Content generation device, method for controlling content generation device, and program

Abstract

To provide a content generation device which allows a user to select an image file to use according to a purpose.SOLUTION: A digital camera 100 generates image data 603c and metadata 601c including original comparison information. The digital camera 100 generates a hash value on the basis of the metadata 601c including the original comparison information and the image data 603c, and generates an image file 600c including the hash value, the image data 603c, and the metadata 601c including the original comparison information as well as generating an image file not including the original comparison information.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a content generation device, a control method for a content generation device, and a program. [Background technology]

[0002] In recent years, information sharing via the Internet has become very popular, and anyone can publish and transmit various information to an unspecified number of people. It has also become possible to perform various types of processing on digital images. In this situation, information may be sent from an unreliable source, or published information may have been illegally tampered with, so there is a demand for technology to guarantee the authenticity of published and transmitted information.

[0003] For example, the technology disclosed in Patent Document 1 has been proposed as a technology for guaranteeing the authenticity of information that is made public or transmitted. In Patent Document 1, a digital camera has a function for assigning a hash value of data combining image data and additional information, such as the image date and time, to an image file that contains image data obtained by shooting and additional information. This makes it possible to use the hash value assigned to the image file to determine whether the image data or additional information included in the image file has been changed since the image was shot.

[0004] Also, in order to authenticate the origin, history, and history of an image file, a technology has been proposed that adds history information to the image file, which indicates the editing content performed on the image file (see Non-Patent Document 1). For example, when a photo is taken, additional information such as the shooting location (e.g., EXIF ​​information), and a thumbnail image that is a reduced version of the image data at the time of shooting, are added to the image file as history information. Also, every time the image file is edited, new history information including the editing content is added. From the history information included in the image file, the user can understand how the image data and additional information have been edited since the time of shooting. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2008-5421 A [Non-patent literature]

[0006] [Non-Patent Document 1] 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> Summary of the Invention [Problem to be solved by the invention]

[0007] However, since the purpose of using an image file differs from user to user, when an image file containing the above-mentioned history information is generated, the user may feel inconvenienced. For example, when an image file is made public to a third party, the user may apply mosaic processing to the face of a person included in the image data or delete the information of the shooting location included in the additional information from the viewpoint of protecting privacy, rather than malicious tampering. Even if an image file is edited for the purpose of anonymization in this way, in the technology of the above-mentioned non-patent document 1, the history information at the time of shooting, for example, the information of the shooting location and the thumbnail image at the time of shooting, remains, and privacy is no longer protected. In this way, it is preferable that an image file that does not contain history information is provided to a user who uses the image file. On the other hand, it is preferable that an image file containing history information is provided to a user who wants to know how the image data and additional information have been edited since the time of shooting. In this way, the appropriate image file configuration differs depending on the purpose of use, but conventionally, it is not possible to allow a user to select an image file to be used according to the purpose.

[0008] An object of the present invention is to provide a content generation device, a control method for a content generation device, and a program that enable a user to select an image file to be used depending on a purpose. [Means for solving the problem]

[0009] In order to achieve the above-mentioned object, the content generation device of the present invention is characterized by comprising: a means for generating content; a means for generating metadata including original comparison information for grasping changes from the time of generation of a content file including the content; a means for generating a hash value based on the metadata including the original comparison information and the content; a means for generating a first content file including the content, the metadata including the original comparison information and the hash value; and a means for generating a second content file including the content but not including the original comparison information. Effect of the Invention

[0010] According to the present invention, it is possible to allow a user to select an image file to be used depending on the purpose. [Brief description of the drawings]

[0011] [Figure 1] 1 is an external view of a digital camera serving as a content generation device according to an embodiment of the present invention. [Diagram 2] 2 is a block diagram showing an example of the configuration of the digital camera shown in FIG. 1. [Diagram 3] 4 is a flowchart showing the procedure of a shooting control process executed by the digital camera of FIG. [Figure 4] FIG. 2 is a diagram showing an example of a screen displayed on the display unit in FIG. [Diagram 5] 4 is a flowchart showing the procedure of the photographing process in S317 of FIG. 3. [Figure 6] 2 is a diagram showing an example of the structure of an image file generated by the digital camera of FIG. 1. [Figure 7] 11 is a table showing image files generated according to conditions in the present embodiment. [Figure 8] 4 is a flowchart showing the procedure of the playback process in S318 of FIG. 3. [Figure 9] FIG. 2 is a diagram showing an example of a screen displayed on the display unit in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, the embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the invention according to the claims. Although the embodiments describe a number of features, not all of these features are essential to the invention, and the features may be combined in any manner.

[0013] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which a content generating device of the present invention is applied to a digital camera capable of taking still images and recording moving images will be described in detail below with reference to the accompanying drawings.

[0014] First, the configuration and functions of a digital camera 100 serving as a content generation device according to the present embodiment will be described with reference to FIGS.

[0015] Fig. 1(a) is a front perspective view of the digital camera 100 with the lens unit 150 removed. Fig. 1(b) is a rear perspective view of the digital camera 100.

[0016] 1, the display unit 28 is an outside-finder display unit that displays images and various information, and is a display device such as an LCD provided on the rear surface of the camera body. The display unit 28 is provided with a touch panel 70a. The touch panel 70a is a touch operation member that can detect contact (touch operation) with the display surface (touch operation surface) of the display unit 28.

[0017] The outside viewfinder display unit 43 is a display unit provided on the top surface of the digital camera 100, and displays various settings of the digital camera 100, including the shutter speed and aperture. The shutter button 61 is an operation member for issuing a shooting instruction. The mode change switch 60 is an operation member for switching between various modes. The terminal cover 40 is a cover that protects a connector (not shown) for a connection cable or the like that connects the digital camera 100 to an external device.

[0018] The main electronic dial 71 is a rotary operation member, and by turning this main electronic dial 71, settings such as shutter speed and aperture can be changed. The power switch 72 is an operation member that switches the power of the digital camera 100 between ON and OFF. The sub electronic dial 73 is a rotary operation member, and by turning this sub electronic dial 73, the selection frame (cursor) can be moved, images can be forwarded, and the like. The four-way key 74 is configured so that the up, down, left, and right parts can each be pressed, and processing can be performed according to the part of the four-way key 74 that is pressed. The SET button 75 is a push button, and is mainly used to confirm a selection item, etc.

[0019] The video button 76 is used to start or stop video shooting (recording). The AE lock button 77 is a push button, and pressing the AE lock button 77 in a shooting standby state fixes the exposure state. The enlargement button 78 is an operation button for switching the enlargement mode ON and OFF in the live view display (LV display) in the shooting mode. By turning the enlargement mode ON and then operating the main electronic dial 71, the live view image (LV image) can be enlarged or reduced. In the playback mode, the enlargement button 78 functions as an operation button for enlarging the playback image or increasing its magnification. The playback button 79 is an operation button for switching between the shooting mode and the playback mode. By pressing the playback button 79 during the shooting mode, the mode is switched to the playback mode, and the latest image among the images recorded in the recording medium 200 in FIG. 2 described later can be displayed on the display unit 28. The menu button 81 is a push button used to perform an instruction operation for displaying a menu screen, and when the menu button 81 is pressed, a menu screen on which various settings can be made is displayed on the display unit 28. The user can intuitively make various settings using the menu screen displayed on the display unit 28, the four-way key 74, and the SET button 75.

[0020] The touch bar 82 (multifunction bar: M-Fn bar) is a line-shaped touch operation member (line touch sensor) capable of receiving touch operations. The touch bar 82 is disposed at a position where it can be touched (touched) by the thumb of the right hand when the grip part 90 is held in the right hand (held with the little finger, ring finger, and middle finger of the right hand) so that the shutter button 61 can be pressed with the index finger of the right hand. That is, the touch bar 82 is disposed at a position where it can be operated when the eyepiece part 16 is placed close to the viewfinder and the user is in a position (shooting posture) so that the shutter button 61 can be pressed at any time. The touch bar 82 is a reception part that can receive tap operations (operations of touching and releasing without moving within a predetermined period) and left and right slide operations (operations of touching and then moving the touch position while keeping the touch) on the touch bar 82. The touch bar 82 is an operation member different from the touch panel 70a and does not have a display function.

[0021] The communication terminal 10 is a communication terminal for the digital camera 100 to communicate with the lens unit 150 in FIG. 2, which will be described later. The eyepiece 16 is an eyepiece for the eyepiece finder 17 (a peer-in type finder). A user can view an image displayed on an internal EVF 29 (Electronic View Finder) in FIG. 2, which will be described later, through the eyepiece 16. The eyepiece detection unit 57 is an eyepiece detection sensor that detects whether a user (photographer) has placed his / her eye on the eyepiece 16. The lid 202 is a lid for a slot that stores a recording medium 200 in FIG. 2, which will be described later. The grip unit 90 is a holding unit that is shaped so that the user can easily hold it with the right hand when holding the digital camera 100. The shutter button 61 and the main electronic dial 71 are located at positions that can be operated with the index finger of the right hand when the digital camera 100 is held by gripping the grip unit 90 with the little finger, ring finger, and middle finger of the right hand. In the same state, the sub electronic dial 73 and touch bar 82 are disposed at positions that can be operated with the thumb of the right hand. The thumb rest section 91 (thumb standby position) is a grip member provided on the rear side of the digital camera 100 at a position where it is easy to place the thumb of the right hand that is holding the grip section 90 when none of the operation members are being operated. The thumb rest section 91 is made of a rubber member or the like to enhance holding power (grip feeling).

[0022] FIG. 2 is a block diagram showing an example of the configuration of the digital camera 100 in FIG. 1. In FIG. 2, the lens unit 150 is a lens unit equipped with an interchangeable photographing lens, and is detachable from the digital camera 100. The lens 103 is usually composed of a plurality of lenses, but is shown here as a single lens for simplicity. The communication terminal 6 is a communication terminal through which the lens unit 150 communicates with the digital camera 100, and the communication terminal 10 is a communication terminal through which the digital camera 100 communicates with the lens unit 150. The lens unit 150 communicates with the system control unit 50 via these communication terminals 6 and 10. The lens unit 150 controls the aperture 1 via the aperture drive circuit 2 by the internal lens system control circuit 4. The lens unit 150 adjusts the focus by displacing the position of the lens 103 via the AF drive circuit 3 by the lens system control circuit 4.

[0023] The shutter 101 is a focal plane shutter that can freely control the exposure time of the imaging unit 22 under the control of the system control unit 50 .

[0024] The imaging unit 22 is an image sensor configured with an imaging element such as a CCD or a CMOS that converts an optical image into an electrical signal. The imaging unit 22 may include an imaging surface phase difference sensor that outputs defocus amount information to the system control unit 50. The A / D converter 23 converts the analog signal output from the imaging unit 22 into a digital signal.

[0025] The image processing unit 24 performs predetermined processing (pixel interpolation, resizing such as reduction, color conversion, etc.) on the data from the A / D converter 23 or the data from the memory control unit 15. The image processing unit 24 also performs predetermined arithmetic processing using the captured image data, and the system control unit 50 performs exposure control and distance measurement control based on the arithmetic results obtained by the image processing unit 24. This allows TTL (through-the-lens) type AF (autofocus) processing, AE (autoexposure) processing, EF (flash pre-flash) processing, etc. to be performed. The image processing unit 24 further performs predetermined arithmetic processing using the captured image data, and performs TTL type AWB (auto white balance) processing based on the obtained arithmetic results.

[0026] The output data from the A / D converter 23 is written to the memory 32 via the image processing unit 24 and the memory control unit 15. Alternatively, the output data from the A / D converter 23 is written to the memory 32 via the memory control unit 15 without going through the image processing unit 24. The memory 32 stores image data obtained by the imaging unit 22 and converted into digital data by the A / D converter 23, and image data to be displayed on the display unit 28 and EVF 29. The memory 32 has a storage capacity sufficient to store a predetermined number of still images, a predetermined period of moving images, and audio.

[0027] The memory 32 also serves as a memory (video memory) for image display. The D / A converter 19 converts the image display data stored in the memory 32 into an analog signal and supplies it to the display unit 28 or the EVF 29. The image data for display written in the memory 32 is displayed on the display unit 28 or the EVF 29 via the D / A converter 19. The display unit 28 and the EVF 29 perform display according to the analog signal from the D / A converter 19. A digital signal that has been A / D converted by the A / D converter 23 and stored in the memory 32 is converted into an analog signal in the D / A converter 19, and the analog signal is sequentially transferred to and displayed on the display unit 28 or the EVF 29, thereby performing a live view display (LV). Hereinafter, an image displayed in the live view display is referred to as a live view image (LV image).

[0028] The system control unit 50 is a control unit consisting of at least one processor and / or at least one circuit, and controls the entire digital camera 100. The system control unit 50 is both a processor and a circuit. The system control unit 50 executes programs recorded in the non-volatile memory 56 to realize each process of this embodiment, which will be described later. The system control unit 50 also performs display control by controlling the memory 32, the D / A converter 19, the display unit 28, the EVF 29, etc.

[0029] The system memory 52 is, for example, a RAM. The system control unit 50 loads constants and variables for the operation of the system control unit 50, programs read from the non-volatile memory 56, and the like, in the system memory 52.

[0030] The non-volatile memory 56 is an electrically erasable and recordable memory, such as an EEPROM. Constants, programs, and the like for operating the system control unit 50 are recorded in the non-volatile memory 56. The programs referred to here are programs for executing various flowcharts described later in this embodiment.

[0031] The system timer 53 is a timing unit that measures the time used for various controls and the time of a built-in clock.

[0032] The communication unit 54 transmits and receives video signals and audio signals to and from an external device connected wirelessly or via a wired cable. The communication unit 54 can also connect to a wireless LAN (Local Area Network) or the Internet. The communication unit 54 can also communicate with an external device via Bluetooth (registered trademark) or Bluetooth Low Energy. The communication unit 54 can transmit images (including LV images) captured by the imaging unit 22 and images recorded in the recording medium 200, and can also receive various information such as image data and a video recording start instruction from an external device. When the communication unit 54 receives a video recording start instruction from an external device, it can notify the user of the receipt of the instruction by causing the light-emitting unit 102 to light up or by generating an electronic sound from the speaker 92. Examples of external devices with which the communication unit 54 communicates include a smartphone, a tablet terminal, and a desktop PC.

[0033] The attitude detection unit 55 detects the attitude of the digital camera 100 with respect to the direction of gravity. Based on the attitude detected by the attitude detection unit 55, it is possible to determine whether the image captured by the imaging unit 22 was captured with the digital camera 100 held horizontally or vertically. The system control unit 50 can add orientation information corresponding to the attitude detected by the attitude detection unit 55 to the image file of the image captured by the imaging unit 22, or rotate and record the image. An acceleration sensor, a gyro sensor, or the like can be used as the attitude detection unit 55. It is also possible to detect the movement of the digital camera 100 (panning, tilting, lifting, whether it is stationary, etc.) using the acceleration sensor or gyro sensor that is the attitude detection unit 55.

[0034] The eyepiece detection unit 57 is an eyepiece detection sensor that detects the approach (approach) and departure (away) of an eye (object) to the eyepiece unit 16 of the eyepiece finder 17. The system control unit 50 switches between display (display state) / non-display (non-display state) of the display unit 28 and the EVF 29 according to the state detected by the eyepiece detection unit 57. More specifically, at least in a shooting standby state and when the display destination switching setting is automatic switching, when the eye is not placed in contact with the camera, the display is turned on as the display unit 28 and the EVF 29 is not displayed. Also, when the eye is placed in contact with the camera, the display is turned on as the display unit 29 and the display is not displayed. For example, an infrared proximity sensor can be used as the eyepiece detection unit 57, and it can detect the approach of an object to the eyepiece unit 16 of the eyepiece finder 17 incorporating the EVF 29. When an object approaches, infrared light projected from a light projecting section (not shown) of the eyepiece detection section 57 is reflected by the object and received by a light receiving section (not shown) of the infrared proximity sensor. The amount of infrared light received can also determine how close the object is to the eyepiece section 16 (eyepiece distance). In this way, the eyepiece detection section 57 performs eyepiece detection to detect the proximity of the object to the eyepiece section 16. When an object is detected approaching within a predetermined distance from the non-eyepiece state (non-approaching state), it is detected that the object has been placed in eye contact. When an object whose approach was detected moves away from the eyepiece state (approaching state) by a predetermined distance or more, it is detected that the object has been removed. The threshold value for detecting eye contact and the threshold value for detecting removal of the eye may be different, for example, by providing a hysteresis. In addition, after the eye is detected, the eye is in the eye contact state until removal of the eye is detected. After the removal of the eye is detected, the eye is in the non-eye contact state until removal of the eye is detected. The infrared proximity sensor is just one example, and other sensors may be used for eye proximity detection unit 57 as long as they can detect a state that can be regarded as eye proximity.

[0035] The GPS receiver 119 receives GPS signals including location information and time information from GPS satellites (artificial satellites). Based on the GPS signals received by the GPS receiver 119, the digital camera 100 specifies the location of the digital camera 100 and adjusts the reference time of the digital camera 100. The digital camera 100 can add information indicating the specified location and a shooting date and time based on the adjusted reference time to a captured image.

[0036] The hash value generation unit 210 executes a hash function on the image file to generate (calculate) a hash value. Note that the system control unit 50, instead of the hash value generation unit 210, may generate the hash value.

[0037] Various settings of the camera, including the shutter speed and aperture, are displayed on the outside viewfinder display section 43 via an outside viewfinder display section drive circuit 44 .

[0038] The power supply control unit 80 is composed of a battery detection circuit, a DC-DC converter, a switch circuit for switching between blocks to which electricity is applied, and the like, and detects whether a battery is attached, the type of battery, and the remaining battery power, etc. The power supply control unit 80 also controls the DC-DC converter based on the detection results and instructions from the system control unit 50, and supplies the necessary voltage for the necessary period to each unit including the recording medium 200. The power supply unit 30 is composed of primary batteries such as alkaline batteries and lithium batteries, secondary batteries such as NiCd batteries, NiMH batteries, and Li batteries, an AC adapter, etc.

[0039] The recording medium I / F 18 is an interface with a recording medium 200 such as a memory card or a hard disk. The recording medium 200 is a recording medium such as a memory card for recording captured images, and is composed of a semiconductor memory, a magnetic disk, or the like. Although only one recording medium 200 is shown in FIG. 2, the digital camera 100 of this embodiment is assumed to have a double-slot configuration, and is provided with a first slot and a second slot (not shown). The digital camera 100 having such a configuration can record captured images in both the recording medium 200 attached to the first slot and the recording medium 200' attached to the second slot, which has the same configuration as the recording medium 200.

[0040] The operation unit 70 is an input unit that accepts operations from the user, and is used to input various operational instructions to the system control unit 50. As shown in Fig. 2, the operation unit 70 includes a shutter button 61, a mode changeover switch 60, a power switch 72, a touch panel 70a, other operation members 70b, etc. The other operation members 70b include a main electronic dial 71, a sub electronic dial 73, a four-way key 74, a SET button 75, a video button 76, an AE lock button 77, a magnification button 78, a playback button 79, a menu button 81, a touch bar 82, etc.

[0041] The shutter button 61 includes a first shutter switch 62 and a second shutter switch 64. The first shutter switch 62 is turned on when the shutter button 61 is pressed halfway (a shooting preparation instruction) during operation of the shutter button 61, and generates a first shutter switch signal SW1. In response to the first shutter switch signal SW1, the system control unit 50 starts shooting preparation operations such as AF processing, AE processing, AWB processing, and EF processing.

[0042] The second shutter switch 64 is turned on when the shutter button 61 is fully pressed (photographing instruction) and generates a second shutter switch signal SW2. The system control unit 50 starts a series of photographing processing operations, from reading out a signal from the imaging unit 22 to writing the captured image to the recording medium 200 as an image file, based on the second shutter switch signal SW2.

[0043] The mode changeover switch 60 changes the operation mode of the system control unit 50 to one of a still image shooting mode, a video shooting mode, a playback mode, etc. Modes included in the still image shooting mode include an auto shooting mode, an auto scene determination mode, a manual mode, an aperture priority mode (Av mode), a shutter speed priority mode (Tv mode), and a program AE mode (P mode). In addition, there are various scene modes and custom modes that are shooting settings according to shooting scenes. The mode changeover switch 60 allows the user to directly switch to one of these modes. Alternatively, after switching to a list screen of shooting modes with the mode changeover switch 60, the user may selectively switch to one of the displayed modes using another operating member. Similarly, the video shooting mode may also include a plurality of modes.

[0044] The touch panel 70a is a touch sensor that detects various touch operations on the display surface of the display unit 28 (the operation surface of the touch panel 70a). The touch panel 70a and the display unit 28 can be configured as one unit. For example, the touch panel 70a is configured so that the light transmittance does not interfere with the display of the display unit 28, and is attached to the upper layer of the display surface of the display unit 28. Then, input coordinates on the touch panel 70a are associated with display coordinates on the display surface of the display unit 28. This makes it possible to provide a GUI (Graphical User Interface) that makes it seem as if the user can directly operate the screen displayed on the display unit 28.

[0045] The system control unit 50 can detect the following operations or states on the touch panel 70a.

[0046] A finger or pen that has not been touching the touch panel 70a touches the touch panel 70a again, that is, the start of touching (hereinafter referred to as touch-down).

[0047] The touch panel 70a is in a state of being touched with a finger or a pen (hereinafter, referred to as Touch-On).

[0048] A finger or a pen is moved while touching the touch panel 70a (hereinafter referred to as Touch-Move).

[0049] The finger or pen that has been touching the touch panel 70a is removed (released) from the touch panel 70a, that is, the end of touch (hereinafter referred to as touch-up).

[0050] Nothing is being touched on the touch panel 70a (hereinafter, referred to as Touch-Off).

[0051] When touch-down is detected, touch-on is also detected at the same time. After touch-down, touch-on will usually continue to be detected unless touch-up is detected. If touch-move is detected, touch-on will also be detected at the same time. Even if touch-on is detected, touch-move will not be detected if the touch position does not move. After it is detected that all fingers or pens that were touching have touched up, touch-off will occur.

[0052] These operations and states, as well as the position coordinates of the touch panel 70a touched by a finger or pen, are notified to the system control unit 50 via the internal bus. The system control unit 50 then determines what kind of operation (touch operation) was performed on the touch panel 70a based on the notified information. For touch moves, the direction of movement of the finger or pen moving on the touch panel 70a can also be determined for each vertical and horizontal component on the touch panel 70a based on the change in position coordinates. If a touch move of a predetermined distance or more is detected, it is determined that a slide operation has been performed. An operation in which a finger is touched on the touch panel 70a, quickly moved a certain distance, and then released is called a flick. In other words, a flick is an operation in which a finger is quickly traced on the touch panel 70a as if flicking it. If a touch move of a predetermined distance or more at a predetermined speed or more is detected and a touch up is detected immediately, it can be determined that a flick has been performed (it can be determined that a flick has occurred following a slide operation). Furthermore, a touch operation in which multiple points (for example, two points) are touched together (multi-touch) and the touch positions are brought closer together is called pinch in, and a touch operation in which the touch positions are moved away from each other is called pinch out. Pinch out and pinch in are collectively called pinch operations. The touch panel 70a may be of any of various touch panel types, such as a resistive film type, a capacitive type, a surface acoustic wave type, an infrared type, an electromagnetic induction type, an image recognition type, and an optical sensor type. There are types that detect a touch by contact with the touch panel, and types that detect a touch by the approach of a finger or a pen to the touch panel, and either type may be used.

[0053] FIG. 3 is a flowchart showing the procedure of the photographing control process executed by the digital camera 100 of FIG. 1. The photographing control process of FIG. 3 is realized by the system control unit 50 expanding the program stored in the non-volatile memory 56 into the system memory 52 and executing it when the power switch 72 is turned on. It is assumed that, at the start of the photographing control process of FIG. 3, the tamper-proof mode is disabled in the digital camera 100, and the setting screen of FIG. 4(a) is displayed on the display unit 28. This setting screen includes a setting item 401 that can be set to either "ON" for enabling the tamper-proof mode or "OFF" for disabling the tamper-proof mode. In this embodiment, when photographing is performed with the setting item 401 set to "ON", the image file generated by the photographing includes history information, which will be described later. On the other hand, when photographing is performed with the setting item 401 set to "OFF", the image file generated by the photographing does not include history information, which will be described later. In this embodiment, it is possible to determine whether or not malicious tampering has been performed based on the presence or absence of changes to the hash value and signature value included in the history information.

[0054] 3, first, in step S301, the system control unit 50 determines whether an instruction to activate the tamper-proof mode has been given. Specifically, the system control unit 50 determines whether an instruction to set the setting item 401 to "ON" or "OFF" has been given.

[0055] If it is determined in S301 that an instruction to activate the tamper-proof mode has not been given, that is, if an instruction to set the setting item 401 to "OFF" has been given, the photography control process proceeds to S302. In S302, the system control unit 50 sets the setting value of the tamper-proof mode to "OFF" which disables the tamper-proof mode. This setting value is stored in the memory 32. Next, the photography control process proceeds to S317 which will be described later.

[0056] When it is determined in S301 that an instruction to activate the tamper-proof mode has been given, that is, when an instruction to set the setting item 401 to "ON" has been given, the shooting control process proceeds to S303. In S303, the system control unit 50 sets the setting value of the tamper-proof mode to "ON" which activates the tamper-proof mode. This setting value is also stored in the memory 32. When the setting value of the tamper-proof mode is set to "ON", a setting item 402 in FIG. 4B is added to the setting screen 400. The setting item 402 can be set to either "ON" for activating the original comparison information imparting function or "OFF" for deactivating the original comparison information imparting function. In this embodiment, when shooting is performed with the setting item 402 set to "ON", history information described later is included in the image file generated by the shooting, and this history information includes original comparison information. The original comparison information is information for grasping changes since the time of generation of the image file, such as thumbnail data (thumbnail image) that is a reduced version of the image data at the time of shooting, and metadata at the time of shooting that includes information on the shooting location, etc. By generating such an image file, not only can it be detected that the image file has been tampered with, but by comparing it with the original comparison information, it is also possible to grasp changes in the image data and metadata since the time of shooting.

[0057] Next, the system control unit 50 judges whether an instruction to enable the original comparison information adding function has been given (S304). Specifically, the system control unit 50 judges whether an instruction to set the setting item 402 to "ON" for enabling the original comparison information adding function or to "OFF" for disabling the original comparison information adding function has been given.

[0058] If it is determined in S304 that an instruction to activate the original comparison information adding function has not been given, that is, if an instruction to set the setting item 402 to "OFF" has been given, the photography control process proceeds to S305. In S305, the system control unit 50 sets the setting value of the original comparison information adding function to "OFF" which disables the original comparison information adding function. This setting value is also stored in the memory 32. Next, the photography control process proceeds to S317 which will be described later.

[0059] If it is determined in S304 that an instruction to activate the original comparison information adding function has been given, that is, if an instruction to set the setting item 402 to "ON" has been given, the shooting control process proceeds to S306. In S306, the system control unit 50 sets the setting value of the original comparison information adding function to "ON" which activates the original comparison information adding function. This setting value is also stored in the memory 32.

[0060] When the setting item 402 is set to "ON", a setting item 403 in FIG. 4(c) for setting the original comparison information automatic determination function is added to the setting screen 400. In the setting item 403, any of "ON (with history)", "ON (without history)", and "OFF" can be set. "ON (with history)" and "ON (without history)" are setting values ​​for activating the original comparison information automatic determination function. "OFF" is a setting value for deactivating the original comparison information automatic determination function. When the setting item 403 is set to ON (with history) or ON (without history) and shooting is performed, whether or not to include original comparison information in the image file is controlled based on the characteristics of the subject. Also, when the setting item 403 is set to ON (with history) and shooting is performed, an image file including history information is generated when it is determined not to include original comparison information in the image file based on the characteristics of the subject. This history information does not include original comparison information. On the other hand, when a photograph is taken with setting item 403 set to "In (no history)", if it is determined based on the characteristics of the subject that the original comparison information should not be included in the image file, an image file is generated that does not include not only the original comparison information but also the history information.

[0061] In addition, when the setting item 402 is set to "ON", a setting item 404 in FIG. 4(c) for setting the function of simultaneously generating images without original comparison information is also added to the setting screen 400. In the setting item 404, any of "ON (with history)", "ON (without history)", and "OFF" can be set. "ON (with history)" and "ON (without history)" are setting values ​​for enabling the function of simultaneously generating images without original comparison information. "OFF" is a setting value for disabling the function of simultaneously generating images without original comparison information. Note that the setting item 404 is operable only when "OFF" is set in the setting item 403. When shooting is performed with the setting item 404 set to "ON (with history)", two image files are generated, specifically, an image file including original comparison information and an image file not including original comparison information. The image file not including the original comparison information includes history information. Furthermore, when shooting is performed with the setting item 404 set to "ON (no history)", an image file including original comparison information and an image file including no original comparison information are generated. The image file including no original comparison information does not include history information.

[0062] Next, the system control unit 50 judges whether an instruction to enable the automatic determination function of adding information for original comparison has been given (S307). Specifically, the system control unit 50 judges whether an instruction to set the setting item 403 to "ON (with history)", "ON (without history)", or "OFF" has been given. If it is judged in S307 that an instruction to enable the automatic determination function of adding information for original comparison has been given, that is, if an instruction to set the setting item 403 to "ON (with history)" or "ON (without history)" has been given, the shooting control process proceeds to S308.

[0063] In S308, the system control unit 50 judges whether or not an instruction to set the setting item 403 to "IN (no history)" has been given. If it is judged in S308 that an instruction to set the setting item 403 to "IN (no history)" has not been given, that is, if an instruction to set the setting item 403 to "IN (with history)" has been given (for example, see the setting screen 400 in FIG. 4(d)), the shooting control process proceeds to S309. In S309, the system control unit 50 sets the setting value of the original comparison information attachment automatic judgment function to "IN (with history)". This setting value is also stored in the memory 32. Next, the shooting control process proceeds to S317, which will be described later.

[0064] If it is determined in S308 that an instruction to set the setting item 403 to "In (no history)" has been given (see, for example, setting screen 400 in FIG. 4(e)), the shooting control process proceeds to S310. In S310, the system control unit 50 sets the setting value of the original comparison information attachment automatic determination function to "In (no history)". This setting value is also stored in the memory 32. Next, the shooting control process proceeds to S317, which will be described later.

[0065] If it is determined in S307 that the instruction to activate the original comparison information attachment automatic determination function has not been given, that is, if an instruction to set the setting item 403 to "OFF" has been given, the shooting control process proceeds to S311. In S311, the system control unit 50 sets the setting value of the original comparison information attachment automatic determination function to "OFF". This setting value is also stored in the memory 32.

[0066] Next, the system control unit 50 judges whether an instruction has been given to activate the function of simultaneously generating images without original comparison information (S312). Specifically, the system control unit 50 judges whether an instruction has been given to set the setting item 404 to "ON (with history)", "ON (without history)", or "OFF".

[0067] If it is determined in S312 that an instruction to activate the function of simultaneously generating images without original comparison information has been given, that is, if an instruction to set the setting item 404 to "IN (with history)" or "IN (without history)" has been given, the shooting control process proceeds to S313. In S313, the system control unit 50 determines whether an instruction to set the setting item 404 to "IN (without history)" has been given.

[0068] If it is determined in S313 that no instruction has been given to set the setting item 404 to "IN (no history)", that is, if an instruction has been given to set the setting item 404 to "IN (with history)" (for example, see the setting screen 400 in FIG. 4(f)), the shooting control process proceeds to S314. In S314, the system control unit 50 sets the setting value of the simultaneous generation function of images without original comparison information to "IN (with history)". This setting value is also stored in the memory 32. Next, the shooting control process proceeds to S317, which will be described later.

[0069] If it is determined in S313 that an instruction to set the setting item 404 to "In (no history)" has been given (for example, see the setting screen 400 in FIG. 4(g)), the shooting control process proceeds to S315. In S315, the system control unit 50 sets the setting value of the function for simultaneously generating images without original comparison information to "In (no history)". This setting value is also stored in the memory 32. Next, the shooting control process proceeds to S317, which will be described later.

[0070] If it is determined in S312 that an instruction to activate the function for simultaneously generating images without original comparison information has not been given, that is, if an instruction to set the setting item 404 to "OFF" has been given (for example, see the setting screen 400 in FIG. 4(c)), the shooting control process proceeds to S316. In S316, the system control unit 50 sets the setting value of the function for simultaneously generating images without original comparison information to "OFF". This setting value is also stored in the memory 32.

[0071] Next, the system control unit 50 executes the shooting process of FIG. 5, which will be described later (S317). Next, the system control unit 50 executes the playback process of FIG. 8, which will be described later (S318). Next, the system control unit 50 determines whether or not a power-off instruction has been received from the user (S319). The system control unit 50 waits until the power-off instruction is received from the user. When the power-off instruction is received from the user (YES in S319), the shooting control process ends.

[0072] Fig. 5 is a flowchart showing the procedure of the photographing process of S317 in Fig. 3. The photographing process in Fig. 5 starts when a photographing start operation such as pressing the shutter button 61 is accepted, and ends when a photographing end operation such as ceasing to press the shutter button 61 is accepted.

[0073] 5, the system control unit 50 drives the shutter 101 arranged on the subject side of the imaging unit 22 to control the exposure time (S501). Next, the system control unit 50 performs imaging processing to convert the light from the subject received by the imaging unit 22 through the shutter 101 into an electrical signal (analog image data) (S502). Next, the system control unit 50 performs image processing such as development processing and encoding processing on the electrical signal obtained by the imaging processing of S502 to generate image data (S503). Next, the system control unit 50 determines whether the setting value of the tamper prevention mode is "ON" (S504).

[0074] If it is determined in S504 that the setting value of the tamper-proof mode is not "ON", that is, if the setting value of the tamper-proof mode is "OFF", the system control unit 50 generates metadata 601a as shown in FIG. 6(a) (S505). The metadata 601a includes shooting information 602a. The metadata 601a generated in S505 does not include history information, which will be described later. The shooting information 602a is information when an image capture process for generating image data 603a is executed, and is, for example, the shooting date and time, the photographer, the image size, the manufacturer and model of the image capture device, various shooting parameters set at the time of shooting, the shooting location, a thumbnail image, and the like. The shooting information 602a is generated in accordance with a predetermined technical standard, for example, EXIF ​​(Exchangeable image file format).

[0075] Next, the system control unit 50 generates an image file that does not include history information (S506). Specifically, the system control unit 50 generates an image file 600a in FIG. 6(a) that is composed of the metadata 601a generated in S505 and the image data 603a generated in S503. In addition, in S506, if the image data is a still image, the image file is generated according to the JPEG format, and if the image data is a moving image, the image file is generated according to the MPEG format. Then, the shooting process ends.

[0076] If it is determined in S504 that the setting value of the tamper prevention mode is "ON", the system control unit 50 determines whether or not the setting value of the original comparison information adding function is "ON" (S507). If it is determined in S507 that the setting value of the original comparison information adding function is not "ON", that is, if the setting value of the original comparison information adding function is "OFF", the shooting process proceeds to S508. In S508, the system control unit 50 determines whether or not the setting value of the recording image quality, which is a setting item related to the number of pixels of the image data to be recorded, is "light", which has the fewest number of pixels.

[0077] If it is determined in S508 that the setting value of the recording image quality is not "lightweight," the shooting process proceeds to S505. In this case, as described above, an image file 600a that does not include history information is generated.

[0078] If it is determined in S508 that the setting value of the recording image quality is "light", the system control unit 50 determines whether or not the remaining storage capacity of the recording medium 200, which is the storage location of the image file to be generated, is less than a predetermined value (S509). If it is determined in S509 that the remaining storage capacity of the recording medium 200 is less than the predetermined value, the shooting process proceeds to S505. In this case, as described above, an image file 600a that does not include history information is generated. Thus, in this embodiment, even if the setting value of the original comparison information addition function is "on", if the setting value of the recording image quality is not "light" or if the remaining storage capacity of the recording medium 200, which is the storage location of the image file to be generated, is less than a predetermined value, an image file 600a that does not include history information and has a reduced amount of data is generated.

[0079] If it is determined in S509 that the remaining storage capacity of the recording medium 200 is not less than the predetermined value, the system control unit 50 generates metadata 601b as shown in FIG. 6(b) (S510). The metadata 601b includes history information 604b in addition to the shooting information 602b having the same configuration as the shooting information 602a described above. Note that the metadata 601b generated in S510 does not include information for original comparison. The history information 604b is information for proving the authenticity of the image data 603b, and is used when verifying the source and history of the image data 603b. The history information 604b is generated in accordance with a predetermined technical standard, for example, C2PA (Cоalitiоn for Content Prоvenance and Authenticity), and has a prescribed structure. The history information 604b includes an assertion 613b, a hash value 623b for assuring the history 613b, and a digital signature 633b.

[0080] The history 613b includes history identification information (Manifest ID) for uniquely identifying the history 613b, an editing history indicating the editing content of the image data 603b, an editing tool indicating the tool used for the editing, and the creator of the image data 603b. Note that since the image data generated in step S503 has just been generated by shooting and has not been edited, information indicating "generated" is recorded in the editing history, and information indicating digital camera 100 is recorded in the editing tool.

[0081] Next, the system control unit 50 generates a hash value 623b (S511). For example, the system control unit 50 executes a hash function on each of the binary data of the image data 603b and the history 613b to generate a hash value 624b of the image data and a hash value 626b of the history included in the hash value 623b. Note that the system control unit 50 may execute a hash function on the binary data of the shooting information 602b to generate a hash value 625b of the shooting information. In addition, for the binary data of the history 613b, hash values ​​may be generated for each finer unit such as an editing history or a production source in order to detect tampering in a finer unit.

[0082] Next, the system control unit 50 generates a digital signature 633b (S512). The digital signature 633b includes information indicating a signature value, a signer, and a signature date and time. The signature value is generated by encrypting the generated hash value 623b with a private key prepared in advance. The public key that pairs with the private key used here is also included in the digital signature 633b. Note that, in order to prove that the public key is from a trustworthy manufacturer, the digital signature 633b may include information indicating the manufacturer of the digital camera 100 as a signer, or a public key certificate indicating that the public key has been authenticated by a certification authority. By adding the digital signature 633b including such a signer to the image file 600b, it is possible to show that the image file 600b is trustworthy. Note that, instead of the manufacturer, the model of the digital camera 100 may be used as the signer. The signature date and time is the date and time when the generation of the digital signature 633b is completed. The shooting date and time may also be included in the history 613b.

[0083] Next, the system control unit 50 generates an image file that does not include original comparison information (S513). Specifically, the system control unit 50 generates an image file 600b in FIG. 6(b) that is composed of metadata 601b and image data 603b generated in S503. Note that in S513 as well, if the image data is a still image, an image file is generated according to the JPEG format, and if the image data is a video, an image file is generated according to the MPEG format. After that, the shooting process ends.

[0084] If it is determined in S507 that the setting value of the original comparison information addition function is "ON", the shooting process proceeds to S514. In S514, the system control unit 50 determines whether the setting value of the original comparison information addition automatic determination function is "OFF".

[0085] When it is determined in S514 that the setting value of the automatic determination function for adding original comparison information is "off", the system control unit 50 generates metadata 601c as shown in FIG. 6(c) (S515). The metadata 601c includes history information 604c in addition to the shooting information 602c having the same configuration as the above-mentioned shooting information 602a. The history information 604c includes a history 613c, a hash value 623c, and a digital signature 633c. The history 613c includes original comparison information in addition to the information included in the above-mentioned history 613b. The hash value 623c and the digital signature 633c have the same configuration as the above-mentioned hash value 623b and digital signature 633b, respectively.

[0086] Next, the system control unit 50 generates a hash value 623c (S516). For example, the system control unit 50 executes a hash function on each of the binary data of the image data 603c and the history 613c to generate a hash value 624c of the image data and a hash value 626c of the history included in the hash value 623c. In addition, the system control unit 50 executes a hash function on the binary data of the shooting information 602c to generate a hash value 625c of the shooting information. Note that, similar to the above-mentioned history 613b, the hash value of the binary data of the history 613c may be generated for each finer unit such as an editing history or a production source in order to detect tampering in a finer unit.

[0087] Next, the system control unit 50 generates a digital signature 633c (S517). Next, the system control unit 50 generates an image file including original comparison information (S518). Specifically, the system control unit 50 generates an image file 600c in FIG. 6(c) that is composed of metadata 601c and image data 603c generated in S503. Note that, also in S518, if the image data is a still image, an image file is generated according to the JPEG format, and if the image data is a video image, an image file is generated according to the MPEG format.

[0088] Next, the system control unit 50 judges whether or not the setting value of the simultaneous generation of images without original comparison information function is "off" (S519). If it is judged in S519 that the setting value of the simultaneous generation of images without original comparison information function is "off", the photographing process ends.

[0089] If it is determined in S519 that the setting value of the simultaneous generation of images without original comparison information function is not "off," that is, if the setting value of the simultaneous generation of images without original comparison information function is "on (with history)" or "on (without history)," the shooting process proceeds to S520.

[0090] In S520, the system control unit 50 determines whether the setting value of the recording image quality is "light" or not.

[0091] If it is determined in S520 that the setting value of the recording image quality is "light," the shooting process proceeds to S521. In S521, the system control unit 50 determines whether the remaining storage capacity of the storage location of an image file that is generated together with the image file 600c generated in S518 and does not contain original comparison information is less than a predetermined value. The storage location of the image file that does not contain original comparison information is a recording medium other than the recording medium 200 that recorded the image file 600c generated in S518, specifically, the recording medium 200' attached to the second slot.

[0092] If it is determined in S521 that the remaining storage capacity of the recording medium 200' is not less than the predetermined value, the shooting process proceeds to S522. In S522, the system control unit 50 changes the storage location of the image file that does not include original comparison information to the recording medium 200' attached to the second slot. This makes it possible to simplify data organization by recording an image file that includes original comparison information and an image file that does not include original comparison information in separate storage locations when both are generated.

[0093] Next, the system control unit 50 stores information relating the two image files in the memory 32 (S523). For example, the system control unit 50 stores information indicating that the image file 600c generated in S518 and the image file not including original comparison information generated in the process described later are image files generated in the same shooting process in the memory 32. This makes it possible to process these two image files in association with each other. In this embodiment, the method of relating the two image files is not limited to this method. For example, the file name of the image file not including original comparison information generated in the process described later may be a file name obtained by adding a predetermined character string indicating the association with the image file 600c to the file name of the image file 600c generated in S518, for example, "AAA", for example, "AAA_C2PA". In addition, when both the image file including original comparison information and the image file not including original comparison information include histories, it may be determined whether or not the data are generated in the same shooting process based on their history identification information (Manifest ID).

[0094] Next, the system control unit 50 determines whether the setting value of the simultaneous generation function of images without original comparison information is "ON (with history)" (S524).

[0095] If it is determined in S524 that the setting value of the simultaneous image generation function without original comparison information is "ON (with history)", the photographing process proceeds to S508, and then S509 to S513 are performed. Thus, in this embodiment, when the setting value of the simultaneous image generation function without original comparison information is "ON (with history)", an image file 600c including original comparison information and an image file 600b are generated. As described above, the image file 600b includes history information 604b, and this history information 604b does not include original comparison information.

[0096] If it is determined in S524 that the setting value of the simultaneous image generation function without original comparison information is not "ON (with history)", that is, if the setting value of the simultaneous image generation function without original comparison information is "ON (without history)", the shooting process proceeds to S505. Then, S506 is performed. Thus, in this embodiment, when the setting value of the simultaneous image generation function without original comparison information is "ON (without history)", an image file 600c and an image file 600a containing original comparison information are generated. Note that, as described above, the image file 600a does not contain either original comparison information or history information.

[0097] If it is determined in S520 that the set value of the recording image quality is not "light," or if it is determined in S521 that the remaining storage capacity of the recording medium 200' is less than a predetermined value, the photographing process ends. Thus, in this embodiment, even if the set value of the simultaneous image generation function without original comparison information is "ON (with history)" or "ON (without history)," if the set value of the recording image quality is not "light," or if the remaining storage capacity of the storage location for image files that do not include original comparison information is less than a predetermined value, only the image file 600c that includes original comparison information is generated.

[0098] When it is determined in S514 that the setting value of the original comparison information addition automatic determination function is not "OFF", that is, when the setting value of the original comparison information addition automatic determination function is "ON (with history)" or "ON (without history)", the photographing process proceeds to S525. In S525, the system control unit 50 determines whether or not a person is included in the subject. When it is determined in S525 that a person is not included in the subject, the photographing process proceeds to S515, and then the processes of S516 to S519 are performed. Here, in this embodiment, as described above, only when the setting item 403 of the original comparison information addition automatic determination function is "OFF", the setting item 404 of the original comparison information free image simultaneous generation function is operable. In other words, both the original comparison information addition automatic determination function and the original comparison information free image simultaneous generation function are not enabled. Since the setting value of the automatic determination function for adding original comparison information is determined to be "ON (with history)" or "ON (without history)" in S514, the setting value of the simultaneous generation function for images without original comparison information is determined to be "OFF" in S519, and the photographing process ends. Thus, in this embodiment, when the setting value of the automatic determination function for adding original comparison information is "ON (with history)" or "ON (without history)" and no person is included in the subject, an image file 600c including original comparison information is generated.

[0099] If it is determined in S523 that the subject includes a person, the system control unit 50 determines whether the setting value of the original comparison information addition automatic determination function is "ON (with history)" (S524).

[0100] If it is determined in S524 that the setting value of the automatic determination function for adding original comparison information is "ON (with history)", the photographing process proceeds to S508, and then S509 to S513 are performed. Thus, in this embodiment, when the setting value of the automatic determination function for adding original comparison information is "ON (with history)" and a person is included in the subject, an image file 600b is generated. As described above, the image file 600b includes history information 604b, but this history information 604b does not include original comparison information.

[0101] If it is determined in S524 that the setting value of the automatic determination function for adding original comparison information is not "ON (with history)", that is, if the setting value of the automatic determination function for adding original comparison information is "ON (without history)", the shooting process proceeds to S505, and then S506 is performed. Thus, in this embodiment, if the setting value of the automatic determination function for adding original comparison information is "ON (without history)" and the subject includes a person, an image file 600a that does not include either original comparison information or history information is generated.

[0102] Fig. 7 is a table showing image files generated according to conditions in this embodiment. As shown in Fig. 7, in this embodiment, image files with different configurations are generated based on the settings of the setting items 401 to 404 and the characteristics of the subject.

[0103] As described above, in this embodiment, when the digital camera 100 captures an image, one of the image files 600a to 600c is generated. Note that any of these image files 600a to 600c may be edited. For example, when the image file 600c is edited using an approved editing tool in a legitimate procedure, new history information is generated in accordance with a predetermined technical standard based on the edited content, and this history information is added to the metadata 601c of the image file 600c. The history information is newly generated and added to the metadata 601c of the image file 600c every time the image file 600c is edited. On the other hand, when the image file 600c is edited using an unauthorized editing tool or in an illegal procedure, the history information may not be added to the image file 600c, or the history information added to the image file 600c may not be consistent with the predetermined technical standard.

[0104] In addition, in this embodiment, it is possible to detect tampering of the image files 600b and 600c by generating a hash value or a signature value. For example, a hash function is applied to the binary data of the image data 603c of the image file 600c to generate a hash value. Then, the generated hash value is compared with a hash value 624c of the image data of the image file 600c. This makes it possible to verify whether the image data 603c has been tampered with. Similarly, a hash function is applied to the binary data of the shooting information 602c of the image file 600c to generate a hash value. Then, the generated hash value is compared with a hash value 625c of the shooting information of the image file 600c. This makes it possible to verify whether the shooting information 602c, including the shooting date and time, the shooting location, etc., has been tampered with. Furthermore, a hash function is applied to the binary data of the history 613c to generate a hash value. Then, the generated hash value is compared with a hash value 626c of the history of the image file 600c. This makes it possible to verify whether the history 613c has been tampered with. At this time, the binary data to be compared may be compared in smaller units such as the editing history, the manufacturer, thumbnail data, metadata, etc. Also, the signature value can be decrypted using a public key, and if the hash values ​​match, it can be determined that the signature value has been successfully verified. In this way, a mechanism for detecting tampering can be built into the image file.

[0105] According to the embodiment described above, an image file 600c including original comparison information and an image file not including original comparison information are generated. This makes it possible to provide the user with two image files with different structures, thereby allowing the user to select the image file to be used depending on the purpose.

[0106] In the above-described embodiment, the original comparison information is a thumbnail image obtained by reducing the image data. This allows the user to select, according to the purpose, whether to use the image file 600c that allows the user to grasp the change in the image data since the time of shooting, or to use an image file that does not allow the user to grasp the change in the image data since the time of shooting but is easy to apply editing processing to protect privacy (an image file that does not include the original comparison information).

[0107] In the above-described embodiment, the original comparison information is metadata at the time of shooting that includes information indicating the shooting location. This allows a user to select, depending on the purpose, whether to use the image file 600c that allows detection of tampering with the shooting location information, or to use an image file that does not allow detection of tampering with the shooting location information but is easy to apply editing processing to protect privacy (an image file that does not include original comparison information).

[0108] 5, the configuration for determining whether or not a person is included in the subject in S525 has been described, but the present invention is not limited to this configuration. For example, the configuration may be such that it is determined whether or not the shooting location is a location where shooting is not recommended.

[0109] In addition, in the shooting process of Fig. 5 described above, a configuration in which control is performed so that original comparison information is not included in the image file has been described, but the present invention is not limited to this configuration. For example, image processing such as mosaic processing may be performed on thumbnail data as original comparison information, or processing may be performed to conceal location data such as the shooting location. It is also possible to control so that processing is not performed on image data even if the original comparison information is processed. Information indicating that the original comparison information has been processed may also be included in the image file.

[0110] Next, the playback process of S318 will be described. In this embodiment, when the setting value of the simultaneous image generation function without original comparison information is "IN (with history)" or "IN (without history)", an image file including original comparison information and an image file not including original comparison information are generated. When two image files are generated in this way, the user may wish to operate only one of these two image files, or may wish to operate both of these two image files simultaneously. To meet such needs, in this embodiment, the process of S318 is performed that can realize optimal operations for these two image files.

[0111] Fig. 8 is a flowchart showing the procedure of the playback process of S318 in Fig. 3. The playback process in Fig. 8 starts when a playback start operation such as pressing the playback button 79 is accepted, and ends when a playback end operation such as pressing the shutter button 61 is accepted.

[0112] 8, the system control unit 50 plays an image file designated by a user from among image files stored in either the recording medium 200 or the recording medium 200' (S801). As a result, an image corresponding to the image file is displayed on the display unit 28. Next, the system control unit 50 determines whether or not an instruction to delete the designated image file has been received from the user (S802).

[0113] If it is determined in S802 that an instruction to delete the image file has been received from the user, the playback process proceeds to S803. In S803, the system control unit 50 determines whether or not another image file associated with the specified image file has been generated in the shooting process of S317. For example, if the specified image file is an image file that includes original comparison information, it is determined whether or not an image file associated with the image file and that does not include original comparison information has been generated in the shooting process of S317. The determination in S803 is made, for example, based on the presence or absence of information that associates the two image files stored in the memory 32 in S523.

[0114] If it is determined in S803 that another image file associated with the specified image file is not generated in the shooting process of S317, the playback process proceeds to S804. In S804, the system control unit 50 erases the image file being played back, i.e., the specified image file, from its storage location.

[0115] If it is determined in S803 that another image file associated with the designated image file has been generated in the shooting process in S317, the playback process proceeds to S805. In S805, the system control unit 50 determines whether the received delete instruction is a simultaneous delete instruction. For example, if both an image file including original comparison information and an image file not including original comparison information have been generated in the shooting process in S317, the user selects one of the delete buttons 901 to 903 shown in FIG. 9A to instruct the deletion of the image file. The delete button 901 is a button for issuing an instruction to delete the image file including original comparison information (hereinafter, referred to as an "instruction to delete only the image file including original comparison information"). The delete button 902 is a button for issuing an instruction to delete the image file not including original comparison information (hereinafter, referred to as an "instruction to delete only the image file not including original comparison information"). The delete button 903 is a button for issuing an instruction to delete both the image file including original comparison information and the image file not including original comparison information (hereinafter, referred to as a "instruction to delete simultaneously").

[0116] If the user selects the delete button 903, in S805, it is determined that the received delete instruction is a simultaneous delete instruction. In this case, the system control unit 50 deletes both the designated image file and the image file associated with the designated image file from their respective storage locations. Specifically, the system control unit 50 deletes the image file including the original comparison information from the recording medium 200, and deletes the image file not including the original comparison information from the recording medium 200' (S806). This allows the user to easily delete the image files including the original comparison information and not including the original comparison information from their storage locations by simply selecting one of them, without having to select both of them. Next, the playback process proceeds to S810, which will be described later.

[0117] On the other hand, if the user selects either the delete button 901 or 902, it is determined in S805 that the received delete instruction is not a simultaneous delete instruction. In this case, the system control unit 50 determines whether or not an instruction to delete only the image file with original comparison information has been issued (S807).

[0118] If the user selects the Delete button 901, in S807 it is determined that the received delete instruction is an instruction to delete only the image file with original comparison information. In this case, the system control unit 50 deletes the designated image file and, of the image files associated with that image file, the image files that include original comparison information from the recording medium 200 (S808). Next, the playback process proceeds to S810, which will be described later.

[0119] On the other hand, if the user selects the Erase button 902, it is determined in S807 that the received erase instruction is not an instruction to erase only the image file with original comparison information. In this case, the system control unit 50 erases the designated image file and image files associated with that image file that do not contain original comparison information from the recording medium 200' (S809). Next, the playback process proceeds to S810, which will be described later.

[0120] If it is determined in S802 that an instruction to delete an image file has not been received from the user, the playback process proceeds to S810. In S810, the system control unit 50 determines whether an instruction to protect an image has been received. In this embodiment, the user can issue an instruction to protect an image by selecting a protect button 904 shown in Fig. 9(b).

[0121] If it is determined in S810 that an image protect instruction has been received, the system control unit 50 determines whether or not another image file associated with the specified image file has been generated in the shooting process of S317 (S811).

[0122] If it is determined in S811 that another image file associated with the specified image file is not generated in the shooting process in S317, the system control unit 50 protects the image file being played back, that is, the specified image file (S812). After that, the playback process proceeds to S814, which will be described later.

[0123] If it is determined in S811 that another image file associated with the specified image file was generated in the shooting process in S317, the playback process proceeds to S813. In S813, the system control unit 50 protects the image file that includes the original comparison information among the specified image file and the image files associated with the image file. Thereafter, the playback process proceeds to S814, which will be described later.

[0124] If it is determined in S810 that the image protection instruction has not been accepted, the system control unit 50 determines whether or not an image transfer instruction has been accepted (S814). In this embodiment, the user can issue an image transfer instruction by selecting an image transfer button 905 shown in Fig. 9(c). If it is determined in S814 that the image transfer instruction has not been accepted, the playback process ends.

[0125] If it is determined in S814 that an image transfer instruction has been accepted, the system control unit 50 determines whether or not another image file associated with the specified image file has been generated in the shooting process of S317 (S815).

[0126] If it is determined in S815 that another image file associated with the specified image file is not generated in the shooting process in S317, the playback process proceeds to S816. In S816, the system control unit 50 transfers the image file being played back, that is, the specified image file, to a transfer destination designated by the user. Note that the user can designate an external device such as a smartphone, PC, or server as the transfer destination. Thereafter, the playback process ends.

[0127] If it is determined in S815 that another image file associated with the designated image file has been generated in the photographing process in S317, the playback process proceeds to S817. In S817, the system control unit 50 transfers both the designated image file and the image file associated with the designated image file to the transfer destination designated by the user. Specifically, the system control unit 50 transfers both the image file including the original comparison information and the image file not including the original comparison information to the transfer destination. Note that a use case in which both the image file including the original comparison information and the image file not including the original comparison information are transferred to an external device is a case in which these two image files have different uses. For example, when the image file is to be made public except for information that is to be kept private to the outside, the image file not including the original comparison information is used. Also, when the image file is to be used in a limited manner within the company so that the history can be compared and confirmed including information that is to be kept private to the outside, the image file including the original comparison information is used. Then, the playback process ends.

[0128] In the above-described embodiment, when an erase instruction is received from a user while either an image file including original comparison information or an image file not including original comparison information is selected, whether to erase both of these two image files or only one of these two image files is controlled according to which of the erase buttons 901 to 903 the user selects. This allows the user to realize the intended erase process by simply selecting one of the image files, without having to select both the image file including original comparison information and the image file not including original comparison information.

[0129] In the above-described embodiment, when an image protection instruction is received from a user while an image file including original comparison information and an image file not including original comparison information are selected, the image file including original comparison information is protected, thereby preventing the image file including the original comparison information, which has a larger amount of information, from being erased due to a user's mistaken operation.

[0130] If it is more useful to protect image files that do not include original comparison information, protection may be applied to image files that do not include original comparison information, rather than image files that include original comparison information.

[0131] In addition, in the above-described embodiment, when an image transfer instruction is received from a user with either an image file including original comparison information or an image file not including original comparison information selected, both the image file including original comparison information and the image file not including original comparison information are transferred to an external device. This allows the user to easily transfer these two image files to an external device by simply selecting one of them, without having to select both the image file including original comparison information and the image file not including original comparison information.

[0132] In this embodiment, the configuration for transferring an image file including original comparison information and an image file not including original comparison information in the reproduction process has been described, but the timing of transferring these image files is not limited to the reproduction process. For example, these image files may be transferred in an automatic transfer process in which an image file generated by shooting is immediately transferred to an external device. In the automatic transfer process, when both an image file including original comparison information and an image file not including original comparison information are generated, these two image files are transferred to the external device. Also, when one of an image file including original comparison information and an image file not including original comparison information is generated, the generated image file is transferred to the external device.

[0133] (Other embodiments) The present invention can also be realized by executing the following process. That is, software (program) that realizes the functions of the above-mentioned embodiments is supplied to a system or device via a network or various storage media, and the computer (or CPU, MPU, etc.) of the system or device reads and executes the program code. In this case, the program and the storage medium storing the program constitute the present invention. It can also be realized by a circuit (e.g., ASIC) that realizes one or more functions.

[0134] The disclosure of this embodiment includes the following configurations and methods. (Configuration 1) A content generation device comprising: a means for generating content; a means for generating metadata including original comparison information for grasping changes from the time of generation of a content file including the content; a means for generating a hash value based on the metadata including the original comparison information and the content; a means for generating a first content file including the content, the metadata including the original comparison information, and the hash value; and a means for generating a second content file including the content but not including the original comparison information. (Configuration 2) The content generating device according to configuration 1, further comprising a control means for controlling, when an instruction to execute a predetermined process is received from a user with one of the first content file and the second content file selected, whether the predetermined process is executed on both the first content file and the second content file, or on only one of the first content file and the second content file, in accordance with the operation performed by the user. (Configuration 3) The content generating device according to configuration 2, wherein the predetermined process is a process of deleting the content file from a storage location. (Configuration 4) The content generating device according to configuration 1, further comprising a control means for controlling the execution of a predetermined process on the first content file when an instruction to execute the predetermined process is received from a user while one of the first content file and the second content file is selected. (Configuration 5) The content generating device according to configuration 4, wherein the predetermined process is a protection process for a content file. (Configuration 6) The content generating device according to configuration 1, further comprising a control means for, when an instruction to execute a predetermined process is received from a user while one of the first content file and the second content file is selected, controlling the execution of the predetermined process on both the first content file and the second content file. (Configuration 7) The content generating device according to configuration 6, wherein the predetermined process is a process of transferring a content file to an external device. (Configuration 8) The content generating device according to any one of configurations 1 to 7, wherein the first content file and the second content file are stored in different storage locations. (Configuration 9) A content generation device described in any one of configurations 1 to 8, characterized in that the content is image data obtained by photographing a subject, and the original comparison information is a thumbnail image that is a reduced version of the content generated by the content generation means. (Configuration 10) A content generating device described in any one of configurations 1 to 9, characterized in that the content is image data obtained by photographing a subject, and the original comparison information is metadata at the time of shooting including information indicating the location of the shooting. (Configuration 11) A content generating device according to any one of configurations 1 to 10, further comprising a memory and a means for recording in the memory that the first content file and the second content file are data generated by the same shooting process. (Configuration 12) A content generating device described in any one of configurations 1 to 10, characterized in that a file name of the second content file is created by adding a predetermined string indicating a relationship with the first content file to the file name of the first content file. (Configuration 13) A content generating device described in any one of configurations 1 to 12, characterized in that the second content file includes the content, metadata that does not include the original comparison information, and a hash value generated based on the metadata that does not include the original comparison information and the content. (Configuration 14) A content generating device as described in configuration 13, characterized in that it is determined whether the data was generated by the same shooting process based on predetermined identification information contained in the metadata including the original comparison information and the metadata not including the original comparison information. (Configuration 15) A content generating device described in any one of configurations 1 to 12, characterized in that the second content file includes the content and does not include metadata that does not include the original comparison information, and metadata that does not include the original comparison information and a hash value generated based on the content. [Explanation of symbols]

[0135] 50 System control section 100 Digital Camera 200 Recording media 600a,600b,600c Image files 601b,601c Metadata 603a, 603b, 603c Image data

Claims

1. A means for generating content; A means for generating metadata including information for comparison with an original for grasping changes from the time of generation of a content file including the content; means for generating a hash value based on the metadata including the original comparison information and the content; means for generating a first content file including the content, metadata including the original comparison information, and the hash value; and generating a second content file including the content and not including the original comparison information.

2. The content generation device according to claim 1, further comprising a control means for controlling, when an instruction to execute a predetermined process is received from a user with one of the first content file and the second content file selected, whether the predetermined process is executed on both the first content file and the second content file, or on only one of the first content file and the second content file, in accordance with the operation performed by the user.

3. 3. The content generating device according to claim 2, wherein the predetermined process is a process of deleting a content file from a storage location.

4. The content generating device according to claim 1, further comprising a control means for, when an instruction to execute a predetermined process is received from a user while one of the first content file and the second content file is selected, controlling the execution of the predetermined process on the first content file.

5. 5. The content generating device according to claim 4, wherein the predetermined process is a protection process for a content file.

6. The content generating device according to claim 1, further comprising a control means for, when an instruction to execute a predetermined process is received from a user with one of the first content file and the second content file selected, performing the predetermined process on both the first content file and the second content file.

7. 7. The content generating device according to claim 6, wherein the predetermined process is a process of transferring a content file to an external device.

8. 2. The content generating device according to claim 1, wherein the first content file and the second content file are stored in different storage locations.

9. the content is image data obtained by photographing a subject, 2. The content generating device according to claim 1, wherein the original comparison information is a thumbnail image obtained by reducing the image data generated by the content generating means.

10. the content is image data obtained by photographing a subject, 2. The content generating apparatus according to claim 1, wherein the original comparison information is metadata at the time of shooting that includes information indicating a shooting location.

11. Memory, 2. The content generating device according to claim 1, further comprising a means for recording in the memory that the first content file and the second content file are data generated by the same shooting process.

12. The content generating device according to claim 1, characterized in that the file name of the second content file is a file name obtained by adding a predetermined character string indicating a relationship with the first content file to the file name of the first content file.

13. The content generating device according to claim 1, characterized in that the second content file includes the content, metadata that does not include the original comparison information, and a hash value generated based on the metadata that does not include the original comparison information and the content.

14. The content generating device according to claim 13, characterized in that it is determined whether the data was generated by the same shooting process based on predetermined identification information contained in the metadata including the original comparison information and the metadata not including the original comparison information.

15. The content generating device according to claim 1, characterized in that the second content file includes the content and does not include metadata that does not include the original comparison information, and does not include a hash value generated based on the metadata that does not include the original comparison information and the content.

16. generating content; generating metadata including information for comparison with an original for grasping changes from the time of generation of a content file including the content; generating a hash value based on the content and metadata including the original comparison information; generating a first content file including the content, metadata including the original comparison information, and the hash value; generating a second content file that includes the content and does not include the original comparison information.

17. A program for causing a computer to execute a method for controlling a content generating device, The method for controlling the content generating device includes: generating content; generating metadata including information for comparison with an original for grasping changes from the time of generation of a content file including the content; generating a hash value based on the content and metadata including the original comparison information; generating a first content file including the content, metadata including the original comparison information, and the hash value; generating a second content file that includes the content and does not include the original comparison information.

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