Imaging device, control method for imaging device, and program

Abstract

The present invention provides, for example, a technique for proving the authenticity of image data captured by an imaging device. [Solution] The imaging device comprises an imaging unit, a generation unit capable of generating image data based on imaging data captured by the imaging unit, and proof data that proves the authenticity of the image data, wherein the proof data includes encrypted data, which includes a viewing image for viewing the image shown by imaging data on which the first processing has not been performed, and recording data that includes a record of the processing of the imaging data.

Description

Technical Field

[0001] The present invention relates to an imaging device, a control method for an imaging device, and a program.

Background Art

[0002] In recent years, information sharing via the Internet and SNS has become active, and it has become an era in which anyone can view and transmit information. Also, in recent years, digital image processing technology has evolved. Under such circumstances, it has become difficult for information viewers to view processed digital images and confirm the authenticity of the viewed content, and as a result, problems such as fake news have become more serious. Therefore, a technique for proving the authenticity of an image by attaching a digital signature to the image is known. Also, in Patent Document 1, an imaging device equipped with a shooting mode for proving such authenticity has been developed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In recent digital cameras, various processing operations are performed on the captured data between when the user gives a shooting instruction and when it is saved as image data. However, Patent Document 1 does not describe at which stage of the image from shooting to saving of the image data a digital signature for proving authenticity is attached. Therefore, when the image with the digital signature is, for example, an image after various processing operations have been performed, there is a suspicion that the image itself with the digital signature is an image with distorted facts. Thus, the authenticity of the captured image may not be proven.

[0005] One aspect of the present invention is to provide a technique for proving the authenticity of image data captured by an imaging device. [Means for solving the problem]

[0006] One aspect of the present invention is, Imaging unit, The system comprises a generation unit capable of generating image data based on imaging data captured by the imaging unit, and proof data that proves the authenticity of the image data, The aforementioned proof data is, A viewing image for viewing the image shown by the imaging data in which the first processing has not been performed, Recording data including a record of the processing of the aforementioned imaging data, Including encrypted data, It is an imaging device. [Effects of the Invention]

[0007] According to the present invention, the authenticity of image data captured by an imaging device can be proven. [Brief explanation of the drawing]

[0008] [Figure 1] External view of an imaging device according to one embodiment. [Figure 2] Block diagram of an imaging device according to one embodiment. [Figure 3] Configuration diagram of image data according to one embodiment [Figure 4] Rear view of a camera according to one embodiment [Figure 5] Diagram illustrating a method for recording authenticity verification data according to one embodiment. [Modes for carrying out the invention]

[0009] The embodiments will be described in detail below with reference to the attached drawings. Note that the following embodiments do not limit the invention as defined in the claims. While the embodiments describe multiple features, not all of these features are essential to the invention, and the features may be combined in any way. Furthermore, in the attached drawings, identical or similar configurations are given the same reference numerals, and redundant descriptions are omitted.

[0010] Using Figures 1(A) and 1(B), a digital camera 100 will be described as an example of a device to which this embodiment can be applied. Figure 1(A) is a front perspective view of the digital camera 100, and Figure 1(B) is a rear perspective view of the digital camera 100. A display unit 28 for displaying images and various information is provided on the back of the digital camera 100. In addition, an external viewfinder display unit 43 for displaying various camera settings, including shutter speed and aperture, is provided on the top surface of the digital camera 100.

[0011] The digital camera 100 is also equipped with a shutter button 61, a mode selector switch 60, a terminal cover 40, a main electronic dial 71, a power switch 72, a sub electronic dial 73, a cross key 74, and a SET button 75. The shutter button 61 is an operation unit for issuing shooting instructions. The mode selector 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.

[0012] The main electronic dial 71 is a rotary control part included in the control 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 operating component that switches the power of the digital camera 100 ON and OFF. The sub electronic dial 73 is a rotary dial included in the control unit 70. By operating this sub electronic dial 73, the user can move the selection frame, advance images, etc. The directional pad 74 is included in the control unit 70 and is a directional pad (4-way key) with up, down, left, and right sections that can be pressed. The user can perform operations according to the part of the directional pad 74 that is pressed. The SET button 75 is included in the control unit 70 and is a push button, mainly used to confirm selection items.

[0013] The digital camera 100 is also equipped with an LV button 76, a zoom in button 77, a zoom out button 78, a playback button 79, a quick-return mirror 12, a communication terminal 10, an eyepiece viewfinder 16, a cover 202, and a grip section 90. The LV button 76 is included in the control unit 70 and is a button that allows switching the live view (hereinafter referred to as LV) ON and OFF in the menu button. In video recording mode, the LV button 76 is used to instruct the start and stop of video recording. The zoom in button 77 is included in the control unit 70 and is an operation button for switching the zoom mode ON and OFF and changing the magnification ratio in the live view display in shooting mode. In playback mode, the zoom in button 77 functions as a zoom button to enlarge the playback image and increase the magnification ratio.

[0014] The minimizing button 78 is included in the operation unit 70 and is used to reduce the magnification of the enlarged playback image, thereby shrinking the displayed image. The playback button 79 is also included in the operation unit 70 and is an operation button for switching between shooting mode and playback mode. By pressing the playback button 79 while in shooting mode, the user can switch to playback mode and display the latest image from the images recorded on the recording medium 200 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 that allows the user to check 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 stores 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.

[0015] Figure 2 illustrates the block configuration of the digital camera 100. The digital camera 100 consists of a lens unit 150, communication terminals (6, 10), a system control unit 50, a lens system control circuit 4, an aperture drive circuit 2, an aperture 1, an AF drive circuit 3, and a lens 103. 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 as a single lens for simplicity. Communication terminal 6 is a communication terminal for the lens unit 150 to communicate with the digital camera 100. 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, 10). 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.

[0016] The digital camera 100 also includes an AE sensor 17, a focus detection unit 11, a quick return mirror 12, an imaging unit 22, an eyepiece finder 16, a pentaprism 14, a focusing screen 13, a shutter 101, and an A / D converter 23. The AE sensor 17 measures the luminance of the subject passing through the lens unit 150. The focus detection unit 11 outputs defocus amount information to the system control unit 50. The system control unit 50 controls the lens unit 150 using this defocus amount information to perform phase difference AF. The quick return mirror 12 (hereinafter also referred to as the mirror 12) is moved up and down by an actuator (not shown) under the instruction from the system control unit 50 during exposure, live view shooting, and video shooting.

[0017] The mirror 12 is a mirror for switching the light beam incident from the lens 103 to the eyepiece finder 16 side and the imaging unit 22 side. The mirror 12 is normally arranged to reflect the light beam to the eyepiece finder 16. However, during shooting or live view display, it jumps upward to avoid from the light beam and guides the light beam to the imaging unit 22 (mirror up). Also, the central part of the mirror 12 is a half mirror so that part of the light can pass through, and part of the light beam is transmitted to the focus detection unit 11 for performing focus detection.

[0018] The photographer can observe the focusing screen 13 through the pentaprism 14 and the eyepiece finder 16 to confirm the focus and composition of the optical image of the subject obtained through the lens unit 150. 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. The imaging unit 22 is an image sensor (image sensor) composed of a CCD, a CMOS element, etc. 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 digital camera 100 is also configured to include an image processing unit 24, a memory control unit 15, a memory 32, a D / A converter 19, a display unit 28, a liquid crystal display unit 41 in the finder, and a drive circuit 42 for the display unit in the finder. The digital camera 100 is also configured to include an external-finder display unit 43 and a drive circuit 44 for the external-finder display unit. The image processing unit 24 performs resizing processes such as predetermined pixel interpolation and reduction, and color conversion processes 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. The system control unit 50 performs exposure control and distance measurement control using the arithmetic result obtained by the image processing unit 24. Thereby, AF (Auto Focus) processing, AE (Automatic Exposure) processing, and EF (Flash Pre-Firing) processing in the TTL (Through-The-Lens) method are performed. The image processing unit 24 further performs predetermined arithmetic processing using the captured image data, and performs AWB (Auto White Balance) processing in the TTL method using the obtained arithmetic result.

[0020] The output data from the A / D converter 23 is directly written into the memory 32 via the image processing unit 24 and the memory control unit 15, or via the memory control unit 15. The memory 32 stores the image data obtained by the imaging unit 22 and converted into digital data by the A / D converter 23, and the image data for display on the display unit 28. The memory 32 includes a storage capacity sufficient to store a predetermined number of still images, a moving image for a predetermined time, and audio. The memory 32 also serves as a memory for image display (video memory). 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. Thus, the image data for display written into the memory 32 is displayed by the display unit 28 via the D / A converter 19.

[0021] The display unit 28 displays information on an LCD or other display device in accordance with the analog signal from the D / A converter 19. The display unit 28 converts the digital signal, which has been temporarily stored in the memory 32 by the A / D converter 23, into an analog signal using the D / A converter 19. The display unit 28 then sequentially transfers the converted analog signal to the display unit 28 for display, thereby functioning as an electronic viewfinder and enabling through-image display (live view display (LV display)). Hereafter, the image displayed in live view will also be referred to as the LV image. The in-finder LCD display unit 41 displays, via the in-finder display unit drive circuit 42, a frame indicating the AF point where autofocus is currently being performed, and icons representing the camera's settings. The external display unit 43 displays various camera settings, including shutter speed and aperture, via the external display unit drive circuit 44.

[0022] The digital camera 100 also includes a non-volatile memory 56, a system timer 53, a mode selector switch 60, a shutter button 61, a first shutter switch 62, a second shutter switch 64, a system memory 52, and an operation unit 70. The non-volatile memory 56 is an electrically erasable and recordable memory, such as an EEPROM. Constants and programs for the operation of the system control unit 50 are stored in the non-volatile memory 56. Here, "program" refers to a program for executing the various flowcharts described later. The system control unit 50 is a control unit that includes at least one processor and / or at least one circuit, and controls the entire digital camera 100. The system control unit 50 realizes the various processes described later by executing the program stored in the non-volatile memory 56. For example, RAM is used for the system memory 52, and constants and variables for the operation of the system control unit 50, programs 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, and the display unit 28, etc.

[0023] The system timer 53 is a timing unit that measures the time used for various controls and the time of the built-in clock. The mode switch 60, shutter button 61, first shutter switch 62, second shutter switch 64, and operation unit 70 are means for inputting various operation instructions to the system control unit 50. More specifically, the mode switch 60 switches the operation mode of the system control unit 50 to one of the modes such as still image recording mode, video recording mode, and playback mode. 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. Modes included in the still image recording mode include various scene modes that are shooting settings for different shooting scenes, or custom modes. The user can directly switch the operation mode to one of these modes using the mode switch 60. Alternatively, the user may switch the display to the shooting mode list screen using the mode switch 60, select one of the displayed modes, and then switch the operation mode using the other operation unit. Similarly, video recording modes may also include multiple modes.

[0024] 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 (instruction 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), or EF (flash pre-flash). The second shutter switch 64 turns ON when the operation of the shutter button 61 is completed, specifically when it is fully pressed (instruction to shoot), and generates the second shutter switch signal SW2. The system control unit 50, upon receiving the second shutter switch signal SW2, initiates a series of shooting operations, from reading the signal from the imaging unit 22 to writing the image data to the recording medium 200.

[0025] Each control unit of the control unit 70 is assigned a function as appropriate for each situation by the user selecting various function icons displayed on the display unit 28, and functions as various function buttons. Examples of function buttons include an exit button, back button, image forward button, jump button, filter button, or attribute change button. 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. The control unit 70 consists of various control units that act as input units that accept operations from the user. The control unit 70 is composed of push buttons, rotary dials, or touch sensors. Specifically, the control unit 70 includes at least a shutter button 61, a main electronic dial 71, a power switch 72, a sub electronic dial 73, a cross key 74, a SET button 75, an LV button 76, a zoom button 77, a zoom button 78, and a playback button 79.

[0026] The digital camera 100 also includes a power control unit 80, a power supply unit 30, a recording medium interface 18, a communication unit 54, and a posture detection unit 55. The power control unit 80 is composed of a battery detection circuit, a DC-DC converter, and a switch circuit for switching which blocks are energized, and detects whether a battery is installed, the type of battery, or the remaining battery level. The power control unit 80 also controls the DC-DC converter using 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 is composed of primary batteries such as alkaline batteries and lithium batteries, secondary batteries such as NiCd batteries, NiMH batteries, and lithium-ion batteries, and an AC adapter, etc.

[0027] 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 can be a semiconductor memory or magnetic disk. The communication unit 54 is composed of a communication module. The communication unit 54 is connected wirelessly or via a wired cable and transmits and receives video signals and audio signals. The communication unit 54 can also connect to a wireless LAN (Local Area Network) or the Internet. In addition, the communication unit 54 can communicate with external devices using Bluetooth® or Bluetooth Low Energy. The communication unit 54 can transmit images captured by the imaging unit 22 (including LV images) and images recorded on the recording medium 200, and can also receive images and other various information from external devices.

[0028] The attitude detection unit 55 detects the orientation of the digital camera 100 relative to the direction of gravity. Using the detected orientation, the attitude detection unit 55 determines 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 data captured by the imaging unit 22, or rotate the image and store it in the storage medium. For example, an acceleration sensor or a gyroscope sensor can be used as the attitude detection unit 55. Furthermore, if an acceleration sensor or a gyroscope sensor is used in the attitude detection unit 55, the attitude detection unit 55 can also detect the movement of the digital camera 100 (pan, tilt, lift, and whether it is stationary or not).

[0029] Figures 3(A) to 3(C) illustrate the image generation process and the authenticity verification mechanism when shooting in authenticity verification mode. Figure 3(A) illustrates the data structure of an image file shot in normal shooting mode. Image file 301 represents the entire file containing the captured image data. Image file 301 includes metadata 302 and main image data 303. Metadata 302 represents an area for recording metadata corresponding to image file 301, and stores parameters such as settings at the time of shooting. Main image data 303 is an area where the captured main image data is stored.

[0030] On the other hand, Figures 3(B) and 3(C) illustrate the data structure of an image file containing image data captured in authenticity verification mode. The image file 310 includes a metadata area, authenticity verification data 304 (an example of "verification data"), and a main image data area. The authenticity verification data 304 is information for verifying the authenticity of the image file 301 and is used when verifying the source and history of the image file 301. The authenticity verification data 304 has a structure generated in accordance with a predetermined technical standard (for example, C2PA (Coalition for Content Prevenance and Authenticity)). More specifically, the authenticity verification data 304 includes provenance information (Assertion) 305 (an example of "record data"), a hash value 308 to guarantee the authenticity verification data 304, and a digital signature 309 obtained by encrypting the hash value 308. The provenance information 305 stores provenance identification information (Manifest ID) to uniquely identify the provenance, provenance metadata 306 which stores editing history showing the editing content of the image file 301, and a thumbnail image 307 corresponding to the main image data 303. This thumbnail image 307 may be a copy of the main image data 303 or it may be a resized version.

[0031] The hash value 308 includes the value obtained by inputting the metadata 302, the main image data 303, and the provenance information 305 into a hash function. The digital signature 309 includes the signature value generated by encrypting the hash value 308 using a pre-prepared private key. The public key that forms the pair of the private key used here is also stored in the authenticity verification data 304 along with the digital signature 309. The provenance information 305, the hash value 308, and the digital signature 309 are stored in the authenticity verification data 304. The generated authenticity verification data 304 is then inserted into a predetermined position in the data structure of the image file 301, thereby generating the image file 310 (Figure 3(C)) taken in authenticity verification shooting mode.

[0032] To verify whether this image has been tampered with, the hash value obtained by decrypting the digital signature 309 with a public key is compared with the hash value obtained by inputting the metadata 302, the main image data 303, and the provenance information 305 into a hash function. If the two hash values ​​match, the verification is considered successful. On the other hand, if the two hash values ​​do not match, it means that one of the data input into the hash function has been changed since the time the hash value was obtained, indicating the possibility of data tampering.

[0033] As described above, Figures 3(A) to 3(C) illustrate the mechanism for creating authenticity verification data for an image file, embedding it within the image file, and verifying its authenticity. Here, the thumbnail image 307 corresponds to the main image data 303 and can be said to be an image that has undergone various image processing during shooting. Therefore, it is difficult to determine whether the image represents the actual scene captured by the digital camera 100 or whether it is an image that has been processed and distorted. Thus, using Figures 4 and 5, we will explain a method for determining whether the thumbnail image 307 represents the actual scene captured by the digital camera 100 or whether it is an image that has been processed and distorted.

[0034] <Example of processing> Figures 4 and 5(A) illustrate the processing flow from the start of shooting to the creation of authenticity verification data and the generation of an image file. Each step is realized by the system control unit 50 loading the program stored in the non-volatile memory 56 into memory 32 and executing it. The shooting process in Figure 4 is executed when the system control unit 50 receives a shooting start operation, such as when the photographer presses the shutter button 61 on the digital camera 100.

[0035] In S401, the system control unit 50 drives the shutter to control the exposure time. In S402, the system control unit 50 performs imaging processing, converting the light received from the subject by the imaging unit 22 into an electrical signal. In S403, the system control unit 50 causes the A / D converter 23 to convert the electrical signal (analog signal) output from the imaging unit 22 into a digital signal. In S404, the system control unit 50 generates imaging data by performing basic development processing (an example of "second processing") such as color and gradation correction and optical correction on the data represented by the digital signal generated in S403. Then, the system control unit 50 writes the generated imaging data to the memory 32. Specifically, the processing in S404 consists of a group of image processing operations that are always performed when the shutter is pressed, regardless of user settings.

[0036] In S405, the system control unit 50 (an example of a "determination unit") reads the setting value related to the shooting mode from the non-volatile memory 56 and determines whether the shooting mode is set to normal mode or authenticity verification shooting mode. If the system control unit 50 determines that the shooting mode is set to normal mode, the process proceeds to S406. On the other hand, if the system control unit 50 determines that the shooting mode is set to authenticity verification shooting mode, the process proceeds to S411. In S406, the system control unit 50 reads the setting value related to the image processing process from the non-volatile memory 56 and determines whether the image processing process is set or not. If the system control unit 50 determines that the image processing process is set, the process proceeds to S407; otherwise, the process proceeds to S408.

[0037] In S407, the system control unit 50 performs the image processing applied to the image data expanded in memory 32. In S408, the system control unit 50 compresses the image data expanded in memory 32 into JPEG format or the like to create main image data 303. In S409, the system control unit 50 creates metadata 302 and writes it to memory 32. In S410, the system control unit 50 combines the metadata 302 created in S409 and the main image data 303 created in S408 to create a single recorded image file, and records this recorded image file to the recording medium 200. Then the processing ends. These steps S406 to S410 represent the processing when the digital camera 100 is in normal shooting mode, not authenticity verification shooting mode.

[0038] On the other hand, the following sections will explain the processing flow in authenticity verification shooting mode and the method for generating the recorded image file 509 using S411 to S419 and Figure 5(A). If the system control unit 50 determines in S405 that authenticity verification shooting mode is set, in S411 the system control unit 50 generates a compressed image before the image processing, which is not the timing for generating a compressed image in normal mode. That is, in S404 the system control unit 50 resizes the image data written to memory 32 as needed, compresses it to JPEG format, etc., and creates a thumbnail image 501. In this way, in authenticity verification shooting mode, the compressed image data is created in a state before image processing is performed. This makes it possible to use the image before the image processing in S413 is executed as an image to be saved in the history. The thumbnail image 501 is an example of a "viewing image for viewing the image shown by the image data in which the first processing has not been performed".

[0039] In S412, the system control unit 50 reads setting values ​​related to image processing from the non-volatile memory 56 and determines whether or not image processing is set. If the system control unit 50 determines that image processing is set, the process proceeds to S413; otherwise, the process proceeds to S415. In S413, the system control unit 50 performs image processing (an example of "first processing") on the image data expanded in memory 32. This image processing is the same as the processing in S407. In S414, the system control unit 50 resizes the image data after image processing, which was written to memory 32 in S413, as needed, compresses it into JPEG format, etc., and creates a thumbnail image 502. This thumbnail image 502 is an image that is recorded in the authenticity verification data as an image that is in the same state as the main image after image processing.

[0040] In S415, the system control unit 50 compresses the image data after image processing, which was written to the memory 32 in S413, into JPEG format or the like, to create the main image data 503. If the system control unit 50 determines in S412 that image processing is not set, the system control unit 50 compresses the image data written to the memory in S404 into JPEG format or the like, to create the main image data 503. In S416, the system control unit 50 creates image metadata to be stored in the metadata area 504. In S417, the system control unit 50 inputs the metadata area 504, the main image data 503, and the provenance information 505 into a hash function to generate a hash value 506. In S418, the system control unit 50 encrypts the hash value 506 using a pre-prepared secret key to create a digital signature 507.

[0041] In S419, the system control unit 50 (an example of a "generation unit capable of generating image data and certification data") synthesizes the provenance information 505, hash value 506, and digital signature 507 generated up to S418 as authenticity certification data 508. The process then proceeds to S410, where the metadata area 504, main image data 503, and authenticity certification data 508 are synthesized to create a recorded image file 509, which is then recorded on the recording medium 200. The process then ends. In this way, if image processing is applied to the captured data between the time the metadata 302 and main image data 303 are saved to the recorded image file during a single shooting, the following process is executed: two thumbnail images, one before image processing (S411) and one after image processing (S414), are included in the provenance information. Therefore, the image before image processing in S413 can be visually confirmed in another process that handles the recorded image file.

[0042] Furthermore, if the system control unit 50 determines in S412 that image processing is not set, there is no need to retain the thumbnail image before image processing. Therefore, in S415, the authenticity verification data will consist of a single thumbnail image, as shown in authenticity verification data 304 (Figure 3(B)). Also, the recorded image file 509 generated in S410 will have the same structure as the image file 310 (Figure 3(C)).

[0043] Here, we will provide supplementary information regarding the basic development process in S404 and the image processing process in S413. The thumbnail image generated in S411 must be an image that can be proven to have been taken with the digital camera 100. Therefore, the basic development process in S404, which is performed before S411, does not perform any processing that distorts the facts to the extent that it becomes impossible to prove that the image was taken with the digital camera 100. On the other hand, in the image processing process in S412, which is performed after S411, the thumbnail image and the history of the processing before and after the image processing are recorded, so the development process in S404 may also perform processing that is of a greater degree. Below, we will describe three examples of patterns for the basic development process in S404 and the image processing process in S413.

[0044] In the first example, the basic development process in S404 is debayering, while the processing in S413 is image processing other than debayering. In the second example, the basic development process in S404 is image processing that automatically executes the default settings of the digital camera 100. That is, for example, the basic development process in S404 is debayering, noise reduction, white balance adjustment, or color correction. Alternatively, for example, the basic development process in S404 is brightness adjustment including tone mapping and gamma correction, contrast adjustment, sharpness correction, color space conversion, resizing to match the recorded image size, sensor correction, or optical correction. These processes are performed automatically according to algorithms implemented by the camera manufacturer that produced the digital camera 100. The processing in S413 is image processing (black and white, skin tone correction, manual white balance, etc.) that is performed according to the settings when the user changes the camera settings (an example of "according to user settings"). While the above explanation described white balance and color correction as basic development processes for the S404, if the user sets these parameters, they may also be treated as image processing for the S413.

[0045] The third example is image processing in S413, which involves processing that alters the shape or color of the image. Specifically, image processing in S413 includes processing that combines multiple images, such as fisheye, toy camera, diorama, oil painting, watercolor, HDR (High Dynamic Range) shooting, and multiple exposure shooting, processing that involves AI-based image generation, or manipulation of objects such as faces. The basic development processing in S404 is image processing other than that in S413. It should be noted that there is also a design philosophy in which optical correction, noise reduction, and sharpness alter the shape. If this design philosophy is adopted, these processes may also be considered image processing in S413. Furthermore, there is also a design philosophy in which white balance, color correction, and brightness adjustment alter the color. If this design philosophy is adopted, these processes may also be considered image processing in S413.

[0046] <One aspect of action / effect> According to the digital camera 100 described above, even if image processing is performed in S413, the recorded image file 509 includes a thumbnail image representing the image data before processing in S413. Therefore, the user can verify the authenticity of the main image data contained in the recorded image file 509 by viewing this thumbnail image. Furthermore, the recorded image file 509 includes provenance metadata and a thumbnail image representing the image data after processing in S413. Therefore, the user can verify that the processing in S413 is not a tampering process by viewing the thumbnail images before and after processing in S413 and the provenance metadata.

[0047] Furthermore, the digital camera 100 converts metadata 302, main image data 303, and provenance information 305 into hash values. Therefore, it is possible to determine whether or not the image has been tampered with using these hash values. Moreover, since such conversion is unique and irreversible, the reliability of the determination is ensured. Furthermore, the digital camera 100 converts such hash values ​​into digital signatures 309 using a secret key. Therefore, the confidentiality of the hash values ​​is ensured. Thus, the determination of whether or not the image has been tampered with becomes more reliable.

[0048] <Variation> In the above embodiment, it was explained that the thumbnail image before image processing and the thumbnail image after image processing are stored in a single authenticity verification data. However, as shown in Figure 5(B), the system control unit 50 may create authenticity verification data 510 for the thumbnail image before image processing and authenticity verification data 511 for the thumbnail image after image processing. In this case, authenticity verification data 511 is recorded with the meaning of adding history information that the image has been processed to authenticity verification data 510. By doing so, authenticity verification data can be added in a common format with history addition during image editing other than at the time of shooting, and the image processing at the time of shooting can be recorded as a single history for the image file. Note that this processing is an example of "the generation unit generates recorded data for the image data before and after the execution of the first processing."

[0049] Furthermore, while the process in S404 is an image correction process, the process in S412 may be an image transformation process or an image processing process. Image correction processes include, for example, correcting the contrast, brightness, color, etc. of an image. Image transformation processes include, for example, converting an image to a monochrome image, binarizing image data, or displaying only limited colors. Image processing processes include, for example, removing noise contained in an image, enhancing edges, or enlarging or reducing the image size.

[0050] Furthermore, the determination of whether the shooting mode in S405 is normal mode or authenticity verification shooting mode may be performed before the development process in S404. If the system control unit 50 determines that the shooting mode is authenticity verification shooting mode, a thumbnail image may be created before S404 using the data indicated by the digital signal generated in S403.

[0051] Furthermore, the development process in S404 may include multiple processes. In addition, as a substitute for the provenance metadata 306, record metadata recording combinations of multiple development processes may be generated. A hash value corresponding to the combination of development processes may also be generated. With such modifications, even if the execution order of the multiple development processes differs, the generated image data can be determined to be authentic.

[0052] Furthermore, there are cases where the image processing in S413 is not performed, or even if it is performed, the changes are minor and the content of the main image generated in S415 is not significantly different from the content of the thumbnail generated in S411. To consider such cases, for example, the user may be allowed to choose not to generate a thumbnail in S411. The user may be allowed to explicitly set the ON / OFF status of thumbnail generation in S411, or thumbnail generation may be disabled when it is necessary to generate image files within a limited time, such as when high-speed continuous shooting is enabled. Alternatively, if the image processing in S413 is not performed, thumbnail generation may be disabled in S411. Or, if the degree of change due to the image processing performed in the image processing in S413 is less than a predetermined amount (such as cropping), thumbnail generation may be disabled in S411. In this case, no thumbnail image is recorded in the thumbnail image (before processing) area 501 of the authenticity verification data 508 in Figure 5A. The same applies to the thumbnail image (before processing) area of ​​the authenticity verification data 510 in Figure 5B. This avoids wasting storage space by recording an image that is almost identical to the main image. However, in this case, no data that should be recorded in the area of ​​the thumbnail image (before processing) of the authenticity verification data in Figures 5A and 5B will be generated. Therefore, taking advantage of the fact that the content is almost identical to the main image, if a thumbnail is not generated in S411, information that refers to the thumbnail image (after processing) generated in S414 may be added instead. This makes it possible to avoid wasting storage space while guaranteeing the authenticity of the image. Furthermore, even in this case, the provenance metadata of the provenance information 505 in Figure 5A will contain the same information as when a thumbnail image is recorded in the area 501 of the thumbnail image (before processing) of the authenticity verification data 508 in Figure 5A.

[0053] Furthermore, in the above embodiment, metadata 302 corresponding to the main image was recorded as metadata of the image file 301. In addition to this, metadata corresponding to the image before processing may also be recorded in the image file 301. The metadata corresponding to the image before processing records parameters such as settings at the time of shooting, excluding parameters related to image processing. The metadata corresponding to the image before processing is recorded in a dedicated area in the provenance information 505 in Figure 5A, for example. Alternatively, it is recorded in a dedicated area in the provenance information 510 in Figure 5B, for example. Note that if a thumbnail image (before processing) is not recorded, the metadata corresponding to the image before processing may not be recorded. This metadata corresponding to the image before processing may be generated at the same time as the metadata corresponding to the processed image is created in S416. Alternatively, it may be generated in parallel with the processing from S411 onwards.

[0054] <Other Embodiments> The present invention can also be realized by supplying a program that implements one or more of the functions of the above-described embodiments to a system or device via a network or recording 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., an ASIC) that implements one or more functions.

[0055] The invention is not limited to the embodiments described above, and various modifications and variations are possible without departing from the spirit and scope of the invention. Accordingly, claims are attached to disclose the scope of the invention.

[0056] The disclosures herein include the following imaging device, a method for controlling the imaging device, and a control program for the imaging device. [Item 1] Imaging unit, The system comprises a generation unit capable of generating image data based on imaging data captured by the imaging unit, and proof data that proves the authenticity of the image data, The aforementioned proof data is, A viewing image for viewing the image shown by the imaging data in which the first processing has not been performed, Recording data including a record of the processing of the aforementioned imaging data, Including encrypted data, Imaging device. [Item 2] The system further comprises a processing unit that performs the first process and a second process before the first process, The recorded data includes the history of processing the imaging data, The imaging device described in item 1. [Item 3] The above 1 process includes processes other than debayering, The second process includes a debayering process, The imaging device described in item 2. [Item 4] The first process includes processing that is performed according to user settings, The second process includes processing that is performed according to the default settings. The imaging device described in item 2. [Item 5] The first processing includes at least one of the following: fisheye effect, toy camera effect, diorama effect, oil painting effect, watercolor effect, HDR (high dynamic range) shooting, and multiple exposure shooting. The second process includes processes other than the first process. The imaging device described in item 2. [Item 6] The proof data further includes encrypted data of a viewing image for viewing the image shown in the imaging data on which the first processing has been performed. An imaging device as described in any one of items 2 through 5. [Item 7] The generation unit generates the recording data for the imaging data before and after the execution of the first process, respectively. An imaging device as described in any one of items 1 through 6. [Item 8] The encrypted data includes a hash value. An imaging device as described in any one of items 1 through 7. [Item 9] The encrypted data includes a digital signature obtained by encrypting the hash value. The imaging device described in item 8. [Item 10] The system further includes a determination unit that determines whether the shooting mode is a mode that proves the authenticity of the image, If the determination unit determines that it cannot prove the authenticity of the image, the generation unit generates the image data without generating the proof data. An imaging device as described in any one of items 1 through 9. [Item 11] The generation unit compresses the image data that has not undergone the first processing to generate the viewing image. An imaging device as described in any one of items 1 through 10. [Item 12] The aforementioned recorded data further includes metadata history, which includes parameters related to imaging. An imaging device as described in any one of items 1 through 11. [Item 13] A method for controlling an imaging device, The imaging process performed by the imaging unit, The process includes a generation step capable of generating image data based on imaging data captured by the imaging unit, and proof data that proves the authenticity of the image data, The aforementioned proof data is, A viewing image for viewing the image shown by the imaging data in which the first processing has not been performed, Recording data including a record of the processing of the aforementioned imaging data, Including encrypted data, A method for controlling an imaging device. [Item 14] A program for causing a computer to execute each step in a control method for an imaging device, wherein the control method is: The imaging process performed by the imaging unit, The process includes a generation step capable of generating image data based on imaging data captured by the imaging unit, and proof data that proves the authenticity of the image data, The aforementioned proof data is, A viewing image for viewing the image shown by the imaging data in which the first processing has not been performed, Recording data including a record of the processing of the aforementioned imaging data, Including encrypted data, Control program for imaging device. [Explanation of Symbols]

[0057] 16: Eyepiece viewfinder, 19: D / A converter, 22: Imaging unit, 23: A / D converter, 24: Image processing unit, 28: Display unit, 32: Memory, 50: System control unit, 54: Communication unit, 55: Attitude detection unit, 56: Non-volatile memory, 60: Mode selector switch, 61: Shutter button, 70: Operation unit, 100: Digital camera, 150: Lens unit, 200: Recording medium, 301: Image file, 302: Metadata, 303, 503: Main image data, 304, 508, 510, 511: Authenticity verification data, 305, 505: Provenance information, 307, 501, 502: Thumbnail image, 308, 506: Hash value, 309, 507: Digital signature

Claims

1. Imaging unit, The system comprises a generation unit capable of generating image data based on imaging data captured by the imaging unit, and proof data that proves the authenticity of the image data, The aforementioned proof data is, A viewing image for viewing the image shown by the imaging data in which the first processing has not been performed, Recording data including a record of the processing of the aforementioned imaging data, Including encrypted data, Imaging device.

2. The system further comprises a processing unit that performs the first process and a second process before the first process, The recorded data includes the history of processing the imaging data, The imaging apparatus according to claim 1.

3. The aforementioned first process includes processes other than debayering, The second process includes a debayering process, The imaging apparatus according to claim 2.

4. The first process includes a process that is executed according to user settings, The second process includes processing that is performed according to the default settings. The imaging apparatus according to claim 2.

5. The first process includes at least one of the following: fisheye effect, toy camera effect, diorama effect, oil painting effect, watercolor effect, HDR (high dynamic range) photography, and multiple exposure photography. The second process includes processes other than the first process. The imaging apparatus according to claim 2.

6. The aforementioned proof data further includes encrypted data of a viewing image for viewing the image shown in the imaging data on which the first processing has been performed, The imaging apparatus according to claim 2.

7. The generation unit generates the recording data for the imaging data before and after the execution of the first process, respectively. The imaging apparatus according to claim 1.

8. The encrypted data includes a hash value. The imaging apparatus according to claim 1.

9. The encrypted data includes a digital signature obtained by encrypting the hash value. The imaging apparatus according to claim 8.

10. The system further includes a determination unit that determines whether the shooting mode is a mode that proves the authenticity of the image, If the determination unit determines that it cannot prove the authenticity of the image, the generation unit generates the image data without generating the proof data. The imaging apparatus according to claim 1.

11. The generation unit compresses the image data that has not undergone the first processing to generate the image for viewing. The imaging apparatus according to claim 1.

12. The aforementioned recorded data further includes metadata history, which includes parameters related to imaging. The imaging apparatus according to any one of claims 1 to 11.

13. A method for controlling an imaging device, The imaging process performed by the imaging unit, The process includes a generation step capable of generating image data based on imaging data captured by the imaging unit, and proof data that proves the authenticity of the image data, The aforementioned proof data is, A viewing image for viewing the image shown by the imaging data in which the first processing has not been performed, Recording data including a record of the processing of the aforementioned imaging data, Including encrypted data, A method for controlling an imaging device.

14. A program for causing a computer to execute each step in a control method for an imaging device, wherein the control method is: The imaging process performed by the imaging unit, The process includes a generation step capable of generating image data based on imaging data captured by the imaging unit, and proof data that proves the authenticity of the image data, The aforementioned proof data is, A viewing image for viewing the image shown by the imaging data in which the first processing has not been performed, Recording data including a record of the processing of the aforementioned imaging data, Including encrypted data, Control program for imaging device.

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