JP2019062369A - Imaging apparatus and control method thereof, electronic device and control method thereof, and program - Google Patents

Abstract

To obtain a still image with proper exposure from a movie.SOLUTION: A system control unit 50 obtains a still image evaluation value from a movie being shot using a photometric method for a still image, determines a difference between a still image target value and a still image evaluation value to be an exposure correction value, and causes the determined exposure correction value to be included in meta information to be recorded in the movie for each frame. The system control unit 50 reads the meta information recorded in the same frame as the selected frame and determines the exposure correction value included in the meta information to be an exposure correction value used for exposure correction of a still image. Then, the system control unit 50 creates an exposure conversion characteristic obtained by combining exposure correction by the determined exposure correction value and tone correction by gamma characteristics and adapts the exposure conversion characteristic to the frame image to generate a still image.SELECTED DRAWING: Figure 5

Description

  The present invention relates to an imaging device that generates a still image from a moving image, a control method thereof, a control method of the electronic device, and a program.

  In recent years, with the advent of 4K (3840 horizontal pixels × 2160 vertical pixels) and 8K (7680 horizontal pixels × 4320 vertical pixels), the resolution per one frame of a moving image is increased. Therefore, it is required to cut out and use one frame of a moving image as a still image. Conventionally, a still image generating apparatus has been proposed which generates a still image from a moving image captured by moving image shooting in advance. For example, there is known a still image generating apparatus which converts one frame to which gamma for moving image extracted from a moving image is adapted to an image to which gamma for still image is applied (Patent Document 1). In addition, the white balance control value at the time of moving image recording and the white balance control value for a still image are recorded for each frame, and the image is subjected to white balance correction based on the still image white balance control value at the time of still image cutout from the moving image. An apparatus is also known (Patent Document 2).

JP 2007-189466 A JP, 2010-119109, A

  However, the apparatuses of Patent Documents 1 and 2 can not generate a still image in consideration of differences in photometric method and target value between still image shooting control and moving image shooting control. At the time of moving image shooting control, usually, the subject is continuously captured, and the exposure is controlled so as not to change rapidly in the flow of a series of moving images. On the other hand, at the time of still image shooting control, the photometric value of the area of the main subject detected from the angle of view is reflected in the evaluation value on a priority basis. Also with regard to the exposure target value, the moving image shooting control is set to be relatively low so that the subject is not overexposed due to a slight change in exposure. On the other hand, in still image shooting control, control is performed to capture an image with proper exposure as the main subject using the evaluation value acquired from the main subject, so the exposure target value is usually set higher than that for video shooting control. Be done.

  As described above, in the conventional apparatus, the exposure when the still image is cut out from the moving image is based on the exposure control of the moving image shooting control and is not necessarily optimal as the still image. In addition, when post-processing appropriate exposure correction as a still image, it is difficult to know how much exposure should be corrected, and it is difficult to obtain an appropriate still image from moving images. There was a problem.

  An object of the present invention is to obtain a still image of appropriate exposure from a moving image.

  In order to achieve the above object, the present invention relates to photographing means for picking up an image of a subject to acquire a moving image, and brightness of the subject using the method for still pictures from the moving image while acquiring the moving picture by the photographing means An acquisition means for acquiring an evaluation value, a determination means for determining an exposure correction value based on the evaluation value acquired by the acquisition means and a target value regarding the brightness of the subject, and an exposure correction value determined by the determination means Is included in the meta information and is recorded in the frame selected by the selecting means, recording means for recording for each corresponding frame in the moving picture, selecting means for selecting a frame to be cut out as a still picture from the frames in the moving picture Reading means for reading an exposure correction value from the meta information, and the frame selected by the selection means based on the exposure correction value read by the reading means And having a generating means for generating a correction to the still image exposure image.

  According to the present invention, a still image of appropriate exposure can be obtained from a moving image.

It is an outline view of an imaging device. It is a block diagram which shows the internal structure of a camera. It is a figure which shows the flowchart of a meta-information recording process. It is a figure which shows the example of acquisition of each evaluation value for still pictures and for moving images. It is a timing chart for each frame of recording of an image and meta information. It is a flowchart of a still picture extraction process. 5 shows a flowchart of a meta information recording process. It is a timing chart for each frame of recording of an image and meta information. It is a timing chart for each frame of recording of an image and meta information. It is a flowchart of a still picture extraction process.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

First Embodiment
FIG. 1 is an external view of an imaging device according to a first embodiment of the present invention. A digital video camera 100 is illustrated as this imaging device. In the camera 100, the display unit 28 displays an image and various information. The recording switch 61 is an operation unit for giving a photographing instruction. The mode switching switch 60 is an operation unit for switching various modes. The connector 112 is a connector for connecting the connection cable and the camera 100. The operation unit 70 includes a plurality of operation members such as various buttons and a cross key for receiving various operations from the user. The power switch 72 switches between power on and power off when operated. The recording medium 200 is a memory card, a hard disk or the like, and is stored in the slot 201. The recording medium 200 stored in the slot 201 can communicate with the main body of the camera 100.

  FIG. 2 is a block diagram showing an internal configuration of the camera 100. As shown in FIG. The photographing lens 103 is a lens group including a zoom lens and a focus lens, and forms an object image. The aperture 101 adjusts the amount of incident light. The ND 104 is an optical element used for light reduction. An imaging unit 22 as an imaging unit is an imaging device configured by a CCD, a CMOS device, or the like, and converts an optical image into an electrical signal. The imaging unit 22 also has a function of changing the analog gain and the reading speed, in addition to the control of accumulation by the electronic shutter. The A / D converter 23 converts an analog signal output from the imaging unit 22 into a digital signal. The barrier 102 covers the imaging system including the imaging lens 103 in the camera 100 to prevent the contamination and damage of the imaging system including the imaging lens 103, the diaphragm 101, and the imaging unit 22.

  The image processing unit 24 performs resizing processing such as predetermined pixel interpolation or reduction, color conversion processing, gamma correction, or the like on data from the A / D converter 23 or data from the memory control unit 15 (recording unit). Perform processing such as addition of digital gain. The image processing unit 24 also performs predetermined arithmetic processing using the captured image data, and transmits the calculation result to the system control unit 50. The system control unit 50 performs exposure control, distance measurement control, white balance control, and the like based on the transmitted calculation result. As a result, TTL (through the lens) AF (Auto Focus) processing, AE (Auto Exposure) processing, AWB (Auto White Balance) processing, etc. are performed.

  Output data from the A / D converter 23 is written to the memory 32 via the image processing unit 24 and the memory control unit 15 or via the memory control unit 15. The memory 32 stores image data captured by the imaging unit 22 and converted into digital data by the A / D converter 23, and image data to be displayed on the display unit 28. The memory 32 has a sufficient storage capacity to store moving images and sounds for a predetermined time. The memory 32 also serves as a memory (video memory) for displaying an image. The D / A converter 13 converts the image display data stored in the memory 32 into an analog signal and supplies the analog signal to the display unit 28. Thus, the display image data written in the memory 32 is displayed by the display unit 28 via the D / A converter 13. The display unit 28 performs display according to the analog signal from the D / A converter 13 on a display such as an LCD. The D / A converter 13 converts the digital signal A / D converted once by the A / D converter 23 and stored in the memory 32 into an analog signal, sequentially transfers it to the display unit 28, and displays it on the display unit 28. The display unit 28 functions as an electronic view finder. Thus, through image display is realized.

  The non-volatile memory 56 is an electrically erasable / recordable memory, and for example, an EEPROM is used. In the non-volatile memory 56, constants, programs and the like for operation of the system control unit 50 are stored. The program referred to here is, for example, a program for executing various flowcharts to be described later. The system control unit 50 controls the entire camera 100 and executes a program stored in the non-volatile memory 56 to implement each process described later. A RAM is used as the system memory 52. In the system memory 52, constants and variables for the operation of the system control unit 50, programs read out from the non-volatile memory 56, and the like are expanded. The system control unit 50 also performs display control by controlling the memory 32, the D / A converter 13, the display unit 28, and the like. The system timer 53 measures the time used for various controls and the time of the built-in clock. The mode switching switch 60, the recording switch 61, and the operation unit 70 are used by the user to input various operation instructions to the system control unit 50.

  The mode switching switch 60 switches the operation mode of the system control unit 50 to any one of a moving image recording mode, a still image recording mode, a reproduction mode, and the like. As modes included in the moving image recording mode and the still image recording mode, there are an auto shooting mode, an auto scene determination mode, a manual mode, various scene modes as shooting settings for each shooting scene, a program AE mode, a custom mode and the like. The user can switch directly to any of these modes included in the moving image shooting mode by the mode switching switch 60. It should be noted that after the user temporarily switches to the moving image shooting mode with the mode switching switch 60, another operation member may be used to switch to any of these modes included in the moving image shooting mode. The recording switch 61 switches between a shooting standby state and a shooting state. The system control unit 50 starts a series of operations from the signal reading from the imaging unit 22 to the writing of the moving image data to the recording medium 200 in response to the operation of the recording switch 61.

  Each operation member in the operation unit 70 is appropriately assigned a function for each scene when the user selects and operates various function icons displayed on the display unit 28, and functions as various function buttons. The function buttons include, for example, an end button, a back button, an image feed button, a jump button, a narrow-down button, and an attribute change button. For example, when the menu button is pressed, various settable menu screens are displayed on the display unit 28. The user can intuitively perform various settings using the menu screen displayed on the display unit 28 and the cross key in the up, down, left, and right directions and the SET button.

  The power supply control unit 80 includes a battery detection circuit, a DC-DC converter, a switch circuit for switching a block to be energized, and the like, and detects the presence or absence of a battery, the type of battery, and the battery remaining amount. Further, the power control unit 80 controls the DC-DC converter based on the detection result and an instruction of the system control unit 50, and supplies necessary voltages to the respective units including the recording medium 200 for a necessary period. The power supply unit 30 is formed of a primary battery, a secondary battery, an AC adapter or the like. The recording medium I / F 18 is an interface with the recording medium 200 such as a memory card or a hard disk. The recording medium 200 is a recording medium such as a memory card for recording a photographed image, and is formed of a semiconductor memory, a magnetic disk, or the like.

  Next, the operation of the present embodiment will be described. Generally speaking, in the present embodiment, when performing control for capturing a moving image, the system control unit 50 separately uses a photometric method for a still image different from that for moving image control, for still images related to brightness. An evaluation value of (hereinafter referred to as a still image evaluation value) is acquired. The system control unit 50 calculates the difference between the still image evaluation value and the still image target value related to brightness different from that for moving image control, and uses the difference as the exposure correction value for the still image corresponding to each frame of the moving image Decide as. The system control unit 50 records the determined exposure correction value as meta information for each frame of the video acquired by the moving image shooting control. Furthermore, after capturing an image, the system control unit 50 cuts out one frame as a still image from the image recorded by the user's operation. In clipping the still image, the system control unit 50 performs exposure correction using the exposure correction value recorded as meta information at the time of shooting.

  Next, processing for recording the exposure correction value as meta information will be described. FIG. 3 is a diagram showing a flowchart of the meta information recording process. This process is realized by the system control unit 50 developing a program stored in the non-volatile memory 56 in the system memory 52 and executing it. This process is started when an operation shooting is instructed. In the process of FIG. 3, the system control unit 50 serves as an acquisition unit and a determination unit in the present invention. First, the system control unit 50 starts moving image shooting control in order to capture a moving image (step S101).

  The differences between the photometric method and the target value between the still image shooting control and the moving image shooting control will be described with reference to FIG. FIG. 4A, FIG. 4B, and FIG. 4C are diagrams showing an example of obtaining each evaluation value for still image and moving image. In FIG. 4, a solid line indicates a moving picture metering frame, and a dotted line indicates a still picture metering frame. In the example of FIG. 4A, when the subject is imaged, the evaluation value for the moving image (hereinafter referred to as a moving image evaluation value) is 67%, and the moving image target value is a target value of the evaluation value for the moving image. Is 50%. The difference between them is 67-50 = 17%. In step S102 in FIG. 3, the system control unit 50 acquires a still image evaluation value from a moving image during shooting (during acquisition) using a photometric method for still images. For example, with respect to the imaging data of the frame shown in FIG. 4A, the system control unit 50 acquires a still image evaluation value in accordance with a photometric method for still images. The still image evaluation value is acquired for the subject in FIG. 4A using the still image metering frame, or acquired by weighting the photometric value acquired in the still image metering frame with a predetermined weight. Here, it is assumed that 82% is acquired as a still image evaluation value.

  Next, in step S103, the system control unit 50 calculates the difference between the still image target value, which is a still image target value, and the still image evaluation value (still image target value-still image evaluation value). In the example of FIG. 4A, when the still image target value is 60%, the difference between the still image target value and the still image evaluation value is 60−82 = −22%. Next, in step S104, the system control unit 50 determines an exposure correction value from the calculated difference. Specifically, the system control unit 50 determines -22%, which is a difference, as the exposure correction value. A difference obtained by multiplying the difference by a predetermined coefficient may be determined as the exposure correction value. Similarly, in the examples of FIGS. 4B and 4C, + 37% and + 21% are determined as exposure correction values for a still image, respectively. Next, in step S105, the system control unit 50 records the calculated exposure correction value as meta information in a data structure for each frame in which a moving image immediately after calculation is stored. That is, the system control unit 50 includes the determined exposure correction value in the meta information and records it for each frame in the moving image. Thereafter, the process of FIG. 3 ends.

  FIG. 5 is a timing chart for each frame of recording of an image and meta information. The system control unit 50 develops the imaging data obtained from the sensor accumulation, and records an image of one frame of the development result in a frame (in the memory 32). The system control unit 50 performs evaluation value detection for each of moving image shooting control and still image shooting control from this image, and records the result as meta information in the frame data. The image of the development result and the meta information acquired from the image are recorded in the same frame in the video. In the moving image shooting process, the system control unit 50 determines the next exposure condition using the latest exposure correction value for moving image, and obtains imaging data. The process of recording the exposure correction value in the meta information is repeated.

  Next, the process of extracting a still image from a moving image and its exposure correction will be described. FIG. 6 is a flowchart of still image clipping processing. This process is realized by the system control unit 50 developing a program stored in the non-volatile memory 56 in the system memory 52 and executing it. This process is started when a still image cutout is instructed. In the process of FIG. 6, the system control unit 50 serves as a selection unit, a readout unit, and a generation unit in the present invention.

  First, in step S201, the system control unit 50 selects a frame to be cut out as a still image from frames in a moving image according to a user's instruction. At this time, for example, the user refers to the video captured by the above-described moving image recording control, and instructs to select a desired one frame from among them as a still image. In step S202, the system control unit 50 reads the meta information recorded in the same frame as the selected frame, and determines the exposure correction value included in the meta information as an exposure correction value to be used for exposure correction of a still image. .

  Next, in step S203, the system control unit 50 creates an exposure conversion characteristic in which the exposure correction based on the determined exposure correction value and the gradation correction based on the gamma characteristic are combined. First, in order to make an image recorded as a moving image have a proper exposure as a still image, it is necessary to once return the gamma characteristic used in the development processing in the moving image shooting control. For this purpose, gamma processing using inverse gamma of gamma characteristics at the time of moving image development is used. Also, an exposure correction value is used for the exposure correction. Furthermore, it is necessary to perform gamma correction for a still image on the image whose gamma characteristic has been restored. Therefore, the system control unit 50 creates an exposure conversion characteristic in which the exposure correction value, the gamma inverse characteristic for moving image shooting, and the gamma characteristic for still image are reflected. In step S204, the system control unit 50 adapts the created exposure conversion characteristics to the frame image to generate a still image. Thereby, a still image with appropriate exposure and gradation can be obtained. Thereafter, the process of FIG. 6 ends. Although these three processes may be performed separately, a lookup table is created by multiplying each correction value and conversion characteristic, and the lookup table is applied to the image to obtain an appropriate still image. It may be converted.

  As described above, at the time of moving image shooting, the system control unit 50 acquires the exposure correction value for a still image and records it as meta information for each frame. Then, at the time of still image clipping from the moving image, the system control unit 50 reads the exposure correction value from the meta information recorded in the selected frame, and performs exposure correction using the exposure correction value. As a result, when acquiring a still image from a video shot as a moving image, it is possible to obtain a still image with an appropriate exposure.

  According to the present embodiment, the system control unit 50 determines an exposure correction value based on the still image evaluation value and the still image target value acquired during shooting of a moving image, and determines the determined exposure correction value as meta information. To record each frame in the movie. Then, the system control unit 50 reads the exposure correction value from the meta information recorded in the selected frame, corrects the exposure of the image of the selected frame based on the read exposure correction value, and displays the still image Generate As a result, when performing post-processing appropriate exposure correction as a still image, it is known how much the exposure should be corrected, so that it is possible to obtain a still image of appropriate exposure from the moving image.

Second Embodiment
In the first embodiment, the system configuration assumes that the recording of the meta information can be performed without delay with respect to the recording timing of the image frame. However, the recording of the meta information or the recording of the image frame may be delayed and the recording frame of the image frame may not match the recording frame of the meta information, depending on the processing amount and configuration order of the imaging system. In the second embodiment of the present invention, a system configuration will be described on the assumption that a shift occurs in the recording timing of meta information and the recording timing of an image frame. This embodiment will be described with reference to FIGS. 8 and 9 instead of FIG. 5 and FIGS. 7 and 10 instead of FIGS. 3 and 6 in the first embodiment.

  FIG. 7 shows a flowchart of the meta information recording process. The conditions for realization and start of this process are similar to the process of FIG. In steps S301 and S302, the system control unit 50 executes processing similar to that in steps S101 and S102 of FIG. In step S303, the system control unit 50 acquires a timing delay amount (timing information). Here, the timing delay amount is determined by the processing time and configuration of the imaging system. The timing delay amount is an amount that indicates a shift in recording timing of meta information with respect to the recording of an image of a moving image frame, and is information indicating a shift in timing in frame units.

  FIG. 8 and FIG. 9 are timing charts for each frame of recording of an image and meta information. In particular, FIG. 8 shows an example in which the recording of meta information is delayed with respect to the recording of an image, and FIG. 9 shows an example in which the recording of an image is delayed with respect to the recording of meta information. In the example of FIG. 8, since the detection timing is later than that of the example of FIG. 5, the meta information is recorded one frame behind the image data. In this case, the timing delay amount is “+1”. In the example of FIG. 9, the development processing is longer than that of the example of FIG. 5, and the image data is recorded one frame behind the meta information. In this case, the timing delay amount is “−1”. The system control unit 50 acquires the amount of timing delay and records it as meta information together with the still image evaluation value in order to cope with the case where the operation is performed according to such a timing chart. That is, in step S304 in FIG. 7, the system control unit 50 includes the still image evaluation value acquired in step S302 and the timing delay amount (information of +1 and −1) acquired in step S303 in the meta information. Record every frame during animation. Although the timing delay amount is recorded for each frame, it may be recorded for each of a plurality of frames, for example, for each scene file. Thereafter, the process of FIG. 7 ends.

  Next, the process of extracting a still image from a moving image and its exposure correction will be described. FIG. 10 is a flowchart of the still image clipping process. The conditions for realization and start of this process are similar to the process of FIG. In step S401, the system control unit 50 executes the same process as step S201 in FIG. In step S402, the system control unit 50 identifies a corresponding frame, and acquires meta information from the identified frame. Here, the corresponding frame is a frame in which meta information corresponding to the selected frame is recorded. That is, first, the system control unit 50 acquires the amount of timing delay from the meta information recorded in the frame selected in step S401, and identifies the corresponding frame based on the amount of timing delay. For example, if the timing delay amount is “+1”, the next (following) frame of the selected frame is identified as the corresponding frame (FIG. 8). On the other hand, if the timing delay amount is “−1”, the previous frame of the selected frame is identified as the corresponding frame (FIG. 9).

  Next, in step S403, the system control unit 50 reads the still image evaluation value from the meta information acquired from the corresponding frame. Next, in step S404, the system control unit 50 calculates the difference between the acquired still image evaluation value and the still image target value (still image target value-still image evaluation value) as in step S103 of FIG. Determined as the exposure correction value for Next, in step S405, the system control unit 50 determines whether overexposure occurs if exposure correction is performed using the determined exposure correction value. Specifically, when the system control unit 50 generates a still image by applying an exposure conversion characteristic in which an exposure correction value, a gamma inverse characteristic for moving image shooting, and a gamma characteristic for still image are reflected to a frame image. , It is determined whether a pixel whose pixel value encounters saturation occurs. As a result of the determination, if the whiteout does not occur, the system control unit 50 proceeds the process to step S407. On the other hand, when overexposure occurs, the system control unit 50 changes the exposure correction value to a value at which overexposure does not occur (step S406), and then the process proceeds to step S407. For example, the system control unit 50 sets the exposure correction value to the limit value at which overexposure does not occur (the value closest to the value determined in step S404 within the range where overexposure does not occur). In steps S407 and S408, the system control unit 50 executes the same processing as in steps S203 and S204 in FIG. 6, and ends the processing in FIG.

  According to the present embodiment, the system control unit 50 identifies the frame in which the meta information corresponding to the selected frame is recorded based on the timing delay amount, and the meta information recorded in the identified frame Read out the still image evaluation value from. Then, the system control unit 50 determines an exposure correction value from the still image evaluation value and the still image target value, corrects the exposure of the image of the selected frame based on the exposure correction value, and generates a still image. As a result, even in a system in which the recording timings of the image data and the meta information are shifted, it is possible to obtain a still image having an appropriate exposure as a still image. Therefore, the same effect as that of the first embodiment can be obtained with regard to obtaining a still image of appropriate exposure from the moving image.

  In addition, when it is assumed that whiteout will occur according to the exposure correction value once determined, the system control unit 50 changes the exposure correction value to a value where whiteout does not occur, and therefore obtains a still image without whiteout. be able to.

  Note that the process of changing the exposure correction value to a value that does not cause overexposure may be applied to the first embodiment, and a step process therefor is provided, for example, immediately before step S203 in FIG. It is also good.

  When the exposure correction value for a still image is determined in step S202 of FIG. 6 or step S404 of FIG. 10, the determined exposure correction value may be displayed on the display unit 28 to notify the user. Alternatively, an example of a still image when the determined exposure correction value is applied may be displayed on the display unit 28. Then, a user who has viewed the displayed exposure correction value or still image may instruct to change the exposure correction value.

  In the embodiment described above, the configuration is described in which the still image is cut out in the imaging device using a moving image acquired in the imaging device, but the present invention is not limited to this. For example, an imaging device capable of acquiring a moving image records meta information on a still image evaluation value and / or an exposure correction value in association with a frame of the moving image. The electronic device (external device) provided outside the imaging apparatus may be configured to generate a still image based on the above-described meta information.

(Other embodiments)
The present invention is also realized by performing the following processing. That is, software (program) for realizing the functions of the above-described embodiment is supplied to a system or apparatus via a network or various storage media, and a computer (or CPU, MPU or the like) of the system or apparatus reads program code It is a process to execute. In this case, the program and the storage medium storing the program constitute the present invention.

  Although the present invention has been described in detail based on its preferred embodiments, the present invention is not limited to these specific embodiments, and various embodiments within the scope of the present invention are also included in the present invention. included. Some of the embodiments described above may be combined as appropriate.

22 imaging unit 32 memory 50 system control unit

Claims (14)

An imaging unit that captures an image of a subject to obtain a moving image;
An acquisition unit configured to acquire an evaluation value on brightness of a subject from the moving image using a method for a still image while acquiring a moving image by the imaging unit;
A determination unit that determines an exposure correction value based on the evaluation value acquired by the acquisition unit and a target value related to the brightness of the subject;
Recording means for including the exposure correction value determined by the determination means in the meta information and recording for each corresponding frame in the moving image;
Selecting means for selecting a frame to be cut out as a still image from frames in the moving image;
Reading means for reading an exposure correction value from the meta information recorded in the frame selected by the selection means;
An imaging apparatus comprising: a generation unit configured to generate a still image by correcting the exposure of the image of the frame selected by the selection unit based on the exposure correction value read by the readout unit.   The imaging apparatus according to claim 1, wherein the determination unit determines a difference between the acquired evaluation value and the target value as the exposure correction value. An imaging unit that captures an image of a subject to obtain a moving image;
A first acquisition unit that acquires an evaluation value related to the brightness of a subject using the still image method from the moving image while the moving image is acquired by the imaging unit;
A second acquisition unit for acquiring timing information indicating a shift in recording timing of meta information with respect to recording of an image of the moving image frame;
The timing information acquired by the second acquisition unit is recorded in the moving image, and the evaluation value acquired by the first acquisition unit is included in the meta information and recorded for each corresponding frame in the moving image. Recording means to
Selecting means for selecting a frame to be cut out as a still image from frames in the moving image;
Based on the timing information recorded by the recording means, a frame in which meta information corresponding to the frame selected by the selection means is recorded is specified, and an evaluation value is calculated from the meta information recorded in the specified frame. Reading means for reading out;
An exposure correction value is determined based on the evaluation value and the target value read by the reading unit, and the exposure of the image of the frame selected by the selection unit is corrected based on the determined exposure correction value. An imaging device having a generation unit configured to generate a still image.   4. The image pickup apparatus according to claim 3, wherein the generation unit determines a difference between the read evaluation value and the target value as the exposure correction value.   5. The imaging according to claim 4, wherein the generation unit changes the exposure correction value to a value at which whiteout does not occur when whiteout is assumed to occur according to the determined exposure correction value. apparatus.   The imaging apparatus according to any one of claims 3 to 5, wherein the timing information is information indicating the deviation of the timing on a frame basis.   The said recording means includes the said timing information in the said meta information with the acquired said evaluation value, and records it for every flame | frame in the said moving image, It is characterized by the above-mentioned. Imaging device.   The generation means may perform, in addition to the exposure correction based on the exposure correction value, a floor of the image of the selected frame by gamma processing of a characteristic reverse to gamma processing for moving image shooting and gamma processing for still images. The imaging device according to any one of claims 1 to 7, wherein the still image is generated by performing tone correction. An electronic device capable of extracting a still image from a moving image output from an imaging device including an imaging device capable of capturing a subject and acquiring a moving image,
Selecting means for selecting a frame to be cut out as a still image from frames in the moving image;
Reading means for reading an exposure correction value from the meta information recorded in the frame selected by the selection means;
Generating means for correcting the exposure of the image of the frame selected by the selection means based on the exposure correction value read by the reading means, and generating a still image,
The meta information includes the exposure correction value based on an evaluation value on the brightness of the subject and a target value on the brightness of the subject using the still image method from the moving image while acquiring the moving image in the imaging device An electronic device characterized by being recorded as corresponding information for each corresponding frame in the moving image. An acquisition step of acquiring an evaluation value related to the brightness of the subject using the still image method from the moving image while acquiring the moving image;
A determination step of determining an exposure correction value based on the evaluation value acquired in the acquisition step and a target value corresponding to the brightness of the subject;
Recording step of including the exposure correction value determined in the determination step in the meta information and recording for each corresponding frame in the moving image;
Selecting the frame to be cut out as a still image from the frames in the moving image;
Reading out the exposure correction value from the meta information recorded in the frame selected by the selecting step;
And generating the still image by correcting the exposure of the image of the frame selected by the selection step based on the exposure correction value read by the reading step. Control method. A first acquisition step of acquiring an evaluation value related to the brightness of the subject using the still image method from the moving image while acquiring the moving image;
A second acquisition step of acquiring timing information indicating a shift in recording timing of meta information with respect to recording of an image of the moving image frame;
The timing information acquired in the second acquisition step is recorded in the moving image, and the evaluation value acquired in the first acquisition step is included in the meta information and recorded for each corresponding frame in the moving image. Step of recording
Selecting the frame to be cut out as a still image from the frames in the moving image;
Based on the timing information recorded in the recording step, a frame in which meta information corresponding to the frame selected in the selection step is recorded is identified, and an evaluation value is calculated from the meta information recorded in the identified frame. Reading step to read out;
An exposure correction value is determined based on the evaluation value and the target value read out in the reading step, and the exposure of the image of the frame selected in the selection step is corrected based on the determined exposure correction value. And a generation step of generating a still image. A control method of an electronic device capable of extracting a still image from a moving image output from an imaging device including an imaging device capable of capturing a subject and acquiring a moving image,
Selecting the frame to be cut out as a still image from the frames in the moving image;
A reading step of reading an exposure correction value from the meta information recorded in the frame selected in the selecting step;
And generating the still image by correcting the exposure of the image of the frame selected in the selection step based on the exposure correction value read in the reading step.
The meta information includes the exposure correction value based on an evaluation value on the brightness of the subject and a target value on the brightness of the subject using the still image method from the moving image while acquiring the moving image in the imaging device A control method of an electronic device, which is recorded as corresponding information for each corresponding frame in the moving image.   A program causing a computer to execute the control method of an imaging apparatus according to claim 10 or 11.   A program causing a computer to execute the control method of an electronic device according to claim 12.

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