Information processing system for processing information concerning content, and method and program for controlling information processing system

Abstract

[Problem] The purpose of the present invention is to provide an information processing system that can prevent deletion omissions, etc. in deleting metadata which is included in a history of an image, and a method and a program that are for controlling the information processing system. [Solution] A history display system 100 comprises a display control means (display control unit 333) that arranges and displays the histories of content in a time-series order, and that also displays, in a selectable manner, pieces of metadata included in the respective histories, and a determination means (deletion target determination unit 335) that, when a piece of metadata is selected as selected metadata from the pieces of metadata included in the respective histories and the selected metadata is a duplicate of metadata included in a history other than the history in which the selected metadata is included, determines, as deletion target metadata to be deleted from the content, the selected metadata, and duplicate metadata, which is a duplicate of the selected metadata, in accordance with the time-series position of the history in which the selected metadata is included.

Description

Information processing system for processing information related to content, method for controlling information processing system, and program

[0001] The present invention relates to an information processing system for processing information relating to content, a control method for the information processing system, and a program.

[0002] In recent years, for example, from the perspective of protecting portrait rights and personal information, it has become important to delete portions of digital images or delete or conceal metadata related to personal information attached to digital images. For example, Patent Literature 1 discloses a system capable of appropriately deleting data (derived data) stored together with digital images. Furthermore, in recent years, information sharing via the Internet has become widespread regardless of time or place. This allows various types of information to be published or disseminated to an unspecified number of people. On the other hand, problems have arisen, such as the distribution of fraudulent digital images or the tampering of digital images to spread fake news. To address this issue, for example, Non-Patent Literature 1 proposes adding metadata (provenance information) indicating the origin of the digital image and the edits made to the digital image, and information (digital signature) indicating the reliability of the edits made to the digital image, to the digital image.

[0003] Japanese Patent Application Laid-Open No. 2022-91308

[0004] Coalition for Content Provenance and Authenticity (C2PA), "C2PA Specifications," <Technical Specifications Version 1.2>, [online], November 3, 2022, [retrieved January 23, 2023], Internet <URL: https: / / c2pa.org / specifications / specifications / 1.2 / specs / C2PA_Specification.html>

[0005] However, when a digital image is edited, the more times the image is edited, the more metadata is included in the image history information. As a result, if there is multiple metadata to be deleted from the image, it may not be possible to select all of the metadata to be deleted. In other words, there is a risk that some of the metadata to be deleted may be overlooked and omitted.

[0006] An object of the present invention is to provide an information processing system, a control method for an information processing system, and a program that can prevent metadata included in the history of content such as images from being overlooked when the metadata is deleted.

[0007] The information processing system of the present invention is an information processing system that processes information related to content, and the content is assigned a history each time it is edited after it is first acquired, and each history includes at least one piece of metadata.The information processing system is characterized by comprising: a display control means that displays each history in chronological order and controls the display of metadata included in each history in a selectable manner; and a determination means that selects one piece of metadata from the metadata included in each history as selected metadata, and, if the selected metadata overlaps with metadata included in a history other than the history including the selected metadata, determines the selected metadata and the overlapping metadata that overlaps with the selected metadata as metadata to be deleted from the content, depending on the chronological position of the history including the selected metadata.

[0008] According to the present invention, when deleting metadata included in the history of content such as images, it is possible to prevent omission of deletion.

[0009] 6 is a block diagram showing a first example of the hardware configuration of the history display system according to the first embodiment. FIG. 7 is a block diagram showing a second example (variant) of the hardware configuration of the history display system according to the first embodiment. FIG. 8 is a block diagram showing an example of the hardware configuration of an imaging device included in the history display system. FIG. 9 is a block diagram showing an example of the hardware configuration of a content management device included in the history display system. FIG. 10 is a block diagram showing an example of the hardware configuration of a user terminal included in the history display system. FIG. 11 is a block diagram showing an example of the functional configuration of an imaging device included in the history display system. FIG. 12 is a block diagram showing an example of the functional configuration of a content management device included in the history display system. FIG. 13 is a block diagram showing an example of the functional configuration of a user terminal included in the history display system. FIG. 14 is a sequence diagram showing processing executed between the imaging device, the content management device, and the user terminal. FIG. 15 is a diagram showing a data structure of a history image displayed in the history display system. FIG. 16 is a diagram showing an example of deleting metadata to be deleted from a history (history image). FIG. 17 is a diagram showing an example of history added when a history image is edited. FIG. 18 is a diagram related to deletion target determination processing executed on a user terminal. FIG. 19 is a diagram for explaining determination of metadata to be deleted in step S507 of the flowchart shown in FIG. 5. FIG. 19 is a diagram for explaining determination of metadata to be deleted in step S507 of the flowchart shown in FIG. 5. FIG. 19 is a diagram showing an example of a screen displayed on a display of a user terminal of the history display system according to the second embodiment. 10A and 10B are diagrams illustrating an example of a screen displayed on a display of a user terminal of the history display system according to the third embodiment.FIG. ...

[0010] Each embodiment of the present invention will be described in detail below with reference to the drawings. However, the configurations described in each of the following embodiments are merely examples, and the scope of the present invention is not limited by the configurations described in each embodiment. For example, each component constituting the present invention can be replaced with any configuration that can perform the same function. Furthermore, any component may be added. Furthermore, any two or more configurations (features) of each embodiment can be combined.

[0011] <<First Embodiment>> A first embodiment will be described below with reference to FIGS. 1A to 6B.

[0012] <Configuration of History Display System> FIG. 1A is a block diagram showing a first example of the hardware configuration of a history display system according to the first embodiment. The history display system (information processing system) 100 shown in FIG. 1A is a system capable of processing information related to content files (content). History information (history) is assigned to a content file each time the content is edited after it is first acquired. Furthermore, each piece of history information includes at least one piece of metadata, as described below. In this embodiment, the history display system 100 executes processes such as displaying history information included in a content file or editing the history information. In this embodiment, the content file is an image file containing image data such as a still image or a video. However, the content file is not limited to this, and may be any file containing at least one of image data and audio data. Hereinafter, a content file (image file) containing history information may be referred to as a "history image."

[0013] The history display system 100 includes an imaging device 101, a content management device 102, and a user terminal 103, which are connected to each other so that they can communicate with each other. This allows the imaging device 101, the content management device 102, and the user terminal 103 to transmit and receive various data such as content files to and from each other. For communication in the history display system 100, high-speed network communication that combines wired and wireless communication is preferably used, but is not limited to this. In particular, it is preferable that the imaging device 101 and the content management device 102 are connected via a high-speed wireless LAN.

[0014] 1B is a block diagram showing a second example (variant) of the hardware configuration of the history display system according to the first embodiment. The history display system 100 shown in FIG. 1B includes an imaging device 101 and a history display device 110. In the history display device 110, the user terminal 103 is configured as a device having a content management function similar to the function of the content management device 102. In the following, the history display system 100 will be described as having the configuration shown in FIG. 1A, as a representative example, out of the configurations shown in FIG. 1A and FIG. 1B.

[0015] <Configuration of Devices in the History Display System> FIG. 2A is a block diagram showing an example of the hardware configuration of an imaging device in the history display system. The imaging device 101 shown in FIG. 2A is a digital camera or video camera, and is capable of capturing images as content. The imaging device 101 assigns history information to image data from the time the image data is first acquired. This history information includes at least one piece of metadata. The imaging device 101 includes a CPU 200, a RAM 201, a ROM 202, a network I / F (interface) 204, an input I / F 205, and an RGB sensor 206, which are communicatively connected to one another via a bus 203. The CPU 200 is a computer that controls the operation of the RAM 201, the ROM 202, the network I / F 204, the input I / F 205, and the RGB sensor 206. The ROM 202 pre-stores an operating system (OS), various processing programs, device drivers, and the like. The processing program includes, for example, a history display program for causing the computers of the devices to execute the various components and means (control methods of the information processing system) of the history display system 100. Note that this history display program is not limited to being stored in the imaging device 101, but may be stored in a distributed manner in, for example, the imaging device 101, the content management device 102, and the user terminal 103. The RAM 201 is the main storage memory of the CPU 200. The RAM 201 is also used as a work area and a temporary storage area for expanding the processing program stored in the ROM 202. The network I / F 204 performs remote communication with the content management device 102. This allows the network I / F 204 to send content files to the content management device 102. The input I / F 205 converts RGB images captured by the RGB sensor 206 into a format that can be processed by the imaging device 101.

[0016] FIG. 2B is a block diagram showing an example of the hardware configuration of a content management device included in the history display system. In this embodiment, the content management device 102 shown in FIG. 2B is a cloud-based service, but is not limited to this. The content management device 102 includes a CPU 210, a RAM 211, a ROM 212, a network I / F 214, a storage I / F 215, and a storage 216, which are communicatively connected to each other via a bus 213. The functions of the CPU 210, RAM 211, and ROM 212 are similar to those of the CPU 200, RAM 201, and ROM 202 of the imaging device 101, respectively. The network I / F 214 remotely communicates with the imaging device 101 and the user terminal 103. This allows the network I / F 214 to receive content files from the imaging device 101 or transmit content files to the user terminal 103. In the content management device 102, history information is assigned each time image data included in a content file is edited. This history information also includes at least one piece of metadata. The storage I / F 215 inputs and outputs content files and the like to and from the storage 216. The storage 216 stores content files (history images), programs that the content management device 102 runs internally, an OS, and the like.

[0017] FIG. 2C is a block diagram showing an example of the hardware configuration of a user terminal included in the history display system. The user terminal 103 shown in FIG. 2C is a desktop or notebook personal computer, a tablet terminal, a smartphone, or the like. The user terminal 103 includes a CPU 220, a RAM 221, a ROM 222, a network I / F 224, a storage I / F 225, a storage 226, a display I / F 227, and an input I / F 229, which are communicatively connected to each other via a bus 223. The functions of the CPU 220, RAM 221, and ROM 222 are similar to those of the CPU 200, RAM 201, and ROM 202 of the imaging device 101, respectively. The network I / F 224 remotely communicates with the content management device 102. This allows the network I / F 224 to receive content files from the content management device 102. The storage I / F 225 inputs and outputs content files to and from the storage 226. The storage 226 stores information required for screen display on a display (display means) 228, as well as programs and an OS that are run internally by the user terminal 103. The display I / F 227 is communicatively connected to the display 228 and converts the information into signals that can be displayed on the screen of the display 228. The input I / F 229 is communicatively connected to input devices (not shown) such as a keyboard and a mouse and converts input information from the input devices into a format that can be processed by the user terminal 103.

[0018] FIG. 3A is a block diagram showing an example of the functional configuration of an imaging device included in the history display system. As shown in FIG. 3A , the imaging device 101 includes an imaging unit 300, an image processing unit 301, a history creation unit 302, and a communication unit 303. These functional units are implemented by the CPU 200 by loading a program stored in the ROM 202 into the RAM 201 and executing it. The imaging unit 300 is implemented by the RGB sensor 206. The imaging unit 300 acquires an RGB image captured by the RGB sensor 206 and stores the image in the RAM 201 as needed. An "RGB image" is an image in which the color of any one point (pixel) in an image is represented using the three primary colors of red, green, and blue, and each pixel in the image has red, green, and blue pixel values. The RGB image stored in the RAM 201 is used as an input image to the image processing unit 301. The image processing unit 301 compresses and converts RGB images stored in the RAM 201 into image data in JPEG format, and also creates metadata such as shooting information. The history creation unit 302 creates history information about the origin of the image data, i.e., the time when the image was first acquired, based on the image data and shooting information. The history creation unit 302 also creates a history image by adding the history information to the image data. The communication unit 303 performs data communication with the content management device 102 via the network I / F 204. This allows the communication unit 303 to transmit (upload), for example, a history image in JPEG format to the content management device 102.

[0019] FIG. 3B is a block diagram showing an example of the functional configuration of a content management device included in the history display system. As shown in FIG. 3B , the content management device 102 includes a communication unit 320, a data acquisition unit 321, a data management unit 322, a storage unit 323, a metadata deletion unit (deletion means) 324, and a history editing unit 325. These functional units are implemented by the CPU 210 by loading a program stored in the ROM 212 into the RAM 211 and executing the program. The communication unit 320 performs data communication between the imaging device 101 and the user terminal 103 via the network I / F 214. This allows the communication unit 320 to receive content files (history images) from the imaging device 101 or transmit content files from the content management device 102 to the user terminal 103. The data acquisition unit 321 stores content files from the imaging device 101 in the RAM 211 as needed. In this embodiment, an example will be described in which the content management device 102 receives content files from one imaging device 101, but the present invention is not limited to this example. For example, the content management device 102 may be capable of receiving content files from multiple imaging devices 101. In this case, it is preferable to assign an ID to each imaging device 101 so as to link each imaging device 101 with the content file from that imaging device 101.

[0020] The data management unit 322 links the content files stored in the RAM 211 with the ID of the imaging device 101. Furthermore, the data management unit 322 manages the history images included in the content files in a format that can be quickly read based on the image capture date and time and the date and time the content file was received, and records the history images in the memory unit 323. The memory unit 323 is implemented by the storage 216. The memory unit 326 stores content files from the imaging device 101. The metadata deletion unit 324 performs editing to delete metadata from the content files. The history editing unit 325 adds a hash value of the image data after deletion and editing by the metadata deletion unit 324 and a deletion history of the metadata to the history information. Furthermore, the history editing unit 325 adds a digital signature to the history information to indicate that the deletion and editing by the metadata deletion unit 324 was performed based on an operation by a legitimate user (reliability).

[0021] FIG. 3C is a block diagram showing an example of the functional configuration of a user terminal included in the history display system. As shown in FIG. 3C , the user terminal 103 includes a communication unit 330, a storage unit 331, a data creation unit 332, a display control unit (display control means) 333, a selection unit 334, and a deletion target determination unit (determination means) 335. These functional units are implemented by the CPU 220 by loading a program stored in the ROM 222 into the RAM 221 and executing it. The communication unit 330 communicates data with the content management device 102 over the network via the network I / F 224. This allows the communication unit 330 to receive content files from the content management device 102. The storage unit 331 is implemented by the storage 226. The data creation unit 332 creates tree-structured data in which each history included in the history image is arranged in chronological order. The display control unit 333 controls the display of a list of history images from the content management device 102 on the display 228. Furthermore, the display control unit 333 displays the tree-structured data created by the data creation unit 332 as a tree view on the display 228. The selection unit 334 receives input operation information from an input device via the input I / F 229. In this embodiment, the input operation information includes, for example, selection information of metadata selected from the history on the tree view displayed on the display 228. The deletion target determination unit 335 determines metadata to be deleted (reduction target) based on the selection information received by the selection unit 334.

[0022] <Processing Executed Between Imaging Device, Content Management Device, and User Terminal> FIG. 4A is a sequence diagram showing processing executed between an imaging device, a content management device, and a user terminal. FIG. 4B is a diagram showing the data structure of a history image displayed in the history display system. FIG. 4C is a diagram showing an example of deleting metadata to be deleted from a history (history image). FIG. 4D is a diagram showing an example of history added when a history image is edited. The processing shown in FIG. 4A is started when the photographer starts up the imaging device 101 and performs a shooting start operation, such as pressing the shooting button of the imaging device 101. As shown in FIG. 4A, in step S400, the imaging unit 300 of the imaging device 101 captures an RGB image and stores it in the RAM 201.

[0023] In step S401, the image processing unit 301 of the imaging device 101 compresses and converts the RGB image stored in the RAM 201 in step S400 into a JPEG image. At this time, the image processing unit 301 creates information 900 shown in FIG. 4B . This information 900 includes image data and shooting information. In this embodiment, the image data is an image in JPEG format, but is not limited to this and may be an image in PNG format, which is a standard compression format. The shooting information includes, for example, the shooting date and time, the photographer, the image size, the manufacturer and model of the imaging device 101, various shooting parameters set at the time of shooting, the shooting location, a thumbnail image, etc. Furthermore, the shooting information is generated in accordance with a predetermined technical standard (e.g., EXIF).

[0024] In step S402, the history creation unit 302 of the imaging device 101 creates history information at the origin of the image data based on the image data and shooting information, and assigns the information to the image data. This creates a history image. The history information is included in information 900 (see FIG. 4B ). The history information is information for proving the authenticity (reliability) of the image data. This history information is used, for example, to verify the origin and history of the image data. The history information is created in accordance with a predetermined technical standard (e.g., C2PA) and has a prescribed structure. As shown in FIG. 4B , the history information includes information 901 that includes a history (assertion), a hash value for guaranteeing the history, and a digital signature. This history is also called an "Origin Manifest," which is the history of the origin of the image data, and includes information 910, such as information about the time the image data was captured and the creator of the image data.

[0025] An example of creating a history when generating and editing a history image in accordance with the C2PA standard will now be described with reference to FIG. 4D . As shown in FIG. 4D , for example, assume that image 1000 is captured by the imaging device 101. In this case, a history 1010 is created at the origin of the image data and assigned to image 1000. History 1010 includes history H1, which includes "author1," "Exif1," and "thumb (thumbnail) 31." Then, assume that image 1000 with history 1010 assigned to it is transmitted from imaging device 101 to user terminal 103, where color correction is performed. As a result, image 1000 becomes image 1001, and history 1010 becomes history 1020. In addition to history H1, history 1020 also includes history H2, which includes "author1," "Exif1," and "thumb 32" and indicates color correction. Also, assume that image 1001 has been cropped at user terminal 103, i.e., a process of cutting out a partial image from image 1001 and removing unnecessary parts around the partial image has been performed. As a result, image 1001 becomes image 1002, and history 1020 becomes history 1030. In addition to having history H1 and history H2, history 1030 also has history H3, which includes "author1," "Exif1," and "thumb33" and indicates a crop. Note that history 1020 and history 1030 can also include information about the tools used to edit the image.

[0026] In step S403a, the communication unit 303 of the imaging device 101 transmits (uploads) the history image created in step S402 to the content management device 102. This history image is, for example, image 1000 having history 1010. Note that steps S400 to S403a are repeated while the photographer is taking pictures.

[0027] In step S403b, the communication unit 330 of the user terminal 103 transmits the history image to the content management device 102. This history image is, for example, the image 1002 having the history 1030. Note that steps S400 to S403a are repeated while the photographer is taking pictures, but this does not apply to step S403b.

[0028] In step S404, the data acquisition unit 321 of the content management device 102 acquires (receives) the history image transmitted in step S403a and also acquires the history image transmitted in step S403b via the communication unit 320. These history images are stored in the RAM 211 of the content management device 102.

[0029] In step S405, the data management unit 322 of the content management device 102 associates the history image stored in the RAM 211 in step S404 with the ID of the imaging device 101. Furthermore, the data management unit 322 stores the history image in the storage unit 323 in a format that can be quickly read, based on the shooting date and time of the image and the date and time of receiving the history image.

[0030] In step S406a, the communication unit 330 of the user terminal 103 transmits (requests) a request to acquire a history image list to the content management device 102.

[0031] In step S406b, the communication unit 330 acquires a list of history images as a response to the request in step S406a from the content management device 102. The list of history images is saved in the RAM 221.

[0032] In step S407, the user terminal 103 executes a deletion target determination process for the history image stored in step S406b in the RAM 221. The deletion target determination process will be described later.

[0033] In step S408, the communication unit 330 of the user terminal 103 requests the content management device 102 to delete metadata based on the result of the deletion target determination process in step S407. This deletion request includes the history image to be edited. The deletion request also includes information regarding the metadata to be deleted from the metadata included in the history image.

[0034] In step S409, the metadata deletion unit 324 of the content management device 102 deletes the metadata to be deleted from the history image to be edited based on the deletion request in step S408. FIG. 4C is a diagram showing an example of deleting metadata to be deleted from a history (history image). As shown in FIG. 4C, information 910 includes "Key: Author, Value: Yamada Taro," which is one piece of metadata. When value 920 included in this metadata is deleted, information 910 becomes information 911. In information 911, the "value" corresponding to "Key: Author" in metadata 930 becomes blank. In addition, editing history 931 indicating that the "value" has become blank is added to information 911.

[0035] In step S410, the history editing unit 325 of the content management device 102 calculates hash values ​​for each of the image data, shooting information, and history after the deletion of the metadata to be deleted, and stores them in the RAM 211. The history editing unit 325 also generates an electronic signature to demonstrate that the deletion and editing were performed by a legitimate user, i.e., to demonstrate authenticity. The electronic signature includes information indicating the signature value, the signer, and the date and time of signing. The signature value is generated by encrypting the hash value stored in the RAM 211 using a private key prepared in advance. A public key (certificate) that pairs with this private key is also included in the electronic signature. The history editing unit 325 adds the history indicating that the metadata to be deleted has been deleted, the hash value, and the electronic signature to the history information as an editing history. Through this processing, a new history image is created.

[0036] In step S411 after step S410 is executed, the process returns to step S405, and the subsequent steps are executed in sequence. Note that in step S405, the data management unit 322 of the content management device 102 associates the history image created in step S410 with the ID of the imaging device 101, and stores the associated image in the storage unit 323.

[0037] Furthermore, in step S412 after step S410 is executed, the communication unit 320 of the content management device 102 notifies the user terminal 103 of the completion of the metadata deletion in step S409.

[0038] In step S413, the communication unit 330 of the user terminal 103 receives the notification that the metadata deletion in step S412 has been completed, and the process returns to step S406a, where the subsequent steps are executed in sequence.

[0039] <Deletion Target Determination Process> Fig. 5 is a diagram relating to the deletion target determination process executed on the user terminal. The flowchart in Fig. 5 is a flowchart illustrating the deletion target determination process, which is a subroutine (step S407) in the sequence diagram shown in Fig. 4A. The screen diagram in Fig. 5 is a diagram illustrating an example of a screen displayed on the display of the user terminal. A program based on the flowchart shown in Fig. 5 is started, for example, when an instruction to start the deletion target determination process is issued on the user terminal 103. As shown in Fig. 5, in step S500, the CPU 220 of the user terminal 103 reads a list of history images stored in the RAM 221 (see step S406b).

[0040] In step S501, the display control unit 333 of the user terminal 103 displays a list of the history images read in step S500 on the display 228. As a result, for example, a history image list screen 510 shown in Fig. 5 is displayed on the display 228. The history image list screen 510 includes history image 001.jpg to history image 008.jpg, which have a JPEG file format.

[0041] In step S502, the CPU 220 of the user terminal 103 determines whether one image from history image 001.jpg to history image 008.jpg has been selected from the history image list screen 510 displayed on the display 228 in step S501. If the determination in step S502 indicates that one image has been selected, the process proceeds to step S503. On the other hand, if the determination in step S502 indicates that no image has been selected, the process returns to step S501, and the subsequent steps are executed sequentially. Here, as an example, it is assumed that history image 003.jpg has been selected from history image 001.jpg to history image 008.jpg. This selection operation is performed, for example, by clicking on history image 003.jpg with a mouse, which is an input device connected to the input I / F 229 of the user terminal 103. Then, the selection unit 334 of the user terminal 103 selects history image 003.jpg. Input information indicating that jpg has been selected is taken in.

[0042] In step S503, the data creation unit 332 of the user terminal 103 creates tree-structured data in which the histories included in the history image 003.jpg are arranged in chronological order, and stores the data in the RAM 221.

[0043] In step S504, the display control unit 333 of the user terminal 103 reads the tree-structured data saved in the RAM 221 in step S503 and displays the data as a tree view on the display 228. As a result, the display 228 displays, for example, a tree view (screen) 530 shown in FIG. 5 (display control process). The tree view 530 includes history image 003.jpg, histories 531, 532, 533, a back button 534, and a delete button 535. History 533 is the history at the origin of history image 003.jpg, and is similar to history H1, for example. History 532 is the history added when the first edit was performed on history image 003.jpg after history image 003.jpg was acquired, and is similar to history H2, for example. History 531 is the history added when the first edit was performed on history image 003.jpg after history image 003.jpg was acquired. This is the history given when the jpg was edited for the second time, and is the same as the history H3, for example.

[0044] The histories 531 to 533 are displayed in chronological order, separated from one another (enclosed in a rectangle). In this embodiment, they are arranged in the order in which they were assigned to the history image 003.jpg, that is, arranged from bottom to top in order of oldest to newest. This allows the order in which the histories 531 to 533 were assigned to be grasped, that is, visually confirmed, on the tree view 530. Note that the histories 531 to 533 are not limited to being arranged from bottom to top in order of oldest to newest, and may be arranged from bottom to top, for example. Furthermore, the histories 531 to 533 are not limited to being arranged along the vertical direction of the tree view 530, and may be arranged along the horizontal direction of the tree view 530, for example.

[0045] Furthermore, the history 531 includes metadata "author1," "Exif1," and "thumb33," which are displayed in a selectable manner. These metadata are arranged in the section of the history 531 along the vertical direction of the tree view 530. The history 532 includes metadata "author1," "Exif1," and "thumb32," which are displayed in a selectable manner. These metadata are arranged in the section of the history 532 along the vertical direction of the tree view 530. The history 533 includes metadata "author1," "Exif1," and "thumb31," which are displayed in a selectable manner. These metadata are arranged in the section of the history 533 along the vertical direction of the tree view 530. Note that the metadata in each section may be arranged horizontally in the tree view 530. By operating (pressing) the back button 534, the user can return to the history image list screen 510. By operating the delete button 535, an instruction is given to delete the metadata to be deleted (see step S507) determined by the deletion target determination unit 335 (described later) from the history image 003.jpg.

[0046] In step S505, the selection unit 334 of the user terminal 103 determines whether the back button 534 in the tree view 530 has been operated. This operation is performed, for example, by clicking the back button 534 with a mouse, which is an input device connected to the input I / F 229 of the user terminal 103. If it is determined in step S505 that the back button 534 has been operated, the process returns to step S501, and the subsequent steps are executed sequentially. On the other hand, if it is determined in step S505 that the back button 534 has not been operated, the process proceeds to step S506.

[0047] In step S506, the selection unit 334 of the user terminal 103 determines whether or not the user has selected one piece of metadata that the user wishes to delete from among the metadata included in the histories 531 to 533. Hereinafter, this selected metadata will be referred to as "selected metadata." The operation of selecting the selected metadata is performed, for example, by clicking on the metadata to be selected with a mouse, which is an input device connected to the input I / F 229 of the user terminal 103. If it is determined in step S506 that the selected metadata has been selected, the process proceeds to step S507. On the other hand, if it is determined in step S506 that the selected metadata has not been selected, the process returns to step S504, and the subsequent steps are executed in sequence.

[0048] In step S507, the deletion target determining unit 335 of the user terminal 103 determines the metadata to be deleted (determination step). The determination of the metadata to be deleted will be described later with reference to FIG.

[0049] In step S508, the display control unit 333 of the user terminal 103 updates the display of the history and highlights the metadata to be deleted determined in step S507 (see FIGS. 6A and 6B ). This highlighting makes it possible to grasp the metadata to be deleted. Note that the method for highlighting the metadata to be deleted is not particularly limited, and examples include a method of highlighting the metadata to be deleted, a method of showing the metadata to be deleted in bold, etc.

[0050] In step S509, the selection unit 334 of the user terminal 103 determines whether the Delete button 535 in the tree view 530 has been operated. This operation is performed, for example, by clicking the Delete button 535 with a mouse, which is an input device connected to the input I / F 229 of the user terminal 103. If the determination in step S509 determines that the Delete button 535 has been operated, the process ends. This allows the metadata deletion unit 324 of the content management device 102 to delete the metadata to be deleted determined in step S507 from the history image 003.jpg (see step S409). On the other hand, if the determination in step S509 determines that the Delete button 535 has not been operated, the process returns to step S504, and the subsequent steps are executed sequentially.

[0051] 6A and 6B are diagrams illustrating the determination of metadata to be deleted in step S507 of the flowchart shown in FIG. 5 . As shown in FIG. 6A , assume that the user selects, for example, metadata 601 as the selected metadata. The metadata 601 is "Exif1" included in the history 531. In this case, the metadata 601 overlaps with metadata 602 included in history 532 (another history) other than the history 531 including the metadata 601, and metadata 603 included in history 533 (another history). The metadata 602 is "Exif1" included in the history 533. The metadata 601 is derived from the metadata 602, i.e., is inherited as is. The metadata 603 is "Exif1" included in the history 533. The metadata 602 is derived from the metadata 602, i.e., is inherited as is. In the history display system 100, when the user selects metadata 601 as the metadata to be deleted, it is determined that the user also wants to retroactively delete its derived metadata 602 and metadata 603. As a result, it is possible to determine the selected metadata 601 and the duplicate metadata 602 and 603 that overlap with the selected metadata as the metadata to be deleted from the history image 003.jpg.

[0052] 6B , suppose the user wishes to retain metadata 601 included in the latest history 531 (history H3) and selects, for example, metadata 602 as selected metadata. In this case, the history display system 100 determines that the user's selection of metadata 602 as the metadata to be deleted means that the user also wishes to retroactively delete metadata 603, from which metadata 602 is derived. As a result, it is possible to determine metadata 602, which is the selected metadata, and metadata 603, which is duplicate metadata that overlaps with the selected metadata, as the metadata to be deleted from the history image 003.jpg.

[0053] In this way, in the history display system 100, the duplicate metadata determined to be deleted is metadata included in histories that were added at a time earlier than the history including the selected metadata. For example, in the case of FIG. 6A , the duplicate metadata determined to be deleted is metadata included in histories 532 and 533 that were added at a time earlier than history 531 including the selected metadata. In the case of FIG. 6B , the duplicate metadata determined to be deleted is metadata included in history 533 that was added at a time earlier than history 532 including the selected metadata. With this configuration, the history display system 100 can delete the metadata collectively when deleting multiple pieces of the same type of metadata included in the histories of the history image 003.jpg. This makes it possible to quickly and easily prevent metadata from being overlooked, thereby preventing, for example, confidential information or personal information from being forgotten to be erased.

[0054] In addition, depending on various conditions such as the type of content file, the history display system 100 can determine that the duplicate metadata to be deleted is metadata included in a history that was added at a later time than the history including the selected metadata. Alternatively, the duplicate metadata to be deleted can be metadata included in a history that was added before or after the history including the selected metadata. In this way, the history display system 100 can appropriately determine the selected metadata and the duplicate metadata as the metadata to be deleted depending on the chronological position of the history including the selected metadata. This configuration contributes to preventing metadata from being overlooked during deletion.

[0055] <<Second Embodiment>> A second embodiment will be described below with reference to Fig. 7, focusing on differences from the previously described embodiment, and a description of similar points will be omitted. This embodiment is similar to the first embodiment except that the function of the deletion target determination unit is different from that of the first embodiment. In this embodiment, a case will be described in which metadata is deleted consecutively from a plurality of history images. Fig. 7 is a diagram showing an example of a screen displayed on the display of a user terminal of the history display system according to the second embodiment.

[0056] The tree view 520 shown in FIG. 7 includes a history image 002.jpg (first content), history 521 (history H4), history 522 (history H3), history 523 (history H2), history 524 (history H1), a back button 534, and a delete button 535. The history 521 is a history derived from the history 522 and history 523. Therefore, the histories 522 and 523 are both histories at the same hierarchical level. The history 523 is a history derived from the history 524. The history 521 includes "author1," "Exif1," and "thumb24" as metadata. The history 522 includes "Exif2" and "thumb23" as metadata. The history 523 includes "author1", "Exif1", and "thumb22" as metadata. The history 524 includes "author1", "Exif1", and "thumb21" as metadata.

[0057] As shown in FIG. 7 , suppose the user selects metadata 701, for example, as selected metadata from the tree view 520. The metadata 701 is "author1" included in the history 521. In this case, the metadata 701 is determined to be the metadata to be deleted. Furthermore, metadata 702 ("author1") of the history 523, from which the history 521 is derived, and metadata 703 ("author1") of the history 524 are duplicated metadata, and are therefore determined to be the metadata to be deleted. Then, suppose that, following the selection of the metadata 701 in the tree view 520, a selection operation for the selected metadata is performed on the tree view 530 shown in FIG. 7 (reduction operation). As described above, the tree view 530 includes the history image 003.jpg (second content) and the history 531 to the delete button 535. At this time, the deletion target determination unit 335 determines the history 524, which is the starting point of the history image 002.jpg, and the history image 003.jpg. The metadata 611, 612, and 613 included in the history image 003.jpg are then compared with the history 533 of the origin of the history 531. If, as a result of this comparison, the information on the shooting time, shooting location, and shooting equipment included in the histories 524 and 533 is the same, then "author1" in the history image 003.jpg is considered to be the metadata to be deleted, just like the metadata "author1" to be deleted in the history image 002.jpg. As a result, the metadata 611, metadata 612, and metadata 613 included in the history image 003.jpg are considered to be the metadata to be deleted. The metadata 611 is "author1" included in the history 531. The metadata 612 is "author1" included in the history 532. The metadata 613 is "author1" included in the history 533.

[0058] In this way, the history 524 when the history image 002.jpg was first acquired and the history 533 when the history image 003.jpg was first acquired may be the same (or similar). In this case, the deletion target determination unit 335 can reflect the metadata to be deleted determined for the history image 002.jpg as the metadata to be deleted for the history image 003.jpg. This makes it possible to prevent metadata from being overlooked when deleting metadata even if there are multiple history images for which metadata is to be deleted. Note that the history display system 100 may issue a notification urging the user to delete the metadata determined as the metadata to be deleted. This notification may be issued, for example, on the display 228 or via a speaker (not shown).

[0059] <<Third Embodiment>> A third embodiment will be described below with reference to FIGS. 8A and 8B. Differences from the previous embodiments will be mainly described, and similar details will not be described again. This embodiment is similar to the first embodiment except for the function of the display control unit. In this embodiment, a case will be described in which all information useful for verifying the authenticity of a history image is deleted from the history. FIGS. 8A and 8B are diagrams illustrating an example of a screen displayed on a display of a user terminal in a history display system according to the third embodiment. As shown in FIG. 8A, assume that metadata 601 (Exif1) is selected as the selected metadata. In this case, as described above, metadata 601 to 603 are determined as metadata to be deleted. "Exif1" includes information such as the shooting time and shooting location. In this embodiment, "Exif1" relates to the authenticity (reliability) of the history image 003.jpg, regardless of the location of the history. In other words, it is information useful for verifying the authenticity of the history image 003.jpg. If the metadata 601 to 603 are deleted as they are, it may become difficult to guarantee the authenticity of the history image 003.jpg.

[0060] Therefore, in this embodiment, the display control unit 333 displays a warning mark 804 to prompt the user to remove the metadata 601 to 603 determined as the metadata to be deleted from the list of metadata to be deleted. This allows the user to understand that it is preferable to remove the metadata 601 to 603 from the list of metadata to be deleted and to perform the removal. This subsequently prevents the metadata 601 to 603 from being deleted, thereby ensuring the authenticity of the history image 003.jpg. Note that the warning mark 804 is placed to the left of the metadata 601, but this is not a limitation; it may be placed adjacent to any of the metadata 601 to 603. The removal operation for the metadata to be deleted is performed, for example, by clicking the metadata 601 to 603 with a mouse, which is an input device connected to the input I / F 229 of the user terminal 103. The removal operation also removes the highlighted display of the metadata 601 to 603.

[0061] Also, as shown in FIG. 8B , assume that metadata 602 (Exif1) is selected as the selected metadata. In this case, as described above, metadata 602 and metadata 603 are determined to be the metadata to be deleted, but metadata 601 can remain as is without being deleted. The metadata 601 can guarantee the authenticity of the history image 003.jpg. Note that, because metadata 601 remains, the display of the warning mark 804 can be omitted in the tree view 530 shown in FIG. 8B .

[0062] Although preferred embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications and variations are possible within the scope of the gist of the present invention. The present invention can also be realized by supplying a program that realizes one or more functions of the above-described embodiments to a system or device via a network or storage medium, and having one or more processors in the computer of the system or device read and execute the program. The present invention can also be realized by a circuit (e.g., an ASIC) that realizes one or more functions.

[0063] Furthermore, in the history display system 100, for example, the content management device 102 (herein referred to simply as the "server") may be located outside Japan, while the user terminal 103, which serves as a terminal device, may be located within Japan. Even in this case, files and data may be transmitted from the server to the terminal device, and the terminal device may receive the files and data. Even if the server is located outside Japan, the transmission and reception (transmission and reception) of files and data in this system are performed as a single entity. Since the system functions when a terminal device located within Japan receives the files and data, the transmission and reception can be considered to have occurred within Japan. Furthermore, even if the server is located outside Japan and the terminal device is located within Japan, the terminal device can still perform the main functions of the system, and the benefits of those functions can be realized within Japan. For example, even if the server is located outside Japan, if the terminal device constituting the system is located within Japan, the system can be used within Japan using the terminal device. Furthermore, the use of this system may affect the economic interests of, for example, the patent holder.

[0064] This application claims priority based on Japanese Patent Application No. 2024-063848, filed April 11, 2024, the entire contents of which are incorporated herein by reference.

[0065] REFERENCE SIGNS LIST 100 History display system 101 Imaging device 102 Content management device 103 User terminal 228 Display 324 Metadata deletion unit 332 Data creation unit 333 Display control unit 334 Selection unit 335 Deletion target determination unit

Claims

1. An information processing system for processing information related to content, wherein a history is assigned to the content from the time the content is first acquired until each subsequent edit, and each history includes at least one piece of metadata, the information processing system comprising: a display control means for displaying the histories in chronological order and controlling the display of the metadata included in each history in a selectable manner; and a determination means for selecting one piece of metadata from the metadata included in each history as selected metadata, and when the selected metadata overlaps with metadata included in a history other than the history including the selected metadata, determining the selected metadata and the overlapping metadata that overlaps with the selected metadata as metadata to be deleted from the content, depending on the position in the chronological order of the history including the selected metadata.

2. The information processing system described in claim 1, characterized in that the duplicate metadata determined to be the metadata to be deleted is metadata included in a history that was assigned at a time earlier than the history that includes the selected metadata.

3. The information processing system described in claim 1, characterized in that the duplicate metadata determined to be the metadata to be deleted is metadata contained in a history that was added at a later time than the history containing the selected metadata.

4. The information processing system described in claim 1, characterized in that the duplicate metadata determined to be the metadata to be deleted is metadata included in a history that was assigned at a time before or after the history that includes the selected metadata.

5. An information processing system as described in claim 1, further comprising a display means for displaying a screen, wherein the display control means, when displaying each of the histories in chronological order, arranges each of the histories on the screen from bottom to top in the order in which they were assigned to the content.

6. An information processing system as described in claim 1, further comprising a display means for displaying a screen, wherein the display control means displays each history in sections on the screen, and arranges the metadata within each section of the history.

7. An information processing system as described in claim 1, further comprising a display means for displaying a screen, wherein the display control means highlights and displays the metadata to be deleted determined by the determination means on the screen.

8. An information processing system as described in claim 1, further comprising a display means for displaying a screen, wherein the display control means enables an instruction to delete the metadata to be deleted determined by the determination means from the content on the screen.

9. The information processing system described in claim 1, characterized in that if the metadata determined as the metadata to be deleted relates to the authenticity of the content, the display control means displays information prompting the user to remove the metadata determined as the metadata to be deleted from the list of metadata to be deleted.

10. The information processing system described in claim 1, characterized in that the content includes a first content and a second content, and if the history when the first content was first acquired is the same as or similar to the history when the second content was first acquired, the determination means reflects the metadata to be deleted determined for the first content as the metadata to be deleted in the second content.

11. An information processing system as described in claim 1, further comprising a deletion means for deleting the metadata to be deleted determined by the determination means from the content, wherein the deletion means, when deleting the metadata to be deleted, adds information to the content that guarantees the reliability of the deletion.

12. The information processing system according to claim 1, wherein the content includes at least one of image data and audio data.

13. A method for controlling an information processing system that processes information related to content, wherein the content is assigned a history each time it is edited after it is first acquired, and each history includes at least one piece of metadata, the control method for an information processing system comprising: a display control step of displaying each of the histories in chronological order and controlling the display of the metadata included in each history in a selectable manner; and a determination step of selecting one piece of metadata from the metadata included in each history as selected metadata, and, if the selected metadata overlaps with metadata included in a history other than the history including the selected metadata, determining the selected metadata and the overlapping metadata that overlaps with the selected metadata as metadata to be deleted from the content, depending on the position in the chronological order of the history including the selected metadata.

14. A program for causing a computer to execute each means of the information processing system according to claim 1.

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