Imaging device, imaging method, and computer program

Abstract

To provide an imaging device capable of securing the time required for generating a digital signature.SOLUTION: An imaging device includes an imaging unit that captures an image, an image setting unit that sets image data sequentially captured by the imaging unit, and an electronic signature generating unit that generates an electronic signature on the basis of the image data, and the image setting unit changes the settings of the image data on the basis of the time required to generate the electronic signature.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an imaging apparatus, an imaging method, a computer program, and the like. [Background technology]

[0002] It has become easy to edit and tamper with images using smartphones and computers, and the results are so natural that the human eye cannot tell whether an image has been edited or tampered with.

[0003] For this reason, in use cases or situations where the evidentiary value of images is important, it is becoming increasingly important to have technical assurances that the images were taken with a reliable camera with guaranteed security, and that the images have not been edited or tampered with.

[0004] However, when adding an editing / tampering detection function to images captured and saved by a camera, it is impossible to eliminate the possibility that the images may be edited or tampered with between the time they are saved and the time the editing / tampering detection function is added.

[0005] In such cases, it is technically impossible to prove that the images have not been edited or tampered with from the state in which they were taken by the camera. Therefore, it is extremely important to provide a function within the camera that can detect editing or tampering of images at the stage when they are taken by the camera.

[0006] In response to this, there is a technology that generates a digital signature for an image and detects editing or tampering of the image. For example, Patent Document 1 describes a configuration in which a digital signature for an image is generated within a camera and the image and the digital signature are transmitted together.

[0007] Furthermore, Patent Document 2 describes a configuration in which a digital signature is applied to multiple frames collectively depending on conditions such as the CPU usage rate of the digital signature generation device, memory usage, and the frequency of video data being transmitted to the digital signature generation device. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] JP 2017-41841 A [Patent Document 2] JP 2010-245590 A Summary of the Invention [Problem to be solved by the invention]

[0009] However, in the conventional technology disclosed in Patent Document 1, an electronic signature is generated for every image frame captured, so the time it takes to generate the electronic signature becomes a bottleneck, making it difficult to achieve a high frame rate.

[0010] Furthermore, the conventional technology disclosed in Patent Document 2 cannot guarantee that the image has not been tampered with when the electronic signature was generated, and therefore cannot guarantee that the image has not been edited or tampered with since it was captured by the camera.

[0011] SUMMARY OF THE PRESENT EMBODIMENTS Accordingly, one object of the present invention is to provide an imaging device capable of ensuring the time required for generating a digital signature. [Means for solving the problem]

[0012] In the imaging device, An imaging unit that captures video; a video setting unit that sets video data sequentially captured by the imaging unit; an electronic signature generation unit that generates an electronic signature based on the video data; The video setting unit changes the settings of the video data based on the time required to generate the digital signature. Effect of the Invention

[0013] According to the present invention, it is possible to provide an imaging device that is capable of ensuring the time required for generating a digital signature. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a functional block diagram of a camera 100 as an imaging device according to a first embodiment of the present invention. [Diagram 2] 1A and 1B are diagrams illustrating a GOP interval and a time for generating a digital signature according to the first embodiment of the present invention. [Diagram 3] 4 is a flowchart illustrating an imaging method according to the first embodiment of the present invention. [Figure 4] FIG. 11 is an explanatory diagram of a change in GOP interval when dynamic GOP is enabled. [Diagram 5] 10 is a flowchart illustrating an imaging method according to a second embodiment of the present invention. [Figure 6] 13A and 13B are diagrams illustrating a frame rate and a time required for generating a digital signature according to the third embodiment. [Figure 7] 11 is a flowchart illustrating an imaging method according to a third embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. However, the present invention is not limited to the following embodiment. In each drawing, the same members or elements are given the same reference numerals, and duplicated descriptions are omitted or simplified.

[0016] <Embodiment 1> 1 is a functional block diagram of a camera 100 serving as an image capturing apparatus according to a first embodiment of the present invention. The camera 100 in the embodiment of the present invention will be described below with reference to FIG.

[0017] Some of the functional blocks shown in FIG. 1 are realized by causing a CPU serving as a computer included in the camera 100 to execute a computer program stored in a memory serving as a storage medium.

[0018] However, some or all of these functions may be realized by hardware. For the hardware, a dedicated circuit (ASIC) or a processor (reconfigurable processor, DSP) may be used. Furthermore, the functional blocks shown in Fig. 1 do not have to be built into the same housing, and may be configured by separate devices connected to each other via signal paths.

[0019] In the first embodiment, a hash value of a captured image is calculated to create a digital signature for each GOP (Group Of Pictures), and the digital signature is stored in an SEI frame of H.264 or H.265. Also, the GOP interval and frame rate are controlled.

[0020] A GOP usually consists of several consecutive frames, starting with an intra frame, which is a frame in which inter prediction cannot be used. The frames other than the first intra frame are usually inter frames (e.g. P pictures and B pictures) in which inter prediction can be used. Note that intra prediction is mainly used in intra frames.

[0021] In interframes, both inter prediction and intra prediction are mainly used. GOP interval can also be said to be the number of frames contained in one GOP. In other words, GOP interval can also be said to be the number of frames from one intraframe to the next intraframe.

[0022] In FIG. 1, a camera 100 transfers images from an imaging unit 110 that captures video to a controller unit 120, stores the images in a non-volatile memory 123, and distributes the images to an external information processing device 140 over a network.

[0023] The imaging section 110 of the camera 100 is made up of an optical system 111, an imaging element 112, a signal processing circuit 113, an imaging control circuit 114, a memory transfer circuit 115, and a video setting section 116 that sets the GOP interval and frame rate.

[0024] The image sensor 112 is, for example, a CMOS image sensor, which converts light imaged through the optical system 111 into electric charges to generate an image signal. A signal processing circuit 113 receives the image signal captured by the image sensor 112, digitizes it, and generates a captured image.

[0025] The imaging control circuit 114 controls the imaging element 112 at the same cycle as the image output cycle. When the accumulation time of the imaging element 112 is longer than the image output cycle, the imaging control circuit 114 controls the signal processing circuit 113 so that the captured image is held in a frame memory in the signal processing circuit 113 during the period when the imaging element 112 cannot output an imaging signal.

[0026] The memory transfer circuit 115 transfers the captured image digitized by the signal processing circuit 113 to a memory 122 in the controller unit 120 .

[0027] Video setting unit 116 performs various settings related to video data sequentially captured by camera imaging unit 110 under the instruction of CPU 121 in camera controller unit 120 described later. Various video-related settings include resolution, frame rate, brightness, dynamic GOP enable / disable setting, video data group setting (GOP setting), etc.

[0028] Incidentally, enabling dynamic GOP refers to changing the GOP interval according to the state of the video signal (e.g., the difference between frames, etc.). In this embodiment, dynamic GOP can be switched between enabled and disabled, and when dynamic GOP is disabled, the GOP interval is not changed according to the state of the video signal (e.g., the difference between frames, etc.).

[0029] The controller unit 120 of the camera 100 is made up of a CPU 121 as a computer, a memory 122 as a storage medium, a non-volatile memory 123, a network I / F 124, and the like.

[0030] The CPU 121 performs calculations using a hash function for encryption on the image data in the memory 122, and generates a digital signature using a private key (not shown) of the camera 100. Note that in this embodiment, the calculations of the hash function and the generation of the digital signature are executed by the CPU 121, but may be executed by a module separate from the CPU 121.

[0031] The network device 130 enables communication between the camera 100 and an external information processing device 140 via the network I / F 124. The network device 130 is, for example, a switching hub, and the external information processing device 140 is, for example, a personal computer or computer device that stores images.

[0032] 2A and 2B are diagrams for explaining the GOP interval and the time for generating a digital signature according to the first embodiment of the present invention. Hereinafter, with reference to FIG. 2, the GOP interval and the time for generating a digital signature will be explained in the case where a digital signature for an image is generated in a camera in units of GOPs and the image and the digital signature are transmitted together in real time.

[0033] 2A, a case where the GOP interval is 3 frames will be described as an example. In this case, an I-picture (basic frame 201) and a P-picture (complementary frame 202 and complementary frame 203) form GOP#1.

[0034] If it takes five frames to generate an electronic signature within the camera, then as shown in Figure 2(A), the time required for signature processing is two frames longer than the GOP interval, making it impossible to transmit the image and electronic signature together for each GOP in real time.

[0035] Therefore, in the first embodiment, the GOP interval is changed depending on the processing time required for signature processing, so that a signature can be stably produced and transmitted for each GOP in real time.

[0036] That is, as shown in Fig. 2(B), the GOP interval is changed to 6 frames, so that, for example, GOP#1 is composed of an I picture (basic frame 211) and P pictures (complementary frame 212, complementary frame 213, complementary frame 214, complementary frame 215, and complementary frame 216).

[0037] If it takes 5 frames to generate a digital signature in the camera, the processing time required for signature processing is 1 frame shorter than the GOP interval, so the digital signature can be processed in synchronization with the GOP interval, as shown in Fig. 2(B). That is, digital signature processing #1 and #2 can be executed in accordance with the periods of GOP#2 and GOP#3, respectively. Therefore, a signature can be created and transmitted in real time for each GOP.

[0038] Fig. 3 is a flowchart for explaining an imaging method according to the first embodiment of the present invention. Note that the operation of each step in the flowchart in Fig. 3 is performed in sequence by the CPU 121 as a computer in the camera 100 executing a computer program stored in a memory.

[0039] In the flow of Fig. 3, when the number of streams output by the camera is changed while the dynamic GOP setting is disabled, the digital signature processing time is measured and a GOP interval suitable for the digital signature processing time is set. The flow of the first embodiment of the present invention will be described with reference to Fig. 3.

[0040] When the camera 100 is powered on and starts capturing images, the flow of Fig. 3 starts. Then, in step S301, the CPU 121 of the camera acquires the processing time required for generating the electronic signature. The processing time required for generating the electronic signature may be recorded in the camera body at the time of shipment from the factory, or may be actually measured when the camera is started up.

[0041] In step S302, the CPU 121 of the camera sets the GOP interval based on the time required for generating the digital signature acquired in step S301 so that the GOP interval is equal to or longer than the processing time required for generating the digital signature.

[0042] That is, in step S302, the video setting unit 116 changes the setting of the GOP interval as the video data setting based on the time required to generate the digital signature. Here, step S302 functions as a video setting step for setting the video data sequentially captured in the imaging step.

[0043] Next, in step S303, the CPU 121 of the camera performs imaging processing on the images captured by the imaging unit 110, and sequentially transfers the images to the memory 122 in the controller unit 120 by the memory transfer circuit 115. Here, step S303 functions as an imaging step for capturing video.

[0044] In step S304, the CPU 121 of the camera calculates a hash value of the image transferred to the memory 122. Here, step S304 functions as a hash generation step (hash generation unit) that generates a hash value of video data sequentially captured by the imaging unit.

[0045] In step S305, the CPU 121 of the camera encrypts the hash value generated in step S304 with a private key stored in the camera 100, and creates a digital signature. Here, step S305 functions as a digital signature generation step (digital signature generation unit) that generates a digital signature based on the video data.

[0046] In step S306, the CPU 121 of the camera stores the digital signature created in step S305 in an SEI frame supported by, for example, H.264 or H.265.

[0047] In step S307, the camera CPU 121 checks the number of streams being output. In step S308, the camera CPU 121 determines whether the number of streams has changed since the previous check, and if Yes, in step S309, measures the processing time required for digital signature processing.

[0048] That is, when the number of streams output by the camera is changed, the time required for the digital signature generating unit to generate a digital signature is measured. Here, step S309 functions as a measurement step (measurement unit) that measures the time required to generate a digital signature.

[0049] Then, the process returns to step S302 to set the GOP interval. On the other hand, if it is determined in step S308 that the number of streams has not changed since the previous check, the process returns to step S303, and the camera CPU 121 performs image capture processing. Note that the flow of steps S302 to S309 is repeated until it is determined in a power off determination step (not shown) that the camera has been powered off.

[0050] As described above, according to the first embodiment, the GOP interval is changed depending on the processing time required for signature processing, so that a signature can be stably produced and transmitted for each GOP in real time.

[0051] Fig. 4 is an explanatory diagram of the change in GOP interval when dynamic GOP is enabled. In Fig. 4, the horizontal axis represents time, the vertical axis represents the amount of data, the solid lines represent I pictures (basic frames), and the dashed lines represent P pictures (complementary frames).

[0052] For example, consider a case where dynamic GOP is enabled and the GOP is changed based on the state of the video signal (such as the difference between frames). In this case, when shooting an outdoor scene with little movement, the difference between frames is small, so many P pictures (complementary frames) are inserted between an I picture (basic frame) and the next I picture (basic frame). In other words, the GOP interval becomes wider, so the amount of data can be reduced.

[0053] 4, for example, the amount of data can be reduced by enabling dynamic GOP between times T0 and T1. However, for example, if there is rain or snowfall after time T1, the difference between frames increases, and the GOP interval becomes shorter.

[0054] That is, even if the GOP interval between times T0 and T1 is sufficient for the camera to generate an electronic signature, after time T1 the GOP interval may become shorter than the time required for the camera to generate an electronic signature.

[0055] <Embodiment 2> The second embodiment is intended to solve the above problems, and when dynamic GOP is enabled and the GOP interval is changed according to the state of the video signal (e.g., the difference between frames), the digital signature processing time is measured and a lower limit of the GOP interval is set.

[0056] Fig. 5 is a flowchart for explaining an imaging method according to the second embodiment of the present invention. Note that the operation of each step in the flowchart in Fig. 5 is performed sequentially by the CPU 121 as a computer in the camera 100 executing a computer program stored in the memory.

[0057] 5 starts when the camera 100 is powered on and starts capturing images. Then, in step S501, the camera's CPU 121 acquires the processing time required to generate the digital signature. The time required to generate the digital signature may be recorded in the camera body at the time of shipment from the factory, or may be measured when the camera is started up.

[0058] Next, in step S502, the CPU 121 of the camera performs imaging processing on the image captured by the imaging unit 110, and transfers the images one by one to the memory 122 in the controller unit 120 by the memory transfer circuit 115.

[0059] In step S503, the CPU 121 of the camera calculates a hash value of the image transferred to the memory 122. In step S504, the CPU 121 of the camera encrypts the hash value calculated in step S503 with a private key stored in the camera 100, and creates a digital signature.

[0060] In step S504, the CPU 121 of the camera stores the digital signature created in step S504 in an SEI frame supported by, for example, H.264 or H.265.

[0061] In step S506, the camera CPU 121 checks the GOP interval that changes depending on the shooting scene etc. by dynamic GOP. Then, in step S507, the camera CPU 121 determines whether the GOP interval is shorter than a predetermined threshold value.

[0062] If the result of the determination in step S507 is Yes, in step S508, the CPU 121 of the camera changes the lower limit of the GOP interval to a value greater than the current value, that is, in step S508, the lower limit of the GOP interval when the dynamic GOP setting is enabled is set.

[0063] Then, the flow returns to step S502 and the imaging process is performed again. If it is determined in step S507 that the GOP interval is not shorter than the predetermined threshold, the flow returns to step S502 and the imaging process is performed again.

[0064] In this way, in the second embodiment, when dynamic GOP is enabled and the GOP interval is changed according to the state of the video signal (e.g., the difference between frames), the digital signature processing time is measured and the lower limit of the GOP interval is set. Therefore, the image and the digital signature can be synchronized and transmitted in real time.

[0065] When the dynamic GOP setting is enabled and the GOP interval becomes shorter than a predetermined value, the time required for generating the digital signature in the digital signature generating section may be measured.

[0066] <Embodiment 3> 6A and 6B are diagrams for explaining the frame rate and the time for generating a digital signature according to embodiment 3. Hereinafter, with reference to FIG. 6, the GOP interval and the time for generating a digital signature will be explained in the case where a digital signature for an image is generated in a camera in units of a GOP and the image and the digital signature are transmitted together in real time.

[0067] 6A, for example, when the frame rate is 30 FPS and the GOP interval is 3 frames, an I-picture (basic frame) 601 and P-pictures (complementary frames 602 and 603) form GOP#1. Here, it is assumed that a time equivalent to 5 frames at a frame rate of 30 FPS is required to generate a digital signature within the camera.

[0068] In this case, since the time required for signature processing is two frames longer than the GOP interval as shown in Fig. 6(A), it is not possible to transmit the image and the digital signature together in real time. Therefore, in the third embodiment, when the GOP interval is shorter than a predetermined value due to dynamic GOP, the GOP interval is set to, for example, three frames at a frame rate of 15 FPS as shown in Fig. 6(B).

[0069] That is, the frame rate is lowered. In this case, an I-picture (basic frame) 611 and P-pictures (complementary frame 612 and complementary frame 613) become GOP#1.

[0070] As a result, if it takes 5 frames of processing time at a frame rate of 30 FPS to generate a digital signature in the camera, the processing time required for signature processing will be shorter than the GOP interval (3 frames at a frame rate of 15 FPS). Therefore, as shown in Figure 6(B), the timing of the image and the digital signature can be synchronized and transmitted together in real time.

[0071] Fig. 7 is a flowchart for explaining an imaging method according to the third embodiment of the present invention. Note that the operation of each step in the flowchart in Fig. 7 is performed sequentially by the CPU 121 as a computer in the camera 100 executing a computer program stored in the memory.

[0072] In the flow shown in FIG. 7, when dynamic GOP is enabled and the GOP interval changes according to the video signal, the digital signature processing time is measured and the frame rate is changed.

[0073] When the camera 100 is powered on and starts capturing images, the flow of Fig. 7 starts. Then, in step S701, the camera's CPU 121 acquires the processing time required to generate the digital signature. The time required to generate the digital signature may be recorded in the camera body at the time of shipment from the factory, or may be measured when the camera is started up.

[0074] Next, in step S7502, the CPU 121 of the camera performs imaging processing on the image captured by the imaging unit 110, and transfers the images one by one to the memory 122 in the controller unit 120 by the memory transfer circuit 115.

[0075] In step S703, the CPU 121 of the camera calculates a hash value of the image transferred to the memory 122. In step S704, the CPU 121 of the camera encrypts the hash value calculated in step S703 with a private key stored in the camera 100, and creates a digital signature.

[0076] In step S705, the CPU 121 of the camera stores the digital signature created in step S704 in an SEI frame supported by, for example, H.264 or H.265.

[0077] In step S706, the camera CPU 121 checks the GOP interval that changes depending on the shooting scene etc. by dynamic GOP. Then, in step S707, the camera CPU 121 determines whether the GOP interval is shorter than a predetermined threshold value.

[0078] If the result of the determination in step S707 is Yes, then in step S708, the CPU 121 of the camera changes the frame rate to a lower value than the current frame rate, that is, sets the frame rate as a setting for the video data.

[0079] Then, the flow returns to step S702 and the imaging process is performed again. If it is determined in step S707 that the GOP interval is not shorter than the predetermined threshold, the flow returns to step S702 and the imaging process is performed again.

[0080] As described above, in the third embodiment, when dynamic GOP is enabled and the GOP interval changes according to the video signal, the digital signature processing time is measured and the frame rate is changed. Therefore, even in the case of dynamic GOP, in which the GOP interval is set according to the camera usage status and the shooting scene, it is possible to generate a digital signature for an image in the camera on a GOP basis and transmit the image and the digital signature together in real time.

[0081] When generating a digital signature for an image in a camera on a GOP basis and transmitting the image and digital signature together in real time, the process of generating the digital signature may not be able to keep up if the GOP interval is shorter than a predetermined value. The private key used to generate the digital signature in the camera must not be allowed to leak outside the camera, so it is often difficult to keep it constantly stored in a memory area that can be accessed at high speed.

[0082] In contrast, according to the above first to third embodiments, if an image captured by a camera is edited and tampered with, it is possible to detect the editing and tampering by using a digital signature.

[0083] Furthermore, even when dynamic GOP is used according to the camera's usage status or the shooting scene, the digital signature of the image can be generated in the camera on a GOP basis by setting the GOP interval and frame rate so as to secure time for creating the digital signature. Therefore, it is possible to transmit the image and the digital signature together in real time. Furthermore, if an image captured by the camera is edited or tampered with, this can be detected.

[0084] Although the present invention has been described in detail above based on the preferred embodiments, the present invention is not limited to the above-mentioned embodiments, and various modifications and combinations of the above-mentioned embodiments are possible based on the spirit of the present invention, and are not excluded from the scope of the present invention. The present invention includes the following combinations.

[0085] (Configuration 1) An imaging device comprising an imaging unit that captures video, a video setting unit that sets video data captured sequentially by the imaging unit, and an electronic signature generation unit that generates an electronic signature based on the video data, wherein the video setting unit changes the settings of the video data based on the time required to generate the electronic signature.

[0086] (Configuration 2) The imaging device described in Configuration 1, further comprising a hash generation unit that generates a hash value of the video data sequentially captured by the imaging unit, and the electronic signature generation unit encrypts the hash value generated by the hash generation unit to generate the electronic signature.

[0087] (Configuration 3) The imaging device according to configuration 1 or 2, further comprising a measurement unit that measures the time required to generate a digital signature.

[0088] (Configuration 4) The imaging device according to configuration 3, wherein the measurement unit measures the time required for the electronic signature generation unit to generate the electronic signature when the number of streams output by the camera is changed.

[0089] (Configuration 5) The imaging device described in Configuration 3 or 4, characterized in that the measurement unit measures the time required for the electronic signature generation unit to generate the electronic signature when a GOP interval becomes shorter than a predetermined value when dynamic GOP setting is enabled.

[0090] (Configuration 6) The imaging device according to any one of configurations 1 to 5, wherein the video setting section sets a GOP interval or a frame rate as the setting of the video data.

[0091] (Configuration 7) The imaging device according to any one of configurations 1 to 6, wherein the video setting section sets dynamic GOP setting to enabled or disabled.

[0092] (Configuration 8) The imaging device according to any one of configurations 1 to 7, wherein the video setting section sets a GOP interval when dynamic GOP setting is disabled.

[0093] (Configuration 9) The imaging device according to any one of configurations 1 to 8, wherein the video setting section sets a lower limit value of the GOP interval when dynamic GOP setting is enabled.

[0094] (Method) An imaging method comprising: an imaging step of capturing an image; a video setting step of setting video data sequentially captured by the imaging step; and an electronic signature generation step of generating an electronic signature based on the video data, wherein the video setting step changes the settings of the video data based on the time required to generate the electronic signature.

[0095] (Program) A computer program for controlling each unit of the imaging device according to any one of configurations 1 to 9 by a computer.

[0096] In order to realize a part or all of the control in the above-mentioned embodiment, a computer program that realizes the functions of the above-mentioned embodiment may be supplied to an imaging device or the like via a network or various storage media. Then, a computer (or a CPU, MPU, or the like) in the imaging device or the like may read and execute the program. In this case, the program and the storage medium storing the program constitute the present invention. [Explanation of symbols]

[0097] 100: Camera 110: Imaging unit 116: Video settings section 120: Controller section 121:CPU 122: Memory 123: Non-volatile memory

Claims

1. An imaging unit that captures video; a video setting unit that sets video data sequentially captured by the imaging unit; an electronic signature generation unit that generates an electronic signature based on the video data; The imaging device, wherein the image setting unit changes the settings of the image data based on a required time for generating the digital signature.

2. a hash generation unit that generates a hash value of the video data sequentially captured by the imaging unit, 2. The imaging device according to claim 1, wherein the digital signature generating section generates the digital signature by encrypting the hash value generated by the hash generating section.

3. 2. The imaging device according to claim 1, further comprising a measurement unit that measures a time required for generating a digital signature.

4. 4. The imaging device according to claim 3, wherein the measurement unit measures the time required for the digital signature generation unit to generate the digital signature when the number of streams output by the camera is changed.

5. 4. The imaging device according to claim 3, wherein the measurement unit measures the time required for the electronic signature generation unit to generate the electronic signature when a GOP interval becomes shorter than a predetermined value when dynamic GOP setting is enabled.

6. 2. The imaging apparatus according to claim 1, wherein the video setting section sets a GOP interval or a frame rate as the setting of the video data.

7. 2. The image pickup apparatus according to claim 1, wherein the video setting section sets whether a dynamic GOP setting is enabled or disabled.

8. 2. The imaging device according to claim 1, wherein the video setting section sets a GOP interval when a dynamic GOP setting is disabled.

9. 2. The image pickup apparatus according to claim 1, wherein the video setting section sets a lower limit of a GOP interval when a dynamic GOP setting is enabled.

10. An imaging step of capturing an image; an image setting step for setting image data sequentially captured by the imaging step; and generating an electronic signature based on the video data, The imaging method, wherein the image setting step changes the settings of the image data based on a time required for generating the digital signature.

11. A computer program for controlling each unit of the imaging device according to any one of claims 1 to 9 by a computer.

Images