Information processing device, information processing method, and recording medium

Abstract

This information processing device includes: a first image acquisition means for acquiring a first image including a person to be authenticated in a predetermined area; an authentication means for authenticating the person to be authenticated in the first image; a number-of-people acquisition means for acquiring the number of people to be authenticated in the predetermined area; a specification means for specifying a target to be tracked from among the people to be authenticated on the basis of the authentication processing and the number of people to be authenticated; a second image acquisition means for acquiring a second image including the target to be tracked; and a tracking means for tracking the target to be tracked by using the second image.

Description

Information processing device, information processing method, and recording medium

[0001] The present disclosure relates to the technical fields of an information processing device, an information processing method, and a recording medium.

[0002] Known examples of this type of device are those that perform authentication processing for multiple subjects who are present in a predetermined area. For example, Patent Document 1 discloses a device that acquires an image including a predetermined area through which subjects pass, and performs facial recognition while tracking the subjects within the image.

[0003] International Publication No. 2023 / 152970

[0004] An object of this disclosure is to provide an information processing device, an information processing method, and a recording medium that aim to improve upon the techniques disclosed in prior art documents.

[0005] One aspect of the information processing device disclosed herein comprises a first image acquisition means for acquiring a first image including a person to be authenticated in a specified area, an authentication means for performing an authentication process for the person to be authenticated in the first image, a number acquisition means for acquiring the number of people to be authenticated in the specified area, an identification means for identifying a tracking target from among the people to be authenticated based on the result of the authentication process and the number of people to be authenticated, a second image acquisition means for acquiring a second image including the tracking target, and a tracking means for performing a tracking process for the tracking target using the second image.

[0006] One aspect of the information processing method disclosed herein involves using at least one computer to acquire a first image including a person to be authenticated in a specified area, perform an authentication process for the person to be authenticated in the first image, acquire the number of people to be authenticated in the specified area, identify a tracking target from among the people to be authenticated based on the result of the authentication process and the number of people to be authenticated, acquire a second image including the tracking target, and perform tracking process for the tracking target using the second image.

[0007] One aspect of the recording medium of this disclosure is a computer program recorded on at least one computer that causes the computer to execute an information processing method, which includes acquiring a first image including a person to be authenticated in a specified area, performing an authentication process for the person to be authenticated in the first image, acquiring the number of people to be authenticated in the specified area, identifying a tracking target from among the people to be authenticated based on the result of the authentication process and the number of people to be authenticated, acquiring a second image including the tracking target, and performing tracking process for the tracking target using the second image.

[0008] 1 is a block diagram showing the hardware configuration of a gateless authentication system; FIG. 2 is a top view showing an example of operation of the gateless authentication system; FIG. 3 is a block diagram showing the functional configuration of a first information processing device, showing a flowchart showing the flow of operation of the gateless authentication system; FIG. 4 is a flowchart showing the flow of operation of the first information processing device; FIG. 5 is a flowchart showing an example of a second image acquisition operation in the first information processing device; FIG. 6 is a flowchart showing a modified example of the second image acquisition operation in the first information processing device; FIG. 7 is a flowchart showing an example of a second image deletion operation in the first information processing device; FIG. 8 is a flowchart showing the flow of operation of a second information processing device; FIG. 9 is a flowchart showing the flow of operation of a third information processing device; FIG. 10 is a block diagram showing the functional configuration of a fourth information processing device; FIG. 11 is a flowchart showing the flow of a notification operation in a fifth information processing device.

[0009] Hereinafter, embodiments of an information processing device, an information processing method, and a recording medium will be described with reference to the drawings.

[0010] First Embodiment A first information processing apparatus will be described with reference to FIGS. 1 to 8. FIG.

[0011] (Configuration of Gateless Authentication System) First, the hardware configuration of a gateless authentication system to which the first information processing device is applied will be described with reference to Fig. 1. Fig. 1 is a block diagram showing the hardware configuration of the gateless authentication system.

[0012] 1, the gateless authentication system 1 includes a processor 11, a RAM (Random Access Memory) 12, a ROM (Read Only Memory) 13, a storage device 14, an input device 15, an output device 16, a user terminal 20, an authentication device 30, and an outside area device 40. The processor 11, RAM 12, ROM 13, storage device 14, input device 15, output device 16, user terminal 20, authentication device 30, and outside area device 40 are each connected via a data bus 17. Note that the data bus 17 may be an interface other than a data bus (e.g., a LAN, a USB, etc.).

[0013] The processor 11 loads a computer program. For example, the processor 11 is configured to load a computer program stored in at least one of the RAM 12, the ROM 13, and the storage device 14. Alternatively, the processor 11 may load a computer program stored in a computer-readable storage medium using a storage medium reading device (not shown). The processor 11 may acquire (i.e., load) the computer program from a device (not shown) located outside the gateless authentication system 1 via a network interface. The processor 11 executes the loaded computer program to perform various processes. When the processor 11 executes the loaded computer program, functional blocks related to the processes executed by the gateless authentication system 1 are realized within the processor 11. In other words, the processor 11 may function as a controller that executes each control in the gateless authentication system 1 (in other words, the first information processing device).

[0014] The processor 11 may be configured as, for example, a central processing unit (CPU), a graphics processing unit (GPU), a field-programmable gate array (FPGA), a digital signal processor (DSP), an application-specific integrated circuit (ASIC), or a quantum processor. The processor 11 may be configured as one of these, or may be configured to use multiple processors in parallel.

[0015] The RAM 12 temporarily stores computer programs executed by the processor 11. The RAM 12 temporarily stores data that the processor 11 temporarily uses while it is executing the computer programs. The RAM 12 may be, for example, a dynamic random access memory (D-RAM) or a static random access memory (SRAM). Alternatively, other types of volatile memory may be used instead of the RAM 12.

[0016] The ROM 13 stores computer programs executed by the processor 11. The ROM 13 may also store fixed data. The ROM 13 may be, for example, a programmable read-only memory (PROM) or an erasable read-only memory (EPROM). Alternatively, other types of non-volatile memory may be used instead of the ROM 13.

[0017] The storage device 14 stores data that is to be saved long-term by the gateless authentication system 1. The storage device 14 may operate as a temporary storage device for the processor 11. The storage device 14 may store computer programs executed by the processor 11. The storage device 14 may include, for example, at least one of a hard disk device, a magneto-optical disk device, an SSD (Solid State Drive), and a disk array device.

[0018] The input device 15 is a device that receives input instructions from a user of the gateless authentication system 1. The input device 15 may include, for example, at least one of a keyboard, a mouse, and a touch panel. The input device 15 may also be, for example, a device that includes a microphone and is capable of voice input.

[0019] The output device 16 is a device that outputs information related to the gateless authentication system 1 to the outside. For example, the output device 16 may be a display device (e.g., a display or a monitor) that can display information related to the gateless authentication system 1. The output device 16 may also be a speaker or the like that can output information related to the gateless authentication system 1 as audio.

[0020] The user terminal 20 is a terminal used by a user (specifically, a monitor) of the gateless authentication system 1. The user terminal 20 includes a display unit 201. The display unit 201 is a display mounted on the user terminal 20. The user terminal 20 may be configured as, for example, an HMD (Head Mounted Display). The HMD may use AR (Augmented Reality), VR (Virtual Reality), or MR (Mixed Reality). Note that the user terminal 20 may be a terminal other than an HMD, and may be configured as, for example, a smartphone, a tablet, a laptop, or the like.

[0021] The authentication device 30 is a device that executes authentication processing in the gateless authentication system 1. The authentication device 30 includes a camera 301. The camera 301 is positioned so as to capture an image of the authentication area through which the person to be authenticated passes. The authentication device 30 executes authentication processing using the image captured by the camera 301. For example, the authentication device 30 detects the person to be authenticated in the image and acquires biometric information from the person to be authenticated. The authentication device 30 then compares the biometric information of the person to be authenticated with pre-registered registration information (i.e., biometric information of registered users) to execute authentication processing for the person to be authenticated. The authentication device 30 may have a function for storing registration information for multiple registered users. Alternatively, the registration information may be stored in an external storage device or the like, and the authentication device 30 may read it to execute authentication processing. The authentication device 30 may execute authentication processing by calculating a score according to the degree of match between the biometric information and the registration information. In this case, the authentication device 30 may determine that the authentication process is successful (i.e., the target and the registered user match) if the score is higher than a predetermined authentication threshold, and may determine that the authentication process is unsuccessful (i.e., the target and the registered user do not match) if the score is lower than the predetermined authentication threshold. The type of biometric information used by the authentication device 30 is not particularly limited, and the authentication process may be performed using biometric information related to the face or iris, for example.

[0022] The outside-area device 40 is a device installed outside the authentication area where the gateless authentication system 1 performs authentication. The outside-area device 40 is configured to be able to perform tracking processing outside the authentication area. Specifically, the area image device 40 performs tracking processing of a tracking target that exists outside the area using an image captured by the outside-area camera 401. The tracking processing performed by the outside-area device 40 will be described in detail later.

[0023] Each of the components of the gateless authentication system 1 described above may function as a first information processing device. For example, the first information processing device may be configured by the processor 11, RAM 12, and ROM 13 of the components of the gateless authentication system 1. Note that part of the calculation function of the first information processing device may be realized by an external server, a cloud, or the like.

[0024] (Gateless Authentication) Next, an example of the operation of the gateless authentication system 1 to which the first information processing device is applied will be described with reference to Fig. 2. Fig. 2 is a top view showing an example of the operation of the gateless authentication system.

[0025] 2, the gateless authentication system 1 is configured to be able to perform authentication processing (hereinafter referred to as "gateless authentication") for a person to be authenticated 50 passing through an authentication area R. In the example shown in FIG. 2, the person to be authenticated 50 is walking from the left side to the right side of the figure. The authentication area R is set, for example, at the entrance of various facilities, and a person to be authenticated 50 who is successfully authenticated is permitted to enter the facility, and a person to be authenticated 50 who is unsuccessful in authentication is prohibited from entering the facility. There may be multiple people to be authenticated 50 in the authentication area R. In this case, the gateless authentication system 1 simply performs authentication processing for each of the multiple people to be authenticated 50.

[0026] An authentication device 30 is installed at the end of the authentication area R (specifically, the end ahead in the direction of travel of the person to be authenticated 50). The authentication device 30 is provided with a camera 301, which captures an image of the authentication area R. The camera 301 is installed in a position that includes at least a portion of the authentication area R within its imaging range. Note that although an example in which one camera 301 is installed is given here, multiple cameras 301 may also be installed. In this case, it is preferable that the multiple cameras 301 are installed so as to capture images of the authentication area R from different positions and at different angles.

[0027] At least one monitor 60 is positioned near the authentication device 30. The monitor 60 uses the user terminal 20 to monitor the person to be authenticated 50 performing gateless authentication. For example, if there is a person to be authenticated 50 for whom the authentication process has not been successful (hereinafter referred to as an "unauthenticated person"), information about the unauthenticated person may be displayed on the display unit 201 of the user terminal 20. Upon seeing this information, the monitor 60 calls out to the unauthenticated person and prohibits them from passing through. The monitor 60 may also guide the unauthenticated person to perform gateless authentication again. In this case, the monitor 60 may instruct the person to face the camera 301.

[0028] Note that outside the authentication area R (specifically, beyond the authentication device 30), a tracking process is performed by the outside-area device 40. This tracking process is typically performed on an authenticated person who unintentionally passes through the authentication area R (for example, an unauthenticated person who could not be stopped by an observer). A plurality of outside-area cameras 401 may be installed outside the authentication area R. Also, observers 60 may be stationed outside the authentication area R. The observers 60 outside the authentication area R may prohibit the passage of the tracked target depending on the result of the tracking process.

[0029] (Operation of Gateless Authentication System) Next, the flow of operations of the gateless authentication system 1 will be described with reference to Fig. 3. Fig. 3 is a flowchart showing the flow of operations of the gateless authentication system.

[0030] 3, when the gateless authentication system 1 starts operating, the camera 301 first captures an image of the person to be authenticated 50 and acquires an authentication image including the person to be authenticated 50 (step S101). The authentication device 30 then detects the person to be authenticated 50 from the authentication image and starts tracking them (step S102). An individual tracking ID is assigned to each person to be authenticated 50 being tracked. Note that the authentication device 30 may detect multiple people to be authenticated 50 from a single image. In this case, the authentication unit 120 may track multiple people to be authenticated 50 simultaneously in parallel.

[0031] The subsequent processing from step S103 onwards is executed for each target. The authentication device 30 first acquires a target ID and a tracking ID for each target (step S201). Then, the authentication device 30 determines whether a new tracking ID has been assigned (step S202). That is, the authentication device 30 determines whether tracking of a new person to be authenticated 50 has begun. Note that if it is determined that a new tracking ID has not been assigned (step S202: NO), the authentication device 30 determines whether the person to be authenticated 50 being tracked has already been authenticated (step S203). That is, the authentication device 30 executes authentication processing for the person to be authenticated 50 being tracked and determines whether the authentication processing has been successful.

[0032] If the person to be authenticated 50 being tracked has already been authenticated (step S203: YES), the authentication device 30 determines that the person to be authenticated 50 is allowed to pass (step S204). On the other hand, if it determines that a new tracking ID has been assigned (step S202: YES) or if the person to be authenticated 50 being tracked has not already been authenticated (step S203: NO), the authentication device 30 executes authentication processing for the person to be authenticated 50 (step S205). If the authentication processing is successful (step S205: YES), the authentication device 30 associates the tracking ID assigned to the person to be authenticated 50 with the target ID identified by the authentication (i.e., the ID set for each registered user) and stores them (step S207). If the person to be authenticated 50 is successfully authenticated, the authentication device 30 determines that the person to be authenticated 50 is allowed to pass (step S204).

[0033] On the other hand, if the authentication process fails (step S206: NO), the authentication device 30 determines whether an alert has already been issued for the person to be authenticated 50 (step S208). An alert is issued, for example, when the number of authentication failures exceeds a predetermined threshold N. Examples of the number of authentication failures include the number of consecutive frames of authentication failure and the duration of consecutive authentication failures. For the person to be authenticated 50 for whom an alert has already been issued (step S208: YES), the authentication device 30 determines that the person to be authenticated 50 is not allowed to pass (step S29). If an alert has not been issued (step S208: NO), the authentication device 30 determines whether the number of consecutive frames of authentication failure exceeds a predetermined threshold N (step S210). If the number of consecutive frames of authentication failure exceeds the predetermined threshold N (step S210: YES), the authentication device 30 issues an alert for the person to be authenticated 50 and determines that the person to be authenticated 50 is not allowed to pass (step S209). On the other hand, if the number of consecutive frames of authentication failure does not exceed the predetermined threshold N (step S210: NO), authentication device 30 continues tracking of user 50 as being under evaluation (step S211).

[0034] When the processing for each target up to step S104 is completed, the gateless authentication system 1 executes a notification process (step S105). For example, the gateless authentication system 1 notifies the monitor 60 of information about the person to be authenticated 50 by outputting information according to the authentication result to the user terminal 20. The user terminal 20 notifies the monitor 60 by displaying an image or a message on the display unit 201, for example. Alternatively, the user terminal 20 may notify the monitor 60 by outputting sound using a built-in speaker or the like.

[0035] Thereafter, the gateless authentication system 1 determines whether or not the input of the image captured by the camera 301 has been completed (step S106). If the input of the image has been completed (step S106: YES), the series of operations ends. On the other hand, if the input of the image has not been completed (step S106: NO), the process is repeated from step S101.

[0036] (Configuration of Information Processing Apparatus) Next, the functional configuration of the first information processing apparatus applied to the above-described gateless authentication system 1 will be described with reference to Fig. 4. Fig. 4 is a block diagram showing the functional configuration of the first information processing apparatus.

[0037] 4, the first information processing device 10 is configured to be able to execute at least a part of the processes executed by the gateless authentication system 1. Specifically, the first information processing device 10 is configured to be able to execute processes mainly related to the authentication process in the gateless authentication system 1 (i.e., the process of step S205 in FIG. 3) and tracking process outside the authentication area R.

[0038] The first information processing device 10 is configured to include, as components for realizing its functions, a first image acquisition unit 110, an authentication unit 120, a number of people acquisition unit 130, a tracking target identification unit 140, a second image acquisition unit 150, and a tracking unit 160. Each of the first image acquisition unit 110, the authentication unit 120, the number of people acquisition unit 130, the tracking target identification unit 140, the second image acquisition unit 150, and the tracking unit 160 may be a processing block realized by the above-mentioned processor 11 (see FIG. 1 ).

[0039] The first image acquisition unit 110 is configured to be able to acquire a first image including the person to be authenticated 50 in the authentication area R. The image acquisition unit 110 acquires the first image by capturing an image of the authentication area R with a camera 301 (see FIG. 2 ). However, the image acquisition unit 110 may acquire a first image captured with a camera other than the camera 301. The image acquisition unit 110 may acquire a plurality of first images (in other words, a video) that are consecutive in time series. The first image acquired by the image acquisition unit 110 is configured to be output to each of the authentication unit 120 and the number of people acquisition unit 130.

[0040] The authentication unit 120 is configured to be able to perform authentication processing of the person to be authenticated 50 using the first image acquired by the image acquisition unit 110 as an authentication image. The authentication processing performed by the authentication unit 120 is the authentication processing performed by the authentication device 30 already described. That is, the authentication unit 120 may be configured as a part of the authentication device 30. The authentication unit 120 may perform tracking processing of the person to be authenticated 50 in order to perform the authentication processing. Specifically, as already described in FIG. 3 , the authentication unit 120 may be configured to perform tracking processing of the person to be authenticated 50 within the authentication area R and perform authentication processing for the person to be authenticated 50 being tracked. Note that the tracking processing performed by the authentication unit 120 is different from the tracking processing performed by the tracking unit 180 described below (the tracking unit 180 performs tracking processing in the authentication area R). The authentication result by the authentication unit 120 is configured to be output to the tracking target identification unit 140.

[0041] The number-of-persons acquisition unit 130 is configured to be able to acquire the number of persons-to-be-authenticated 50 present in the authentication area R. The number-of-persons acquisition unit 130 may acquire the number of persons-to-be-authenticated 50 present in the authentication area R using the first image acquired by the first image acquisition unit 110. For example, the number-of-persons acquisition unit 130 may have a function of detecting people from the first image and counting the number of people. The number-of-persons acquisition unit 130 may also be configured to acquire the number of persons-to-be-authenticated 50 present in the authentication area R using an image other than the first image. The number-of-persons acquisition unit 130 may also be configured to acquire the number of persons-to-be-authenticated 50 present in the authentication area R using various sensors in addition to the image. Information regarding the number of persons-to-be-authenticated 50 acquired by the number-of-persons acquisition unit 130 is configured to be output to the tracking target acquisition unit 140.

[0042] The tracking target identification unit 140 is configured to be able to identify a tracking target from among the authenticated persons 50 to be tracked by the tracking unit 160 (i.e., tracking outside the authentication area R). The tracking target identification unit 140 identifies the tracking target based on the authentication result by the authentication unit 120 and the number of authenticated persons 50 present in the authentication area R acquired by the number acquisition unit 130. For example, the tracking target identification unit 140 may identify an unauthenticated person who has not been successfully authenticated by the authentication unit 120 as the tracking target. Furthermore, the tracking target identification unit 140 may identify a tracking target when there are a large number of authenticated persons 50 present in the authentication area R (e.g., when there are so many that a monitor cannot handle them). The tracking target identification unit 140 may identify multiple authenticated persons 50 as tracking targets. The identification result by the tracking target identification unit 140 (i.e., information on the authenticated persons 50 identified as tracking targets) is configured to be output to the second image acquisition unit 150.

[0043] The second image acquisition unit 150 is configured to be able to acquire a second image including the tracking target. The second image is used for tracking processing outside the authentication area R by the tracking unit 160. The second image acquisition unit 150 may acquire the second image by capturing an image of the authentication area R with the camera 301 (see FIG. 2 ). That is, the first image and the second image may be images captured by a common camera. However, the second image acquisition unit 110 may acquire the second image by capturing an image of the authentication area R with a camera other than the camera 301. It is preferable that the first image and the second image are captured at different angles of view. It is also preferable that the first image and the second image are captured at different times. In this way, by varying the angle of view or timing of capturing images, more appearance information of the tracking target can be obtained, thereby enabling the tracking processing to be performed appropriately.

[0044] The second image acquisition unit 150 may acquire multiple second images. In this case, it is preferable that the second images are captured at different angles of view or different timings. For example, if the first image is a front image of the target's face captured from the front, the second image may include a right image of the target's face captured from the right side and a left image of the target's face captured from the left side. Furthermore, if a facial orientation suitable for tracking processing is known in advance, a camera capable of capturing images of that facial orientation may be selected to acquire the second images. The second image acquisition unit 150 may have a function to select a camera to be used or control the camera orientation and capture timing in order to acquire the desired second image. The second image acquired by the second image acquisition unit 150 is configured to be output to the tracking unit 160.

[0045] The tracking unit 160 is configured to be able to perform tracking processing outside the authentication area R using the second image acquired by the second image acquisition unit 150. The tracking unit 160 may perform tracking processing by, for example, storing the second image in a database or the like and comparing an image captured by a camera installed outside the authentication area R with the stored second image. More specifically, the tracking unit 160 may track the tracking target while comparing appearance information of a person included in an image captured by a camera installed outside the authentication area R with appearance information of a person included in the stored second image. Furthermore, the tracking unit 160 may perform tracking processing outside the authentication area R using the first image in addition to the second image. In this case, both the first image and the second image may be stored as images indicating the appearance information of the tracking target.

[0046] The tracking unit 160 may perform the tracking process using only images of a predetermined quality or higher among the multiple second images acquired by the second image acquisition unit 150. In this case, second images below the predetermined quality may be appropriately deleted. The predetermined quality may be set in advance based on, for example, the degree of contribution to the tracking process. For example, second images that can significantly improve the accuracy of the tracking process may be set to a predetermined quality or higher, while second images that do not significantly improve or even decrease the accuracy of the tracking process may be set to a quality below the predetermined quality. In this way, the accuracy of the tracking process can be improved while reducing the storage capacity used for the second images.

[0047] Furthermore, when there are second images in which the tracking target is wearing an accessory and second images in which the tracking target is not wearing an accessory, the second image acquisition unit 150 may perform the tracking process by preferentially using the second image in which the tracking target is not wearing an accessory. For example, when there are second images in which the tracking target is wearing a mask and second images in which the tracking target is not wearing the mask, the second image acquisition unit 150 may perform the tracking process by using the second image in which the tracking target is not wearing the mask.

[0048] The result of the tracking process by the tracking unit 160 may be used to stop the authenticated person 50 who has unintentionally passed through the authentication area R. For example, the tracking unit 160 may transmit the result of the tracking process to the user terminal 20 to notify the monitor 60 of information regarding the tracking target who is outside the authentication area R. Such a notification operation based on the tracking process will be described in detail in another embodiment described later.

[0049] <Operation Flow> Next, the operation flow of the first information processing device 10 (i.e., the flow of the processes executed by the components shown in Fig. 4) will be described with reference to Fig. 5. Fig. 5 is a flowchart showing the operation flow of the first information processing device.

[0050] 5, when the first information processing device 10 operates, the first image acquisition unit 110 first acquires a first image (step S11). Then, the authentication unit 120 uses the first image acquired by the first image acquisition unit 110 to perform authentication processing on the person to be authenticated 50 in the image (step S12). Furthermore, the number-of-persons acquisition unit 130 acquires the number of people to be authenticated 50 present in the authentication area R (step S13).

[0051] Next, the tracking target specifying unit 140 specifies a tracking target from among the authentication targets 50 based on the authentication result by the authentication unit 120 and the number of authentication targets 50 present in the authentication area R acquired by the number acquisition unit 130 (step S14). Note that if there is no authentication target 50 to be tracked, the subsequent processing may be omitted.

[0052] Next, the second image acquisition unit 150 acquires a second image including the tracking target identified by the tracking target identification unit 140 (step S15). After that, the tracking unit 160 performs a tracking process of the tracking target outside the authentication area R using the second image acquired by the second image acquisition unit 150 (step S16).

[0053] <Second Image Acquisition Operation> Next, the flow of the second image acquisition operation by the first information processing device 10 (i.e., the operation when the second image acquisition unit 150 acquires a second image) will be described in detail with reference to Fig. 6. Fig. 6 is a flowchart showing an example of the second image acquisition operation in the first information processing device.

[0054] 6, when the first information processing device 10 starts the second image acquisition operation, the second image acquisition unit 140 first determines whether or not the tracking target has been identified based on the information input from the tracking target identification unit 130 (step S21). If the tracking target has not been identified (step S21: NO), the subsequent processing is omitted.

[0055] On the other hand, if the tracking target has been identified (step S21: YES), the second image acquisition unit 140 controls the camera to capture an image including the identified tracking target (step S22), and acquires the image captured in step S22 as a second image (step S23).

[0056] 6, an image captured after the tracking target is identified is acquired as the second image. In this way, only images including the tracking target are captured, thereby reducing the processing load required to acquire the second image.

[0057] <Modification of Second Image Acquisition Operation> Next, a modification of the above-described second image acquisition operation will be described with reference to Fig. 7. Fig. 7 is a flowchart showing a modification of the second image acquisition operation in the first information processing apparatus.

[0058] 7, when the second image acquisition operation according to the modified example is started, first, the second image acquisition unit 140 controls a camera that captures an image of the person to be authenticated 50 who is present in the authentication area R (step S31). At this stage, the tracking target has not yet been identified, so it is preferable to capture as many images of the person to be authenticated as possible so as not to miss any images.

[0059] Next, the second image acquisition unit 140 determines whether or not the tracking target has been identified based on the information input from the tracking target identification unit 130 (step S32). If the tracking target has not been identified (step S32: NO), the subsequent processing is omitted.

[0060] On the other hand, if the tracking target has been identified (step S32: YES), the second image acquisition unit 140 selects an image including the identified tracking target from among the images already captured (step S33).Then, the second image acquisition unit 140 acquires the image selected in step S33 as the second image (step S34).Note that, among the captured images, images that have not been acquired as the second image (for example, images of the person to be authenticated 50 other than the tracking target) may be deleted.

[0061] 7, an image is captured before the tracking target is identified, and after the tracking target is identified, at least a portion of the captured image is acquired as the second image. This allows image capture to begin earlier than when image capture is performed after the tracking target is identified, increasing the likelihood of acquiring an appropriate second image. For example, the second image acquisition unit 140 can more easily acquire second images captured from various angles of view.

[0062] <Second Image Deletion Operation> Next, the flow of the second image deletion operation (i.e., the operation when deleting the second image acquired in the above-described second image acquisition operation) by the first information processing device 10 will be described with reference to Fig. 8. Fig. 8 is a flowchart showing an example of the second image deletion operation in the first information processing device.

[0063] 8, when the first information processing device 10 starts the second image deletion operation, the tracking unit 160 first determines whether the authentication process of the tracking target has been successful (step S41). That is, the tracking unit 160 identifies an unauthenticated person as the tracking target, and then determines whether the authentication process has been successful. Note that if the authentication process of the tracking target has not been successful (step S41: NO), the subsequent processes are omitted.

[0064] On the other hand, if the authentication process of the tracking target is successful (step S41: YES), the tracking unit 160 deletes the second image related to the tracking target whose authentication process has been successful (step S42).The tracking unit 160 then excludes the tracking target whose authentication process has been successful from the tracking targets (step S43).If the tracking process of the tracking target has already started, the tracking unit 160 may stop the tracking process of the tracking target whose authentication process has been successful.

[0065] In the second image deletion operation shown in Fig. 8, when the authentication process of the tracking target is successful, the second image is deleted and excluded from the tracking target. In this way, it is possible to reduce the storage capacity used for the second image and prevent unnecessary tracking processes from being executed.

[0066] (Technical Effects) Next, technical effects obtained by the first information processing device 10 will be described.

[0067] As described with reference to FIGS. 1 to 8 , when a tracking target is identified in the first information processing device 10, a second image of the tracking target is acquired, and a tracking process for the tracking target is executed outside the authentication area R. In this manner, even if the person to be authenticated 50 unintentionally passes through the authentication area R, the person to be authenticated can be tracked. Note that persons to be authenticated 50 who should not be allowed to pass (e.g., unauthenticated persons) should be stopped before passing through the authentication area R. However, for example, if many persons to be authenticated 50 pass through at the same time, the monitor 60 may not be able to respond to all of them. Even in such cases, by executing the tracking process outside the authentication area R, the person to be authenticated 50 who should not be allowed to pass can be identified later. Therefore, even if an unauthenticated person passes through the authentication area R, no substantial inconvenience occurs. Furthermore, particularly in this embodiment, since a second image is additionally acquired for the tracking target, the tracking process can be executed with greater accuracy than, for example, when the tracking process is executed using only the first image.

[0068] Second Embodiment A second information processing device 10 will be described with reference to Fig. 9. The second information processing device 1 differs in some configurations and operations from the first information processing device 10 described above, but other parts may be similar to the first information processing device 10. Therefore, the following will describe in detail the parts that differ from the first embodiment, and will omit explanations of other overlapping parts as appropriate.

[0069] (Operation Flow) First, the operation flow of the second information processing device 10 will be described with reference to Fig. 9. Fig. 9 is a flowchart showing the operation flow of the second information processing device. Note that in Fig. 9, the same processes as those shown in Fig. 5 are denoted by the same reference numerals.

[0070] 9, when the second information processing device 10 operates, the first image acquisition unit 110 first acquires a first image (step S11). Then, the authentication unit 120 uses the first image acquired by the first image acquisition unit 110 to perform authentication processing on the person to be authenticated 50 in the image (step S12). Furthermore, the number-of-persons acquisition unit 130 acquires the number of people to be authenticated 50 present in the authentication area R (step S13).

[0071] Next, the tracking target identification unit 140 determines whether the number of persons to be authenticated 50 present in the authentication area R acquired by the number acquisition unit 130 is equal to or greater than a predetermined threshold (step S51). The predetermined threshold here is a threshold for determining whether the number of persons to be authenticated 50 is large enough to determine that the monitor 60 may be unable to respond. The predetermined threshold may be set in advance based on, for example, the size of the authentication area R, the number of monitors, etc.

[0072] If the number of authenticated persons 50 present in the authentication area R is equal to or greater than a predetermined threshold (step S51: YES), the tracking target identification unit 140 identifies unauthenticated persons present in the authentication area R as tracking targets (step S52). On the other hand, if the number of authenticated persons 50 present in the authentication area R is less than the predetermined threshold (step S51: NO), the tracking target identification unit 140 determines whether the number of unauthenticated persons present in the authentication area R is greater than the number of monitors 60 (step S53).

[0073] If the number of unauthenticated individuals present in the authentication area R is smaller than the number of monitors 60 (step S53: NO), it can be determined that the monitors 60 can handle all unauthenticated individuals, and the tracking target identification unit 140 does not identify a tracking target. In this case, the subsequent processing is omitted. On the other hand, if the number of unauthenticated individuals present in the authentication area R is greater than the number of monitors 60 (step S53: YES), it can be determined that the monitors 60 cannot handle all unauthenticated individuals, and the tracking target identification unit 140 identifies the unauthenticated individuals present in the authentication area R as tracking targets (step S52).

[0074] Next, the second image acquisition unit 150 acquires a second image including the tracking target identified by the tracking target identification unit 140 (step S15). After that, the tracking unit 160 performs a tracking process of the tracking target outside the authentication area R using the second image acquired by the second image acquisition unit 150 (step S16).

[0075] (Technical Effects) Next, technical effects obtained by the second information processing device 10 will be described.

[0076] As described with reference to FIG. 9 , in the second information processing device 10, an unauthenticated person is identified as a tracking target when the number of authenticated persons present in the authentication area R is equal to or greater than a predetermined threshold. In this manner, even if a large number of authenticated persons 50 pass through the authentication area R at once, potentially overwhelming the monitors 60, it is possible to identify the unauthenticated person later through tracking processing outside the authentication area R. Furthermore, if an unauthenticated person is stopped while a large number of authenticated persons 50 are passing through, there is a possibility that the flow of people in the authentication area R will be stagnated. However, since the unauthenticated person is identified as a tracking target when the number of authenticated persons present in the authentication area R is equal to or greater than a predetermined threshold, it is possible to reduce the occurrence of stagnation. Furthermore, in the second information processing device 10, even if the number of authenticated persons present in the authentication area R is less than the predetermined threshold, the unauthenticated person is identified as a tracking target if there are more unauthenticated persons than the number of monitors. In this manner, it is possible to identify the unauthenticated person later through tracking processing outside the authentication area R, even if there are not enough monitors 60 to handle the unauthenticated persons.

[0077] <Third Embodiment> A third information processing device 10 will be described with reference to Fig. 10. The third information processing device 10 differs in some configurations and operations from the first and second information processing devices 10 described above, but other parts may be similar to the first and second information processing devices 10. Therefore, the following will describe in detail the parts that differ from the embodiments already described, and will omit explanations of other overlapping parts as appropriate.

[0078] (Operational Flow) First, the operational flow of the third information processing device 10 will be described with reference to Fig. 10. Fig. 10 is a flowchart showing the operational flow of the third information processing device. Note that in Fig. 10, the same processes as those shown in Figs. 5 and 9 are denoted by the same reference numerals.

[0079] 10, when the third information processing device 10 operates, the first image acquisition unit 110 first acquires a first image (step S11). Then, the authentication unit 120 uses the first image acquired by the first image acquisition unit 110 to perform authentication processing on the person to be authenticated 50 in the image (step S12). Furthermore, the number-of-persons acquisition unit 130 acquires the number of people to be authenticated 50 present in the authentication area R (step S13).

[0080] Next, the tracking target identification unit 140 determines whether the number of authenticated persons 50 present in the authentication area R acquired by the number acquisition unit 130 is equal to or greater than a predetermined threshold (step S51). If the number of authenticated persons 50 present in the authentication area R is equal to or greater than the predetermined threshold (step S51: YES), the tracking target identification unit 140 identifies unauthenticated persons present in the authentication area R as tracking targets (step S52). On the other hand, if the number of authenticated persons 50 present in the authentication area R is less than the predetermined threshold (step S51: NO), the tracking target identification unit 140 determines whether the number of unauthenticated persons present in the authentication area R is greater than the number of monitors 60 (step S53).

[0081] If the number of unauthenticated individuals in the authentication area R is smaller than the number of monitors 60 (step S53: NO), it can be determined that the monitors 60 can handle all unauthenticated individuals, and the tracking target identification unit 140 does not identify a tracking target. In this case, the subsequent processing is omitted. On the other hand, if the number of unauthenticated individuals in the authentication area R is greater than the number of monitors 60 (step S53: YES), the authentication unit 120 changes the authentication threshold so that authentication is more likely to be successful (step S61). For example, the authentication unit 120 lowers the authentication threshold from the initial value by a predetermined value.

[0082] After the authentication threshold is changed, the process starts again from step S12. That is, the authentication process is executed again with the authentication process changed. By changing the authentication process, the authentication process is more likely to succeed than the first time. Therefore, the number of unauthenticated people decreases in the second and subsequent authentication processes. As a result, the number of unauthenticated people eventually becomes smaller than the number of monitors 60 (step S53: NO). The changed authentication threshold may be restored after a predetermined period has passed, or when it is determined that the number of unauthenticated people has been sufficiently reduced.

[0083] On the other hand, if the tracking target is identified in step S52, the second image acquisition unit 150 acquires a second image including the tracking target identified by the tracking target identification unit 140 (step S15). Thereafter, the tracking unit 160 performs a tracking process of the tracking target outside the authentication area R using the second image acquired by the second image acquisition unit 150 (step S16).

[0084] (Technical Effects) Next, technical effects obtained by the third information processing apparatus 10 will be described.

[0085] 10 , in the third information processing device 10, when the number of unauthenticated individuals in the authentication area R is greater than the number of monitors 60, the authentication threshold is changed so that the authentication process is more likely to succeed. In this way, the number of unauthenticated individuals decreases, and it is possible to reduce the number of unauthenticated individuals that the monitors 60 cannot handle. Furthermore, if the authentication threshold is changed so that the number of unauthenticated individuals in the authentication area R is less than the number of monitors 60, the monitors 60 can more reliably handle the unauthenticated individuals.

[0086] Note that lowering the authentication threshold may result in authentication-subjects 50 who are normally prohibited from passing through the authentication area R passing through. For this reason, when the authentication threshold is lowered, different information from normal may be notified to the monitor 60. For example, the monitor 60 may be notified that the authentication threshold has been temporarily lowered. Furthermore, when the authentication threshold is lowered, some of the authentication-subjects 50 who are successfully authenticated may also be identified as tracking targets. For example, an authentication-subject 50 who is successfully authenticated when his / her authentication score is slightly higher than the changed authentication threshold may be identified as a tracking target. In other words, an authentication-subject 50 whose authentication score is between the changed authentication threshold and the authentication threshold before the change and who is successfully authenticated due to the change of the authentication threshold may be identified as a tracking target.

[0087] <Fourth embodiment> A fourth information processing device 10 will be described with reference to Figures 11 and 12. The fourth information processing device 10 differs in some configurations and operations from the first to third information processing devices 10 described above, but other parts may be similar to the first to third information processing devices 10. Therefore, hereinafter, parts that differ from the embodiments already described will be described in detail, and descriptions of other overlapping parts will be omitted as appropriate.

[0088] (Functional Configuration) First, the functional configuration of the fourth information processing device 10 will be described with reference to Fig. 11. Fig. 11 is a block diagram showing the functional configuration of the fourth information processing device. Note that in Fig. 11, the same elements as those shown in Fig. 4 are denoted by the same reference numerals.

[0089] 11 , the fourth information processing device 10 is configured to include, as components for realizing its functions, a first image acquisition unit 110, an authentication unit 120, a number of people acquisition unit 130, a tracking target identification unit 140, a second image acquisition unit 150, a tracking unit 160, a notification unit 170, and a notification control unit 180. That is, the fourth information processing device 10 further includes, in addition to the configuration described in the first embodiment (see FIG. 4 ), a notification unit 170 and a notification control unit 180. Note that each of the notification unit 170 and the notification control unit 180 may be a processing block realized by the above-mentioned processor 11 (see FIG. 1 ).

[0090] The notification unit 170 is configured to be able to notify the monitor 60 based on the result of the tracking process performed by the tracking unit 160 outside the authentication area R. The notification unit 170 may notify the monitor 60 by transmitting notification information (i.e., information about the current tracking target) generated based on the result of the tracking process to the user terminal 20. For example, the notification unit 170 may display a message on the user terminal 20 saying, "This is a user who has passed through without being authenticated. Please call out to stop him." Furthermore, the notification unit 170 may output location information of the tracking target to the user terminal 20 based on the result of the tracking process.

[0091] The notification control unit 180 is configured to be able to control notifications by the notification unit 170. Specifically, the notification control unit 180 controls the notification unit 170 to notify information about the tracking target when the population density of the area in which the tracking target that has passed through the authentication area R is located falls below a predetermined density. The predetermined density is a threshold value for determining that the population density is low enough to determine that it is now easy for the monitor 60 to call out to the tracking target.

[0092] Furthermore, the notification control unit 180 may control the notification unit 170 to notify information about the tracking target when the distance between the tracking target and the monitor 60 who is the notification target becomes equal to or less than a predetermined distance. The predetermined distance is a threshold value for determining whether the distance has become close enough for the monitor 60 to determine that it is now easier to call out to the tracking target.

[0093] (Notification Operation) Next, the flow of the notification operation by the fourth information processing device 10 (i.e., the operation when the notification unit 170 notifies the monitor 60) will be described with reference to Fig. 12. Fig. 12 is a flowchart showing the flow of the notification operation in the fifth information processing device.

[0094] 12 , when the notification operation by the fourth information processing device 10 is started, first, the notification control unit 170 acquires information about the tracking process outside the authentication area R from the tracking unit 160 (step S71). Note that the notification control unit 170 may be configured to acquire information about the tracking process periodically (for example, every few seconds).

[0095] Next, the notification control unit 170 determines whether the population density of the area where the tracking target that has passed through the authentication area R is located is equal to or lower than a predetermined density (step S72), based on the information related to the tracking process acquired from the tracking unit 160. If the population density is not equal to or lower than the predetermined density (step S72: NO), the process may be restarted from step S71 after a predetermined time has elapsed.

[0096] If the population density is equal to or less than the predetermined density (step S72: YES), the notification control unit 170 determines whether the distance between the tracking target that has passed through the authentication area R and the monitor 60 who is the notification target is equal to or less than a predetermined distance, based on the information related to the tracking process acquired from the tracking unit 160 (step S73). Note that if the distance between the tracking target and the monitor 60 is not equal to or less than the predetermined distance (step S73: NO), the process may be restarted from step S71 after a predetermined time has elapsed.

[0097] If the distance between the tracking target and the monitor 60 is equal to or less than the predetermined distance (step S73: YES), the notification control unit 170 controls the notification unit 170 to notify the monitor 60 about the tracking target (step S74).

[0098] (Technical Effects) Next, technical effects obtained by the fourth information processing apparatus 10 will be described.

[0099] As described with reference to FIGS. 11 and 12 , the fourth information processing device 10 notifies the monitor 60 when the population density of the area in which the tracking target that has passed through the authentication area R is located is equal to or lower than a predetermined density. In this way, it is possible to notify the monitor 60 at a timing when it is easy to call out to the tracking target. In other words, it is possible to notify the monitor 60 at a timing when calling out to the tracking target is unlikely to cause a stagnation of people. Furthermore, the fourth information processing device 10 notifies the monitor 60 when the distance between the tracking target that has passed through the authentication area R and the monitor 60 who is the notification target is equal to or lower than a predetermined distance. In this way, it is possible to notify the monitor 60 at a timing when it is easy to call out to the tracking target. In other words, it is possible to notify the monitor 60 at a timing when calling out to the tracking target is unlikely to cause a stagnation of people.

[0100] The scope of each embodiment also includes a processing method in which a program that operates the configuration of each embodiment to realize the functions of the above-described embodiments is recorded on a recording medium, the program recorded on the recording medium is read as code, and the program is executed on a computer. In other words, a computer-readable recording medium is also included in the scope of each embodiment. Furthermore, each embodiment includes not only a recording medium on which the above-described program is recorded, but also the program itself.

[0101] Examples of recording media that can be used include floppy disks, hard disks, optical disks, magneto-optical disks, CD-ROMs, magnetic tapes, non-volatile memory cards, and ROMs. Furthermore, the scope of each embodiment is not limited to programs that execute processes by themselves, but also includes programs that execute processes by operating on an OS in conjunction with other software or expansion board functions. Furthermore, the program itself may be stored on a server, and part or all of the program may be downloadable from the server to a user terminal. The program may be provided to the user in, for example, a SaaS (Software as a Service) format.

[0102] <Supplementary Notes> The above-described embodiment may be further described as in the following supplementary notes, but is not limited to the following.

[0103] (Supplementary Note 1) The information processing device described in Supplementary Note 1 is an information processing device that includes a first image acquisition means that acquires a first image including a person to be authenticated in a specified area, an authentication means that performs an authentication process for the person to be authenticated in the first image, a number acquisition means that acquires the number of people to be authenticated in the specified area, an identification means that identifies a tracking target from among the people to be authenticated based on the result of the authentication process and the number of people to be authenticated, a second image acquisition means that acquires a second image including the tracking target, and a tracking means that performs tracking process for the tracking target using the second image.

[0104] (Supplementary Note 2) The information processing device described in Supplementary Note 2 is the information processing device described in Supplementary Note 1, wherein the second image acquisition means acquires the second image by capturing an image of the tracking target after the tracking target is identified.

[0105] (Supplementary Note 3) The information processing device described in Supplementary Note 3 is the information processing device described in Supplementary Note 1 or 2, wherein the second image acquisition means acquires, as the second image, an image including the tracking target from among images captured before the tracking target is identified.

[0106] (Appendix 4) The information processing device described in Appendix 4 is the information processing device described in any one of Appendices 1 to 3, wherein the second image acquisition means deletes the second image including the tracking target for which the authentication process has been successful, if the authentication process of the tracking target has been successful after acquiring the second image.

[0107] (Supplementary Note 5) The information processing device according to Supplementary Note 5 is the information processing device according to any one of Supplementary Notes 1 to 4, in which the second image is an image captured at a different angle of view or at a different timing from the first image.

[0108] (Appendix 6) The information processing device described in Appendix 6 is the information processing device described in any one of Appendices 1 to 5, wherein the identification means identifies the authenticated person for whom the authentication process has not been successful as the tracking target when the number of the authenticated people is equal to or greater than a predetermined threshold.

[0109] (Appendix 7) The information processing device described in Appendix 7 is the information processing device described in Appendix 6, in which the identification means identifies the authenticated persons for whom the authentication process has not been successful as the tracking target when the number of the authenticated persons for whom the authentication process has not been successful is greater than the number of monitors monitoring the authenticated persons, even if the number of the authenticated persons is less than a predetermined threshold.

[0110] (Appendix 8) The information processing device described in Appendix 8 is the information processing device described in any one of Appendices 1 to 7, wherein the authentication means performs the authentication process by determining whether the authentication score calculated from the first image exceeds an authentication threshold, and the authentication threshold is lowered when the number of people to be authenticated for whom the authentication process has not been successful is greater than the number of monitors monitoring the people to be authenticated.

[0111] (Appendix 9) The information processing device described in Appendix 9 is the information processing device described in Appendix 8, wherein the authentication means changes the authentication threshold so that the number of people to be authenticated who have not successfully completed the authentication process is less than or equal to the number of monitors.

[0112] (Appendix 10) The information processing device described in Appendix 10 is the information processing device described in any one of Appendices 1 to 9, wherein the second image acquisition means acquires a plurality of the second images, and the tracking means performs the tracking process of the tracked object using the second images of a predetermined quality or higher among the plurality of the second images.

[0113] (Appendix 11) The information processing device described in Appendix 11 is the information processing device described in any one of Appendices 1 to 10, further comprising a notification means for notifying an observer monitoring the authenticated person of information related to the tracking target, and a notification control means for controlling the notification means to notify information related to the tracking target when the population density of the area in which the tracking target is located after passing through the specified area falls below a specified density.

[0114] (Appendix 12) The information processing device described in Appendix 12 is the information processing device described in Appendix 11, wherein the notification control means controls the notification means to notify information about the tracking target when the distance between the tracking target and the monitor becomes less than a predetermined distance.

[0115] (Supplementary Note 13) The information processing method described in Supplementary Note 13 is an information processing method that, by at least one computer, acquires an image including a person to be authenticated in a specified area, performs an authentication process for the person to be authenticated in the image, recognizes attributes of the person to be authenticated in the image, determines whether or not the attributes of the person to be authenticated determined to be a notification target based on the result of the authentication process overlap with attributes of other people to be authenticated who are present in the specified area, determines notification information including the attributes of the notification target based on the determination result, and notifies the notification information by voice.

[0116] (Appendix 14) The recording medium described in Appendix 14 is a recording medium having recorded thereon a computer program for causing at least one computer to execute an information processing method, which includes acquiring an image including a person to be authenticated in a specified area, performing an authentication process for the person to be authenticated in the image, recognizing attributes of the person to be authenticated in the image, determining whether or not the attributes of the person to be authenticated who is determined to be a notification target based on the result of the authentication process overlap with attributes of other people to be authenticated who are present in the specified area, determining notification information including the attributes of the person to be notified based on the determination result, and notifying the notification information by voice.

[0117] (Appendix 15) The computer program described in Appendix 15 is a computer program that causes at least one computer to execute an information processing method, which includes acquiring an image including a person to be authenticated in a specified area, performing an authentication process for the person to be authenticated in the image, recognizing attributes of the person to be authenticated in the image, determining whether or not the attributes of the person to be authenticated who has been determined to be a notification target based on the result of the authentication process overlap with attributes of other people to be authenticated who are present in the specified area, determining notification information including the attributes of the notification target based on the determination result, and notifying the notification information by voice.

[0118] This disclosure may be modified as appropriate within the scope that does not contradict the gist or idea of ​​the invention that can be read from the claims and the entire specification, and information processing devices, information processing methods, and recording media that involve such modifications are also included in the technical idea of ​​this disclosure.

[0119] REFERENCE SIGNS LIST 10 Information processing device 11 Processor 12 RAM 13 ROM 14 Storage device 15 Input device 16 Output device 17 Data bus 20 User terminal 201 Display unit 30 Authentication device 301 Camera 40 Outside area device 401 Outside area camera 50 Person to be authenticated 60 Surveillance officer 110 First image acquisition unit 120 Authentication unit 130 Number of people acquisition unit 140 Tracking target identification unit 150 Second image acquisition unit 160 Tracking unit 170 Notification unit 180 Notification control unit R Authentication area

Claims

1. An information processing device comprising: a first image acquisition means for acquiring a first image including a person to be authenticated in a specified area; an authentication means for performing an authentication process for the person to be authenticated in the first image; a number acquisition means for acquiring the number of people to be authenticated in the specified area; an identification means for identifying a tracking target from among the people to be authenticated based on the result of the authentication process and the number of people to be authenticated; a second image acquisition means for acquiring a second image including the tracking target; and a tracking means for performing a tracking process for the tracking target using the second image.

2. The information processing device according to claim 1, wherein the second image acquisition means acquires the second image by capturing an image of the tracking target after the tracking target has been identified.

3. The information processing device according to claim 1, wherein the second image acquisition means acquires, as the second image, an image including the tracking target from among images captured before the tracking target is identified.

4. An information processing device as described in any one of claims 1 to 3, wherein the second image acquisition means deletes the second image including the tracking target for which the authentication process was successful if the authentication process for the tracking target is successful after acquiring the second image.

5. The information processing device according to any one of claims 1 to 3, wherein the second image is an image captured at a different angle of view or at a different timing than the first image.

6. The information processing device according to any one of claims 1 to 3, wherein the identification means identifies, as the tracking target, a person to be authenticated who has not been successful in the authentication process, when the number of people to be authenticated is equal to or greater than a predetermined threshold.

7. The information processing device according to claim 6, wherein the identification means identifies the person who has not been successfully authenticated as the tracking target when the number of the person to be authenticated is less than a predetermined threshold but the number of the person to be authenticated who has not been successfully authenticated is greater than the number of monitors monitoring the person to be authenticated.

8. An information processing device according to any one of claims 1 to 3, wherein the authentication means performs the authentication process by determining whether the authentication score calculated from the first image exceeds an authentication threshold, and lowers the authentication threshold when the number of persons to be authenticated for whom the authentication process has not been successful is greater than the number of monitors monitoring the persons to be authenticated.

9. The information processing device according to claim 8, wherein the authentication means changes the authentication threshold so that the number of people to be authenticated who have not been successfully authenticated is equal to or less than the number of observers.

10. An information processing device described in any one of claims 1 to 3, wherein the second image acquisition means acquires a plurality of the second images, and the tracking means performs the tracking process of the tracking target using those of the plurality of second images that are of a predetermined quality or higher.

11. An information processing device as described in any one of claims 1 to 3, further comprising: a notification means for notifying an observer monitoring the authenticated person of information regarding the tracking target; and a notification control means for controlling the notification means to notify information regarding the tracking target when the population density of the area in which the tracking target is located after passing through the specified area falls below a specified density.

12. The information processing device according to claim 11, wherein the notification control means controls the notification means so as to notify information about the tracking target when the distance between the tracking target and the monitor becomes equal to or less than a predetermined distance.

13. An information processing method comprising: acquiring, by at least one computer, a first image including persons to be authenticated in a specified area; performing an authentication process for the persons to be authenticated in the first image; acquiring the number of persons to be authenticated in the specified area; identifying a tracking target from among the persons to be authenticated based on the result of the authentication process and the number of persons to be authenticated; acquiring a second image including the tracking target; and performing tracking process for the tracking target using the second image.

14. A recording medium having recorded thereon a computer program for causing at least one computer to execute an information processing method, which comprises acquiring a first image including persons to be authenticated in a specified area, performing an authentication process for the persons to be authenticated in the first image, acquiring the number of persons to be authenticated in the specified area, identifying a tracking target from among the persons to be authenticated based on the result of the authentication process and the number of persons to be authenticated, acquiring a second image including the tracking target, and performing a tracking process for the tracking target using the second image.

Images