication control device according to any one of Supplementary Notes 5 to 11, wherein the biometric information acquisition means acquires a facial image of the authentication target approaching the authentication control device as a first image, and after acquiring the first image, acquires a facial image of the authentication target as a second image, and the facial authentication control means controls the facial authentication using the first image if the eye-to-eye distance in the first image is equal to or greater than a first threshold, and the iris authentication control means controls the iris authentication using the second image if the eye-to-eye distance in the second image is equal to or greater than a second threshold that is greater than the first threshold. (Supplementary Note 13) The authentication control device according to any one of Supplementary Notes 1 to 12, wherein the iris authentication control means controls the iris authentication using an iris image included in an image used for face authentication of the authentication target. (Supplementary Note 14) An authentication system comprising: a camera that photographs an authentication target, an authentication control device, and an authentication device, wherein the authentication control device has: biometric information acquisition means that acquires face information and iris information of the authentication target as acquired face information and acquired iris information, respectively, from the image photographed by the camera, target identification means that identifies target iris information to be used as a match target in iris authentication of the authentication target from pre-registered iris information based on the acquired face information, and iris authentication control means that controls the iris authentication using the target iris information and the acquired iris information, and the authentication device performs biometric authentication of the authentication target using the target iris information and the acquired iris information.(Supplementary Note 15) An authentication system comprising: a camera that photographs an authentication target; an authentication control device; and an authentication device, wherein the authentication control device has: biometric information acquisition means that acquires facial information and iris information of the authentication target as acquired facial information and acquired iris information, respectively, based on the facial image and iris image of the authentication target photographed by the camera; facial authentication control means that controls facial authentication using the acquired facial information and acquires a result of the facial authentication; iris authentication control means that controls iris authentication using the acquired iris information and acquires a result of the iris authentication; and exposure control means that controls brightness of at least one of the facial image and the iris image acquired by the biometric information acquisition means, based on at least one of a relationship between luminance of the facial image and the result of the facial authentication, and a relationship between luminance of the iris image and the result of the iris authentication, and the authentication device performs the facial authentication and the iris authentication. (Supplementary Note 16) An authentication control method, comprising: acquiring face information and iris information of an authentication target as acquired face information and acquired iris information, respectively, from an image captured by a camera that captures the authentication target; specifying target iris information to be used as a match target in iris authentication of the authentication target from pre-registered iris information based on the acquired face information; and controlling the iris authentication using the target iris information and the acquired iris information. (Supplementary Note 17) An authentication control method, comprising: acquiring face information and iris information of the authentication target as acquired face information and acquired iris information, respectively, based on a face image and iris image of the authentication target; controlling face authentication using the acquired face information and acquiring a result of the face authentication; controlling iris authentication using the acquired iris information and acquiring a result of the iris authentication; and controlling brightness of at least one of the acquired face image and the iris image, based on at least one of a relationship between luminance of the face image and a result of the face authentication, and a relationship between luminance of the iris image and a result of the iris authentication.(Supplementary Note 18) A program causing a computer to execute an authentication control method, which comprises acquiring face information and iris information of an authentication target as acquired face information and acquired iris information, respectively, from an image captured by a camera that captures the authentication target, specifying target iris information to be used as a match target in iris authentication of the authentication target from pre-registered iris information based on the acquired face information, and controlling the iris authentication using the target iris information and the acquired iris information. (Supplementary Note 19) A program causing a computer to execute an authentication control method, which comprises acquiring face information and iris information of the authentication target as acquired face information and acquired iris information, respectively, based on a face image and iris image of the authentication target, controlling face authentication using the acquired face information and acquiring a result of the face authentication, controlling iris authentication using the acquired iris information and acquiring a result of the iris authentication, and controlling brightness of at least one of the acquired face image and the iris image, based on at least one of a relationship between luminance of the face image and a result of the face authentication, and a relationship between luminance of the iris image and a result of the iris authentication.

[0158] Some or all of the elements (e.g., configurations and functions) described in Supplementary Notes 2 to 4 and Supplementary Note 13, which are dependent on Supplementary Note 1, may also be dependent on Supplementary Note 14, Supplementary Note 16, and Supplementary Note 18 in the same dependent relationship as Supplementary Note 2 to Supplementary Note 4 and Supplementary Note 13. Also, some or all of the elements described in Supplementary Note 6 to Supplementary Note 13, which are dependent on Supplementary Note 5, may also be dependent on Supplementary Note 15, Supplementary Note 17, and Supplementary Note 19 in the same dependent relationship as Supplementary Note 6 to Supplementary Note 13. Some or all of the elements described in any Supplementary Note may be applicable to various hardware, software, recording means for recording software, systems, and methods.

[0159] REFERENCE SIGNS LIST 1, 1a Authentication control device 2 Authentication device 5, 5a Authentication system 11 Biometric information acquisition unit 12 Face authentication control unit 13 Object identification unit 14 Iris authentication control unit 15 Update unit 16 Photography control unit 17 Lighting control unit 18 Processing control unit 19 Exposure control unit 21 Authentication storage unit 22 Detection unit 23 Feature point extraction unit 24 Registration unit 25 Authentication unit 100, 100a Authentication control device 101 Biometric information acquisition unit 102 Face authentication control unit 103 Object identification unit 104 Iris authentication control unit 109 Exposure control unit 211 Face feature data 212 Iris feature data 900 Computer 902 Bus 904 Processor 906 Memory 908 Storage device 910 Input / output interface 912 Network interface C Camera L Lighting N Network

Claims

1. An authentication control device comprising: a biometric information acquisition means for acquiring facial information and iris information of an authentication target as acquired facial information and acquired iris information, respectively, from an image captured by a camera that captures the authentication target; a target identification means for identifying target iris information to be used as a match target in iris authentication of the authentication target from pre-registered iris information based on the acquired facial information; and an iris authentication control means for controlling the iris authentication using the target iris information and the acquired iris information.

2. The authentication control device according to claim 1, further comprising a face authentication control means for controlling face authentication of the authentication target using the acquired face information, wherein the target identification means identifies the target iris information based on the result of the face authentication.

3. The authentication control device according to claim 2, wherein the result of the face authentication includes a face authentication score indicating the degree of match between pre-registered registered face information and the acquired face information, and the target identification means identifies, as the target iris information, the registered iris information associated with the registered face information that satisfies at least one of the following: the face authentication score is equal to or higher than a predetermined value; and the ranking of the face authentication score is equal to or higher than a predetermined value.

4. An authentication control device as described in claim 2, further comprising an update means for updating the registered face information of the authentication target, wherein the update means updates the registered face information of the authentication target when at least one of the following is satisfied: the face recognition score of the authentication target, which indicates the degree of match between the registered face information of the authentication target and the acquired face information, is less than a predetermined value, and the ranking of the face recognition score of the authentication target is less than a predetermined value.

5. An authentication control device comprising: a biometric information acquisition means for acquiring facial information and iris information of a subject to be authenticated as acquired facial information and acquired iris information based on the facial image and iris image of the subject; a facial authentication control means for controlling facial authentication using the acquired facial information and acquiring the result of the facial authentication; an iris authentication control means for controlling iris authentication using the acquired iris information and acquiring the result of the iris authentication; and an exposure control means for controlling the brightness of at least one of the facial image and the iris image acquired by the biometric information acquisition means based on at least one of the relationship between the luminance of the facial image and the result of the facial authentication and the relationship between the luminance of the iris image and the result of the iris authentication.

6. An authentication control device according to claim 5, wherein the exposure control means controls the brightness using at least one of an imaging control means that controls a camera that captures an image of the object to be authenticated, and an illumination control means that controls lighting that illuminates the object to be authenticated.

7. The authentication control device according to claim 6, wherein the photography control means controls at least one of the exposure time and analog gain of the camera, and the lighting control means controls the lighting intensity of the lighting.

8. An authentication control device as described in claim 5, wherein the iris image includes a left-eye image which is an iris image of the left eye of the subject to be authenticated, and a right-eye image which is an iris image of the right eye of the subject to be authenticated, and the exposure control means controls the brightness of the iris image acquired by the biometric information acquisition means when the brightness of at least one of the left-eye image and the right-eye image is outside a predetermined range.

9. The authentication control device described in claim 6, wherein the iris image includes a left-eye image which is an iris image of the left eye of the subject to be authenticated, and a right-eye image which is an iris image of the right eye of the subject to be authenticated, and the photographing control means causes the camera to photograph at least one of the right-eye image and the left-eye image again when the difference in brightness between the right-eye image and the left-eye image is equal to or greater than a predetermined value.

10. The authentication control device described in claim 9, wherein the photographing control means, when causing the camera to photograph at least one of the right-eye image and the left-eye image again, controls photographing for the right eye using an analog gain based on the luminance of the right-eye image, and controls photographing for the left eye using an analog gain based on the luminance of the left-eye image.

11. The authentication control device according to claim 6, wherein the biometric information acquisition means acquires a plurality of facial images of the authentication target from a single image captured by the camera, and the facial authentication control means compares a predetermined range of brightness in each of the acquired facial images of the authentication target, and controls the facial authentication using a facial image whose brightness is relatively suitable for authentication.

12. The authentication control device described in claim 5, wherein the biometric information acquisition means acquires a facial image of the authentication target approaching the authentication control device as a first image, and after acquiring the first image, acquires a facial image of the authentication target as a second image; the facial authentication control means controls the facial authentication using the first image if the eye-to-eye distance in the first image is equal to or greater than a first threshold; and the iris authentication control means controls the iris authentication using the second image if the eye-to-eye distance in the second image is equal to or greater than a second threshold that is greater than the first threshold.

13. An authentication control device according to claim 1 or 5, wherein the iris authentication control means controls the iris authentication using an iris image included in an image used for face authentication of the authentication target.

14. An authentication system comprising: a camera that photographs an object to be authenticated; an authentication control device; and an authentication device, wherein the authentication control device has: biometric information acquisition means that acquires facial information and iris information of the object to be authenticated as acquired facial information and acquired iris information, respectively, from an image photographed by the camera; target identification means that identifies target iris information to be used as a matching target in iris authentication of the object to be authenticated from pre-registered iris information based on the acquired facial information; and iris authentication control means that controls the iris authentication using the target iris information and the acquired iris information, and the authentication device performs biometric authentication of the object to be authenticated using the target iris information and the acquired iris information.

15. An authentication system comprising: a camera that photographs an object to be authenticated; an authentication control device; and an authentication device, wherein the authentication control device has: biometric information acquisition means that acquires facial information and iris information of the object to be authenticated as acquired facial information and acquired iris information, respectively, based on the facial image and iris image of the object to be authenticated photographed by the camera; facial authentication control means that controls facial authentication using the acquired facial information and acquires the result of the facial authentication; iris authentication control means that controls iris authentication using the acquired iris information and acquires the result of the iris authentication; and exposure control means that controls brightness of at least one of the facial image and the iris image acquired by the biometric information acquisition means, based on at least one of the relationship between the luminance of the facial image and the result of the facial authentication, and the relationship between the luminance of the iris image and the result of the iris authentication, and the authentication device performs the facial authentication and the iris authentication.

16. An authentication control method comprising: acquiring face information and iris information of an authentication target as acquired face information and acquired iris information, respectively, from an image captured by a camera that captures the authentication target; identifying target iris information to be used as a match target in iris authentication of the authentication target from pre-registered iris information based on the acquired face information; and controlling the iris authentication using the target iris information and the acquired iris information.

17. An authentication control method comprising: acquiring facial information and iris information of a subject to be authenticated as acquired facial information and acquired iris information, respectively, based on a facial image and iris image of the subject to be authenticated; controlling facial authentication using the acquired facial information and acquiring a result of the facial authentication; controlling iris authentication using the acquired iris information and acquiring a result of the iris authentication; and controlling brightness of at least one of the acquired facial image and iris image based on at least one of the relationship between the brightness of the facial image and the result of the facial authentication and the relationship between the brightness of the iris image and the result of the iris authentication.

18. A program that causes a computer to execute an authentication control method, which acquires facial information and iris information of an authentication target as acquired facial information and acquired iris information, respectively, from an image captured by a camera that photographs the authentication target, identifies target iris information to be used as a match target in iris authentication of the authentication target from pre-registered iris information based on the acquired facial information, and controls the iris authentication using the target iris information and the acquired iris information.

19. A program that causes a computer to execute an authentication control method, which comprises acquiring facial information and iris information of a subject to be authenticated as acquired facial information and acquired iris information based on the facial image and iris image of the subject, controlling facial authentication using the acquired facial information and acquiring the result of the facial authentication, controlling iris authentication using the acquired iris information and acquiring the result of the iris authentication, and controlling the brightness of at least one of the acquired facial image and iris image based on at least one of the relationship between the brightness of the facial image and the result of the facial authentication and the relationship between the brightness of the iris image and the result of the iris authentication.

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