Patent Publication Number: US-2023142023-A1

Title: Imaging apparatus, information processing method, and program

Description:
TECHNICAL FIELD 
     The present disclosure relates to an imaging apparatus, an information processing method, and a program and, in particular, to an imaging apparatus, an information processing method, and a program that make it possible to control imaging by strangers. 
     BACKGROUND ART 
     Hitherto, there has been proposed a method for digital cameras or the like, including converting a captured image or the like to a hash value and giving an electronic signature with the hash value to the captured image, to thereby detect alterations (for example, see PTL 1). 
     Further, in recent years, a service that rents imaging apparatuses to users has been considered. In such a service, a user who is a stranger to an imaging apparatus provider operates an imaging apparatus provided by the provider to perform imaging, thereby generating captured images. 
     CITATION LIST 
     Patent Literature 
     [PTL 1] 
     Japanese Patent Laid-open No. 2008-22372 
     SUMMARY 
     Technical Problem 
     The present disclosure makes it possible to control imaging by users who are strangers in such a service, for example. 
     Solution to Problem 
     According to one aspect of the present technology, there is provided an imaging apparatus including an association unit configured to associate a captured image with a hash value of signature metadata including imaging apparatus identification information that is identification information regarding the imaging apparatus itself and user identification information. 
     According to one aspect of the present technology, there is provided an information processing method including associating a captured image with a hash value of signature metadata including imaging apparatus identification information that is identification information regarding an imaging apparatus and user identification information. 
     According to one aspect of the present technology, there is provided a program for causing a computer to function as an association unit configured to associate a captured image with a hash value of signature metadata including imaging apparatus identification information that is identification information regarding an imaging apparatus and user identification information. 
     According to another aspect of the present technology, there is provided an imaging apparatus including an imaging control unit configured to control imaging on the basis of license information that is information regarding a license and includes imaging apparatus identification information that is identification information regarding the imaging apparatus itself, user identification information, and an imaging parameter that is a parameter for imaging. 
     According to another aspect of the present technology, there is provided an information processing method including controlling imaging on the basis of license information that is information regarding a license and includes imaging apparatus identification information that is identification information regarding an imaging apparatus, user identification information, and an imaging parameter that is a parameter for imaging. 
     According to another aspect of the present technology, there is provided a program for causing a computer to function as an imaging control unit configured to control imaging on the basis of license information that is information regarding a license and includes imaging apparatus identification information that is identification information regarding an imaging apparatus itself, user identification information, and an imaging parameter that is a parameter for imaging. 
     In an imaging apparatus, an information processing method, and a program according to one aspect of the present technology, a captured image is associated with a hash value of signature metadata including imaging apparatus identification information that is identification information regarding the imaging apparatus and user identification information. 
     In an imaging apparatus, an information processing method, and a program according to another aspect of the present technology, imaging is controlled on the basis of license information that is information regarding a license and includes imaging apparatus identification information that is identification information regarding the imaging apparatus, user identification information, and an imaging parameter that is a parameter for imaging. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG.  1    is a diagram illustrating an outline of imaging control. 
         FIG.  2    is a diagram illustrating a main configuration example of a rental system. 
         FIG.  3    is a block diagram illustrating a main configuration example of a company terminal apparatus and the like. 
         FIG.  4    is a functional block diagram illustrating functions that are implemented in the company terminal apparatus and the like. 
         FIG.  5    is a diagram illustrating an exemplary license key. 
         FIG.  6    is a block diagram illustrating a main configuration example of a camera. 
         FIG.  7    is a functional block diagram illustrating functions that are implemented in the camera. 
         FIG.  8    is a flowchart illustrating an exemplary flow of activation processing. 
         FIG.  9    is a flowchart following  FIG.  8   , illustrating the exemplary flow of activation processing. 
         FIG.  10    is a flowchart illustrating an exemplary flow of activation processing. 
         FIG.  11    is a flowchart following  FIG.  10   , illustrating the exemplary flow of activation processing. 
         FIG.  12    is a flowchart illustrating an exemplary flow of activation processing. 
         FIG.  13    is a flowchart following  FIG.  13   , illustrating the exemplary flow of activation processing. 
         FIG.  14    is a flowchart illustrating an exemplary flow of activation processing. 
         FIG.  15    is a flowchart following  FIG.  10   , illustrating the exemplary flow of activation processing. 
         FIG.  16    is a flowchart illustrating an exemplary flow of activation processing. 
         FIG.  17    is a flowchart following  FIG.  10   , illustrating the exemplary flow of activation processing. 
         FIG.  18    is a flowchart illustrating an exemplary flow of imaging control processing. 
         FIG.  19    is a diagram illustrating an exemplary flow of electronic signature generation processing. 
         FIG.  20    is a diagram illustrating an exemplary flow of electronic signature verification processing. 
     
    
    
     DESCRIPTION OF EMBODIMENT 
     Now, a mode for carrying out the present disclosure (hereinafter referred to as an “embodiment”) is described. Note that the description is made in the following order. 
     1. Imaging Control 
     2. First Embodiment (Rental System) 
     3. Supplementary Note 
     1. Imaging Control 
     &lt;Imaging Apparatus Rental Service&gt; 
     For example, PTL 1 describes the method for digital cameras or the like, including converting a captured image or the like to a hash value and giving an electronic signature with the hash value to the captured image, to thereby detect alterations. The electronic signature can also include imaging apparatus information, for example. 
     Incidentally, in recent years, a service that rents imaging apparatuses to users has been considered. For example, there is a case where a business organization lends or rents cameras belonging to it to its employees or outsourcing destinations (outsourcing photographers or service users). 
     In such a service, it is desired that a business organization (company) that is an imaging apparatus provider can control information regarding electronic signatures to be given to captured images generated by a user, who is a stranger to the business organization (company), performing imaging by operating an imaging apparatus. 
     Further, it is desired that the business organization (company) can control terms of use of an imaging apparatus as follows, for example: the imaging apparatus can be used only by authorized users or the imaging apparatus can be used only in authorized places or dates and times. Moreover, it is desired that the business organization (company) can control imaging setting. 
     &lt;Control of Imaging by Stranger&gt; 
     Accordingly, it is intended to make it possible to control imaging by strangers. For example, imaging is controlled on the basis of license information that is information regarding a license and that includes imaging apparatus identification information that is identification information regarding an imaging apparatus, user identification information, and imaging parameters that are parameters for imaging. With this, imaging can be controlled by license information. License information is given to an imaging apparatus under the approval of an imaging apparatus provider. That is, an imaging apparatus provider can control imaging. 
     For example, as illustrated in  FIG.  1   , a company  10  rents a camera  21  to a user  31 , rents a camera  22  to a user  32 , and rents a camera  23  to a user  33 . Further, the camera  21  has set therein license information approved by the provider of the camera  21 . The license information at least includes identification information (ID) regarding the camera  21  itself and identification information (ID) regarding the user  31  who is a rental destination (legitimate user). Imaging can be controlled on the basis of those pieces of information to prevent anyone other than the legitimate user  31 , who is indicated by the license information, from using the camera  21 . For example, it is possible to prohibit an illegitimate user  34  from using the camera  21  (prevent the user  34  from using the camera  21 ). That is, a camera provider can control who uses a camera. 
     Imaging parameters included in license information may include information regarding the terms of use of an imaging apparatus, for example. With this, it is possible to allow a legitimate user to use an imaging apparatus (that is, perform imaging) only in a case where the terms of use are met. 
     The terms of use may be freely determined and relate to locations, times, or both of them, for example. For example, the use of an imaging apparatus is allowed only in a predetermined place, only at a predetermined date and time, or only at a predetermined date and time in a predetermined place. With this, a camera provider can limit dates and times or places in which the use of a camera is allowed. 
     Note that, here, dates and times are used as exemplary time conditions for allowing the use of a camera in the description, but any time information (that is, any information indicating a time range (period) in which the use of a camera is allowed) may be employed. For example, periods of time in which the use of a camera is allowed may be limited (that is, start time and end time may be indicated). Needless to say, only the start time may be indicated or only the end time may be indicated. Further, a time range in which the use of a camera is allowed may be indicated in any unit, such as years, half terms, quarter terms, months, weeks, days, odd months, even months, the beginning of months, the end of months, days of week, weekends, weekdays, national holidays, before noon, afternoon, morning, noon, night, hours, minutes, or seconds. For example, the use of a camera may be allowed only in designated months, only on designated days of week, or only on designated days (for example, days that end with the numeral 2) in every month. 
     Further, this similarly applies to locations (places), and any location information (that is, any information indicating the range of a region in which the use of a camera is allowed) may be employed. For example, a range may be indicated by GPS coordinates or the like, by administrative districts such as countries, prefectures, municipalities, or addresses, by postal codes, or by fixed-line area codes. Further, for example, a range may be indicated by the names of facilities or venues such as park names or play facility names. Moreover, for example, floors (basement floors, above-ground floors, N-th floor, or the like) may be designated. 
     Further, the terms of use may relate to subjects. For example, the use of a camera is allowed only in a case where a predetermined subject is imaged. With this, for example, subjects may be limited. That is, the purpose of imaging can be limited. Further, for example, it can be required that the merchandise of sponsors or the like always be arranged in the angle of field. With this, captured images can possess a value as an advertisement. Further, for example, it can be required that a predetermined building, a predetermined view, or the like be included in the background. With this, imaging places, times, or the like can be limited. 
     Further, imaging parameters included in license information may include imaging setting information that is information regarding imaging setting, for example. With this, for example, a camera provider can control the setting of a camera. 
     For example, information regarding imaging setting may include information regarding the resolution of captured images. That is, a resolution that is allowed with a license may be limited. In this case, a camera generates captured images at a resolution (or less) designated by license information. With this, a camera provider can control the resolution of captured images that are generated by a camera on the basis of license fees, user authority, or intended use, for example. 
     Further, for example, information regarding imaging setting may include information regarding the addition of credits to captured images. For example, information indicating whether or not to add credits to captured images generated by a camera and information designating the details of the credits to be added may be included as credit addition information. With this, a camera provider can control credits to be added to captured images generated by a camera. 
     Note that license information can include any information. For example, identification information (for example, company name) regarding a camera provider (company) may be included. Needless to say, information other than this may be included. 
     For example, license information may further include information indicating a license validity period. That is, imaging may be controlled by license information with a validity period. With this, for example, a period in which activation is allowed can be limited, or imaging setting available within or outside the period can be changed. 
     Further, for example, a hash value of signature metadata including imaging apparatus identification information that is identification information regarding an imaging apparatus and user identification information is associated with captured images. With this, an imaging apparatus provider can control signature metadata to be given to captured images generated by a user, who is a stranger, using an imaging apparatus. That is, an imaging apparatus provider can guarantee that an imaging apparatus that has generated captured images and the user thereof are authentic. 
     For example, in the case of  FIG.  1   , metadata  42  to be given to a captured image  41  generated by the user  31  performing imaging by using the camera  21  can include signature metadata such as the ID (Cam ID) of the camera  21  and the ID (A) of the user  31 . 
     Further, for example, signature metadata may further include the company name of a company that provides imaging apparatuses to users. With this, the authenticity of an imaging apparatus provider (for example, owner of captured images) can be guaranteed. 
     Further, a hash value derived from signature metadata included in license information that is information regarding a license may be associated with captured images. That is, signature metadata included in license information may be associated with captured images. With this, an imaging apparatus provider can guarantee that an imaging apparatus that has generated captured images and the user thereof are authentic. 
     For example, the hash value of signature metadata and captured images may be associated with each other according to the details of a license. For example, this association may be performed only with a license with which captured images are protected. Further, this association may be performed only with respect to captured images taken under predetermined conditions designated by a license. Moreover, this association may be performed only with respect to captured images obtained by imaging a predetermined subject designated by a license. Various types of control are possible in this way. 
     Further, for example, the hash value of signature metadata and captured images may be associated with each other according to a validity period included in license information. For example, signature metadata (hash value thereof) may be associated with captured images generated within a validity period, or signature metadata (hash value thereof) may be associated with captured images generated outside the validity period. Various types of validity period-based control are possible in this way. 
     For example, an electronic signature including the hash value of signature metadata may be generated and the generated electronic signature may be associated with a captured image. That is, signature metadata may be included in the electronic signature of a captured image. With this, with use of electronic signature specifications, it can be guaranteed that an imaging apparatus that has generated captured images and the user thereof are authentic. For example, a captured image may be converted to a hash value, the hash value of the captured image and signature metadata may be converted to a hash value, and the hash value may be encrypted, to thereby generate an electronic signature. Then, the signature metadata may further be associated with the captured image associated with the electronic signature. 
     2. First Embodiment 
     &lt;Rental System&gt; 
       FIG.  2    is a diagram illustrating a main configuration example of a rental system that is an embodiment of an information processing system to which the present technology is applied. A rental system  100  illustrated in  FIG.  2    is a system configured to manage the rental of a camera  140  from the company  10  to a user  30 . 
     The company  10  is the provider of the camera  140  in the rental system  100 . The company  10  may or may not be the owner of the camera  140 . For example, the company  10  may provide the camera  140  owned by another company. 
     The user  30  is a user who uses the camera  140  rented from the company  10 . That is, the user  30  images a subject by using the camera  140  to generate captured images. 
     For example, the user  30  may be an employee of the company  10 . In this case, the user  30  who is an employee performs imaging by using the shared camera  140  owned by the company  10  to generate captured images. For example, there is a case where a journalist who works at a newspaper company collects news (performs imaging) by using a camera owned by the newspaper company. The rental system  100  may manage which camera  140  is to be rented to which employee in such a company. Further, in this case, it is possible that the company  10  has the rights of captured images generated by the camera  140 . The rental system  100  can also manage such captured images. 
     Further, for example, the user  30  may be a person to which the company  10  outsources tasks. For example, there is a case where the user  30  is a freelance photographer who has accepted an imaging job offer from a newspaper company. The rental system  100  may manage such a rental agreement between the company  10  and a party outside the company  10 . Further, in this case, it is possible that captured images generated by the camera  140  are delivered to the company  10 . The rental system  100  can also manage such captured images. 
     Moreover, for example, the user  30  may be a user of a service for renting the camera  140  provided by the company  10 . For example, there is a case where the company  10  provides a service for renting the camera  140  and the user  30  rents the camera  140  by using the service and performs imaging by using the rented camera  140 . The rental service may be a paid or free service. For example, the camera  140  may be rented at no charge and captured images generated by using the camera  140  may be provided with charge. The rental system  100  may manage which camera  140  is to be rented to which user in such a service. Further, in this case, it is possible that captured images generated by the camera  140  may be printed or distributed to be provided to the user  30 . In such a case, the company  10  preferably has the rights of the captured images. The rental system  100  can also manage such captured images. 
     As illustrated in  FIG.  2   , the rental system  100  includes a server  110 , a company terminal apparatus  120 , a user terminal apparatus  130 , and the camera  140 . The apparatuses are connected to each other via a network  150  for communication. However, the camera  140  may not be connected to the network  150  (may be offline). Further, the camera  140  may be connected, for communication, to the network  150  through another apparatus such as the company terminal apparatus  120  or the user terminal apparatus  130 . 
     The server  110  performs processing for the management of a license agreement between the company  10  and the user  30  in terms of the rental of the camera  140 . For example, the server  110  performs processing for license information generation, the activation of the user  30 , and the like. 
     The company terminal apparatus  120  is a terminal apparatus owned by the company  10  and performs processing for the setting of the license of the camera  140  to be rented. The user terminal apparatus  130  is a terminal apparatus owned by the user  30  and performs processing for the registration of information regarding the user  30 . 
     The camera  140  is an imaging apparatus to be rented and performs processing such as the activation of the user  30 , imaging control, and captured image generation. 
     Note that, in  FIG.  2   , the server  110 , the company  10  (company terminal apparatus  120 ), the user  30  (user terminal apparatus  130 ), and the camera  140  are each illustrated as a single component, but in the rental system  100 , the number of each component is freely determined and may be one or more. Further, the network  150  may include multiple networks. 
     &lt;Server&gt; 
       FIG.  3    is a diagram illustrating a main configuration example of the server  110  that is an embodiment of an information processing apparatus to which the present technology is applied. The server  110  illustrated in  FIG.  3    is a computer configured to install an application program (software) for performing processing for the management of the rental of the camera  140  and execute the application program. Here, examples of the computer include computers incorporated in dedicated hardware or general-purpose personal computers capable of executing various functions with various programs installed thereon. The server  110  executes the application program to perform the processing for the rental of the camera  140 . 
     In the server  110  illustrated in  FIG.  3   , a CPU (Central Processing Unit)  201 , a ROM (Read Only Memory)  202 , and a RAM (Random Access Memory)  203  are connected to each other through a bus  204 . 
     The bus  204  is also connected to an input-output interface  210 . The input-output interface  210  is connected to an input unit  211 , an output unit  212 , a storage unit  213 , a communication unit  214 , and a drive  215 . 
     The input unit  211  includes, for example, a keyboard, a mouse, a microphone, a touch panel, an input terminal, or the like. The output unit  212  includes, for example, a display, a speaker, an output terminal, or the like. The storage unit  213  includes, for example, a hard disk, a RAM disk, a non-volatile memory, or the like. The communication unit  214  includes a network interface, for example. The drive  215  drives a removable recording medium  221  such as a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory. 
     In the server  110  configured as described above, the series of processing processes described above is performed by the CPU  201  loading the application program stored in the storage unit  213  on the RAM  203  through the input-output interface  210  and the bus  204  to execute the application program, for example. In the RAM  203 , for example, data necessary for the CPU  201  to execute various types of processing is also stored as appropriate. 
     The application program that the server  110  executes can be recorded on the removable recording medium  221 , which is a package medium or the like, to be applied, for example. In this case, the application program can be installed on the storage unit  213  through the input-output interface  210  with the removable recording medium  221  mounted on the drive  215 . 
     Further, the application program can also be provided through a wired or wireless transmission medium such as a local area network, the Internet, or digital satellite broadcasting. In this case, the application program can be received by the communication unit  214  to be installed on the storage unit  213 . 
     Besides, the application program can also be installed on the ROM  202  or the storage unit  213  in advance. 
     Note that the configuration of the server  110  is freely determined and not limited to the example of  FIG.  3   . For example, the server  110  may be implemented as cloud computing in which multiple apparatuses share processing in cooperation with each other via a network. That is, the server  110  (cloud server) may perform the processing for the management of the rental of the camera  140  or provide a service, as a cloud service. 
     Further, the company terminal apparatus  120  and the user terminal apparatus  130  also have configurations similar to that of the server  110  illustrated in  FIG.  3   . That is, the block diagram of  FIG.  3    can be used to describe the company terminal apparatus  120  and the user terminal apparatus  130 . 
     Functions that are implemented by the company terminal apparatus  120  executing the application program are illustrated as functional blocks in A of  FIG.  4   . As illustrated in A of  FIG.  4   , the company terminal apparatus  120  executes the application program, thereby being capable of achieving the functional blocks such as an apparatus-specific information registration request unit  301 , a linking request processing unit  302 , a validity period setting request unit  303 , an imaging parameter request unit  304 , and a license key recording unit  305 . 
     The apparatus-specific information registration request unit  301  performs processing for the request of the registration of apparatus-specific information that is information unique to the camera  140 . For example, the apparatus-specific information registration request unit  301  performs processing for the request of the registration of an apparatus-specific ID that is identification information unique to the camera  140 . That is, an apparatus-specific ID is imaging apparatus identification information that is identification information regarding an imaging apparatus. 
     The linking request processing unit  302  performs processing for the request of linking between the apparatus-specific ID of the camera  140  to be rented and a user ID that is identification information regarding the user  30  who is a rental destination of the camera  140 . That is, the linking request processing unit  302  performs license construction processing. 
     The validity period setting request unit  303  performs processing for the request of validity period setting. The imaging parameter request unit  304  performs processing for the request of imaging parameters. The license key recording unit  305  performs processing for the recording of license keys. 
     A function that is implemented by the user terminal apparatus  130  executing the application program is illustrated as a functional block in B of  FIG.  4   . As illustrated in B of  FIG.  4   , the user terminal apparatus  130  executes the application program, thereby being capable of achieving the functional block such as a user registration request unit  311 . The user registration request unit  311  performs processing for the request of user registration. 
     Functions that are implemented by the server  110  executing the application program are illustrated as functional blocks in C of  FIG.  4   . As illustrated in C of  FIG.  4   , the server  110  executes the application program, thereby being capable of achieving the functional blocks such as a user registration unit  321 , an apparatus-specific information registration unit  322 , a signature metainformation generation unit  323 , a login processing unit  324 , a validity period setting unit  325 , an imaging parameter generation unit  326 , a user confirmation unit  327 , and a license key issuing unit  328 . 
     The user registration unit  321  performs processing for the registration of user information regarding the user  30  who is a rental destination. The apparatus-specific information registration unit  322  performs processing for the registration of apparatus-specific information regarding the camera  140  to be rented. The signature metainformation generation unit  323  performs processing for the generation of signature metainformation that is used for electronic signature generation. The login processing unit  324  performs processing for the login of the user  30  who is a rental destination. The validity period setting unit  325  performs processing for the setting of license validity periods. The imaging parameter generation unit  326  performs processing for the generation of imaging parameters. The user confirmation unit  327  performs processing for user confirmation in login processing or the like. The license key issuing unit  328  performs processing for the issuing of a license key that is exemplary license information. 
     &lt;License Key&gt; 
     An exemplary license key is illustrated in  FIG.  5   . As illustrated in  FIG.  5   , a license key  350  that is issued in the server  110  includes system-unique information that is identification information (ID) unique to a key in the system, for example. 
     Further, the license key  350  may include information regarding a validity period that is used for imaging control. For example, within the validity period described here, the activation of the user  30  in the camera  140  may be allowed. Further, the addition of electronic signatures to captured images may be allowed. In contrast, the addition of electronic signatures to captured images may be prohibited. Further, for example, outside the validity period described here, the activation of the user  30  in the camera  140  may be rejected (deactivation). Further, the addition of electronic signatures to captured images may be allowed. In contrast, the addition of electronic signatures to captured images may be prohibited. 
     Moreover, the license key  350  may include an apparatus-specific ID. Further, the license key  350  may include a user FIDO (Fast IDentity Online) public key. 
     Further, the license key  350  includes signature metainformation including the apparatus-specific ID of the camera  140  and the user ID of the user  30 . Moreover, signature metainformation may include information regarding the company  10  (for example, company name), which is the provider of the camera  140 . 
     Moreover, the license key  350  may include imaging parameters that are parameters for imaging. Imaging parameters may be any information regarding imaging. For example, imaging parameters may include information regarding imaging setting. For example, imaging parameters may include information regarding the resolution of captured images as the information regarding imaging setting. For example, imaging parameters may include control information that allows the generation of HD captured images and prohibits the generation of  4 K captured images. Further, imaging parameters may include control information that allows the generation of  4 K captured images only in a license period. 
     Further, for example, imaging parameters may include information regarding context control in imaging (terms of use information). For example, imaging parameters may include, as the information regarding context control in imaging, control information that limits periods of time or places (locations or times) in which imaging is allowed. Further, for example, imaging parameters may include, as the information regarding context control in imaging, control information that allows imaging (or activation) only in a case where there is a predetermined subject. 
     Moreover, for example, imaging parameters may include control information regarding captured image generation. For example, imaging parameters may include, as the control information regarding captured image generation, control information regarding the addition of credits to captured images. 
     &lt;Camera&gt; 
       FIG.  6    is a diagram illustrating a main configuration example of the camera  140  that is an embodiment of an imaging apparatus to which the present technology is applied. The camera  140  illustrated in  FIG.  6    is a computer configured to install an application program (software) for performing processing for the rental of the camera  140  or imaging processing and execute the application program. Here, examples of the computer include computers incorporated in dedicated hardware or general-purpose personal computers capable of executing various functions with various programs installed thereon. The camera  140  executes the application program to perform the processing for the rental of the camera  140  or the imaging processing. 
     In the camera  140  illustrated in  FIG.  6   , a CPU  401 , a ROM  402 , and a RAM  403  are connected to each other through a bus  404 . 
     The bus  404  is also connected to an input-output interface  410 . The input-output interface  410  is connected to an input unit  411 , an output unit  412 , a storage unit  413 , a communication unit  414 , and a drive  415 . 
     The input unit  411  includes, for example, a keyboard, a mouse, a microphone, a touch panel, an input terminal, or the like. The output unit  412  includes, for example, a display, a speaker, an output terminal, or the like. The storage unit  413  includes, for example, a hard disk, a RAM disk, a non-volatile memory, or the like. The communication unit  414  includes a network interface, for example. The drive  415  drives a removable recording medium  421  such as a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory. 
     Moreover, the input-output interface  410  is connected to an imaging unit  431 . The imaging unit  431  includes an optical system including a lens and an aperture, for example, and an image sensor and images a subject to generate captured images. Note that the imaging unit  431  may further include components other than those described above, such as an image processing unit configured to perform image processing on generated captured images or a memory configured to store data of captured images. 
     In the camera  140  configured as described above, the series of processing processes described above is performed by the CPU  401  loading the application program stored in the storage unit  413  on the RAM  403  through the input-output interface  410  and the bus  404  to execute the application program, for example. In the RAM  403 , for example, data necessary for the CPU  401  to execute various types of processing is also stored as appropriate. 
     The application program that the camera  140  executes can be recorded on the removable recording medium  421 , which is a package medium or the like, to be applied, for example. In this case, the application program can be installed on the storage unit  413  through the input-output interface  410  with the removable recording medium  421  mounted on the drive  415 . 
     Further, the application program can be provided through a wired or wireless transmission medium such as a local area network, the Internet, or digital satellite broadcasting. In this case, the application program can be received by the communication unit  414  to be installed on the storage unit  413 . 
     Besides, the application program can be installed on the ROM  402  or the storage unit  413  in advance. 
     Functions that are implemented by the camera  140  executing the application program are illustrated as functional blocks in  FIG.  7   . As illustrated in  FIG.  7   , the camera  140  executes the application program, thereby being capable of achieving the functional blocks such as a login processing unit  441 , an apparatus-specific common key generation unit  442 , a license key verification unit  443 , an activation processing unit  444 , a user authentication unit  445 , a terms of use determination unit  446 , an imaging setting unit  447 , an imaging control unit  448 , and an electronic signature processing unit  449 . 
     The login processing unit  441  performs login processing. The apparatus-specific common key generation unit  442  performs processing for the generation of apparatus-specific common keys. The license key verification unit  443  performs processing for the verification of license keys supplied from the server  110 . The activation processing unit  444  performs offline activation processing. The user authentication unit  445  performs user authentication processing. The terms of use determination unit  446  performs processing for the determination of terms of use based on license information. The imaging setting unit  447  performs processing for imaging setting based on license information. The imaging control unit  448  performs imaging control processing. The electronic signature processing unit  449  performs processing for electronic signatures to be associated with captured images. 
     &lt;Flow of Online Processing 1&gt; 
     Next, an exemplary flow of activation processing that is executed by the rental system  100  as described above is described with reference to the flowcharts of  FIG.  8    and  FIG.  9   . The activation processing in this case is performed with the camera  140  being online (being capable of communicating with the server  110 ). 
     First, processing for registering user IDs and apparatus-specific IDs on the server  110  is performed. The user registration request unit  311  of the user terminal apparatus  130  requests the server  110  to register a user in Step S 111  of  FIG.  8   . For example, the user registration request unit  311  supplies the server  110  with user information that is information regarding a user through the communication unit  214  of the user terminal apparatus  130 . The user registration unit  321  of the server  110  acquires the user information through the communication unit  214  of the server  110  in Step S 121 , and generates a user ID corresponding to the user information and registers the user ID on a database in Step S 122 . The user registration unit  321  of the server  110  supplies the user terminal apparatus  130  with the registered user ID through the communication unit  214  of the server  110  in Step S 123 . The user registration request unit  311  of the user terminal apparatus  130  acquires the user ID through the communication unit  214  of the user terminal apparatus  130  in Step S 112  and stores the user ID in the storage unit  213  of the user terminal apparatus  130 , for example. 
     Further, the apparatus-specific information registration request unit  301  of the company terminal apparatus  120  requests the server  110  to register an apparatus-specific ID in Step S 101 . For example, the apparatus-specific information registration request unit  301  supplies the server  110  with the apparatus-specific ID of the camera  140  to be rented through the communication unit  214  of the company terminal apparatus  120 . The apparatus-specific information registration unit  322  of the server  110  acquires the apparatus-specific ID through the communication unit  214  of the server  110  in Step S 124  and registers the apparatus-specific ID on the database in Step S 125 . 
     Note that the user registration processing and the apparatus-specific ID registration processing can be performed independently of each other, and which one is performed first does not matter. Further, these processing processes can also be performed in parallel. 
     After the user  30  (user ID thereof) and the apparatus-specific ID of the camera  140  are registered on the server  110 , processing for the generation of signature metainformation corresponding to a license is performed. Note that this processing can be performed at any timing after the registration of the user (user ID) and the apparatus-specific ID. In other words, the user ID and the apparatus-specific ID already registered on the server  110  can be linked to each other at any timing. 
     Note that, herein, pieces of data are “linked” to each other means that pieces of data are “associated” with each other. Here, the term “associate” means, for example, that one piece of data may be processed by using (linking) another piece of data. That is, pieces of data associated with each other may be integrated as one piece of data or provided as separate pieces of data. For example, multiple pieces of information associated with each other may be transmitted on transmission lines different from each other. Further, for example, multiple pieces of information associated with each other may be recorded on recording media different from each other (or different recording areas in the same recording medium). Note that pieces of data may be “associated” with each other in part, rather than entirely. For example, an image and information corresponding to the image may be associated with each other in any unit, such as multiple frames, a single frame, or a part of a frame. 
     Note that, herein, other than “link” described above, the terms such as “combine,” “multiplex,” “add,” “integrate,” “include,” “store,” “put in,” “place into,” and “insert” each mean grouping multiple things together and mean one of the ways of “associate” described above. 
     In Step S 102  of  FIG.  8   , the linking request processing unit  302  of the company terminal apparatus  120  requests, through the communication unit  214  of the company terminal apparatus  120 , linking between the apparatus-specific ID of the camera  140  to be rented and the user ID of the user  30  who is a rental destination of the camera  140 . 
     The signature metainformation generation unit  323  of the server  110  generates signature metainformation including the designated user ID and apparatus-specific ID on the basis of the request and registers the signature metainformation on the database in Step S 126 . The signature metainformation is information that can be included in an electronic signature and includes an apparatus-specific ID indicating a device that has generated a captured image to which the electronic signature is to be added and a user ID indicating a user who has operated the device. That is, with the signature metainformation, the user ID and the apparatus-specific ID are linked to each other. 
     Further, the signature metainformation may further include a company name (or identification information) indicating a company that is a provider which has provided the user with the device. That is, with signature metainformation, a company name may further be linked to a user ID and an apparatus-specific ID. Note that a company name may indicate the right holder of captured images. Moreover, signature metainformation may include other information. In the following, signature metainformation includes an apparatus-specific ID, a user ID, and a company name. That is, the signature metainformation generation unit  323  generates signature metainformation including the designated user ID and apparatus-specific ID and the company name of the company  10  and registers the signature metainformation on the database. 
     After those pieces of information are registered, the camera  140  is rented to the user  30  according to the license (that is, signature metainformation generated in Step S 126 ). That is, the camera  140  having the apparatus-specific ID included in the signature metainformation is rented from the company  10  to the user  30  corresponding to the user ID included in the same signature metainformation. 
     After the camera  140  is rented, the activation processing of  FIG.  9    is performed. That is, the user  30  to whom the camera  140  has been rented performs a procedure for activating himself/herself, thereby making the camera  140  ready. In this case, the activation processing is performed online as described above. That is, the user  30  operates the rented camera  140  to communicate with the server  110  and perform activation. 
     The login processing unit  441  of the camera  140  operated by the user  30  transmits login information, the apparatus-specific ID, and the like to the server  110  through the communication unit  414  to request a login in Step S 131  of  FIG.  9   . Login information includes information regarding login such as a user ID and a password. 
     The login processing unit  324  of the server  110  acquires the request through the communication unit  214  and accepts the login when the user is legitimate (user ID and password are correct) in Step S 141 . In Step S 142 , the login processing unit  324  confirms linking between the login user and the apparatus. That is, the login processing unit  324  confirms the registered signature metainformation and confirms whether there is signature metainformation linking the user ID and apparatus-specific ID supplied from the camera  140  to each other. That is, the login processing unit  324  confirms linking between the login user and the apparatus-specific ID. 
     In a case where there is such signature information, that is, in a case where linking between the login user and the camera  140  is confirmed, the login processing unit  324  supplies the camera  140  with license information regarding the license corresponding to the user ID and the apparatus-specific ID through the communication unit  214 . That is, the login processing unit  324  transmits the license information including the signature metainformation linking the user ID and apparatus-specific ID supplied from the camera  140  to each other and the user ID to the camera  140 . Note that license information may include other information. 
     The login processing unit  441  of the camera  140  acquires the license information through the communication unit  414  in Step S 132  and performs activation in Step S 133 . 
     Through the processing executed as described above, online activation can be performed. 
     &lt;Flow of Online Processing 2&gt; 
     As described above, license information may include information other than signature metainformation and user IDs. For example, license validity period information may be included. An exemplary flow of activation processing in this case is described with reference to the flowcharts of  FIG.  10    and  FIG.  11   . The activation processing in this case is performed with the camera  140  being online (being capable of communicating with the server  110 ) as in the case of  FIG.  8    and  FIG.  9   . 
     Processing up to the signature metainformation generation is executed as in the case of  FIG.  8   . That is, the processing in Step S 151  and Step S 152  ( FIG.  10   ) that is executed by the company terminal apparatus  120  is executed similarly to the processing in Step S 101  and Step S 102  ( FIG.  8   ) described above. Further, the processing in Step S 161  and Step S 162  ( FIG.  10   ) that is executed by the user terminal apparatus  130  is executed similarly to the processing in Step S 111  and Step S 112  ( FIG.  8   ) described above. Moreover, the processing in Step S 171  to Step S 176  ( FIG.  10   ) that is executed by the server  110  is executed similarly to the processing in Step S 121  to Step S 126  ( FIG.  8   ) described above. 
     After the signature metainformation is generated, the validity period setting request unit  303  of the company terminal apparatus  120  supplies the server  110  with validity period information through the communication unit  214  of the company terminal apparatus  120  to request validity period setting in Step S 153 . The validity period setting unit  325  of the server  110  acquires the request (validity period information) through the communication unit  214  of the server  110  and sets the validity period of the license on the basis of the request (validity period information) in Step S 177 . That is, the validity period setting unit  325  sets the validity period of the license to the validity period designated by the validity period information supplied from the company terminal apparatus  120  and registers the validity period on the database. 
     Activation processing that is executed after the camera  140  is rented is performed along a flow similar to that in the case of  FIG.  9    basically. That is, the processing in Step S 181  to Step S 183  ( FIG.  11   ) that is executed by the camera  140  is executed similarly to the processing in Step S 131  to Step S 133  ( FIG.  9   ) described above. Further, the processing in Step S 191 , Step S 192 , and Step  3194  that is executed by the server  110  is executed similarly to the processing in Step S 141  to Step S 143  ( FIG.  9   ) described above. 
     However, when linking between the login user and the camera  140  is confirmed, that is, when linking between the user ID of the login user and the apparatus-specific ID (signature metainformation) is confirmed in Step S 192 , the login processing unit  324  of the server  110  confirms the validity period of the license in Step S 193 . Then, in a case where it is within the validity period at that point in time, the login processing unit  441  generates license information and transmits the license information to the camera  140  in Step S 194 . The license information includes the user ID, the signature metainformation, the validity period, and the like. The login processing unit  441  of the camera  140  acquires the license information in Step  3182 . Then, the login processing unit  441  performs activation on the basis of the license information in Step S 183 . 
     Through the processing executed as described above, setting regarding validity periods can also be performed. 
     &lt;Flow of Online Processing 3&gt; 
     As described above, license information may include information other than signature metainformation and user IDs. For example, imaging parameter information may be included. An exemplary flow of activation processing in this case is described with reference to the flowcharts of  FIG.  12    and  FIG.  13   . The activation processing in this case is performed with the camera  140  being online (being capable of communicating with the server  110 ) as in the case of  FIG.  8    and  FIG.  9   . 
     Processing up to the signature metainformation generation is executed as in the case of  FIG.  8   . That is, the processing in Step S 201  and Step S 202  ( FIG.  12   ) that is executed by the company terminal apparatus  120  is executed similarly to the processing in Step S 101  and Step S 102  ( FIG.  8   ) described above. Further, the processing in Step S 211  and Step S 212  ( FIG.  12   ) that is executed by the user terminal apparatus  130  is executed similarly to the processing in Step S 111  and Step S 112  ( FIG.  8   ) described above. Moreover, the processing in Step S 221  to Step S 226  ( FIG.  12   ) that is executed by the server  110  is executed similarly to the processing in Step S 121  to Step S 126  ( FIG.  8   ) described above. 
     After the signature metainformation is generated, the imaging parameter request unit  304  of the company terminal apparatus  120  accesses the server  110  through the communication unit  214  of the company terminal apparatus  120  to request imaging parameter setting in Step S 203 . The imaging parameter generation unit  326  of the server  110  generates imaging parameters on the basis of the request and registers the imaging parameters on the database in Step S 227 . 
     Activation processing that is executed after the camera  140  is rented is performed along a flow similar to that in the case of  FIG.  9    basically. That is, the processing in Step S 231  to Step S 233  ( FIG.  13   ) that is executed by the camera  140  is executed similarly to the processing in Step S 131  to Step S 133  ( FIG.  9   ) described above. Further, the processing in Step S 241  to Step S 243  that is executed by the server  110  is executed similarly to the processing in Step S 141  to Step S 143  ( FIG.  9   ) described above. 
     Note that the license information that is supplied from the server  110  to the camera  140  (Step S 243  or Step S 232 ) includes the imaging parameters generated as described above in addition to the user ID and the signature metainformation. 
     Through the processing executed as described above, imaging parameters can also be generated. 
     &lt;Flow of Offline Processing 1&gt; 
     Next, an exemplary flow of activation processing that is performed with the camera  140  being offline (being incapable of communicating with the server  110 ) is described with reference to the flowcharts of  FIG.  14    and  FIG.  15   . Note that, here, a case where license information includes neither validity period information nor imaging parameters is described as an example. That is, the example of  FIG.  14    and  FIG.  15    corresponds to the example of  FIG.  8    and  FIG.  9   . 
     First, processing for registering user IDs and apparatus-specific IDs on the server  110  is performed. The user registration request unit  311  of the user terminal apparatus  130  requests the server  110  to register a user in Step S 271  of  FIG.  14   . For example, the user registration request unit  311  supplies the server  110  with user information that is information regarding a user through the communication unit  214  of the user terminal apparatus  130  to request the registration of the user information. The user registration unit  321  of the server  110  acquires the user information through the communication unit  214  of the server  110  in Step S 281 , and generates a user ID corresponding to the user information and registers the user ID on the database in Step S 282 . 
     Further, the apparatus-specific common key generation unit  442  of the camera  140  generates an apparatus-specific common key in Step S 251 . In Step S 252 , the apparatus-specific common key generation unit  442  supplies the company terminal apparatus  120  with apparatus-specific information that includes the generated apparatus-specific common key and is information unique to the apparatus. For example, the apparatus-specific common key generation unit  442  supplies the company terminal apparatus  120  with an apparatus-specific ID, an apparatus-specific common key encrypted with a public key of the server  110 , and the hash value of the apparatus-specific ID and the apparatus-specific common key derived by using the apparatus-specific common key, as apparatus-specific information. 
     The apparatus-specific information registration request unit  301  of the company terminal apparatus  120  acquires the apparatus-specific information through the communication unit  214  of the company terminal apparatus  120  in Step S 261 . Further, in Step S 262 , the apparatus-specific information registration request unit  301  supplies the server  110  with the apparatus-specific information through the communication unit  214  of the company terminal apparatus  120 . For example, the apparatus-specific information registration request unit  301  supplies the server  110  with apparatus-specific information as described above and a user ID to be linked to the apparatus-specific ID. At this time, signature metainformation or imaging parameters may also be supplied from the company terminal apparatus  120  to the server  110 . 
     The apparatus-specific information registration unit  322  of the server  110  acquires the apparatus-specific information, the user ID, and the like through the communication unit  214  of the server  110  in Step S 283 . In Step S 284 , the signature metainformation generation unit  323  generates signature metainformation including the apparatus-specific ID, the user ID, the company name, and the like on the basis of those pieces of information. Note that the signature metainformation may be generated by the company terminal apparatus  120  to be supplied to the server  110 . 
     The license key issuing unit  328  of the server  110  performs hash value verification in Step S 285 . That is, the license key issuing unit  328  decrypts, by using a secret key of the server  110 , the apparatus-specific common key that is included in the supplied apparatus-specific information and that has been encrypted with the public key of the server  110 . Then, the license key issuing unit  328  derives, by using the decrypted apparatus-specific common key, the hash value of the apparatus-specific ID and the apparatus-specific common key. Moreover, the license key issuing unit  328  compares the derived hash value and the hash value included in the supplied apparatus-specific information (hash value of apparatus-specific ID and apparatus-specific common key) to each other. 
     When the hash values coincide with each other and it is thus confirmed that no alteration has been made, the license key issuing unit  328  issues a license key as license information with respect to the company terminal apparatus  120 . Information included in a license key has been described with reference to  FIG.  5   . Note that, here, the license key includes system-unique information and signature metainformation. The license key issuing unit  328  derives the hash value of the license key by using the apparatus-specific common key. Then, the license key issuing unit  328  supplies the company terminal apparatus  120  with the license key and the hash value. 
     In Step S 263 , the license key recording unit  305  of the company terminal apparatus  120  acquires the issued license key (and hash value thereof). When confirming the hash value, the license key recording unit  305  records the license key on a recording medium in Step S 264 . 
     When the camera  140  is rented to the user  30 , the recording medium having recorded thereon the license key as described above is also rented. The user  30  mounts the recording medium on a predetermined position of the camera  140  when using the camera  140 . Processing that is executed in the camera  140  thereafter is performed along the flow of  FIG.  15   , for example. 
     The license key verification unit  443  of the camera  140  confirms that a recording medium having recorded thereon a license key has been mounted in Step S 291  of  FIG.  15   . With the recording medium mounted on the predetermined position, the license key verification unit  443  verifies the license key recorded on the recording medium in Step S 292 . That is, the license key verification unit  443  verifies the hash value of the license key to verify whether or not the license key has been altered. For example, the license key verification unit  443  derives, by using the apparatus-specific common key of the camera  140 , the hash value of a license key recorded on a recording medium. Then, the license key verification unit  443  compares the derived hash value and the hash value of the license key recorded on the recording medium to each other. 
     When the hash values coincide with each other and it is thus proved that the license key has not been altered, the license key verification unit  443  verifies the apparatus-specific ID included in the license key in Step S 293 . 
     In a case where the apparatus-specific ID is legitimate, the license key verification unit  443  determines whether or not the license key is an unused key in Step S 294 . License keys used in the past cannot be used. The license key verification unit  443  determines whether or not the license key is an unused key on the basis of the system-unique information, for example. 
     In a case where it is determined that the license key is an unused key, the activation processing unit  444  performs activation in Step S 295 . This allows the user  30  to use the camera  140 . 
     Through the processing executed as described above, offline activation can be performed by using a recording medium. 
     Note that, also in this case, as in the case of online activation, license validity periods can also be set. That is, information indicating a validity period may be included in the license key issued by the license key issuing unit  328 . In this case, it is sufficient that, as in the case of online activation ( FIG.  10   ), after the signature metainformation is generated (after processing in Step S 284  of  FIG.  14   ), processing similar to that in Step S 153  and Step S 177  ( FIG.  10   ) is performed to set a validity period, and that the license key verification unit  443  confirms whether or not it is within the validity period included in the license key at that point in time when verifying the license key (processing between Step S 291  to Step S 294  of  FIG.  15   ). 
     Further, also in this case, as in the case of online activation, imaging parameters may be set and included in the license key issued by the license key issuing unit  328 . In this case, it is sufficient that, as in the case of online activation ( FIG.  12   ), after the signature metainformation is generated (after processing in Step S 284  of  FIG.  14   ), processing similar to that in Step S 203  and Step S 227  ( FIG.  12   ) is performed to generate imaging parameters. 
     &lt;Flow of Offline Processing 2&gt; 
     Note that FIDO (Fast IDentity Online) may be applied to user authentication. In FIDO, instead of authentication using IDs and passwords, authentication using USB (Universal Serial Bus) keys having embedded therein secret keys (security tokens) or biological information such as fingerprints or irises is performed, for example. 
     An exemplary flow of activation processing in this case is described with reference to the flowcharts of  FIG.  16    and  FIG.  17   . Note that the activation processing is performed offline. Further, license information includes neither validity period information nor imaging parameters. That is, the example of  FIG.  16    and  FIG.  17    corresponds to the example of  FIG.  14    and  FIG.  15   . 
     The registration and linking of a user ID and an apparatus-specific ID and the issuing of a license key are performed similarly to those in the case described with reference to the flowcharts of  FIG.  14    and  FIG.  15   . That is, the processing in Step S 301  and Step S 302  ( FIG.  16   ) that is executed by the camera  140  is executed similarly to the processing in Step S 251  and Step S 252  ( FIG.  14   ) described above. Further, the processing in Step S 311  to Step S 313  ( FIG.  16   ) that is executed by the company terminal apparatus  120  is executed similarly to the processing in Step S 261  to Step S 263  ( FIG.  14   ) described above. Moreover, the processing in Step S 321  ( FIG.  16   ) that is executed by the user terminal apparatus  130  is executed similarly to the processing in Step S 271  ( FIG.  14   ) described above. Further, the processing in Step S 331  to Step S 336  ( FIG.  16   ) that is executed by the server  110  is executed similarly to the processing in Step S 281  to Step S 286  ( FIG.  14   ) described above. 
     However, in this case, a processing unit  332  of the user terminal apparatus  130  registers a FIDO public key of the user in addition to the user. Note that user registration and user FIDO public key registration may be executed simultaneously or independently. A FIDO public key is included in a license key to be supplied to the camera  140 , thereby being used by the user authentication unit  445  for FIDO user authentication. That is, the license key issued by the license key issuing unit  328  includes the FIDO public key. 
     In this case, the license key recording unit  305  of the company terminal apparatus  120  supplies the camera  140  with the license key acquired in Step S 313  to cause the license key to be recorded, in Step S 314 . The camera  140  acquires the license key and records the license key on a recording medium or the like in Step S 303 . A license key can be supplied from the company terminal apparatus  120  to the camera  140  in any way. For example, a license key may be supplied by using a removable recording medium or by communication. 
     When the camera  140  is rented to the user  30 , the camera  140  is rented with a license key as described above recorded on a removable recording medium mounted on the camera  140  or on an internal memory, for example. The user  30  to whom the camera  140  has been rented performs activation by using the camera  140 . This processing is performed along the flow of  FIG.  17   , for example. 
     The user authentication unit  445  of the camera  140  detects that a UIM (User Identity Module) card has been mounted on a predetermined position of the camera  140  in Step S 341  of  FIG.  17   . 
     With the UIM card mounted, the user authentication unit  445  performs FIDO user authentication by using the FIDO public key included in the license key in Step S 342 . 
     In Step S 343 , the license key verification unit  443  verifies the apparatus-specific ID included in the license key. 
     When it is determined that the apparatus-specific ID is a legitimate ID, the activation processing unit  444  performs activation in Step S 344 . This allows the user  30  to use the camera  140 . 
     Through the processing executed as described above, offline activation can be performed by using FIDO. 
     Note that, also in this case, as in the case of online activation, license validity periods can also be set. That is, information indicating a validity period may be included in the license key issued by the license key issuing unit  328 . In this case, it is sufficient that, as in the case of online activation ( FIG.  10   ), after the signature metainformation is generated (after processing in Step S 334  of  FIG.  16   ), processing similar to that in Step S 153  and Step S 177  ( FIG.  10   ) is performed to set a validity period, and that the license key verification unit  443  confirms whether or not it is within the validity period included in the license key at that point in time when verifying the license key (before or after the processing in Step S 343  of  FIG.  17   ). 
     Further, also in this case, as in the case of online activation, imaging parameters may be set and included in the license key issued by the license key issuing unit  328 . In this case, it is sufficient that, as in the case of online activation ( FIG.  12   ), after the signature metainformation is generated (after processing in Step S 334  of  FIG.  16   ), processing similar to that in Step S 203  and Step S 227  ( FIG.  12   ) is performed to generate imaging parameters. 
     &lt;Flow of Imaging Control Processing&gt; 
     After activation is performed in various ways as described above, the user  30  images a subject by using the camera  140  to generate captured images. At this time, imaging control, imaging setting, electronic signature generation, and the like are performed on the basis of information included in license information. An exemplary flow of such imaging control processing that is performed in the camera  140  is described with reference to the flowchart of  FIG.  18   . 
     When the imaging control processing starts, the terms of use determination unit  446  determines whether or not usage limitation conditions (terms of use) based on imaging parameters included in license information (including license key) are met in Step S 401 . That is, the terms of use determination unit  446  confirms the imaging parameters included in the license information to determine whether or not the terms of use set with the imaging parameters are met. 
     For example, as described with reference to  FIG.  5   , with imaging parameters, locations or dates and times in which the use of a camera (imaging) is allowed can be set. For example, in a case where it is determined that such terms of use are met, that is, in a case where imaging is allowed, the processing proceeds to Step S 402 . 
     In Step S 402 , the imaging setting unit  447  sets imaging functions (specifications) on the basis of the imaging parameters included in the license information. For example, the imaging setting unit  447  sets the resolution of captured images and the like on the basis of imaging parameters. With this, captured images can be generated with the functions (specifications) designated by the imaging parameters included in the license information. 
     In Step S 403 , the imaging control unit  448  controls the imaging unit  431  to image a subject, thereby generating a captured image. 
     The electronic signature processing unit  449  generates an electronic signature by using the license information in Step S 404  and associates the generated electronic signature with the captured image in Step S 405 . When the processing in Step S 405  ends, the imaging control processing ends. Further, in a case where it is determined that the terms of use are not met in Step S 401 , the imaging control processing ends since imaging is not to be performed. 
     Through the imaging control processing executed as described above, license information-based imaging control can be performed. Note that, in a case where moving images are captured, it is sufficient that such imaging control processing is performed in every frame. 
     &lt;Electronic Signature Generation&gt; 
     An exemplary method for electronic signature generation in Step S 404  of  FIG.  18    is described with reference to  FIG.  19   . When a subject is imaged to generate a captured image  501  (S 501 ), a hash value  502  of the captured image  501  is derived by using the apparatus-specific common key (S 502 ). 
     Then, an electronic signature  504  is generated by using the hash value  502  and signature metainformation  503  included in the license information (S 503 ). The signature metainformation  503  includes information such as an apparatus-specific ID, a user ID, and a company name as described above. Further, the electronic signature  504  is generated by any method. For example, the signature metainformation  503  may be added to the hash value  502  of an image, the hash value of them may be derived by using the apparatus-specific common key of the camera  140 , and the hash value may be encrypted with the public key of the server, to thereby generate the electronic signature  504 . Further, the hash value may be encrypted by using a secret key to generate the electronic signature  504 . Further, the hash value may be encrypted by using a common key to generate the electronic signature  504 . 
     Then, the signature metainformation  503  and the electronic signature  504  are associated with the captured image  501  (S 504 ). Note that whether or not to associate an electronic signature and signature metainformation with a captured image may be controlled according to the details of a license. Further, whether or not to associate an electronic signature and signature metainformation with a captured image may be controlled according to the validity period of a license. 
     &lt;Electronic Signature Verification&gt; 
     An exemplary method of verifying an electronic signature associated with a captured image as described above is described with reference to  FIG.  20   . When the captured image  501  as well as the signature metainformation  503  and the electronic signature  504  that are associated with the captured image  501  are acquired as content (S 551 ), a hash value  511  of the captured image  501  is derived by using the apparatus-specific common key of the camera  140  (S 552 ). 
     Then, an electronic signature  512  is generated by using the hash value  511  and the acquired signature metainformation  503  (signature metainformation  503  associated with captured image  501 ) (S 553 ). The signature metainformation  503  includes information such as an apparatus-specific ID, a user ID, and a company name as described above. Further, the electronic signature  504  may be generated by any method similar to that in the case of  FIG.  19   . 
     Then, the derived electronic signature  512  and the acquired electronic signature  504  (electronic signature  504  associated with captured image  501 ) are compared to each other to perform electronic signature verification (S 554 ). 
     Note that the acquired electronic signature  504  may be decrypted by using the secret key of the server or the like to derive the hash value  502  of an image and the hash value of the signature metainformation  503  and the hash values may be compared to the hash value  511  of the image and the hash value of the signature metainformation  503 , to thereby perform electronic signature verification. 
     With this, alterations of captured images and signature metainformation (apparatus-specific ID, user ID, and company name) can be detected (authenticity of captured images and signature metainformation (apparatus-specific ID, user ID, and company name) can be guaranteed). 
     Here, an apparatus-specific ID indicates a device used for generating captured images (imaging). Further, a user ID indicates a photographer (a person who has generated captured images). Moreover, a company name indicates the owner of the rights of captured images (owner of captured images). That is, with signature metainformation included in electronic signatures, the authenticity of a device used for imaging, a photographer, the owner (right holder) of captured images, and the like can be guaranteed. 
     Application Example 
     Note that, although the company  10  is used as the provider of the camera  140  (owner of captured images) in the description of the rental system  100 , the provider of the camera  140  (owner of captured images) is not limited to a company and may be an individual or an organization. Further, although the user  30  of the camera  140  is an individual in the description, the user  30  is not limited thereto and may be a company or an organization, for example. 
     Further, the way of providing the camera  140  is freely determined and may be ways other than rental. For example, the camera  140  may be transferred to the user  30 . Further, a contract that the camera  140  is returned to the company  10  after the camera  140  has been rented to the user  30  for a certain period or a contract that the camera  140  is transferred to the user  30  after the camera  140  has been rented to the user  30  for a certain period may be formed. 
     Further, in the above, the camera  140  (that is, imaging apparatus) is described as an exemplary product to be provided, but products to be provided are freely determined and may be products other than imaging apparatuses. For example, recording apparatuses or any electronic apparatuses may be provided. 
     3. Supplementary Note 
     &lt;Hardware&gt; 
     The series of processing processes described above can be executed by software (application program) or hardware. 
     &lt;Application Target of Present Technology&gt; 
     The present technology is applicable to any configuration. For example, the present technology can also be implemented as a part of an apparatus, such as a processor serving as a system LSI (Large Scale Integration) or the like, a module that uses multiple processors or the like, a unit that uses multiple modules or the like, or a set that includes other additional functions in addition to a unit. 
     Further, for example, the present technology is also applicable to a network system including multiple apparatuses. For example, the present technology may be implemented as cloud computing in which multiple apparatuses share processing in cooperation with each other via a network. For example, the present technology may be implemented in a cloud service for providing a service to any terminal such as computers, portable information processing terminals, or IoT (Internet of Things) devices. 
     Note that, herein, “system” means a set of multiple components (apparatuses, modules (parts), or the like), and it does not matter whether or not all the components are in a single housing. Thus, multiple apparatuses that are accommodated in separate housings and connected to each other via a network and a single apparatus in which multiple modules are accommodated in a single housing are both “system.” 
     &lt;Field and Purpose to which Present Technology is Applicable&gt; 
     Systems, apparatuses, processing units, and the like to which the present technology is applied can be used in any field such as traffic, medical care, crime prevention, agriculture, livestock raising, mining, beauty business, factories, home electronics, meteorology, or natural surveillance. Further, such systems, apparatuses, processing units, and the like can be used for any purpose. 
     &lt;Others&gt; 
     The embodiment of the present technology is not limited to the embodiment described above, and various modifications can be made within the scope of the gist of the present technology. 
     For example, the configuration described as a single apparatus (or processing unit) may be divided into multiple apparatuses (or processing units). In contrast, the configurations described above as multiple apparatuses (or processing units) may be put into a single apparatus (or processing unit). Further, needless to say, configurations other than those described above may be added to the configuration of each apparatus (or each processing unit). Moreover, as long as the configuration and operation of the entire system is substantially unchanged, the configuration of a certain apparatus (or processing unit) may be partially included in the configuration of another apparatus (or another processing unit). 
     Further, for example, the program described above may be executed by any apparatus. In this case, it is sufficient that the apparatus has necessary functions (functional blocks or the like) and can thus obtain necessary information. 
     Further, for example, the steps of a single flowchart may be executed by a single apparatus or shared and executed by multiple apparatuses. Moreover, in a case where multiple processing processes are included in a single step, the multiple processing processes may be executed by a single apparatus or shared and executed by multiple apparatuses. In other words, multiple processing processes included in a single step can be executed as processing in multiple steps. In contrast, the processing processes described as multiple steps can collectively be executed as a single step. 
     Further, for example, as for the program that is executed by the computer, the processing processes in the steps describing the program may be executed chronologically in the order described herein or in parallel. Alternatively, the processing processes may be individually executed at right timings, for example, when the program is called. That is, as long as no contradiction arises, the processing processes in the respective steps may be executed in an order different from the order described above. Moreover, the processing in the steps describing the program may be executed in parallel or in combination with the processing of another program. 
     Further, for example, the multiple technologies according to the present technology can be implemented independently of each other as long as no contradiction arises. Needless to say, the multiple present technologies can be implemented in any combination. For example, part or whole of the present technology described in any embodiment can be implemented in combination with part or whole of the present technology described in another embodiment. Further, part or whole of any of the present technologies described above can also be implemented in combination with another technology not described above. 
     Note that the present technology can also take the following configurations. 
     (1) An imaging apparatus including: 
     an association unit configured to associate a captured image with a hash value of signature metadata including imaging apparatus identification information that is identification information regarding the imaging apparatus itself and user identification information. 
     (2) The imaging apparatus according to Item (1), in which the signature metadata further includes a company name of a company that provides a user with the imaging apparatus. 
     (3) The imaging apparatus according to Item (1) or (2), in which the association unit associates the captured image with the hash value derived from the signature metadata included in license information that is information regarding a license. 
     (4) The imaging apparatus according to Item (3), in which the association unit associates, according to a detail of the license, the hash value of the signature metadata and the captured image with each other. 
     (5) The imaging apparatus according to Item (3) or (4), in which the association unit associates, according to a validity period included in the license information, the hash value of the signature metadata and the captured image with each other. 
     (6) The imaging apparatus according to any one of Items (1) to (5), in which the association unit generates an electronic signature including the hash value of the signature metadata and associates the generated electronic signature with the captured image. 
     (7) The imaging apparatus according to Item (6), in which the association unit converts the captured image into a hash value, converts the hash value of the captured image and the signature metadata into a hash value, and encrypts the hash value, to thereby generate the electronic signature. 
     (8) The imaging apparatus according to Item (6) or (7), in which the association unit further associates the signature metadata with the captured image associated with the electronic signature. 
     (9) An information processing method including: associating a captured image with a hash value of signature metadata including imaging apparatus identification information that is identification information regarding an imaging apparatus and user identification information. 
     (10) A program for causing a computer to function as: 
     an association unit configured to associate a captured image with a hash value of signature metadata including imaging apparatus identification information that is identification information regarding an imaging apparatus and user identification information. 
     (11) An imaging apparatus including: 
     an imaging control unit configured to control imaging on the basis of license information that is information regarding a license and includes imaging apparatus identification information that is identification information regarding the imaging apparatus itself, user identification information, and an imaging parameter that is a parameter for imaging. 
     (12) The imaging apparatus according to Item (11), in which the imaging parameter includes information regarding a term of use of the imaging apparatus. 
     (13) The imaging apparatus according to Item (12), in which the term of use relates to a location, a time, or both of them. 
     (14) The imaging apparatus according to Item (12) or (13), in which the term of use relates to a subject. 
     (15) The imaging apparatus according to any one of Items (11) to (14), in which the imaging parameter includes information regarding imaging setting. 
     (16) The imaging apparatus according to Item (15), in which the information regarding imaging setting includes information regarding a resolution of a captured image. 
     (17) The imaging apparatus according to Item (15) or (16), in which the information regarding imaging setting includes information regarding addition of a credit to a captured image. 
     (18) The imaging apparatus according to any one of Items (11) to (17), in which the license information further includes information indicating a validity period of the license. 
     (19) An information processing method including: 
     controlling imaging on the basis of license information that is information regarding a license and includes imaging apparatus identification information that is identification information regarding an imaging apparatus, user identification information, and an imaging parameter that is a parameter for imaging. 
     (20) A program for causing a computer to function as: 
     an imaging control unit configured to control imaging on the basis of license information that is information regarding a license and includes imaging apparatus identification information that is identification information regarding an imaging apparatus itself, user identification information, and an imaging parameter that is a parameter for imaging. 
     REFERENCE SIGNS LIST 
     
         
         
           
               10 : Company 
               30  to  34 : User 
               100 : Rental system 
               110 : Server 
               120 : Company terminal apparatus 
               130 : User terminal apparatus 
               140 : Camera 
               301 : Apparatus-specific ID registration unit 
               302 : Linking processing unit 
               311 : User ID registration unit 
               321 : User ID generation unit 
               322 : Apparatus-specific ID registration unit 
               323 : Signature metainformation generation unit 
               324 : Validity period setting unit 
               325 : Imaging parameter generation unit 
               326 : User confirmation unit 
               327 : License key issuing unit 
               431 : Imaging unit 
               441 : Login processing unit 
               442 : License key verification unit 
               443 : Validity period confirmation unit 
               444 : Terms of use determination unit 
               445 : Imaging setting unit 
               446 : Imaging control unit 
               447 : Electronic signature processing unit