JP6786643B2 - Exposure control device, exposure control method, and program - Google Patents

Description

The present invention relates to an exposure control device, an exposure control method, and a program, and more particularly to an exposure control during moving image shooting.

Generally, when a still image is photographed by an imaging device such as a digital camera, the photographing screen is divided into a plurality of areas for photometry. Then, there is evaluative metering that determines the exposure according to the balance between the bright part and the dark part in a plurality of areas, and further, there is spot metering that measures only a specific narrow area. In any of the side lights, the position information of the focus detection region for focusing is used when determining the metering region or the weighting for each divided area.

On the other hand, in photometry used when shooting a moving image, exposure control is performed with an emphasis on exposure stability with respect to movement of the subject and change of composition. For this reason, there is an imaging device provided with a center-weighted average metering as a dedicated metering mode, which averagely measures a relatively wide range while placing a weight in the center of the screen.

Further, in recent years, a method of detecting and tracking a person's face from a captured image has been used in an imaging device. Then, when a person's face is detected during movie shooting, an imaging device that controls switching from center-weighted average metering to face-evaluation metering that weights the face division area (photometric division area). There is.

If the face of a person cannot be detected in this imaging device, exposure control is performed using center-weighted average metering. In this case, for example, if the center of the screen is bright and there is a person with a slight backlight at the edge of the screen, overexposure is suppressed in the center of the screen and the exposure is at an appropriate level, but the face of the person is darkened. Will be exposed.

In addition, if the state in which it is delicate whether or not the face of a person can be detected continues, that is, when the state in which the face can be detected and the state in which the face cannot be detected appear alternately, the above image pickup apparatus performs face evaluation metering. And the central focused average metering will be switched intermittently. As a result, the exposure changes intermittently, resulting in a moving image with flickering brightness.

In order to suppress the occurrence of switching of photometry as described above, there is known an imaging device that determines a photometric method by chattering the face detection result, that is, referring to a plurality of face detection results (Patent Document 1). reference).

Japanese Unexamined Patent Publication No. 2010-41399

However, when trying to suppress the fluctuation of the face detection result by the chattering process, there are the following problems.

If another object crosses the screen while shooting a video with a composition in which a person exists on the screen, as a result of referring to the face detection results multiple times, it is judged that the face cannot be detected after the other object starts crossing in front of the person. There will be a delay before the results are available. For this reason, from the time when another object starts to cross in front of the person until the judgment result that the face cannot be detected is obtained, the brightness of the crossed object is regarded as the brightness of the person's face and face evaluation metering is performed and the face is crossed. A phenomenon occurs in which exposure control is affected by an object.

For example, if the crossed object is black, the face that was properly exposed may be temporarily overexposed and the exposure may fluctuate. In particular, in a shooting scene in which two people are present, if a black object crosses the main subject (main face), the exposure to the other subject will be out of the proper state.

Therefore, an object of the present invention is an exposure control device, an exposure control method, and a program capable of preventing the influence of exposure due to false detection and fluctuation of face detection and suppressing the influence of exposure when an object crosses. Is to provide.

In order to achieve the above object, the exposure control device according to the present invention includes a detection means for detecting a face region from an image obtained by photographing a subject, and a first photometric measurement in which the face region is weighted and metered. It has an exposure control means for performing exposure control based on a method or a second photometric method different from the first photometric method, and in the first photometric method, one or more by the detection means. When the face area is detected, the face area satisfying a predetermined condition is weighted and measured, and the exposure control means performs exposure control by the first light measuring method during acquisition of a moving image. In a predetermined period after the face region satisfying the predetermined condition is no longer detected, the detection means newly detects the new face region according to the detection of the new face region satisfying the predetermined condition. When the face region is weighted and the exposure control is performed again using the first photometric method, and the detection means does not detect a new face region satisfying the predetermined condition in the predetermined period. When exposure control is performed using the second photometric method according to the elapse of the predetermined period and the first photometric method is changed to the second photometric method, the first photometric method before the change is performed. After maintaining the exposure based on the photometric result by the photometric method according to the above predetermined period, the exposure is controlled by using the second photometric method, and the exposure control means uses the first photometric method during the acquisition of the moving image. If the exposure control is not performed and the face region satisfying the predetermined condition is not detected, the exposure control is performed using the second photometric method regardless of the elapse of the predetermined period. It is a feature.

According to the present invention, it is possible to prevent the influence of exposure caused by false detection and fluctuation when detecting a specific area such as a face area, and to suppress the influence of exposure when an object crosses.

It is a figure for demonstrating an example of moving image shooting in a conventional image pickup apparatus, (A) is a figure which shows the image of the state which a face can detect, (B) is a figure which shows the image of the state where a face cannot be detected. .. It is a figure for demonstrating another example of moving image shooting in a conventional image pickup apparatus, (A) is the figure which shows the state which the object crossed when there is one person, (A) is the figure which there are two people. It is a figure which shows the state which the object crossed in the case. It is a figure which shows the structure about the example of the image pickup apparatus by embodiment of this invention. It is a flowchart for demonstrating the shooting operation performed by the camera shown in FIG. It is a flowchart for demonstrating the exposure control shown in FIG. It is a flowchart for demonstrating the face use determination process shown in FIG. It is a figure for demonstrating the face list stored in the camera microcomputer shown in FIG. 1, (a) is a figure which shows an example of a face list, (b) is a figure which shows the face list after rearranging. It is a flowchart for demonstrating the fluctuation removing process shown in FIG. It is a figure for demonstrating the effect by the fluctuation removing process explained with FIG.

An example of the image pickup apparatus according to the embodiment of the present invention will be described below with reference to the drawings.

Here, before explaining the image pickup apparatus according to the embodiment of the present invention, first, the exposure control when moving image is taken by the conventional image pickup apparatus will be outlined.

FIG. 1 is a diagram for explaining an example of moving image shooting in a conventional imaging device. FIG. 1A is a diagram showing an image in a state where the face can be detected, and FIG. 1B is a diagram showing an image in a state where the face cannot be detected.

Now, as shown in FIG. 1A, it is assumed that a moving image is taken of a composition in which the center of the screen is bright and a person with a slight backlight exists at the edge of the screen. Here, if the image pickup device can correctly detect the face (specific area) of the person, the image pickup device performs exposure control using the evaluation metering described above. As a result, the backlit state on the face of the person is eliminated, and a moving image having an appropriate exposure to the face portion can be obtained.

On the other hand, if the face cannot be detected because the face part is dark, the face part is small, or the feature points of the face cannot be extracted depending on the orientation of the face in the image, the image pickup device performs exposure control using the center-weighted average metering. .. As a result, the high-brightness portion in the center of the screen has an appropriate exposure in which overexposure is suppressed, but the exposure is low in the face portion of the person (see FIG. 1 (B)).

Further, when a state in which the face of a person cannot be detected intermittently occurs, the image pickup apparatus intermittently switches between evaluative metering and center-weighted average metering to perform exposure control. When the metering is switched intermittently in this way, the exposure changes repeatedly and the brightness of the moving image flickers.

In order to suppress such flickering of the brightness of the moving image, there is an imaging device in which the face detection result is chattered. In this imaging device, the photometric method is determined by referring to the detection results of a plurality of times.

FIG. 2 is a diagram for explaining another example of moving image shooting in a conventional imaging device. Then, FIG. 2A is a diagram showing a state in which an object crosses when there is one person, and FIG. 2A is a diagram showing a state in which an object crosses when there are two people. ..

As shown in FIG. 2A, it is assumed that another object (here, a car) crosses the screen while shooting a moving image in a composition in which one person exists on the screen. Since the photometric method is determined based on the results of multiple face detections in the image pickup apparatus, the determination of the photometric method is delayed. As a result, a phenomenon occurs in which the exposure control is affected by another object.

If the color of another object is black, the moving image whose face was properly exposed will be temporarily overexposed and the exposure will fluctuate. In particular, as shown in FIG. 2B, in a composition in which two people exist, when a black object crosses the main subject (the person on the left side of the figure), the other subject (the person on the right side of the figure) becomes On the other hand, the exposure becomes inappropriate.

FIG. 3 is a diagram showing a configuration of an example of an image pickup apparatus according to an embodiment of the present invention.

The illustrated imaging device is, for example, a digital camera (hereinafter, simply referred to as a camera), and has a camera body 100 and an interchangeable lens type lens unit 200.

The camera body 100 includes a microcomputer (CCPU: hereinafter referred to as a camera microcomputer) 101, and the camera microcomputer controls the entire camera. In the camera body 100, an image sensor 102 such as a CCD or CMOS image sensor is arranged on the optical axis (optical path) of the lens unit 200. Although not shown, the image sensor 102 is provided with an infrared cut filter and a low-pass filter. Then, a subject image (optical image) is formed on the image sensor 102 via the lens unit 200, and the image sensor 102 outputs an image signal (analog signal) corresponding to the optical image.

The image signal output from the image sensor 102 is converted into a digital image signal by the A / D converter (A / D) 109. Then, the digital image signal is sent to the signal processing circuit 111. The signal processing circuit 111 performs image processing on the digital image signal based on a predetermined parameter to generate image data.

The photometric circuit (AE) 106 performs photometric control, which will be described later, according to the image data output from the signal processing circuit 111. Further, the focus detection circuit (AF) 107 performs focus detection control described later based on the image data.

The gain switching circuit 108 is a circuit for switching the gain in the image pickup element 102, and the gain switching by the gain switching circuit 108 is controlled by the camera microcomputer 101 according to the shooting conditions, the input of the photographer, and the like.

The timing generator (TG) 110 synchronizes the input of the image signal, which is the output of the image sensor 102, with the timing of the A / D conversion by the A / D converter 109 under the control of the camera microcomputer 101. Here, the description of the memory for storing the image data obtained as a result of the signal processing by the signal processing circuit 111 will be omitted.

The lens mount 130 is an interface with the lens microcomputer 201 described later, and has a communication terminal for performing data communication between the lens microcomputer 201 and the camera microcomputer 101. Through the data communication, the camera microcomputer 101 can determine the type and state of the lens unit 200 mounted on the camera body 100.

The input unit 112 includes, for example, a shooting standby button (standby button) 114 and a recording start button (recording button) 115 that put the camera in the shooting standby state. Further, although not shown, the input unit 112 has switches and buttons for switching between the AF area arbitrary selection mode and the multi-point / face tracking mode, and a shooting mode switching dial for switching between the shutter speed priority mode and the aperture priority mode. And so on. The user can input camera settings and the like through the input unit 112.

The display unit 113 includes a liquid crystal device, a light emitting element, and the like, and displays information on the set mode and other shooting. The face detection circuit 116 detects a person's face (face area: specific area) in the image data output from the signal processing circuit 111, and sends the face area detection result to the camera microcomputer 101. The face detection circuit 116 specifies the number of face regions in the image data, the position and size of each face region in the image data, the orientation of the face region, and the like.

As a face region detection method, for example, a method of extracting facial feature portions such as eyes, nose, and mouth from image data to specify the face region is used. Further, the skin color data may be extracted from the image data and the region determined to be the skin color range may be detected as the face region. Further, the face region may be detected by paying attention to the contour of the face region and using the elliptical shape information indicating the contour.

As shown in the figure, the camera microcomputer 101 is provided with a face use determination circuit 117, and the face use determination circuit 117 determines whether or not to use the face area detection result for determining the exposure as described later. Then, the determination result (face use determination result) by the face use determination circuit 117 is used for the photometric control in the photometric circuit 106.

The lens unit 200 is provided with a microcomputer (LPU: lens microcomputer) 201, and the lens microcomputer 201 controls the operation of the lens unit 200. That is, the lens microcomputer 201 controls the lens unit 200 and determines various conditions.

The lens unit 200 has a lens group 202 having a plurality of lenses. The lens group 202 includes a focus lens that is movably arranged along the optical axis and adjusts the focus.

The lens driving unit 203 is an actuator for moving the optical system for focusing detection and focusing in the lens group 202. The camera microcomputer 101 obtains the control amount of the lens drive unit 202, that is, the drive amount of the lens group 202 (lens drive amount) based on the focus detection result of the focus detection circuit 107.

The camera microcomputer 101 sends the calculated lens drive amount to the lens microcomputer 201. On the other hand, the position of the lens group 202 is detected by the encoder 204 and sent to the lens microcomputer 101 as lens position information.

The lens microcomputer 201 controls the lens driving unit 203 according to the lens driving amount while referring to the lens position information, and moves the lens group 202 to the focusing position. At the time of focus detection, focus detection information indicating the drive direction and drive speed of the lens group 202 is sent from the camera microcomputer 101 to the lens microcomputer 201. Then, the lens microcomputer 201 controls the lens driving unit 203 according to the focus detection information to drive the lens group 202 along the optical axis.

The aperture 205 is for adjusting the amount of light incident on the camera body 100. The aperture control circuit 206 drives and controls the aperture 205 under the control of the lens microcomputer 201. The aperture drive amount required to control the aperture 205 is sent from the camera microcomputer 101 to the lens microcomputer 201. The focal length of the lens group 202 may be a single focal length, or the focal length may be variable like a zoom lens.

FIG. 4 is a flowchart for explaining a shooting operation performed by the camera shown in FIG.

When the shooting operation is started, the camera microcomputer 101 first determines whether or not the shooting standby button 114 has been operated (step S101). If the shooting standby button 114 is not operated, that is, if the shooting standby button 114 is not pressed (NO in step S101), the camera microcomputer 101 stands by.

On the other hand, when the shooting standby button 114 is operated (YES in step S101), the camera microcomputer 101 selects center-weighted average metering (medium weight) as the metering method (photometric method) at the time of the first exposure control (medium weight). Step S102). As described above, in the center-weighted average metering, a weight is placed in the center of the screen to averagely measure a relatively wide range.

Subsequently, the camera microcomputer 101 detects the face in the image data by the face detection circuit 116 (step S103). Then, the camera microcomputer 101 identifies and stores the number of face regions, the position and size of each face region in the image data, the orientation of the face, and the like according to the face region detection result detected by the face detection circuit 116. To do.

Next, the camera microcomputer 101 performs exposure control as described later (step S104). Then, the camera microcomputer 101 determines whether or not the recording start button 115 has been operated (step S105). When the recording start button 115 is operated (YES in step S105), the camera microcomputer 101 determines whether or not recording is currently in progress (step S106).

If recording is not currently in progress (NO in step S106), the camera microcomputer 101 controls the camera and starts recording (step S107). On the other hand, if recording is currently in progress (YES in step S106), the camera microcomputer 101 stops recording (step S108).

After the process of step S107 or S108, the camera microcomputer 101 determines whether or not the shooting standby button 114 has been operated (step S109). When the shooting standby button 114 is operated (YES in step S109), the camera microcomputer 101 ends shooting.

On the other hand, if the shooting button is not operated (NO in step S109), the camera microcomputer 101 returns to the process of step S103. If the recording start button 115 is not operated (NO in step S105), the camera microcomputer 101 proceeds to the process of step S109.

FIG. 5 is a flowchart for explaining the exposure control shown in FIG.

When the exposure control is started, the camera microcomputer 101 refers to the face detection result by the face detection circuit 116 and determines whether or not the number of detected face regions is 1 or more (step S201). When the number of detected face regions is 1 or more, that is, when the face region exists in the image data (YES in step S201), the camera microcomputer 101 performs exposure control among the face regions detected by the face use determination circuit 117. It is determined whether or not the face area to be used exists, and prioritization is performed as described later (step S202).

Subsequently, the camera microcomputer 101 determines whether or not the face area detection result is used in the current exposure control (step S203). If the face area detection result is not used in the current exposure control (NO in step S203), that is, the face to be newly used for the exposure control in the state where the face area detection result is not used in the current exposure control. When the region is detected, the camera microcomputer 101 performs a fluctuation removing process on the face use determination result as described later (step S204).

Subsequently, the camera microcomputer 101 determines whether or not there is a face region used in the new exposure control (AE) according to the face use determination result or the face use determination result after the fluctuation removal process (step S205). .. If the face area detection result is used in the current exposure control (YES in step S203), the camera microcomputer 101 proceeds to the process of step S205.

If there is a face region to be used in the new exposure control (YES in step S205), the camera microcomputer 101 uses the metering method (photometric mode) as the evaluative metering (step S206). On the other hand, if there is no face region to be used in the new exposure control (NO in step S205), the camera microcomputer 101 selects center-weighted average metering as the metering method (step S207).

As a result, even if a new face area is detected while the exposure control is performed without using the face area, if the face area detection result is not output stably, the face area is immediately applied to the exposure control. Exposure control will continue without use. Here, center-weighted average metering will continue to be used as the metering method.

If the face region is not detected in the image data (NO in step S201), the camera microcomputer 101 determines whether or not the face region detection result is used in the current exposure control (step S208). When the face area detection result is used in the current exposure control (YES in step S208), the camera microcomputer 101 fixes (locks) the exposure control value for a predetermined time, assuming that the face of the person has disappeared (AE). Lock: Step S209). That is, when the face area detection result is used in the current exposure control and the face area used for the exposure control disappears, the camera microcomputer 101 locks the AE for a predetermined time.

This predetermined time is, for example, 5 seconds, and in the AE lock, the photometric result that is the target value of the exposure control, that is, the update of the subject brightness is stopped. The exposure fixing method is not particularly limited, and the photometric results are continuously updated to control the exposure control values such as TV (shutter speed), AV (aperture value), and ISO sensitivity. It may be fixed.

Subsequently, the camera microcomputer 101 selects center-weighted average metering as the metering method (step S210). If the face area detection result is not used in the current exposure control (NO in step S208), the camera microcomputer 101 proceeds to the process of step S210.

When the AE lock is performed in step S209, the metering method is switched from the evaluation metering to the center-weighted average metering, but the exposure in the image does not change immediately. Further, if the face area of the person is detected again during the AE lock period and can be used for exposure control, the metering method returns to the evaluation metering again. As a result, the exposure of the image does not change.

After the processing of steps S206, S207, or S210, the camera microcomputer 101 obtains the target luminance in the exposure control using the determined photometric method (step S211). The target brightness is not updated during the AE lock.

Subsequently, the camera microcomputer 101 determines the exposure control values of TV, AV, and ISO sensitivity according to the target brightness (step S212). The exposure control value is not updated during the AE lock. Then, the camera microcomputer 101 ends the exposure control and proceeds to the process of step S105 shown in FIG.

FIG. 6 is a flowchart for explaining the face use determination process shown in FIG.

When the face use determination process is started, the camera microcomputer 101 detects the face area in the image data based on the feature points of the face of the person by the face detection circuit 116, and obtains the face area detection result. Then, based on the face area detection result, the camera microcomputer 101 assigns an identification number (ID) to each face area, lists the size, orientation, and position (coordinates) of the identification number (ID), and stores it as a face list.

FIG. 7 is a diagram for explaining a face list stored in the camera microcomputer 101 shown in FIG. FIG. 7A is a diagram showing an example of the face list, and FIG. 7B is a diagram showing the rearranged face list.

As shown in FIG. 7A, an ID is assigned to the face area detected in the image data, and the size, orientation, and coordinates indicating the center position of the face area in the image are defined for each face area. Has been done.

The camera microcomputer 101 rearranges the face areas in the face list shown in FIG. 7A in the order of face size (step S301). Then, the camera microcomputer 101 examines the orientation of the face region and excludes the face region other than the face region facing the front direction or the oblique direction. That is, here, the camera microcomputer 101 excludes the sideways and backward face regions (step S302).

The camera microcomputer 101 excludes, for example, a face region in which the orientation of the face region is not within a range of 45 degrees to the left and right from the front direction. By excluding the sideways and backward face regions in this way, it is possible to prevent the exposure control from being affected by, for example, the color of the hair during the exposure control.

By rearranging the face list shown in FIG. 7A in this way, for example, the rearranged face list shown in FIG. 7B can be obtained. In the rearranged face list, ID, orientation, and coordinates are associated with the rank. In FIG. 7B, the face area in which "None" is inserted in the ID column is an excluded face area.

Subsequently, the camera microcomputer 101 selects the face region (selection detection result) having the highest priority from the sorted face list based on the selection condition. That is, the camera microcomputer 101 outputs the orientation and coordinates (face use determination result) related to the face region having the highest priority in the rearranged face list (step S303), and ends the face use determination process. Then, the camera microcomputer 101 proceeds to the process of step S203 shown in FIG.

In the exposure control, the face region of the coordinates output in step S303 is used. Regarding the orientation of the face, the face region within a range of 45 degrees to the left and right from the front direction is used, but the face use determination result may not be stable depending on the condition of the subject in consideration of the error. Therefore, the fluctuation removing process is performed as follows.

FIG. 8 is a flowchart for explaining the fluctuation removing process shown in FIG. When a plurality of face areas are detected, the fluctuation removal process is performed on each face area.

When the fluctuation removal process is started, the camera microcomputer 101 compares the current face use determination result Fn with the previous face use determination result F (n-1), and determines whether or not they are the same (step S401). .. If Fn = F (n-1) (YES in step S401), the camera microcomputer 101 adds 1 to the variable count, which is a counter for determining the number of repetitions (step S402). On the other hand, if Fn = F (n-1) (NO in step S401), the camera microcomputer 101 clears the variable count to zero (step S403).

After the process of step S402 or S403, the camera microcomputer 101 determines whether or not the variable count is equal to or greater than a predetermined count value, for example, 5 or more (step S404). When the variable count is 5 or more (YES in step S404), the camera microcomputer 101 uses the latest face use determination result Fn as the fluctuation removal result Fout for the face use determination result (step S405). Then, the camera microcomputer 101 ends the fluctuation removing process, and proceeds to the process of step S205 shown in FIG.

On the other hand, when the variable count is less than 5 (NO in step S404), the camera microcomputer 101 ends the fluctuation removing process and proceeds to the process of step S205 shown in FIG.

FIG. 9 is a diagram for explaining a fluctuation removing operation performed by the camera shown in FIG.

Now, it is assumed that the face region is detected twice in a row and then the face region is not detected five times in a row. In this case, the camera determines that there is no face area in the face area used in the exposure control if the state in which the face area is not detected continues four times. That is, the camera switches the face area used in the exposure control after referring to the face area determination result a plurality of times. As a result, the exposure of the image does not react hypersensitively to the fluctuation of the face area determination result.

On the other hand, even when the face of the person is shielded by the crossing of the object, the coordinates of the face of the shielded person are used in the exposure control for a while. Therefore, as described above, when the face region used for exposure control disappears, the fluctuation removing process shown in step S204 of FIG. 5 is not performed.

As a result, if there is another face region to which the exposure control is transferred when the object crosses, the exposure control is promptly performed by the face region. Then, when the face area does not exist separately, the exposure for a predetermined time can be fixed (AE lock), and after the face area of the person is not shielded, the proper exposure control can be restored again.

As described above, in the embodiment of the present invention, when a new face region appears during exposure control, fluctuation removal processing is performed, and when the face region used for exposure control disappears, fluctuation is performed. Another face area is used for exposure control without removing. As a result, it is possible to suppress the influence on the exposure of the image due to the false detection of the face region or the fluctuation of the face region detection result near the limit of the detection ability.

Further, in the embodiment of the present invention, when the face area used for the exposure control disappears and the face area does not exist separately, the exposure for a predetermined period is fixed without performing the fluctuation removing process. .. As a result, it is possible to eliminate the influence on the exposure of the image due to the false detection of the face region or the fluctuation of the face region detection result near the limit of the detection ability. Furthermore, the influence of the object crossing the person on the exposure can be suppressed.

Although the present invention has been described above based on the embodiments, the present invention is not limited to these embodiments, and various embodiments within the scope of the gist of the present invention are also included in the present invention. ..

For example, the function of the above embodiment may be used as a control method, and the exposure control device may be made to execute this control method. Further, the computer provided with the exposure control device may execute the program having the function of the above-described embodiment. The program is recorded on, for example, a computer-readable recording medium.

[Other Embodiments]
The present invention supplies a program that realizes one or more functions of the above-described embodiment to a system or device via a network or storage medium, and one or more processors in the computer of the system or device reads and executes the program. It can also be realized by the processing to be performed. It can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

100 Camera body 101 Camera microcomputer (CCPU)
102 Image sensor 106 Photometric circuit (AE)
111 Signal processing circuit 116 Face detection circuit 117 Face use judgment circuit 200 Lens unit 201 Lens microcomputer (LPU)
206 Aperture control circuit

Claims (7)

A detection means that detects the face area from the image obtained by imaging the subject,
It has a first metering method that weights the face region and performs photometry, or an exposure control means that controls exposure based on a photometric result by a second photometric method different from the first photometric method.
In the first photometric method, when one or more of the face regions are detected by the detection means, the face regions satisfying a predetermined condition are weighted and photometrically measured.
The exposure control means is the detection means during a predetermined period after the face region satisfying the predetermined condition is no longer detected when the exposure is controlled by the first photometric method during the acquisition of a moving image. In response to the detection of a new face region satisfying the predetermined condition, the newly detected face region is weighted and the exposure control is performed again using the first photometric method to perform the exposure control again. in the period, when said detecting means does not detect the predetermined condition is satisfied a new face region performs exposure control using the second metering mode in response to the predetermined time period has elapsed, the When changing from the first photometric method to the second photometric method, the second photometric method is used after maintaining the exposure based on the photometric results of the first photometric method before the change for the predetermined period. To control the exposure
If the exposure control means does not control the exposure by the first photometric method during the acquisition of the moving image and the face region satisfying the predetermined condition is not detected, the exposure control means depends on the elapse of the predetermined period. An exposure control device characterized in that exposure control is performed using the second photometric method without the need for exposure control. The second photometric method according to claim 1, wherein the second photometric method is executed when the detection means does not detect a face region satisfying the predetermined condition, and the photometry is performed by weighting the center of the image. Exposure control device. The predetermined condition is a condition for selecting a face region having a high priority based on at least one of the size, position, and orientation of the face region, according to claim 1 or 2 . The exposure control device described. After the shooting operation of the subject is started, the exposure control means first performs exposure control based on the photometric result by the second photometric method, and then the detection means creates a face region satisfying the predetermined condition. The exposure control device according to any one of claims 1 to 3 , wherein when it is detected, exposure control is performed based on the photometric result by the first photometric method. The exposure control device according to any one of claims 1 to 4 , wherein the exposure control device is an image pickup device including an image pickup means. A detection process that detects the face area from the image obtained by imaging the subject,
It has a first metering in which the face region is weighted and metered, or an exposure control step in which exposure control is performed based on a metering result by a second metering different from the first metering.
In the first metering, when one or more of the face regions are detected by the detection step, the face regions satisfying a predetermined condition are weighted and metered.
In the exposure control step, when the exposure control based on the first photometry is performed during the acquisition of the moving image, the predetermined period after the face region satisfying the predetermined condition is no longer detected. In response to the detection of a new face area satisfying the condition, the newly detected face area is weighted and the exposure control based on the first photometry is performed, and the predetermined condition is performed in the predetermined period. When a new face region satisfying the condition is not detected, the exposure control based on the second photometry is performed according to the elapse of the predetermined period, and the exposure control based on the first photometry is performed to the second When changing to exposure control based on photometry, after maintaining the exposure based on the photometric result of the first photometry before the change for the predetermined period, the exposure control by the second photometry is performed.
If the exposure control based on the first photometry is not performed during the acquisition of the moving image and the face region satisfying the predetermined condition is not detected in the detection step, the predetermined period elapses. An exposure control method characterized in that exposure control is performed based on the second photometry regardless of the exposure. A computer-readable program for executing the exposure control method according to claim 6 on a computer.