JP2007166266A - Electronic camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic camera capable of acquiring image data of excellent image quality without missing the optimum moment for taking a picture even during flash charging. <P>SOLUTION: A flash charging light emitting circuit 14 charges and starts a flash 15. A brightness correction table generating part 20 generates a brightness correction table for correcting a brightness level of a pixel under consideration of image data on the basis of a brightness distribution of a plurality of pixels around the pixel under consideration of generated image data. A brightness correcting part 30 corrects the brightness level of the pixel under consideration of the image data on the basis of the brightness correction table. A CPU 13 controls correction processing by the brightness correcting part 30 in accordance with the quantity of light necessary for acquiring the image data. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electronic camera, and more particularly to an electronic camera having a function of automatically emitting a flash that illuminates a subject at the time of shooting.

  An electronic camera that captures an image of a subject that has passed through a photographing lens using an image sensor such as a CCD and digitizes the image signal to obtain image data has a built-in flash to enable photographing even in a dark place. Many things are seen. Many of such conventional electronic cameras have a release lock function that continues charging while flash charging is not completed, but does not allow photographing during that time. An electronic camera with such a release lock function may not be able to take a picture immediately after the flash is emitted, and may miss a photo opportunity. In particular, such a problem is likely to occur when continuous shooting is performed or when pre-flash is performed for red-eye reduction or photometry. In addition, when the battery of the camera body is insufficient, the flash charging time is longer than usual, so that the user has to wait longer.

  On the other hand, in view of the above problem, an electronic camera that permits photographing even during flash charging has been reported. FIG. 6 shows a configuration of a conventional electronic camera capable of photographing even during flash charging. Hereinafter, each configuration shown in FIG. 6 will be described. The subject image is formed on the image sensor 104 via the optical lens 101, the diaphragm 102, and the shutter 103, and is converted into an electric signal by the image sensor 104.

  An electrical signal obtained from the image sensor 104 is processed by a CDS (Correlated Double Sampling) 105, an AGC (Auto Gain Control) 106, and a preprocessing unit 107, and then stored in the memory 108. The The CDS 105 removes unnecessary noise components, and the AGC 106 adjusts the imaging signal level by adjusting the gain based on the gain control signal from the CPU 113. Digitized shooting data is input to the preprocessing unit 107, and the preprocessing unit 107 performs preprocessing such as shading correction.

  The image processing unit 109 acquires pre-processed shooting data stored in the memory 108, performs image processing such as YC generation, resizing, and compression / decompression, and stores the image processing result in the memory 108. The display IF unit 110 acquires the image processing result stored in the memory 108 according to the display timing, and outputs it to the liquid crystal monitor 111. Access to the memory 108 is performed via the memory controller 112.

  The flash charging light emitting circuit 114 has a charging capacitor, starts charging when receiving a charging command from the CPU 113, supplies charging power to the flash 115 when receiving a lighting command from the CPU 113, and activates the flash 115, Make it emit light. Further, the voltage level of the charging capacitor in the flash charging light emitting circuit 114 can be captured by the CPU 113 as charging information.

  The aperture drive unit 116 drives the aperture 102 in accordance with the aperture control signal from the CPU 113 and adjusts the aperture amount. The shutter driving unit 117 opens and closes the shutter 103 based on a shutter control signal from the CPU 113. The CPU 113 can control the shutter speed by the shutter control signal. The photometric sensor 118 receives light from the subject and performs photometry. A signal obtained by this photometry is taken into the CPU 113 as photometric information.

  In such a conventional electronic camera, an operation when photographing is performed while the flash is charged will be described. When the user presses the shutter button halfway, the CPU 113 determines whether or not flash emission is necessary based on photometric information from the photometric sensor 118. When the shutter button is further fully pressed, the CPU 113 acquires charging information from the flash charging and light emitting circuit 114. In situations where the subject is dark and requires flash emission, even if the flash 115 is being charged, the camera will shoot without waiting for the charging to be completed. Minutes are supplemented by the aforementioned aperture control, shutter speed control, gain control, and the like.

For example, Patent Document 1 describes a method of adjusting brightness by aperture control as much as the charging voltage is reduced by pre-emission. Patent Document 2 describes a method of increasing the gain by an AGC circuit in order to shorten the charging time during continuous shooting. According to such a conventional technique, it is possible to shoot even during flash charging, so it is possible to shoot without missing a photo opportunity. Further, by performing aperture control, shutter speed control, and gain control with respect to a shortage of flash light, it is possible to compensate for the shortage of light.
Japanese Patent No. 2969543 JP 2001-358888 A

  However, in the method of controlling the aperture, there are cases where the amount of light is insufficient even when the aperture is fully opened. When the shutter speed is increased, camera shake and image blur tend to occur. In the method of increasing the gain by the AGC circuit, the gain control is uniformly performed on the entire image, and it is difficult to obtain a good image depending on the subject. In particular, in a case where a bright part and a dark part are mixed, if the gain is increased, the bright part will fly white, and if the gain is reduced, the dark part cannot be improved.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide an electronic camera that can acquire image data with good image quality without missing a photo opportunity even during flash charging. .

  The present invention has been made to solve the above-described problems, and is based on a flash charging light emitting circuit that charges and activates a flash that irradiates a subject with light, and a brightness level of each pixel of image data related to the subject. A brightness correction table generating unit that generates a brightness correction table for correcting the brightness level of each pixel of the image data, a brightness correction unit that corrects the brightness level of the image data based on the brightness correction table, and An electronic camera comprising: a control unit that controls the brightness correction unit in accordance with a light amount when acquiring image data.

  Further, in the electronic camera of the present invention, the control unit causes the brightness correction unit to execute the correction processing of the image data when the amount of charge in the flash charging light emitting circuit is insufficient. To do.

  In the electronic camera of the present invention, the control unit further controls the flash charging light emitting circuit to activate the flash.

  In the electronic camera of the present invention, the control unit further causes a brightness level adjustment function unit having a function of adjusting a brightness level of the image data, which is different from the brightness correction unit.

  In the electronic camera of the present invention, the lightness correction table generation unit generates the lightness correction table based on a spatial distribution of lightness levels around each pixel of the image data.

  The electronic camera of the present invention can alternatively set a forced acquisition mode for forcibly acquiring the image data and a normal acquisition mode for acquiring the image data after the charge amount reaches a specified amount. And a mode setting unit, wherein the control unit controls the brightness correction unit in accordance with the mode set by the mode setting unit.

  According to the present invention, the brightness level of the image data is corrected in accordance with the brightness level of each pixel of the image data at the time of image data acquisition even when shooting without waiting for the completion of flash charging. There is an effect that it is possible to acquire image data with good image quality without missing a chance.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows the configuration of an electronic camera according to the first embodiment of the present invention. The optical lens 1 includes a zoom lens and a focus lens. The diaphragm 2 controls the amount of light. The shutter 3 adjusts the exposure time. The imaging element 4 is a CCD sensor, a CMOS sensor, or the like, converts a subject image formed in the imaging region into an electrical signal by photoelectric conversion, and outputs it as an imaging signal. The CDS 5 removes unnecessary noise components from the imaging signal. The AGC 6 adjusts the imaging signal level by adjusting the gain based on the gain control signal from the CPU 13. The preprocessing unit 7 performs preprocessing such as shading correction on the digitized shooting data (image data). The memory 8 is an SDRAM (Synchronous Dynamic Random Access Memory) or the like for storing shooting data and the like.

  The image processing unit 9 performs image processing such as YC generation, resizing, and compression / decompression on the captured data stored in the memory 8. The display IF unit 10 acquires the image data after image processing stored in the memory 8 according to the display timing, and outputs it to the liquid crystal monitor 11. The liquid crystal monitor 11 is a liquid crystal monitor such as a TFT (Thin Film Transistor). The memory controller 12 executes access to the memory 8. The CPU 13 (control unit) controls the entire electronic camera. The flash charging light emitting circuit 14 activates and charges the flash 15 based on a command from the CPU 13. The flash 15 is composed of a xenon tube or the like, and emits flash when receiving power from the flash charging and light emitting circuit 14.

  The aperture drive unit 16 drives the aperture 2 based on the aperture control signal from the CPU 13. The shutter drive unit 17 opens and closes the shutter 3 based on a shutter control signal from the CPU 13. The CPU 13 can control the shutter speed by the shutter control signal. The photometric sensor 18 is a sensor including a photodiode or the like that receives light from a subject and performs photometry. The signal obtained by this photometry is taken into the CPU 13 as photometric information (light quantity information). The brightness correction table generation unit 20 generates a brightness correction table based on the gradation level of the shooting data. The brightness correction unit 30 corrects the photographic data based on the brightness correction table generated by the brightness correction table generation unit 20.

  Next, main operations at the time of shooting will be described. The subject image is formed on the image sensor 4 through the optical lens 1, the diaphragm 2, and the shutter 3, and is converted into an electric signal by the image sensor 4. Unnecessary noise components are removed by the CDS 5 with respect to the electrical signal obtained from the image sensor 4, the image signal level is adjusted by the AGC 6, and preprocessing such as shading correction is performed by the preprocessing unit 7. Thereafter, it is stored in the memory 8. The image processing unit 9 acquires pre-processed shooting data stored in the memory 8, performs image processing such as YC generation, resizing, and compression / decompression, and stores the image processing result in the memory 8. The display IF unit 10 acquires the image processing result stored in the memory 8 according to the display timing, and outputs it to the liquid crystal monitor 11. Access to the memory 8 is performed via the memory controller 12.

  The flash charging light emitting circuit 14 has a charging capacitor inside, starts charging when receiving a charging command from the CPU 13, and supplies charging power to the flash 15 when receiving a lighting command from the CPU 13 to activate the flash 15. And emit light. Further, the voltage level of the charging capacitor inside the flash charging light emitting circuit 14 can be captured by the CPU 13 as charging information.

  The aperture driving unit 16 drives the aperture 2 based on the aperture control signal from the CPU 13 and adjusts the aperture amount. The shutter drive unit 17 opens and closes the shutter 3 based on a shutter control signal from the CPU 13. The AGC 6 performs gain adjustment based on a gain control signal from the CPU 13. The photometric sensor 18 receives light from the subject and performs photometry.

  The lightness correction table generation unit 20 extracts lightness information from the photographing data and, for example, for each pixel of the photographing data based on a known local histogram equalization method (see, for example, JP-T-2004-530368). A lightness correction table for correcting the lightness level of each pixel is created according to the lightness level distribution around each pixel. In addition, the lightness correction unit 30 corrects the lightness level of each pixel of the photographic data based on the generated lightness correction table. The lightness correction table generation unit 20 and the lightness correction unit 30 can set whether or not to execute lightness level correction according to a lightness correction command from the CPU 13. For example, in a situation where the flash 15 needs to emit light, if the amount of charge of the flash 15 at the time of shooting is sufficient (charging is complete), or if the flash 15 does not need to be emitted, lightness level correction is executed. If the flash 15 needs to emit light and the amount of charge of the flash 15 at the time of shooting is not sufficient (charging has not been completed), the brightness level correction is performed.

  Next, an operation when shooting is performed during flash charging will be described. When the user presses the shutter button halfway, the CPU 13 determines whether or not the flash 15 needs to be emitted based on the photometric information from the photometric sensor 18. Further, when the shutter button is fully pressed, the CPU 13 acquires charging information from the flash charging light emitting circuit 14. Even in a situation where the subject is dark and originally requires flash emission, the CPU 13 operates so as to shoot without waiting for the completion of charging even when the flash is not fully charged.

  At this time, in this embodiment, since the light quantity deficiency is corrected by the lightness correction unit 30, it does not matter whether the flash 15 is caused to emit light at a voltage level during charging or not.

  Subsequently, when shooting is performed without waiting for the completion of charging (in this case, even if the flash 15 is not fired, as a result, the image data at the time of acquisition is insufficient in light amount), the CPU 13 corrects the brightness. The command is given to the lightness correction table generation unit 20 and the lightness correction unit 30. The lightness correction table generation unit 20 generates a lightness correction table upon receiving a lightness correction command. Unlike the conventional method in which a uniform coefficient is given to the entire subject, in the present embodiment, the brightness correction table generation unit 20 generates a lightness correction table. The amount of gain is determined according to the distribution level of the lightness level. In particular, based on the spatial distribution of the brightness level around each pixel, a brightness correction table that gives a large gain to the overall dark part of the subject and a small gain to the overall bright part. create. The brightness correction unit 30 corrects the brightness level of the captured image based on the created brightness correction table.

  Next, the configuration of the brightness correction table generation unit 20 will be described with reference to FIG. The gain table storage unit 21 stores a gain table for adjusting the gain of the photographic data. FIG. 3 shows the characteristics of the gain table, and shows the relationship between the brightness values of the photographic data before and after conversion (indicated by IN and OUT). However, the relationship between the lightness values is indicated by normalized values of 0 to 1. The gain brightness data generation unit 22 generates gain brightness data from the shooting data and the gain table. The brightness range instruction unit 23 outputs the brightness value width and the boundary value as brightness range instruction information.

  The lightness conversion coefficient calculation units 24a to 24h calculate the lightness conversion coefficient based on the lightness gain data and the lightness range instruction information. Although details will be described later, the lightness conversion coefficient calculation units 24 a to 24 h are configured by a binarization unit 26, an LPF unit 27, a lightness extraction unit 28, and a multiplier 29. The conversion coefficient sum calculation unit 25 obtains the sum of the lightness conversion coefficients calculated by the individual lightness conversion coefficient calculation units.

  Next, the operation of the brightness correction table generation unit 20 will be described. When shooting data is input, the gain brightness data generation unit 22 generates gain brightness from the imaging data for each pixel. Here, when the imaging data is expressed in RGB format, in the present embodiment, the maximum value of R, G, and B is handled as the representative brightness of the pixel. Subsequently, the gain brightness data generation unit 22 generates gain brightness data from the representative brightness according to the gain table stored in the gain table storage unit 21. FIG. 3 shows curves (1) to (4) as examples of the gain table. Here, IN corresponds to representative brightness, and OUT corresponds to gain brightness data. If it is desired to clearly show the correction effect, the curve (1) should be selected. If it is desired to reduce the correction effect, the curve (4) should be selected.

It is not necessary for the gain table storage unit 21 to store all the data of the curves (1) to (4). For example, the result obtained by subtracting the numerical value indicated by the straight line (5) from the numerical value indicated by the curve (1) may be held in the gain table storage unit 21, and the other remaining curves may be obtained from this result. The other remaining curve equations can be expressed as follows using an arbitrary coefficient α.
(Formula of curve (1)-Formula of straight line (5)) x α + Formula of straight line (5)

  The lightness range instruction unit 23 generates lightness range instruction information for dividing the range of gain lightness data. Here, for example, in the example in which the gain lightness data is expressed by 0 to 255 and is divided into eight, the width of the lightness value is 32, and eight kinds of boundary values are 32 × n (n is 0 to 7) Integer). The eight brightness ranges of 0 to 31, 32 to 63, 64 to 95, 96 to 127, 128 to 159, 160 to 191, 192 to 223, and 224 to 255 are distinguished by the brightness range instruction information.

  Subsequently, the lightness conversion coefficient calculating units 24a to 24h calculate the lightness conversion coefficient in each lightness range of the pixel of interest from the gain lightness data and the lightness range instruction information. The binarization unit 26 outputs 1 if the value of the gain brightness data of the pixel of interest is included in the range indicated by the brightness range instruction information, and outputs 0 if it is not included. The LPF unit 27 performs a low-pass filtering process using the binarized data relating to the pixel of interest and the binarized data relating to each of a plurality of pixels around the pixel of interest from the binarizing unit 26, Multi-value data is generated so that the change between pixels is smooth. The brightness extraction unit 28 outputs the value of the gain brightness data as it is when the value of the gain brightness data of the target pixel is smaller than the boundary value (the value at the upper end of the brightness range) indicated by the brightness range instruction information, and when it is larger 0 is output. The multiplier 29 multiplies the value output from the LPF unit 27 and the value output from the lightness extraction unit 28 and outputs the result to the transform coefficient sum calculation unit 25.

  The conversion coefficient sum calculation unit 25 calculates the sum of the lightness conversion coefficients of the pixel of interest in each lightness range output from the lightness conversion coefficient calculation units 24a to 24h, and performs lightness correction in which the pixel position and the value of the lightness conversion coefficient are associated with each other. Output as a table. As a result, the value of the brightness correction table for each pixel becomes a value based on the brightness distribution including not only the brightness of the shooting data of one pixel but also the brightness of the shooting data of surrounding pixels. In the present embodiment, the lightness correction table generation unit 20 obtains a lightness correction table from the shooting data, but it is also possible to reduce the amount of calculation using data obtained by reducing the shooting data by resolution conversion.

Next, the operation of the brightness correction unit 30 will be described. When the photographing data and the lightness correction table are input to the lightness correction unit 30, the lightness correction unit 30 performs lightness correction on the photographing data based on the lightness correction table. The brightness correction unit 30 first multiplies the value of each pixel of the photographic data by the value of the brightness correction table corresponding to each pixel position to obtain an intermediate correction result. Further, the final correction result is obtained by mixing the photographic data and the intermediate correction result by the following arithmetic expression. In the following arithmetic expression, the intensity of lightness correction can be adjusted by adjusting the value of the mixture ratio α.
Brightness correction result = shooting data × α + intermediate correction result × (1-α)
However, (0 <α <1)

  According to the above-described embodiment, when the amount of light is insufficient at the time of image data acquisition (when the flash 15 does not emit light due to insufficient charging or when the flash 15 is forced to emit light even when charging is insufficient), the CPU 13 determines the brightness. By activating the brightness correction processing by the correction table generation unit 20 and the brightness correction unit 30, the brightness level of the pixel of interest in the image data is corrected based on the distribution state of the brightness levels of the surrounding pixels, so that the amount of light is insufficient. Even image data shot in such a state can obtain image data with good image quality.

  Therefore, even if the charging amount of the flash 15 is insufficient, it is possible to take a picture without missing a photo opportunity and obtain image data with good image quality.

  In the present embodiment, the gain amount (correction coefficient) is determined according to the distribution state of the brightness level around the pixel of interest of the subject. In particular, a large gain is set for a dark portion and a small gain is set for a bright portion in the subject. The brightness correction table is created and corrected based on the spatial distribution of the brightness levels of the image data. As a result, it is possible to obtain image data that compensates for the shortage of the light amount of the flash 15, and it is possible to obtain good image data as compared with the conventional method in which the same gain is uniformly applied to the entire screen.

  In the above description, the method of correcting the lightness by the lightness correction unit 30 has been described. However, it can be combined with the conventional aperture control, shutter speed control, and auto gain control control. When adjusting the brightness of the image data by combining the brightness level adjustment function including any one of the aperture, shutter speed, and auto gain control, or the brightness correction by the brightness correction unit 30, the brightness correction unit 30 alone Compared with the case where the correction process is performed, the degree of freedom of correction can be increased.

  Next, a second embodiment of the present invention will be described. FIG. 4 shows the configuration of the electronic camera according to the present embodiment. In the present embodiment, a mode selection button 31 (mode setting unit) for the user to select a flash mode is provided. When the user operates the mode selection button 31, a signal corresponding to the content of the operation is output to the CPU 13. The CPU 13 sets the flash mode based on the signal. Since the configuration other than the mode selection button 31 is the same as that of the first embodiment, description thereof is omitted.

  When the user presses the mode selection button 31, the first mode (normal acquisition mode) in which shooting is prohibited until charging of the flash 15 is completed, and shooting is permitted without waiting for the charging of the flash 15 to be completed. The second mode (forced acquisition mode) can be selected. The mode selection button 31 may be a dedicated button, but may be realized by a general-purpose button such as a cross key or a determination button depending on a method of displaying a menu on the liquid crystal monitor 11.

  FIG. 5 shows an example of a menu display displayed on the liquid crystal monitor 11. The user can select the flash mode while viewing such a menu display. As shown in FIG. 5, the flash mode includes, for example, “forced light emission”, “auto”, “red-eye reduction”, and “OFF”, which can be selected. From “Auto”, “Normal” and “Shutter opportunity priority” can be selected. The first mode for prohibiting shooting until the charging of the flash 15 is completed refers to “auto” “normal”, and the second mode for allowing shooting without waiting for the charging of the flash 15 to be completed. “Auto” means “priority for photo opportunity”.

  Hereinafter, each flash mode will be described. When the “forced light emission” mode is selected, the CPU 13 controls the flash 15 to emit light regardless of the brightness of the subject. When the “normal” mode of “auto” is selected, the CPU 13 determines whether or not to emit the flash 15 according to the brightness of the subject. If the release button is pressed while the flash 15 is being charged, the CPU 13 performs control to continue charging, but does not allow photographing until the flash charging is completed.

  If the “auto” “shutter chance priority” mode is selected, the CPU 13 determines whether or not to emit the flash according to the brightness of the subject. When the release button is pressed during flash charging, the CPU 13 controls the lightness correction unit 30 to perform lightness correction while photographing without waiting for completion of flash charging. When the “red-eye reduction” mode is selected, the CPU 13 performs control to perform main light emission after performing pre-flash of the flash 15 in order to reduce red eyes. When the “OFF” mode is selected, the CPU 13 performs control to perform shooting without always firing the flash.

  In the above, an example in which the “auto” mode is divided into the “normal” mode and the “shutter chance priority” mode has been described, but the “normal” mode and the “red-eye reduction” mode are similarly described in the “forced flash” mode and the “red-eye reduction” mode. It is also possible to divide into “photo opportunity priority” mode. According to the present embodiment, the user can select a first mode that prohibits shooting until the flash 15 is fully charged and a second mode that enables shooting without waiting for the flash 15 to be fully charged. Since the lightness correction processing by the lightness correction unit 30 is performed according to the set mode, it is possible to perform shooting according to the user's preference.

  As described above, the embodiments of the present invention have been described in detail with reference to the drawings. However, the specific configuration is not limited to these embodiments, and includes design changes and the like without departing from the gist of the present invention. .

It is a block diagram which shows the structure of the electronic camera by the 1st Embodiment of this invention. It is a block diagram which shows the structure of the brightness correction table production | generation part with which the electronic camera by the 1st Embodiment of this invention is provided. It is a reference figure which shows an example of the gain table in the 1st Embodiment of this invention. It is a block diagram which shows the structure of the electronic camera by the 2nd Embodiment of this invention. In the 2nd Embodiment of this invention, it is a reference figure which shows an example of the screen displayed when selecting flash mode. It is a block diagram which shows the structure of the conventional electronic camera.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Optical lens, 2 ... Aperture, 3 ... Shutter, 4 ... Imaging element, 5 ... CDS, 6 ... AGC, 7 ... Pre-processing part, 8 ... Memory, 9 ... Image processing unit, 10 ... Display IF unit, 11 ... Liquid crystal monitor, 12 ... Memory controller, 13 ... CPU, 14 ... Flash charge light emitting circuit, 15 ... Flash: 16 ... Aperture drive unit, 17 ... Shutter drive unit, 18 ... Photometric sensor, 20 ... Lightness correction table generation unit, 21 ... Gain table storage unit, 22 ... Gain Lightness data generation unit, 23... Lightness range instruction unit, 24a, 24b, 24c, 24d, 24e, 24f, 24g, 24h... Lightness conversion coefficient calculation unit, 25. ..Binarization unit, 27 ... LPF unit, 28 ... Brightness extraction unit, 30 ... brightness correction unit, 31 ... mode select button

Claims (6)

A flash charging light-emitting circuit that charges and activates a flash that irradiates the subject with light; and
A brightness correction table generating unit that generates a brightness correction table for correcting the brightness level of each pixel of the image data based on the brightness level of each pixel of the image data relating to the subject;
A brightness correction unit for correcting the brightness level of the image data based on the brightness correction table;
A control unit for controlling the brightness correction unit according to the amount of light when acquiring the image data;
An electronic camera comprising:   2. The electronic camera according to claim 1, wherein the control unit causes the brightness correction unit to execute a correction process of the image data when a charge amount in the flash charging and light emitting circuit is insufficient. .   The electronic camera according to claim 2, wherein the control unit further controls the flash charging and light emitting circuit to activate the flash.   4. The control unit according to claim 1, further comprising a brightness level adjustment function unit having a function of adjusting a brightness level of the image data, which is different from the brightness correction unit. The electronic camera according to item.   The brightness correction table generation unit generates the brightness correction table based on a spatial distribution of brightness levels around each pixel of the image data. Electronic camera as described in. A mode setting unit that can alternatively set a forced acquisition mode for forcibly acquiring the image data and a normal acquisition mode for acquiring the image data after the charge amount reaches a specified amount; The electronic controller according to claim 1, wherein the control unit controls the brightness correction unit according to a mode set by the mode setting unit.

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