JP2014003361A - Transmitter, control method and control program thereof - Google Patents

Abstract

An image is transmitted and recorded on a recording medium so that the image can always be optimally adjusted when the image recorded on the recording medium is reproduced.
A gain adjustment circuit adjusts a gain of an image signal to obtain a RAW signal. When the system controller 15 generates an exposure parameter for performing aperture control and gain adjustment according to the RAW signal, the system controller 15 obtains a first exposure parameter and a predetermined RAW signal when the RAW signal is obtained as the exposure parameter. The second control parameter is generated. The information adding circuit 12 adds additional information to the RAW according to the first and second exposure parameters, and the transmission processing circuit 11 transmits the RAW with the added information to the outside as transmission data.
[Selection] Figure 1

Description

  The present invention relates to a transmission apparatus used when transmitting and recording an image to an external device such as a recording medium, a control method therefor, and a control program.

  In general, an imaging device such as a digital camera or a video camera is provided with a transmission device that transmits and records a still image or a moving image (hereinafter collectively referred to as an image) obtained as a result of shooting to a recording medium. When an image is recorded on a recording medium, additional information related to the image is added to the image and recorded on the recording medium.

  For example, in synchronization with a video signal obtained as a result of shooting by an imaging device, camera information of a still image / moving image, aperture, gain, shutter, and white balance is transmitted to a recording medium, and the device information is transmitted together with the video signal. Some are recorded on a recording medium (see Patent Document 1). And here. Camera information is used for video signal correction and editing.

  Furthermore, when the imaging output signal output by the imaging unit is recorded as image data on a recording medium, imaging signal format identification information for identifying the signal format of the imaging output signal is recorded separately from the image data ( Patent Document 2). In Patent Document 2, for example, shutter speed, aperture value, gain, and the like are recorded as additional information (identification information) when RAW data is recorded, and the RAW data is developed using the additional information during reproduction. I am trying to process it.

Japanese Patent Laid-Open No. 7-212737 Japanese Patent Application Laid-Open No. 2001-223979

  By the way, when recording an image on a recording medium, if additional information indicating AE (automatic exposure) in the imaging apparatus is recorded on the recording medium, the AE additional information may not necessarily be optimal for the image. For example, in AE, when controlling an aperture value in an optical system and a gain value for amplifying an electric signal (analog signal) output in accordance with an optical image from an image sensor, a time lag is inevitably generated. Exists. For this reason, if the brightness of the subject changes suddenly or if a subject with different brightness is photographed by changing the direction of the imaging device, it takes several fields to optimize the aperture value and gain value.

  For example, when a bright image is suddenly darkened, when the image is reproduced, the reproduced image becomes darker and then gradually becomes brighter. As a result, as described in Patent Document 1 or 2, when only additional information related to an image is recorded, an image based on the additional information is reproduced when a transitional image such as a sudden change in brightness is reproduced. Is not optimally adjusted.

  Accordingly, an object of the present invention is to provide a transmission apparatus for transmitting and recording an image to a recording medium so that the image can always be optimally adjusted when the image recorded on the recording medium is reproduced, and its control. A method and a control program are provided.

  In order to achieve the above object, a transmission apparatus according to the present invention includes an imaging unit that outputs an image signal corresponding to an optical image received through an optical system including a diaphragm, and gain adjustment by adjusting a gain of the image signal. A transmission device that transmits image data corresponding to the gain-adjusted image signal to an external device from an imaging device including a gain adjustment unit that sets the adjusted image signal, and controls the aperture according to the gain-adjusted image signal and When generating an exposure control parameter for adjusting the gain, when obtaining the first exposure control parameter and a predetermined gain adjusted image signal when the gain adjusted image signal is obtained as the exposure control parameter Parameter generating means for generating the second exposure control parameter, and the first exposure control parameter and the second exposure control parameter. And information adding means for adding additional information to the image data Te, and having a transmitting means for transmitting the image data to which the additional information is added to the outside as a transmission data.

  The control method according to the present invention includes an image pickup unit that outputs an image signal corresponding to an optical image received through an optical system including a diaphragm, and a gain adjustment unit that adjusts the gain of the image signal to obtain a gain-adjusted image signal. A transmission apparatus for transmitting image data corresponding to the gain-adjusted image signal to the outside from an imaging apparatus comprising: an aperture control and a gain adjustment according to the gain-adjusted image signal. When generating an exposure control parameter to be performed, as the exposure control parameter, a first exposure control parameter when obtaining the gain-adjusted image signal and a second exposure when obtaining a predetermined gain-adjusted image signal. A parameter generation step for generating a control parameter; and the image according to the first exposure control parameter and the second exposure control parameter And having an information adding step of adding additional information to the chromatography data, and a transmission step of transmitting the image data to which the additional information is added to the outside as a transmission data.

  The control program according to the present invention includes an image pickup unit that outputs an image signal corresponding to an optical image received through an optical system including a diaphragm, and a gain adjustment unit that adjusts the gain of the image signal to obtain a gain-adjusted image signal. A control program used in a transmission device that transmits image data corresponding to the gain-adjusted image signal to an external device from an imaging device that includes: a computer provided in the transmission device according to the gain-adjusted image signal When generating an exposure control parameter for adjusting the aperture and adjusting the gain, the first exposure control parameter obtained when the gain-adjusted image signal is obtained and a predetermined gain adjusted as the exposure control parameter A parameter generating step for generating a second exposure control parameter for obtaining an image signal; and the first exposure control parameter. An information adding step for adding additional information to the image data in accordance with a meter and the second exposure control parameter, and a transmission step for transmitting the image data with the additional information added to the outside as transmission data are executed. It is characterized by.

  According to the present invention, when an image recorded on a recording medium or the like is reproduced, the image can always be optimally adjusted.

It is a block diagram which shows an example of the imaging device provided with the transmission apparatus by embodiment of this invention. It is a figure which shows an example of the aperture value and gain in AE control performed with the imaging device shown in FIG. FIG. 2 is a diagram for explaining an AE operation when the subject image is suddenly changed from a bright state to a dark state in the imaging apparatus shown in FIG. 1, and (a) shows the brightness of the subject image incident on the imaging lens of the optical system. (B) is a diagram showing changes in the actual AE parameters related to the target AE parameter and gain in AE control, (c) is a diagram showing changes in the aperture value and gain, and (d) is an image to be transmitted. It is a figure which shows the additional information added to data (transmission data) and the said transmission data. It is a figure for demonstrating the correction | amendment at the time of reproducing | regenerating the transmission data to which the additional information shown in FIG.3 (d) was added.

  Hereinafter, an example of a transmission apparatus according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram illustrating an example of an imaging apparatus provided with a transmission apparatus according to an embodiment of the present invention.

  In FIG. 1, the imaging apparatus has an optical system 1 including an imaging lens and a diaphragm. An optical image is formed on a photoelectric conversion sensor (hereinafter simply referred to as a sensor) 2 such as an image sensor through the optical system 1. The sensor 2 outputs an electrical signal (analog signal) corresponding to the optical image. This analog signal is converted into a digital signal by the AD converter 3 and given to the correction circuit 4.

  The correction circuit 4 performs flaw correction for interpolating defective pixels (hereinafter referred to as flaws) in the sensor 2 with respect to the digital signal, and corrects the distortion of the image due to distortion of the imaging lens or the like to obtain a corrected digital signal ( Image signal). The corrected digital signal is given to a gain adjustment circuit (gain adjustment means) 5.

  The gain adjustment circuit 5 adjusts the gain of the corrected digital signal under the control of the system controller 15 to set the brightness of the subject image in the image to a predetermined appropriate brightness. Then, the gain adjustment circuit 5 outputs a gain-adjusted image signal (that is, image data). In the illustrated example, the aperture of the optical system 1, the shutter speed, which is the accumulation time of the sensor 2, and the gain adjustment are used as the AE (automatic exposure) function.

  Here, the processing by the AD converter 3, the processing by the correction circuit 4, and the adjustment by the gain adjustment circuit 5 are called preprocessing, and the gain-adjusted image signal is used as RAW data (image data).

  The RAW data is input to the development processing circuit 6, and the development processing circuit 6 adjusts the white balance of the RAW data and performs a gamma (γ) correction process. Further, the development processing circuit 6 converts the RAW data into a luminance (Y) signal and a color difference (Cr, Cb) signal using a color difference matrix.

  The luminance signal and the color difference signal are input to a luminance / color difference (YC) processing circuit, and the YC processing circuit 7 performs an aperture process on the luminance signal and the color difference signal and outputs image data. The panel display 8 displays an image corresponding to the image data on the monitor.

  On the other hand, the output of the YC processing circuit 7 is given to the compression encoding circuit 9, and the compression encoding circuit 9 performs format conversion (compression encoding processing) such as MPEG or JPEG on the image data to convert the compressed image data into Output. For example, the compression encoding circuit 9 converts the image data into low-rate compressed image data.

  As shown in the figure, a transmission processing circuit (transmission means) 11 is connected to a gain adjustment circuit 5 and a compression encoding circuit 9 via a switch circuit (selection means) 10. The transmission processing circuit 11 is selectively connected to the gain adjustment circuit 5 or the compression encoding circuit 9 by switching the switch circuit 10. That is, either the compressed image data or the RAW data is selected by the switch circuit 10 and is given to the transmission processing circuit 11 as a selection signal.

  For example, when displaying a reproduced image on a television during image reproduction, when it is desired to correct white balance and γ characteristics in accordance with the characteristics of the television, the RAW data is selected by the switch circuit 10 and the transmission processing circuit 11 is selected. Given to. This makes it possible to adjust the image during reproduction.

  The transmission processing circuit 11 transmits the selection signal to the network or records the selection signal on a recording medium. That is, the transmission processing circuit 11 transmits the selection signal to the outside. At this time, the transmission processing circuit 11 converts the selection signal into a signal suitable for network transmission or recording on a recording medium.

  The information adding circuit (information adding means) 12 is connected to the system controller 15, and as will be described later, the information adding circuit 12 receives actual AE parameter information (first exposure control parameter) and target AE parameter information (first AE parameter information) from the system controller 15. 2 exposure control parameters). The information adding circuit 12 adds additional information to the image data transmitted to the network or the image data (selection signal) recorded on the recording medium. Here, in addition to the AE parameter information, for example, the recording date and time, the number of pixels, zoom information, and the like are added as additional information.

  The optical system control circuit 13 includes a motor and the like, and controls the optical system (for example, zoom, focus, and aperture control) under the control of the system controller 15. The sensor control circuit 14 performs readout control and electronic shutter control of the sensor 2 under the control of the system controller 15. The system controller 15 controls the entire imaging apparatus. In the illustrated example, the system controller 15 also performs AE control.

  FIG. 2 is a diagram for explaining an example of an aperture value and a gain in AE control performed by the imaging apparatus shown in FIG.

  In the example shown in FIG. 2, the upper side shows the aperture value, and the lower side shows the gain adjusted by the gain adjustment circuit 5. Here, aperture control and gain control (AE control) are performed with the electronic shutter speed (hereinafter simply referred to as shutter speed) fixed.

  The system controller 15 obtains an appropriate AE value according to the aperture value, shutter speed, and image data in the photometric area. In FIG. 2, when the photometric area in the subject image is dark, the appropriate AE value is “E value”. At the “E value”, the aperture is fully open (Open), and the gain is increased by the gain adjustment circuit 5 to obtain a bright image.

  In the drawing, the image (here, the subject image) becomes brighter as it goes to the right side, and the gain is reduced by the gain adjustment circuit 5. When the image has a predetermined brightness, the aperture is reduced by the optical system control circuit 13 and the appropriate exposure is obtained. Adjusted to The appropriate AE value sequentially changes as “D value”, “C value”, “B value”, and “A value” as the image changes from a dark state to a bright state. On the other hand, as the image changes from a bright state to a dark state, the appropriate AE value sequentially changes as “A value”, “B value”, “C value”, “D value”, and “E value”.

  FIG. 3 is a diagram for explaining the AE operation when the subject image suddenly changes from a bright state to a dark state in the imaging apparatus shown in FIG. FIG. 3A is a diagram showing the brightness of a subject image incident on the imaging lens of the optical system 1, and FIG. 3B is a target AE parameter (second exposure control parameter) and gain in AE control. It is a figure which shows the change of the real AE parameter (2nd exposure control parameter) which concerns on. FIG. 3C is a diagram showing changes in aperture value and gain, and FIG. 3D is a diagram showing image data (transmission data) to be transmitted and additional information added to the transmission data. .

  In FIG. 3, the horizontal axis is a time axis, and time elapses from left to right in the figure. In FIGS. 3A to 3C, the passage of time is aligned at the same time.

  FIG. 3A shows the brightness every 1 V time, that is, the brightness after N (V time) has elapsed, and 1 V time corresponds to the vertical synchronization period (1 field). / 60 seconds. N is an integer of 1 or more. When N = 1 (that is, 1V time), the subject image is brighter than the predetermined brightness, and when N = 2 (that is, 2V time), the subject image suddenly becomes darker than the predetermined brightness. It is dark. Thereafter, the subject image is in a dark state even when N = 3 to N = 11.

  Incidentally, the brightness of the image data obtained as a result of reading out the electric charges accumulated in the sensor 2 is also related to the aperture value at the time of shooting. Now, charge is accumulated in the sensor 2 at N = 1. When reading the charge accumulated in the sensor 2 at N = 1, the reading is performed in a time of about 1 V time. That is, the charge accumulated in the sensor 1 at N = 1 is read from the sensor 2 at N = 2, and further, the charge related to the image data of N = 2 (dark) is accumulated in the sensor 2 during this period. become.

  The correction circuit 4 temporarily stores the image data of one screen in a memory (not shown) and performs a two-dimensional correction process. For this reason, the processing in the correction circuit 4 is delayed by 1 V time, and when N = 3 and the charge accumulated in the sensor 2 at N = 2 is read, the correction circuit 4 is N = 1. Thus, flaw correction and optical correction of the digital signal related to the electric charge accumulated in the sensor 2 are performed.

  Further, when N = 4 and the charge accumulated in the sensor 2 when N = 3 is read, the gain adjustment circuit 4 performs gain of the digital signal related to the charge accumulated in the sensor 2 when N = 1. Adjustments will be made. At this time, the correction circuit 4 corrects the digital signal related to the charge accumulated in the sensor 2 when N = 2.

  As described above, the digital signal to be subjected to the AE (exposure correction) control is performed with a delay of about 3 V time from the accumulation of the electric charge of the sensor 2.

  Therefore, as shown in FIG. 3B, the image data of N = 1 (bright) is sent to the gain adjustment circuit 5 with a delay at the time when the light received by the photographing lens is N = 4 (dark). The system controller 15 measures the brightness in a predetermined photometric area using one screen with M = 1 (bright) as AE reference data (AE information).

  As a result, the system controller 15 sets “A value” as the AE parameter (here, the target AE parameter) based on the AE information at M = 1 (bright) even though the light reception is dark at N = 4. Set.

  Since the AE reference data becomes M = 2 (dark) image data when the light received by the photographic lens reaches N = 5 (dark), the system controller 15 assumes that the “E value” is the optimum target AE parameter. judge. However, this “E value” is a target value, and when the system controller 15 sets the actual AE parameter to “E value”, the “A value”, “B value”, “C value”, “ Hunting (oscillation) or the like is prevented by changing the actual AE parameter to “D value” and “E value”.

  As shown in FIG. 3B, at the time when the AE reference data is M = 3 (dark), the system controller 15 sets “B value” as the actual AE parameter for the aperture of the optical system 1. As a result, as shown in FIG. 3C, the aperture is slightly opened at the time when the AE reference data is M = 3 (dark).

  In the example shown in the figure, the gain adjustment circuit 5 is delayed by 3V time from the reception of the photographing lens, so that “B value” is set in the gain adjustment circuit 5 3 hours after the aperture is set to “B value”. Become. Therefore, when the AE reference data is M = 3 (dark), the actual AE parameter related to the gain is “A value”, and when the AE reference data is M = 6 (dim), the actual AE related to the gain. The parameter is set to “B value”. In the illustrated example, the gain is “A value” = “B value” = 0 dB.

  At the time when the AE reference data is M = 4 (dark), the system controller 15 sets “C value” as the actual AE parameter for the aperture of the optical system 1. This further opens the aperture. Then, at the time when the AE reference data is M = 5 (dark) and M = 5 (twilight), the system controller 15 sets “D value” and “E value” as actual AE parameters for the diaphragm of the optical system 1, respectively. .

  As described above, at the time when the AE reference data is M = 6 (twilight), the actual AE parameter related to the gain is set to “B value”, and thereafter, the actual AE parameter for the gain adjustment circuit 5 is “C value”, “ “D value” and “E value”.

  In FIG. 3D, it is assumed that the RAW data is selected by the switch circuit 10 now. When N = 1 (bright), image data corresponding to the charge accumulated in the sensor 2 is referred to as AE information by the system controller 15 when M = 1 (bright). Then, the system controller 15 gives the actual AE parameter and the target AE parameter corresponding to the AE information to the information adding circuit 12 as actual AE parameter information and target AE parameter information, respectively.

  At this time, the transmission processing circuit 11 transmits the RAW data as transmission data of K = 1 (bright). An actual AE parameter indicating the “A value” and a target AE parameter are added as additional information to the transmission data by the information adding circuit 12.

  When N = 2 (dark), which suddenly becomes dark, image data corresponding to the electric charge accumulated in the sensor 2 is referred to as AE information by the system controller 15 when M = 2 (dark). The transmission processing circuit 11 transmits RAW data as transmission data of K = 2 (dark). An actual AE parameter and a target AE parameter indicating “A value” and “E value”, respectively, are added to the transmission data by the information adding circuit 12 as additional information.

  In this way, the transmission processing circuit 11 sequentially has K = 3 (dark), K = 4 (dark), K = 5 (dark), K = 6 (dim), K = 7 (dim), K = 8 ( Transmission data of (bright) and K = 9 (bright). When K = 6 (twilight), the information addition circuit 12 adds the actual AE parameter and the target AE parameter indicating the “B value” and “E value” to the transmission data of K = 6 (twilight) as additional information. It will be.

  When compressed data is selected in the switch circuit 10, a time delay may occur in the compression encoding circuit 9, but the transmission processing circuit 11 and the information addition circuit 12 add actual AE parameters and transmission data to the transmission data in accordance with the compressed data. The target AE parameter is added as additional information. Although the time lag in the AE control after the change in the brightness of the subject image can be reduced by devising the circuit configuration, a delay of several V hours is inevitably caused regardless of the devisation of the circuit configuration.

  Next, use of transmission data to which additional information is added will be described. As described above, the transmission data is recorded on a recording medium or transmitted to a server via a network and stored in the server.

  FIG. 4 is a diagram for explaining correction when reproducing transmission data to which the additional information shown in FIG. 3D is added.

  As described above, if the light received by the photographing lens suddenly becomes dark like K = 1 (bright) to K = 2 (dark) due to the time lag of AE control at the time of photographing, bright image data is obtained in AE control. It takes up to K = 8 (bright) to obtain. In the case of K = 2 (dark) to K = 5 (dark), the brightness is corrected based on the difference between the actual AE parameter “A value” and the target AE parameter “E value” as additional information during reproduction. Correct the image data that became dark for a moment. When K = 6 (dim), brightness correction is performed based on the difference between the actual AE parameter “B value” and the target AE parameter “E value”.

  In the case of RAW data, development processing is performed when the correction is performed as described above and the image is viewed on a television or the like. In this case, after brightness correction, white balance, γ processing, color difference matrix processing, and the like are performed and converted into a television signal.

  In the case of gain-adjusted RAW data or compressed data, when dark image data is gained up and reproduced, there may be noisy image data. However, when the difference between the actual AE parameter and the target AE parameter is large, the noise You may make it perform brightness correction by performing reduction.

  As described above, in the embodiment of the present invention, in consideration of the time lag of the AE control at the time of shooting, the actual AE parameter indicating the AE control applied to the image data and the target AE indicating the optimum AE control for the image data. Since the parameters are added to the transmission data as image data as additional information, the image data in the AE control transition period can be optimally corrected and reproduced.

  In the above-described embodiment, the case where RAW data is transmitted with additional information added as gain-adjusted image data as RAW data has been mainly described. However, RAW data may be RAW data before gain adjustment or compressed data. Even so, if the target AE parameter is added to the image data as additional information together with the actual AE parameter, the time lag of the AE control can be easily corrected. As a result, an image free from unnaturalness can be easily obtained during reproduction.

  Furthermore, in the above-described embodiment, the example in which the actual AE parameter and the target AE parameter are added to the transmission data as additional information has been described. However, the difference between the actual AE parameter and the target AE parameter is added to the transmission data as additional information. You may do it. Further, the transmission processing circuit 11 transmits not only still image data but also moving image data as image data.

  As is clear from the above description, in the example shown in FIG. 1, the switch circuit 10, the transmission processing circuit 11, the information addition circuit 12, and the system controller 15 constitute a transmission device.

  In addition, the sensor 2, the AD converter 3, and the correction circuit 4 function as an imaging unit, and the system controller 15 functions as a parameter generation unit.

  As mentioned above, although this invention was demonstrated based on embodiment, this invention is not limited to these embodiment, Various forms of the range which does not deviate from the summary of this invention are also contained in this invention. .

  For example, the function of the above embodiment may be used as a control method, and this control method may be executed by the transmission apparatus. Further, a program having the functions of the above-described embodiments may be used as a control program, and the control program may be executed by a computer included in the transmission apparatus. The control program is recorded on a computer-readable recording medium, for example.

  Each of the control method and the control program has at least a parameter generation step, an information addition step, and a transmission step.

  The present invention can also be realized by executing the following processing. That is, software (program) for realizing the functions of the above-described embodiments is supplied to a system or apparatus via a network or various recording media, and a computer (or CPU, MPU, etc.) of the system or apparatus reads the program. It is a process to be executed.

2 sensor 4 correction circuit 5 gain adjustment circuit 6 development processing circuit 7 YC processing circuit 9 compression coding circuit 10 switch circuit 11 transmission processing circuit 12 information addition circuit 15 system controller

Claims (9)

From an imaging apparatus comprising: an imaging unit that outputs an image signal corresponding to an optical image received through an optical system including an aperture; and a gain adjustment unit that adjusts the gain of the image signal to obtain a gain-adjusted image signal. A transmission device that transmits image data according to a gain-adjusted image signal to the outside,
When generating an exposure control parameter for controlling the aperture and adjusting the gain according to the gain-adjusted image signal, the first gain-adjusted image signal is obtained as the exposure control parameter. Parameter generating means for generating a second exposure control parameter for obtaining an exposure control parameter and a predetermined gain-adjusted image signal;
Information adding means for adding additional information to the image data in accordance with the first exposure control parameter and the second exposure control parameter;
A transmission apparatus comprising: transmission means for transmitting the image data to which the additional information is added as transmission data to the outside.   The transmission apparatus according to claim 1, wherein the information adding unit adds the first exposure control parameter and the second exposure control parameter to the image data as the additional information.   The transmission apparatus according to claim 1, wherein the information adding unit adds a difference between the first exposure control parameter and the second exposure control parameter to the image data as the additional information.   The transmission apparatus according to claim 1, wherein the image data is moving image data.   The transmission apparatus according to claim 1, wherein the image data is RAW data.   The transmission apparatus according to claim 1, wherein the image data is compressed and encoded image data.   3. The selecting apparatus according to claim 1, further comprising a selection unit that selectively gives the transmission unit as the image data the gain-adjusted image signal and an image signal obtained by compression-coding the gain-adjusted image signal. The transmission device described. From an imaging apparatus comprising: an imaging unit that outputs an image signal corresponding to an optical image received through an optical system including an aperture; and a gain adjustment unit that adjusts the gain of the image signal to obtain a gain-adjusted image signal. A control method for a transmission device for transmitting image data according to a gain-adjusted image signal to the outside,
When generating an exposure control parameter for controlling the aperture and adjusting the gain according to the gain-adjusted image signal, the first gain-adjusted image signal is obtained as the exposure control parameter. A parameter generation step of generating a second exposure control parameter when obtaining the exposure control parameter and a predetermined gain-adjusted image signal;
An information adding step of adding additional information to the image data in accordance with the first exposure control parameter and the second exposure control parameter;
And a transmission step of transmitting the image data to which the additional information is added as transmission data to the outside. From an imaging apparatus comprising: an imaging unit that outputs an image signal corresponding to an optical image received through an optical system including an aperture; and a gain adjustment unit that adjusts the gain of the image signal to obtain a gain-adjusted image signal. A control program used in a transmission device that transmits image data according to a gain-adjusted image signal to the outside,
In the computer provided in the transmission device,
When generating an exposure control parameter for controlling the aperture and adjusting the gain according to the gain-adjusted image signal, the first gain-adjusted image signal is obtained as the exposure control parameter. A parameter generation step of generating a second exposure control parameter when obtaining the exposure control parameter and a predetermined gain-adjusted image signal;
An information adding step of adding additional information to the image data in accordance with the first exposure control parameter and the second exposure control parameter;
And a transmission step of transmitting the image data to which the additional information is added as transmission data to the outside.

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