Imaging apparatus, control method for imaging apparatus, program, and recording medium

Abstract

An imaging apparatus according to the present disclosure comprises: a development means that performs development by applying prescribed image processing to RAW image data which is obtained through imaging and is composed of a signal corresponding to an array of prescribed color components; a setting means that sets whether to enable storage of history information of a captured image in an image file in order to ensure the authenticity of the captured image; and a control means that, if storage of the history information of the captured image is enabled, performs control to generate an image file including image data obtained through development and a header in which the history information of the image data is stored. The control means stores first information including setting information related to the prescribed image processing in such a format that a viewer of the image file can ascertain setting details related to the prescribed image processing and in a region within the header where the history information of the image data is stored.

Description

Imaging Device, Control Method Thereof, Program, and Recording Medium , ,

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[0003] ,

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[0001] The present disclosure relates to an imaging device, a control method thereof, a program, and a recording medium.

[0002] In recent years, with the evolution of digital image processing technology, it has become difficult to verify the authenticity of the content of digital images, and there is a need for a technology to prove the authenticity (that is, no processing or tampering has been done) of digital images. Therefore, a technology has been proposed in which data obtained by adding a digital signature to the hash value of image data is used as tampering detection data, and the authenticity of the image data can be verified by adding the tampering detection data to the image data (Patent Document 1). In Patent Document 1, when imaging is performed with the image authenticity verification function that enables verification of the authenticity of image data enabled, the tampering detection data is added to the image data, so that the captured image data cannot be tampered with.

[0003] Japanese Patent Application Laid-Open No. 2008-5421

[0004] By the way, in recent digital cameras, various image processes are performed before the data captured by the imaging element is stored in an image file (that is, during development). In Patent Document 1, although hashing processing is performed on the captured image data to guarantee the authenticity of the image, it was not considered that the image may be processed by various image processes during development and the authenticity of the image may be affected.

[0005] The present disclosure has been made in view of the above problems, and realizes a technology that can easily grasp the content of the image process performed during development when guaranteeing the authenticity of an image.

[0006] To solve this problem, for example, the imaging device according to the present disclosure has the following configuration. That is, it comprises: a developing means that develops RAW image data, which is composed of signals corresponding to a predetermined arrangement of color components obtained by imaging, by applying predetermined image processing; a setting means that sets whether or not to enable the storage of history information of the captured image in the image file in order to guarantee the authenticity of the captured image; and a control means that, when the storage of history information of the captured image is enabled, controls the generation of an image file including image data obtained through the developing process and a header storing the history information of the image data, wherein the control means stores first information, including setting information related to the predetermined image processing, in an area in the header that stores the history information of the image data, in a format that allows a viewer of the image file to understand the setting content related to the predetermined image processing.

[0007] According to this disclosure, when guaranteeing the authenticity of an image, it becomes possible to easily understand the details of the image processing performed during development.

[0008] Other features and advantages of the technical ideas derived from this disclosure will become apparent from the following description with reference to the attached drawings. In the attached drawings, the same or similar components are given the same reference numeral.

[0009] The attached drawings are included in the specification and constitute a part thereof, illustrating embodiments in this disclosure and used to explain the technical ideas derived from this disclosure together with their descriptions. This is a diagram showing the external configuration of a digital camera as an example of an imaging device according to this embodiment. This is a rear perspective view of the digital camera according to this embodiment. This is a block diagram showing an example of the configuration of the digital camera according to this embodiment. This is a diagram illustrating an example of the configuration of an image file generated in authenticity verification shooting mode. This is a diagram illustrating an example of the configuration of an image file generated in authenticity verification shooting mode. This is a flowchart illustrating a series of operations for the image file generation process in authenticity verification shooting mode according to this embodiment. This is a diagram illustrating an example of the configuration of an image file captured in authenticity verification shooting mode according to this embodiment. This is a diagram illustrating an example of image processing information according to this embodiment. This is a diagram showing the relative relationship between the log described in Exif and the log of image processing information according to this embodiment. This is a diagram showing the relative relationship between the log described in Exif and the log of image processing information according to this embodiment.

[0010] (Embodiment 1) Hereinafter, embodiments will be described in detail with reference to the attached drawings. Note that the following embodiments do not limit the scope of the claims. Multiple features are described in the embodiments, but not all of these features are necessary, and the multiple features may be combined arbitrarily. Furthermore, in the attached drawings, the same or similar configurations are given the same reference numeral, and redundant descriptions are omitted.

[0011] In the following, an example of an imaging device will be described using a digital camera capable of generating image files containing authenticity verification data. However, this embodiment is not limited to digital cameras and can be applied to other devices capable of generating image files containing authenticity verification data. These devices may include, for example, smartphones, game consoles, tablet devices, eyeglass-type information terminals, medical devices, surveillance devices, or in-vehicle devices.

[0012] <Configuration of the Digital Camera> Figures 1A and 1B show an external view of a digital camera 100 as an example of an imaging device to which this disclosure can be applied. Figure 1A is a front perspective view of the digital camera 100, and Figure 1B is a rear perspective view of the digital camera 100. In Figures 1A and 1B, the display unit 28 is a display unit located on the back of the camera that displays images and various information. The viewfinder-external display unit 43 is a display unit located on the top of the camera that displays various camera settings, including shutter speed and aperture. The shutter button 61 is an operation unit for giving shooting instructions. The mode switch 60 is an operation unit for switching between various modes. The terminal cover 40 is a cover that protects connectors (not shown) such as connection cables that connect external devices to the digital camera 100. The main electronic dial 71 is a rotating operation member included in the operation unit 70, and by rotating 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 ON and OFF. The sub-electronic dial 73 is included in the operation unit 70 and is a rotating operating member included in the operation unit 70, which can be used to move the selection frame and advance images. The directional pad 74 is included in the operation unit 70 and is a directional pad (four-way key) whose up, down, left, and right parts can be pressed. Operations can be performed according to the part of the directional pad 74 that is pressed. The SET button 75 is included in the operation unit 70 and is a push button, mainly used to confirm selection items. The LV button 76 is included in the operation unit 70 and is a button that switches the live view (hereinafter referred to as LV) ON and OFF in the menu button. In video recording mode, it is used to instruct the start and stop of video recording. The zoom button 77 is included in the operation unit 70 and is an operation button for turning the zoom mode ON and OFF and changing the magnification ratio in the live view display in shooting mode. In playback mode, it functions as a zoom button to enlarge the playback image and increase the magnification ratio. The minimizing button 78 is included in the control unit 70 and is used to reduce the magnification ratio of the enlarged playback image, thereby shrinking the displayed image. The playback button 79 is also included in the control unit 70 and is used to switch between shooting mode and playback mode.By pressing the playback button 79 during shooting mode, the camera switches to playback mode, and the latest image recorded on the recording medium 200 can be displayed on the display unit 28. The quick-return mirror 12 is raised and lowered by an actuator (not shown) instructed by the system control unit 50. The communication terminal 10 is a communication terminal for the digital camera 100 to communicate with the lens side (detachable). The eyepiece viewfinder 16 is a look-through type viewfinder for checking the focus and composition of the optical image of the subject obtained through the lens unit 150 by observing the focusing screen 13. The cover 202 is the cover of the slot that houses the recording medium 200. The grip part 90 is a holding part shaped to be easily gripped by the user with their right hand when holding the digital camera 100.

[0013] Figure 2 is a block diagram showing an example configuration of the digital camera 100 according to this embodiment. In Figure 2, the lens unit 150 is a lens unit equipped with an interchangeable photographic lens. The lens 103 is usually composed of multiple lenses, but here it is shown simply as a single lens. Communication terminal 6 is a communication terminal for the lens unit 150 to communicate with the digital camera 100, and communication terminal 10 is a communication terminal for the digital camera 100 to communicate with the lens unit 150. The lens unit 150 communicates with the system control unit 50 via these communication terminals 6 and 10, and the internal lens system control circuit 4 controls the aperture 1 via the aperture drive circuit 2, and focuses by displacing the position of the lens 103 via the AF drive circuit 3.

[0014] The AE sensor 17 measures the brightness of the subject as seen through the lens unit 150.

[0015] The focus detection unit 11 outputs defocus amount information to the system control unit 50. Based on this, the system control unit 50 controls the lens unit 150 and performs phase-detection autofocus.

[0016] The quick-return mirror 12 (hereinafter referred to as mirror 12) is raised and lowered by an actuator (not shown) at the command of the system control unit 50 during exposure, live view shooting, and video recording. Mirror 12 is a mirror that switches the light beam incident from the lens 103 between the viewfinder 16 side and the image sensor 22 side. Normally, mirror 12 is positioned to reflect the light beam to guide it towards the viewfinder 16, but when shooting is performed or live view is displayed, it flips up to guide the light beam towards the image sensor 22 and moves out of the way of the light beam (mirror up). In addition, the central part of mirror 12 is a half-mirror that allows some light to pass through, and transmits a portion of the light beam so that it enters the focus detection unit 11 for focus detection.

[0017] The photographer can observe the focusing screen 13 through the pentaprism 14 and viewfinder 16, thereby confirming the focus and composition of the optical image of the subject obtained through the lens unit 150.

[0018] The shutter 101 is a focal-plane shutter that allows the exposure time of the imaging unit 22 to be freely controlled by the system control unit 50. The imaging unit 22 is an image sensor composed of a CCD or CMOS element that converts an optical image into an electrical signal. The A / D converter 23 converts an analog signal into a digital signal. The A / D converter 23 is used to convert the analog signal output from the imaging unit 22 into a digital signal.

[0019] The image processing unit 24 performs development processing such as predetermined pixel interpolation, noise reduction, edge enhancement, optical correction, resizing, and color conversion on the data from the A / D converter 23 (RAW image data) or the data from the memory control unit 15. In this embodiment, the RAW image data is data composed of signals corresponding to a predetermined arrangement of color components. The image processing unit 24 also performs predetermined calculation processing using the captured image data. Based on the calculation results obtained by the image processing unit 24, the system control unit 50 performs exposure control and distance measurement control. This enables TTL (through-the-lens) AF (autofocus), AE (automatic exposure), and EF (flash pre-flash) processing. The image processing unit 24 further performs predetermined calculation processing using the captured image data and performs TTL (auto white balance) processing based on the obtained calculation results.

[0020] 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, or directly via the memory control unit 15. The memory 32 stores image data obtained by the imaging unit 22 and converted into digital data by the A / D converter 23, as well as image data for display on the display unit 28. The memory 32 has sufficient storage capacity to store a predetermined number of still images, a predetermined amount of video footage, and audio.

[0021] Furthermore, memory 32 also serves as memory for image display (video memory). The D / A converter 19 converts the image display data stored in memory 32 into an analog signal and supplies it to the display unit 28. In this way, the display image data written to memory 32 is displayed by the display unit 28 via the D / A converter 19. The display unit 28 displays on a display device such as an LCD according to the analog signal from the D / A converter 19. The digital signal, which has been A / D converted once by the A / D converter 23 and stored in memory 32, is converted to analog by the D / A converter 19 and sequentially transferred to the display unit 28 for display. This allows it to function as an electronic viewfinder and perform through-image display (live view display (LV display)). Hereinafter, the image displayed in live view will be referred to as an LV image.

[0022] The in-viewfinder LCD display 41 displays, via the in-viewfinder display drive circuit 42, a frame indicating the autofocus point currently being focused on (AF frame), and icons representing the camera's settings. The external display 43 displays various camera settings, including shutter speed and aperture, via the external display drive circuit 44.

[0023] The non-volatile memory 56 is an electrically erasable and recordable memory, such as an EEPROM. The non-volatile memory 56 stores constants for the operation of the system control unit 50, programs, etc. The program referred to here is a program for executing various flowcharts described later in this embodiment.

[0024] 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. It realizes each of the processes of this embodiment, which will be described later, by executing the program recorded in the non-volatile memory 56. For example, RAM is used in the system memory 52, and constants, variables for the operation of the system control unit 50, the program read from the non-volatile memory 56, etc. are stored there. The system control unit 50 also performs display control by controlling the memory 32, the D / A converter 19, the display unit 28, etc. The system timer 53 is a timing unit that measures the time used for various controls and the time of the built-in clock.

[0025] The mode switch 60, first shutter switch 62, second shutter switch 64, and operation unit 70 are operating means for inputting various operation instructions to the system control unit 50. The mode switch 60 switches the operating mode of the system control unit 50 to one of the following: still image recording mode, video recording mode, playback mode, etc. Modes included in the still image recording mode include auto shooting mode, auto scene detection mode, manual mode, aperture priority mode (Av mode), shutter speed priority mode (Tv mode), and program AE mode. There are also various scene modes and custom modes that provide shooting settings for different shooting scenes. The user can directly switch to any of these modes using the mode switch 60. Alternatively, the user may first switch to a list screen of shooting modes using the mode switch 60, then select one of the displayed modes and switch using other operating members. Similarly, the video recording mode may also include multiple modes.

[0026] The first shutter switch 62 turns ON during the operation of the shutter button 61 on the digital camera 100, specifically when it is half-pressed (instructing to prepare for shooting), and generates the first shutter switch signal SW1. The first shutter switch signal SW1 initiates operations such as AF (autofocus), AE (automatic exposure), AWB (auto white balance), and EF (flash pre-flash).

[0027] The second shutter switch 64 turns ON when the shutter button 61 is fully pressed (shooting instruction), generating the second shutter switch signal SW2. The system control unit 50 starts a series of shooting processes, from reading the signal from the imaging unit 22 to writing the image data to the recording medium 200, in response to the second shutter switch signal SW2.

[0028] Each operating element of the operation unit 70 is assigned a function as appropriate for each situation by selecting various function icons displayed on the display unit 28, and acts as various function buttons. Examples of function buttons include an exit button, back button, image advance button, jump button, filter button, attribute change button, etc. For example, when the menu button is pressed, various configurable menu screens are displayed on the display unit 28. The user can intuitively make various settings using the menu screen displayed on the display unit 28 and the four directional buttons (up, down, left, right) and the SET button. For example, the user can set whether or not to enable the authenticity verification shooting mode (a mode that stores the history information of the captured image in the image file) to guarantee the authenticity of the captured image via the operation unit 70. The storage of the history information of the captured image will be described later.

[0029] The operation unit 70 consists of various operating components that act as an input unit for receiving user input. The operation unit 70 includes, for example, push buttons, rotary dials, and touch sensors. The operation unit 70 includes, for example, a shutter button 61, a main electronic dial 71, a power switch 72, a sub electronic dial 73, a directional pad 74, a SET button 75, an LV button 76, a zoom in button 77, a zoom out button 78, and a playback button 79.

[0030] The power control unit 80 consists of a battery detection circuit, a DC-DC converter, a switch circuit for switching which blocks are energized, and the like, and detects whether a battery is installed, the type of battery, and the remaining battery level. The power 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 to each part, including the recording medium 200, for the required period of time. The power supply unit 30 consists of primary batteries such as alkaline batteries and lithium batteries, secondary batteries such as NiCd batteries, NiMH batteries, and lithium-ion batteries, an AC adapter, and the like.

[0031] The recording medium I / F 18 is an interface to the recording medium 200, such as a memory card or hard disk. The recording medium 200 is a recording medium such as a memory card for recording captured images, and is composed of semiconductor memory, magnetic disks, etc.

[0032] The communication unit 54 is connected wirelessly or via a wired cable and transmits and receives video and audio signals. The communication unit 54 can also connect to a wireless LAN (Local Area Network) or the internet. Furthermore, the communication unit 54 can communicate with external devices using Bluetooth® or Bluetooth Low Energy. The communication unit 54 can transmit images (including LV images) captured by the imaging unit 22 and images recorded on the recording medium 200, and can also receive images and other various information from external devices.

[0033] The attitude detection unit 55 detects the orientation of the digital camera 100 relative to the direction of gravity. Based on the orientation detected by the attitude detection unit 55, it is possible to determine whether the image captured by the imaging unit 22 was taken with the digital camera 100 held horizontally or vertically. The system control unit 50 can add orientation information corresponding to the orientation detected by the attitude detection unit 55 to the image file of the image captured by the imaging unit 22, or rotate the image before recording. An acceleration sensor or a gyro sensor can be used as the attitude detection unit 55. It is also possible to detect the movement of the digital camera 100 (pan, tilt, lift, whether it is stationary or not, etc.) using the acceleration sensor or gyro sensor in the attitude detection unit 55.

[0034] <Overview of Image Files Generated in Authenticity Verification Shooting Mode> Referring to Figures 3A to 3C, an overview of image files generated in authenticity verification shooting mode will be explained. First, Figure 3A schematically shows the general structure of a JPEG image file as an example of an image file. Image file 300 represents the entire captured image file. Region 301 is a region called "APP0". Region 301 stores JFIF information (version, pixel density, etc.). Region 302 is a region called APP1. Region 302 stores Exif information (shooting date and time, exposure settings at the time of shooting, GPS data, etc.). Generally, the information described in regions 301 to 304 is called metadata. APP0 and APP1 store parameters such as shooting settings corresponding to image file 300. Region 303 is a region called DQT. Region 303 stores the quantization table of the image data. Region 304 is a region called DHT. Area 304 stores the Huffman coding table. Area 305 is the area for storing the main image data.

[0035] The authenticity verification data 306 shown in Figure 3B is information used to verify the authenticity of the origin information of the image file 300, and is used when verifying the source and origin of the image file 300. The authenticity verification data 306 can be generated, for example, according to a predetermined technical standard for verifying the origin of digital content. The prescribed technical standards include, for example, C2PA (Coalition for Content Provenance and Authenticity). The authenticity verification data 306 includes, for example, provenance information (Assertion) 307, a hash value 310 to guarantee the authenticity verification data 306, and a digital signature 311. In one example, the provenance information 307 stores provenance metadata 308 which stores provenance identification information (Manifest ID) that uniquely identifies the provenance and editing history showing the editing content of the image file 300, and a thumbnail image 309 corresponding to the main image data. The thumbnail image 309 may be a copy of the main image data or it may have been resized. In this embodiment, as will be described in detail later, the format of the provenance information 307 is extended to further store image processing information in the provenance information.

[0036] The hash value 310 stores the hash value obtained by executing a hash function on the set of metadata (before the storage of authenticity proof data 306) stored in areas 301 to 304, the main image data, and the provenance information 307. The hash value will differ if the data input to the hash function is different. Therefore, if any of the metadata in areas 301 to 304, the main image data, or the provenance information 307 is changed, the hash value generated from the changed data will be different from the hash value generated from the data before the change. In other words, by comparing the stored hash value with the hash value for the current data, it is possible to detect whether or not the main image data or provenance information 307 has been changed. The digital signature 311 includes a signature value generated by encrypting the hash value 310 using a pre-prepared private key. The public key that forms the pair of the private key used here is also stored together with the digital signature 311.

[0037] The provenance information 307, hash value 310, and digital signature 311 described above are stored in authenticity verification data 306. Then, by inserting the generated authenticity verification data 306 into a predetermined location (within APP1) in the image file 300, an image file 312 (Figure 3C) captured in authenticity verification shooting mode is generated. Therefore, by comparing the hash value obtained by decrypting the digital signature 311 with the public key with the hash value obtained by executing a hash function on the metadata (301-304), main image data, and provenance information 307, if they match, it can be determined that the image has not been tampered with. If they do not match, it means that one of the data areas input to the hash function has been changed since the time the hash value was obtained (i.e., when the image file was generated), indicating that there is a possibility that the image has been tampered with.

[0038] In this way, by creating authenticity verification data for an image file and embedding it within the image file, it is possible to determine whether or not the image has been tampered with through verification using the authenticity verification data.

[0039] In the explanation above, a JPEG file was used as an example of an image file. However, the method of converting data that you want to guarantee as proof of origin within the metadata into a hash value and then digitally signing it is applicable not only to JPEG but also to other image formats.

[0040] Next, we will discuss the challenges of authenticating RAW image data. The main image data mentioned above can be said to be the image obtained from RAW image data acquired through imaging, after various image processing steps have been applied during development. In that case, depending on the image processing steps applied, it may be impossible to distinguish whether the main image data represents a real scene or is a manipulated image that distorts the facts.

[0041] Furthermore, in general, image processing during development is based on proprietary algorithms within each digital camera, resulting in differences in image rendering between cameras. For this reason, details of the image processing during development are not disclosed to digital camera users or image viewers. Consequently, image viewers cannot understand the content of the image processing performed during development by the digital camera, raising concerns about the potential for jeopardizing image authenticity. For example, strong noise reduction processing can distort text in an image, making it unreadable or even resembling different characters. Additionally, development settings can generally be changed by the user through the digital camera's GUI menu. Changing settings such as noise reduction intensity, color saturation, or contrast may alter the impact on image authenticity.

[0042] For example, in the JPEG format, information regarding the user settings and image processing of a digital camera may be described as information specific to each digital camera in the manufacturer's note area within the Exif standard located in APP1 of area 302. Furthermore, shooting information such as shutter speed, aperture value, ISO sensitivity, and GPS information is also described as Exif information in APP1 of area 302. The information in the manufacturer's note area (stored as Exif information in area 302) and the shooting information are guaranteed not to have been tampered with by the hash value 310 and digital signature 311. However, the contents described in the manufacturer's note area are usually obfuscated and not disclosed to the image viewer. Obfuscation involves altering and processing information to make it difficult for humans to read, thereby making it difficult for third parties to decipher and analyze the information. In other words, even if an image viewer can obtain the contents described in the manufacturer's note area, they cannot grasp the details of the image processing during development at a glance, and therefore cannot determine whether the development processing by the digital camera compromises the authenticity of the image.

[0043] Therefore, in the present embodiment, when ensuring the authenticity of an image, the content of the image processing during development, which is performed before being saved in the image file, is made easily understandable to the viewer who views the image file. By doing so, the viewer can grasp the impact of the image processing on the authenticity of the image.

[0044] <Image File Generation Process in the Authenticity Proof Shooting Mode> Hereinafter, the image file generation process in the authenticity proof shooting mode according to the present embodiment will be described with reference to FIG. 4. FIG. 4 shows a series of operations from when the digital camera 100 starts shooting until creating authenticity proof data and making it into an image file. Each operation of the generation process described here can be realized by the system control unit 50 expanding the program stored in the non-volatile memory 56 into the memory 32 and executing it, unless otherwise specified. Each operation of the generation process may also be realized by a circuit or module such as the image processing unit 24 executing the program stored in the non-volatile memory 56. Also, the series of processes shown in FIG. 4 is executed, for example, when the digital camera 100 receives a shooting start operation such as pressing the shutter button 61.

[0045] In S401, the system control unit 50 drives the shutter to control the exposure time. In S402, the system control unit 50 performs an imaging process of converting the light from the subject received by the imaging unit 22 into an electrical signal. In S403, the A / D converter 23 converts the analog signal output from the imaging unit 22 into a digital signal, for example, according to an instruction from the system control unit 50, and outputs RAW image data.

[0046] In S404, the image processing unit 24 executes a development process including predetermined image processing such as pixel interpolation, noise reduction, edge enhancement, optical correction, resizing processing, and color conversion processing on the obtained RAW image data, for example, according to an instruction from the system control unit 50. The image processing unit 24 writes the generated image data into the memory 32. In S405, the system control unit 50 compresses the image data expanded in the memory 32 after the above development process into a JPEG format or the like, and creates main image data to be stored in the area 305.

[0047] In S406, the system control unit 50 determines whether the authenticity verification shooting mode is enabled (that is, whether the authenticity verification shooting mode is ON). For example, the system control unit 50 reads the setting value regarding the authenticity verification shooting mode from the non-volatile memory 56 and determines whether the setting value indicates that the authenticity verification shooting mode is enabled. If the system control unit 50 determines that the authenticity verification shooting mode is enabled (the authenticity verification shooting mode is ON), the process proceeds to S408; otherwise, the process proceeds to S407.

[0048] In S407, since the authenticity verification shooting mode is OFF, the system control unit 50 generates metadata such as shooting information (aperture, ISO sensitivity, shutter speed, shooting date and time) and writes it to the memory 32.

[0049] In S413, the system control unit 50 generates an image file for recording. The system control unit 50 stores metadata written to the memory 32 in APP1 (the manufacturer note area within the Exif area) of the area 302. The system control unit 50 further stores the main image data in the image file. At this time, since the system control unit 50 has not generated the authenticity verification data 306, the authenticity verification data is not stored in APP1 of the area 302 of the generated image file. When the process of S413 ends, the system control unit 50 ends this series of operations.

[0050] Next, in S408, when the authenticity verification shooting mode is enabled (that is, when the authenticity verification shooting mode is ON), the system control unit 50 generates metadata. Specifically, the system control unit 50 generates metadata for storage in the manufacturer note area (within the APP1 Exif area), that is, metadata such as shooting information (aperture, ISO sensitivity, shutter speed, shooting date and time), and writes it to the memory 32. In addition, separately from the manufacturer note area, the system control unit 50 generates the image processing information 501 shown in FIG. 5 for storage in the history information 502.

[0051] The format of the authenticity verification data 500 is the same as that of the authenticity verification data 306, except that the provenance information 502 includes image processing information 501. The authenticity verification data 500 includes, for example, provenance information 502, a hash value 503 to guarantee the authenticity verification data 500, and a digital signature 504. The provenance information 502 stores the image processing information 501 as described above. The provenance information 502 also stores provenance metadata 308, which stores provenance identification information (Manifest ID) that uniquely identifies the provenance and editing history showing the editing content of the image file 300, as well as a thumbnail image 309 corresponding to the main image data. The hash value 503 stores the hash value obtained by executing a hash function on the set of metadata (before storing the authenticity verification data 500) stored in areas 301 to 304, the main image data, and the provenance information 502. The digital signature 504 contains a signature value generated by encrypting the hash value 503 using a pre-prepared private key. The public key that forms the pair with the private key used here is also stored together with the digital signature 504.

[0052] An example of the information stored in the image processing information 501 is shown in Figure 6. In the example of image processing information 501 shown in Figure 6, the image processing settings during development in the digital camera 100 are described in a way that is "easy for the viewer to understand" and "allows the settings to be reproduced on the digital camera." The image processing settings during development include various settings that affect the image, such as the shooting mode, noise reduction processing method, noise reduction processing intensity, sharpness, contrast, or optical correction settings.

[0053] For example, the system control unit 50 stores the image processing information 501 in the history information 502 in an unobfuscated format. The image processing information 501 may describe the image processing during development in association with the item name (information that identifies the image processing) and the setting value of each item. For example, the image processing information 501 may describe the item "Pixel Interpolation" corresponding to pixel interpolation processing and "Linear Interpolation" as the setting value for pixel interpolation processing in association. In this way, viewers can easily understand which image processing was performed during development and with what setting values. The image processing information 501 may also describe the item name (information that identifies the image processing) in association with information indicating whether the setting related to the item has been changed from the initial state of the digital camera 100 (for example, the factory default state). For example, the image processing information 501 may describe the item name "Noise Reduction Intensity" corresponding to noise reduction processing and "Yes" indicating that the setting related to that item has been changed from the initial state in association. In this way, viewers can easily identify image processing settings that have been changed from the initial state. Furthermore, viewers can easily understand which image processing caused the difference between the image recorded with the initial settings and the image being viewed.

[0054] The item name (information identifying the image processing) may be associated with the name of the image processing that can be set by the viewer via the operation unit 70 in the digital camera 100. Furthermore, the setting value for each item may be associated with the setting value that can be set by the viewer via the operation unit 70 in the digital camera 100. In this way, the viewer can easily reproduce the image processing settings in the digital camera 100 according to the image processing information 501. The item names in the image processing information 501 may be written in text that is legible to the viewer, but they may also be written using predetermined numerical values ​​(for example, 0 for shooting mode, 1 for compression ratio, etc.). If the item names in the image processing information 501 are written numerically, the viewer only needs to be able to understand the item name text based on information such as a table that associates the text of the item name with the numerical value.

[0055] In the above explanation, the system control unit 50 described an example in which it includes both setting information for image processing that has been changed from the initial state of the digital camera 100 and setting information for image processing that has not been changed from the initial state in the image processing information 501. However, the system control unit 50 may also include in the image processing information 501 only the setting information for image processing that has been changed from the initial state of the digital camera 100.

[0056] With this image processing information 501, viewers can set the image processing based on the information described in the image processing information 501 and take a test shot of any subject to understand the impact that the image processing of the digital camera 100 has on the authenticity of the image. After confirming the authenticity of the image based on the results of the test shot, viewers can use the image with confidence. Furthermore, as described above, since the system control unit 50 stores the image processing information 501 as part of the provenance information, the image processing information 501 is protected so that tampering can be detected by a digital signature mechanism.

[0057] The relationship between the information described in obfuscated form in the manufacturer's notes in area 302 (log 701) and the information described in unobfuscated form in the image processing information 501 (log 702) may be as shown in Figures 7A and 7B. Log 701 includes the information stored in log 702, as well as additional information. That is, the information stored in log 702 is less than the information stored in log 701. Alternatively, log 701 and log 702 may have some common information, while each possessing its own unique information.

[0058] Referring again to Figure 4, the series of operations in the image file generation process will be explained. In S409, the system control unit 50 executes a hash function on the set of metadata area (area 301 to area 304), main image data, provenance information 502, and thumbnail image 309 to generate a hash value 310.

[0059] In S410, the system control unit 50 encrypts the hash value 310 using a pre-prepared secret key to create a digital signature 311. In S411, the system control unit 50 generates authenticity proof data 500 from the provenance information 502, hash value 503, and digital signature 504 generated up to S410.

[0060] In S412, the system control unit 50 generates a recording image file 312 as shown in Figure 5 and records it on the recording medium 200. Specifically, the system control unit 50 stores authenticity verification data 500 in APP1 of area 302 of the image file, and also stores the metadata written to memory 32 in APP1 of area 302 (manufacturer note area within Exif area). Furthermore, the system control unit 50 also stores the main image data in the image file. Once the system control unit 50 has recorded the image file 312 on the recording medium 200, it terminates this process.

[0061] Furthermore, after the image generation process shown in Figure 4, the system control unit 50 can obtain image processing information 501 contained in the provenance information 502 from the header of the image file generated in the process. The system control unit 50 can then display the settings related to image processing during development on a display device (e.g., display unit 28) based on the image processing information 501. In this way, viewers of the image file can understand the settings related to image processing during development. At this time, for example, the system control unit 50 compares the hash value 503 contained in the authenticity verification data 500 stored in the image file with the hash value calculated from the provenance information 502 of the image file and data such as the main image data. If the two hash values ​​match, the system control unit 50 can determine that the image processing information 501 contained in the authenticity verification data 500 has not been tampered with. If the system control unit 50 determines that the image processing information 501 has not been tampered with, it may display the contents of the image processing information 501 on the display device. On the other hand, if the two hash values ​​do not match, the system control unit 50 may cause the display device to display a message indicating that the image file may have been tampered with.

[0062] The system control unit 50 may display the item names described in the image processing information 501 and their corresponding setting values ​​on the display device (e.g., display unit 28). In this way, viewers can easily understand which items were performed with what setting values ​​during image processing during development. The system control unit 50 may also display the item names and the corresponding information indicating whether the setting related to the item name described in the image processing information 501 has been changed from the initial state of the digital camera 100 (e.g., factory default state) on the display device (e.g., display unit 28). The system control unit 50 may also display only the image processing that has been changed from the initial state of the digital camera 100 on the display device. In this way, viewers can easily understand which items cause the difference between the image recorded with the initial settings and the image being viewed.

[0063] Furthermore, the displayed item names (information identifying the image processing) may be associated with the names of image processing settings that the viewer can set via the control unit 70 in the digital camera 100. Also, the setting values ​​for each item may be associated with setting values ​​that the viewer can set via the control unit 70 in the digital camera 100. In this way, the viewer can easily reproduce the image processing settings in the digital camera 100 according to the image processing information 501.

[0064] As described above, in this embodiment, when the storage of history information of captured images is enabled, an image file is generated that includes image data obtained after development and a header that stores the history information of the image data. At this time, in the area of ​​the header that stores the history information of the image data, first information including setting information related to image processing during development is stored in a format that allows the viewer of the image file to understand the settings related to image processing during development. In this way, when guaranteeing the authenticity of the image, the content of the image processing performed during development can be easily understood. Furthermore, even if it is difficult to understand the content of the image processing in the digital camera 100 from the information in the manufacturer's notes area, the viewer of the image can easily understand the impact of the image processing in the digital camera 100 on the authenticity of the image through the image processing information 501.

[0065] (Other Embodiments) The present invention can also be realized by supplying a program that implements one or more of the functions of the above embodiments to a system or device via a network or storage medium, and by having one or more processors in the computer of that system or device read and execute the program. It can also be realized by a circuit (e.g., ASIC) that implements one or more functions.

[0066] The technical ideas derived from this disclosure are not limited to the exemplary embodiments disclosed, but are intended to encompass various modifications of the exemplary embodiments, or substitutions with equivalent structures or functions. The scope of the following claims should be interpreted in the broadest way to encompass all such modifications and equivalent structures and functions.

[0067] This application claims priority based on Japanese Patent Application No. 2025-025227, filed on 19 February 2025, and all of its contents are incorporated herein by reference.

[0068] 100...Digital camera, 28...Display unit, 50...System control unit, 305...Main image data area, 312...Image file, 500...Authenticity verification data, 501...Image processing information, 502...Provenance information

Claims

1. An imaging device comprising: a developing means that develops RAW image data, which is composed of signals corresponding to a predetermined arrangement of color components obtained by imaging, by applying predetermined image processing; a setting means that sets whether or not to enable the storage of history information of the captured image in the image file in order to guarantee the authenticity of the captured image; and a control means that, when the storage of history information of the captured image is enabled, controls the generation of an image file including image data obtained through the development and a header storing the history information of the image data, wherein the control means stores first information, including setting information related to the predetermined image processing, in an area in the header that stores the history information of the image data, in a format that allows a viewer of the image file to understand the setting content related to the predetermined image processing.

2. The imaging apparatus according to claim 1, characterized in that the control means further stores second information, including setting information related to the predetermined image processing, in a region within the header separate from the region that stores the history information of the image data.

3. The imaging apparatus according to claim 1, further comprising the control means obtaining setting information relating to the predetermined image processing included in the history information from the header of the generated image file, and causing the display means to display the setting content relating to the predetermined image processing based on the obtained setting information relating to the predetermined image processing.

4. The imaging apparatus according to claim 1, characterized in that the control means includes only the image processing from which the settings of the imaging apparatus have been changed from the initial state among the predetermined image processing in the first information.

5. The imaging apparatus according to claim 3, characterized in that the control means causes only the image processing for which the settings have been changed from the initial state of the imaging apparatus to be displayed on the display means.

6. The imaging apparatus according to claim 1, characterized in that the first information includes information relating to the predetermined image processing, namely information that identifies the image processing and the setting value of the image processing.

7. The imaging device according to claim 1, characterized in that the first information includes information relating to the predetermined image processing, which includes information that identifies the image processing and information indicating that the settings related to the image processing have been changed from the initial state of the imaging device.

8. The imaging device according to claim 6, characterized in that the information identifying the image processing is associated with the name of the image processing that can be set by the viewer via the operating means in the imaging device, and the setting value of the image processing is associated with a setting value that can be set by the viewer via the operating means in the imaging device.

9. The imaging apparatus according to claim 2, characterized in that the control means stores the first information in the history information of the image data in an unobfuscated format and the second information in the header in an obfuscated format.

10. The imaging apparatus according to claim 2, characterized in that the second information includes the information stored in the first information and additional information, or that the first information and the second information have common information in which they each store information, while each also contains unique information.

11. A control method for an imaging device, comprising: a development step of developing RAW image data, which is composed of signals corresponding to a predetermined sequence of color components obtained by imaging, by applying predetermined image processing; a setting step of setting whether or not to enable the storage of history information of an image image in an image file in order to guarantee the authenticity of the image image; and a control step of controlling the device to generate an image file that includes the image data obtained through the development and a header storing the history information of the image data, wherein in the control step, first information including setting information related to the predetermined image processing is stored in an area in the header that stores the history information of the image data, in a format that allows a viewer of the image file to understand the setting content related to the predetermined image processing.

12. A program for causing a computer to function as one of the means of an imaging apparatus according to any one of claims 1 to 10.

13. A recording medium for storing a program for causing a computer to function as one of the means of an imaging apparatus according to any one of claims 1 to 10.

Images