JP2015195499A - Imaging apparatus, method for controlling the same, and control program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To highly accurately correct the reduction of the light quantity of an image peripheral part with a simple configuration.SOLUTION: A camera includes an illumination part 412 illuminating an object and photographs the object through an imaging optical system, to obtain an image. An illumination control part 411 determines whether or not the object is illuminated by the illumination part. When correcting peripheral light quantity drop being the reduction of the light quantity occurring at the image peripheral part, a video signal processing part 408 decides whether or not the peripheral light quantity drop caused by illumination by the illumination part is corrected, according to the determination result.

Description

  The present invention relates to an imaging apparatus, a control method thereof, and a control program, and more particularly to correction of luminance variation in the imaging apparatus.

  In general, in an imaging apparatus such as a digital camera, a so-called peripheral light amount drop (peripheral light amount drop due to optics) is known as its lens characteristics. Here, the peripheral light amount drop in the imaging apparatus will be described.

  FIG. 7 is a diagram for explaining a decrease in peripheral light amount in a conventional imaging apparatus.

  The peripheral light amount drop 101 derived from optics is a phenomenon in which the light amount decreases (falls) as the distance from the center of the optical axis of the lens increases. As a result, the peripheral portion of the captured image corresponding to the peripheral portion of the lens becomes dark. When this peripheral light amount drop 101 is schematically shown, a peripheral light amount drop curve 102 is obtained. Here, the horizontal axis indicates the distance from the center of the image, and the vertical axis indicates the amount of light. Then, by correcting the peripheral light amount drop as described above, the luminance unevenness on the screen is corrected to obtain a screen with uniform brightness.

  By the way, conditions that affect the peripheral light amount drop include, for example, focal length information such as a zoom position and a focus position, and an aperture diameter. When correcting the peripheral light amount drop, the peripheral light amount depends on the condition. Drop compensation is performed.

  FIG. 8 is a diagram for explaining correction of an image in which a peripheral light amount drop has occurred.

  In FIG. 8, the horizontal axis indicates the distance from the center of the image, and the vertical axis indicates the amount of light. In the image 201 in which the peripheral light amount has dropped, the gain 202 is increased in the peripheral portion with respect to the central portion, and the luminance value is electrically increased. Thereby, the luminance on the screen (that is, the image) 203 is kept uniform.

  On the other hand, when the shooting environment is dark, shooting is generally performed by illuminating the subject. At this time, the light is emitted so as to illuminate the subject, but particularly when photographing with a wide-angle imaging device, sufficient illumination cannot be performed in the peripheral portion, and the peripheral portion becomes dark. (Such a phenomenon is called a decrease in the amount of ambient light derived from lighting).

  As described above, the peripheral light amount drop includes the optically-derived peripheral light amount drop and the illumination-derived peripheral light amount drop. When both occur, the degree of the peripheral light amount drop becomes severe.

  FIG. 9 is a diagram for explaining an image when an optical peripheral light amount drop and an illumination-derived peripheral light amount drop occur.

  When the peripheral light amount drop 301 derived from the optics and the illumination occurs, the light amount drop in the peripheral portion becomes more intense than the light amount drop 101 derived from the optics shown in FIG. When this peripheral light amount drop 301 is schematically shown, a peripheral light amount drop curve 302 is obtained. Here, the horizontal axis indicates the distance from the center of the image, and the vertical axis indicates the amount of light.

  As described above, in a shooting environment in which a subject is illuminated and shot, if the illumination light is not uniform, unevenness in brightness occurs at the shooting angle of view.

  In order to avoid such a decrease in the amount of peripheral light due to uneven brightness, for example, a correction table is provided to compare the brightness between the center of the image and the peripheral part so that the peripheral part becomes bright when the peripheral part is dark. However, there is an imaging apparatus that corrects the peripheral portion to be dark when the peripheral portion is bright (see Patent Document 1).

  Furthermore, there is an imaging device that compares an image when illumination is turned on with an image when illumination is turned off, calculates a correction amount for each pixel from the difference in luminance, and corrects the image ( Patent Document 2).

JP 2001-203910 A JP 2004-88409 A

  However, in the imaging device described in Patent Document 1 described above, a processing unit for calculating the luminance difference between the image center (that is, the imaging center) and the peripheral portion is required, and the load on the imaging device is accordingly increased. Will become bigger. Further, when the decrease in the amount of peripheral light caused by the lens is taken into consideration, a luminance difference occurs between the photographing center and the peripheral portion regardless of the presence or absence of illumination.

  In other words, regardless of the presence or absence of illumination, if the luminance difference between the central portion and the peripheral portion of the captured image is not corrected, the peripheral portion of the image remains dark. In Japanese Patent Laid-Open No. 2004-228561, a decrease in the amount of peripheral light due to the lens is not taken into account, and when the illumination is off, the light amount (that is, the luminance) in the peripheral part may be reduced.

  On the other hand, in the image pickup apparatus described in Patent Document 2, when performing image correction, it is necessary to take two images with the illumination on and off. For this reason, it is difficult to perform correction in a situation where two images cannot be obtained.

  Considering the situation where two images cannot be obtained, it is necessary not only to store an image for comparison in a memory or the like in advance, but also to require a processing unit for performing comparison processing. When the shooting scene changes, it is difficult to obtain two images immediately by turning on and off the illumination, which is inconvenient for the user.

  In addition, when correcting the peripheral light loss due to illumination, it is necessary to accurately align the two images. If the alignment is not performed accurately, it is difficult to correct the peripheral light loss. It becomes.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an imaging apparatus, a control method therefor, and a control program that can accurately correct a light loss in the peripheral portion of an image with a simple configuration.

  In order to achieve the above object, an imaging apparatus according to the present invention is an imaging apparatus that includes an illuminating unit that illuminates a subject, captures the subject through an imaging optical system, and obtains an image at a peripheral portion of the image. A correction unit that corrects a decrease in peripheral light amount that is a decrease in the amount of light generated; and a determination unit that determines whether or not the subject is illuminated by the illumination unit, wherein the correction unit is a determination result by the determination unit Accordingly, it is determined whether or not to correct the decrease in the amount of peripheral light caused by illumination by the illumination unit.

  A control method according to the present invention is a control method for an image pickup apparatus that includes an illuminating unit that illuminates a subject and obtains an image by photographing the subject via an image pickup optical system. A correction step for correcting a certain amount of peripheral light loss, a determination step for determining whether or not the subject is illuminated by the illumination means, and illumination by the illumination means in the correction step according to a determination result by the determination step And a determination step for determining whether or not to correct the peripheral light amount drop due to the above.

  The control program according to the present invention is a control program used in an imaging apparatus that includes an illuminating unit that illuminates a subject and captures the subject via an imaging optical system to obtain an image. According to a correction step for correcting a decrease in peripheral light amount, which is a decrease in the light amount that occurs in the peripheral portion of the image, a determination step for determining whether or not the subject is illuminated by the illumination means, and a determination result by the determination step And a determination step for determining whether or not to correct the decrease in the amount of peripheral light caused by illumination by the illumination means in the correction step.

  According to the present invention, since it is determined whether or not to correct the peripheral light amount drop caused by the illumination by the illumination unit depending on whether or not the subject is illuminated by the illumination unit, with a simple configuration It is possible to accurately correct the light loss in the peripheral portion of the image.

1 is a block diagram illustrating a configuration of an example of an imaging apparatus according to a first embodiment of the present invention. It is a flowchart for demonstrating the peripheral light amount fall correction | amendment process performed with the camera shown in FIG. It is a figure for demonstrating correction | amendment of the peripheral light amount fall derived from the illumination performed with the camera shown in FIG. It is a figure which shows the zooming of the illumination irradiation area | region at the time of using the camera shown in FIG. It is a flowchart for demonstrating the peripheral light amount fall correction | amendment process performed with the camera by the 2nd Embodiment of this invention. It is a flowchart for demonstrating the peripheral light amount fall correction | amendment process performed with the camera by the 3rd Embodiment of this invention. It is a figure for demonstrating the surrounding light amount fall in the conventional imaging device. It is a figure for demonstrating correction | amendment of the image in which the peripheral light amount fall has generate | occur | produced. It is a figure for demonstrating the image at the time of the peripheral light amount fall derived from optics, and the peripheral light quantity drop derived from illumination produced.

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

[First Embodiment]
FIG. 1 is a block diagram showing the configuration of an example of an imaging apparatus according to the first embodiment of the present invention.

  The illustrated imaging apparatus is, for example, a digital camera (hereinafter simply referred to as a camera) and includes a lens group 401. The lens group 401 is an optical system for condensing (imaging) light from a subject on the image sensor 405. The lens group 401 includes a focus lens for focusing on a subject, a zoom lens for adjusting a field angle, and the like.

  The amount of light (optical image) that has passed through the lens group 401 is adjusted by the diaphragm 403 via the optical filter 402. As the optical filter 402, for example, an infrared cut filter (IRCF) is used.

  The optical image that has passed through the diaphragm 403 is formed on the light receiving surface of the image sensor 405. Color filters arranged in a predetermined order are disposed on the light receiving surface of the image sensor 405. The image sensor 405 outputs an electrical signal (analog signal) corresponding to the optical image.

  An analog signal that is an output of the image sensor 405 is sent to an AGC (automatic gain control unit) 106, where the gain is adjusted to adjust its luminance. The output of the AGC 106 is A / D converted by the A / D converter 107 and output as a digital signal (digital imaging signal).

  The video signal processing unit 408 performs predetermined processing on the digital imaging signal, and outputs a luminance signal and a color signal for each pixel as a video signal (also referred to as image data). Here, a video signal for output is generated, and parameters for controlling the camera are generated. As parameters for controlling the camera, for example, there are parameters used in aperture control, focus control, or white balance control for adjusting color.

  The video signal processing unit 408 includes a peripheral light amount decrease correction unit (not shown) that corrects the peripheral light amount decrease, and corrects the peripheral light amount decrease that is a luminance decrease in the peripheral portion of the screen by the peripheral light amount decrease correction unit. . That is, the peripheral light amount drop correction unit corrects a peripheral light amount drop that is a reduction in the light amount that occurs in the peripheral portion of the image. When the peripheral light amount drop correction is performed, the video signal processing unit 408 obtains the aperture degree and subject distance data as parameters from the exposure adjustment unit 410 and the lens control unit 413, respectively.

  The video signal output unit 409 outputs the video signal generated by the video signal processing unit 108 to the outside. The exposure adjustment unit 410 obtains the luminance on the shooting screen according to the luminance information output from the video signal processing unit 108. The exposure adjustment unit 410 controls the diaphragm 403 and the AGC 406 in order to adjust the captured image (that is, the video signal) to a predetermined brightness based on the luminance. Note that the exposure adjustment unit 410 may adjust the brightness by adjusting the shutter speed and controlling the charge accumulation time of the image sensor 105. Further, when the subject is dark in the image, the exposure control unit 410 controls the illumination control unit 411 to perform lighting and dimming processing of the illumination unit 412.

  The lens control unit 413 drives and controls the lens group 401 to perform focusing. At the time of focusing, the lens control unit 413 extracts a high frequency component from the video signal generated by the video signal processing unit 408, and uses the high frequency component as focus focus information (focus evaluation value). Then, the lens control unit 413 drives and controls the lens group 401 so that the focus evaluation value is maximized.

  The external setting unit 414 is used when setting the camera. For example, using the external setting unit 414, the user performs camera operations such as focusing, brightness designation, and zoom magnification designation. The control setting unit 416 performs, for example, exposure adjustment, lens control, illumination control, and the like according to the control command input from the external setting unit 414.

  The illumination control unit 414 turns on the illumination unit 415 when the exposure control unit 410 determines that the subject is dark. On the other hand, when it is determined that the subject is sufficiently bright, the illumination control unit 414 turns off the illumination unit 415 and adjusts the subject brightness by dimming.

  FIG. 2 is a flowchart for explaining peripheral light amount drop correction processing performed by the camera shown in FIG.

  When the peripheral light amount drop correction process is started, the video signal processing unit 408 acquires camera parameters that affect the peripheral light amount drop (step S501). Here, for example, the aperture value is obtained from the exposure adjustment unit 410 as the video signal processing unit 408 and the camera parameter, and the focal length information such as the focus position and the zoom position is obtained from the lens control unit 413.

  Subsequently, the video signal processing unit 408 obtains illumination unit information indicating the state of the illumination unit 412 from the illumination control unit 411, that is, whether the illumination unit 412 is on or off. Then, the video signal processing unit 408 determines whether or not the illumination is turned on based on the illumination unit information (step S502).

  If the illumination unit 412 is not turned on (YES in step S502), the video signal processing unit 408 corrects the peripheral light amount loss derived from the optics for correcting the light amount loss in the peripheral portion of the image caused by the lens group 401 and the like. Is performed (step S503). Then, the video signal processing unit 408 ends the peripheral light amount drop correction process.

  Note that, as described above, the peripheral light loss due to optics is caused by the optical characteristics of the lens group 401 and the like, and changes according to the focal length information and the aperture value.

  In step S503, the video signal processing unit 408 stores in advance a correction pattern corresponding to the camera parameter as peripheral light amount correction data, and the video signal processing unit 408 stores the peripheral light amount correction data based on the camera parameter. It reads out and corrects the video signal in accordance with the peripheral light amount correction data to perform peripheral light amount drop correction.

  For example, when generating peripheral light amount correction data, a video signal obtained by photographing a bright subject with a uniform brightness in advance while changing camera parameters, that is, measuring the light loss in the peripheral portion of the image. To do. Then, according to the measurement result, peripheral light amount correction data indicating the correction location and the correction intensity is generated.

  As described with reference to FIG. 8, the peripheral light amount drop generally occurs concentrically with respect to the center of the optical axis. Therefore, the correction intensity is changed according to the distance of each pixel or area from the center of the image. (As shown in FIG. 8, the gain 202 is changed according to the distance from the center of the image).

  When the illumination unit 412 is turned on (NO in step S502), the video signal processing unit 408 corrects the peripheral light amount drop caused by the illumination and the peripheral light amount drop caused by illumination due to the lighting of the illumination (step step). S504), the brightness in the captured image is kept uniform. Then, the video signal processing unit 408 ends the peripheral light amount drop correction process.

  In the process of step S504, as described later, it is necessary to perform correction according to the light distribution characteristic of the illumination in addition to correction using the peripheral light loss correction data derived from optics.

  FIG. 3 is a diagram for explaining correction of a peripheral light amount drop caused by illumination performed by the camera shown in FIG.

  When correcting the peripheral light loss due to illumination, the peripheral light loss correction data corresponding to the light distribution characteristic of the illumination is stored in advance in the video signal processing unit 408 in the same manner as the correction of the peripheral light loss derived from the optical. . Then, the video signal processing unit 408 corrects the peripheral light amount drop resulting from illumination using the peripheral light amount drop correction data.

  As shown in FIG. 3, when the peripheral light amount drop occurs in the image 601, the video signal processing unit 408 increases the gain 602 in the peripheral portion with respect to the central portion to increase the luminance. As a result, the video signal processing unit 408 keeps the screen luminance 603 uniform.

  FIG. 4 is a diagram showing zooming of the illumination irradiation area when the camera shown in FIG. 1 is used.

  As shown in FIG. 4, when the illumination irradiation area 701 is zoomed in the image, the degree of luminance drop due to illumination changes. For this reason, the light distribution characteristic data indicating the light distribution characteristic of the illumination is stored in the video signal processing unit 408 in advance. Then, the video signal processing unit 408 performs peripheral light amount drop correction for each zoom area (cutout area) 702 according to the light distribution characteristic data.

  It should be noted that the correction amount related to the optical peripheral light loss and illumination peripheral light loss may be stored as a data table, and the correction amount is calculated using a calculation formula such as an approximate expression in consideration of the memory capacity. You may make it ask.

  In this manner, in the first embodiment of the present invention, not only the optical peripheral light loss but also the peripheral light loss caused by illumination can be corrected. As a result, the luminance unevenness of the image can be suppressed regardless of whether the illumination is on or off.

[Second Embodiment]
Next, an example of a camera according to the second embodiment of the present invention will be described. The configuration of the camera according to the second embodiment is the same as that of the camera shown in FIG.

  FIG. 5 is a flowchart for explaining peripheral light amount drop correction processing performed by the camera according to the second embodiment of the present invention. In FIG. 5, the same steps as those in the flowchart shown in FIG.

  If the illumination is on in step S502 (NO in step S502), the video signal processing unit 408 acquires illumination dimming data (dimming information) related to the illumination unit 412 from the illumination control unit 411 (step S502). S801). Here, the light control information refers to the light intensity of the illumination unit 412 and the irradiation area (light distribution characteristics).

  For example, the illumination unit 412 is provided with a so-called auto zoom mechanism, and the illumination unit 412 changes the illumination range (that is, the illumination angle) according to the focal length information under the control of the illumination control unit 411. Change the light distribution characteristics (that is, change the light control conditions).

  When the illumination unit 412 includes an auto zoom mechanism, the peripheral light amount drop correction cannot be performed correctly unless the illumination-derived peripheral light amount correction is performed in consideration of the dimming condition. Therefore, the video signal processing unit 408 performs the peripheral light amount drop correction due to illumination according to the dimming information indicating the dimming condition.

  Subsequently, the video signal processing unit 408 performs the optical-origin peripheral light amount drop correction described with reference to FIG. 2 and performs the illumination-derived peripheral light amount drop correction based on the dimming information acquired in Step S801. The brightness in the image is kept uniform (step S802). Then, the video signal processing unit 408 ends the peripheral light amount drop correction process.

  As described above, when correcting both the peripheral light amount drop resulting from the illumination and the peripheral light amount drop resulting from illumination by the dimmable illumination unit 412, as described above, according to the peripheral light amount drop correction data derived from the optical To correct the loss of peripheral light due to optics. Further, based on the light distribution characteristics according to the light control conditions of the illumination unit 412, the peripheral light amount drop correction derived from illumination is performed.

  When the illumination unit 412 changes the irradiation area or the light emission intensity according to the focal length, the degree of luminance drop by the illumination unit 412 changes. For this reason, the video signal processing unit 408 stores in advance light distribution characteristic data indicating the light distribution characteristic of the illumination unit 412 for each focal length, and the illumination derived peripheral light amount correction for the illumination-derived peripheral light amount drop correction. Perform peripheral light loss correction.

  In this manner, in the second embodiment of the present invention, not only the optical peripheral light amount drop correction but also the peripheral light amount drop correction caused by the change in the light distribution characteristics of the illumination unit and the change in the light amount are performed together. Therefore, luminance unevenness in an image obtained as a result of photographing with illumination can be suppressed.

[Third Embodiment]
Next, an example of a camera according to the third embodiment of the present invention will be described. The configuration of the camera according to the third embodiment is the same as that of the camera shown in FIG.

  FIG. 6 is a flowchart for explaining peripheral light amount drop correction processing performed by the camera according to the third embodiment of the present invention. In FIG. 6, the same steps as those in the flowchart shown in FIG.

  In the third embodiment, it is assumed that at least the lens group 401 is a replaceable lens unit, and that the illumination unit 412 can be replaced.

  When the peripheral light amount drop correction process is started, the video signal processing unit 408 acquires feature data (also referred to as illumination data) indicating the characteristics of the illumination unit 412 currently attached to the camera from the illumination control unit 411 (step S901). Here, the illumination data includes light distribution characteristics, illumination intensity, light source type, light source wavelength, and illumination identification data for identifying the illumination unit 412 of the illumination unit 412.

  Depending on the illumination unit 412 (that is, for each type of illumination), the illumination data is different, and when the illumination data is different, the peripheral light amount drop characteristic changes. Then, the peripheral light amount drop correction data derived from illumination corresponding to the illumination data is stored in advance in the video signal processing unit 408, for example. When the illumination unit 412 has the illumination-related peripheral light amount drop correction data and the illumination unit 412 is attached to the camera, the illumination unit 412 corrects the peripheral light amount drop from the illumination via the illumination control unit 411. Data may be notified to the video signal processing unit 408.

  Subsequently, the video signal processing unit 408 acquires lens data related to the lens unit attached to the camera from the lens control unit 413 (step S902). The lens data includes, for example, an operating range of focus and zoom, an aperture range, peripheral light loss correction data derived from optics, and lens identification data for identifying a lens unit. The video signal processing unit 408 determines how much the peripheral light amount drop occurs in the image obtained as a result of shooting according to the lens data, that is, for each type of lens unit.

  Thereafter, the video signal processing unit 408 acquires camera parameters in step S501, and determines whether the illumination unit 412 is turned on in step S502. If the illumination unit is not turned on (YES in step S502), the video signal processing unit 408 causes the optical-derived peripheral light amount drop correction data according to the lens data and the optical-derived peripheral light amount drop according to the camera parameter. Based on the correction data, the peripheral light amount drop correction derived from the optical is performed (step S903). Here, the video signal processing unit 408 performs optical-derived peripheral light amount drop correction in the operating range of the focus, zoom, and aperture according to the determination result described above. Then, the video signal processing unit 408 ends the peripheral light amount drop correction process.

  The optically-derived peripheral light amount drop correction data corresponding to the lens data is stored in advance in the video signal processing unit 408, for example. Note that when the lens unit has optical-derived peripheral light amount drop correction data and the lens unit is attached to the camera, the optical-derived peripheral light amount drop correction data is imaged via the lens control unit 413. You may make it notify to the signal processing part 408. FIG.

  If it is determined in step S502 that the illumination unit 412 is turned on (NO in step S502), the video signal processing unit 408 determines the peripheral light amount in accordance with the peripheral light amount drop correction data derived from the illumination in accordance with the illumination data. Perform drop correction. Further, the video signal processing unit 408 performs optical-derived peripheral light amount drop correction data based on the optical-derived peripheral light amount drop correction data corresponding to the lens data and the optical-derived peripheral light amount drop correction data corresponding to the camera parameter. (Step S904), the luminance in the image is kept uniform. Then, the video signal processing unit 408 ends the peripheral light amount drop correction process.

  As described above, in the third embodiment of the present invention, it is possible to appropriately correct the peripheral light amount drop even if the combination of the illumination unit and the lens unit is changed. As a result, the user can take a picture without considering the combination of the illumination unit and the lens unit.

  In the third embodiment, the illumination unit and the lens unit are replaceable. However, even when only the lens unit is replaceable, the peripheral light amount drop correction may be performed in the same manner.

  As is clear from the above description, in the example shown in FIG. 1, the video signal processing unit 408 functions as a correction unit, and the video signal processing unit 408 and the illumination control unit 411 function as a determination unit. In the example shown in FIG. 1, at least the lens group 401, the optical filter 4-2, and the diaphragm 403 constitute an imaging optical system.

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

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

  Each of the above control method and control program has at least a correction step, a determination step, and a determination step.

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

401 Lens Group 403 Aperture 405 Image Sensor 406 AGC
408 Video signal processing unit 410 Exposure control unit 411 Illumination control unit 412 Illumination unit 413 Lens control unit 415 Control setting unit

Claims (8)

An imaging apparatus that includes an illuminating unit that illuminates a subject and obtains an image by photographing the subject via an imaging optical system,
Correction means for correcting a decrease in the amount of peripheral light that is a decrease in the amount of light that occurs in the peripheral portion of the image;
Determining means for determining whether or not the subject is illuminated by the illumination means;
The image pickup apparatus according to claim 1, wherein the correction unit determines whether or not to correct the decrease in peripheral light amount caused by illumination by the illumination unit, according to a determination result by the determination unit.   When the determination result indicates that the subject is illuminated, the correction unit corrects the peripheral light amount drop caused by the imaging optical system, and also corrects the periphery caused by illumination by the illumination unit. The imaging apparatus according to claim 1, wherein the light quantity drop is corrected.   The correction unit corrects a peripheral light amount drop caused by illumination by the illumination unit according to a dimming condition indicating an illumination intensity and an illumination angle of illumination when the subject is illuminated. The imaging apparatus according to claim 2, wherein the pattern is changed. The illumination means can be exchanged for the imaging device,
The correction unit corrects a peripheral light amount drop caused by illumination by the illumination unit according to a peripheral light amount drop correction pattern derived from illumination corresponding to a light distribution characteristic at the time of lighting for each type of the illumination unit. The imaging apparatus according to claim 2. The imaging optical system is a lens unit exchangeable with the imaging device,
The correction means corrects a peripheral light amount drop caused by the lens unit according to an optically-derived peripheral light amount drop correction pattern determined for each type of the lens unit. Imaging device. The illumination means is replaceable with the imaging device, and the imaging optical system is a lens unit replaceable with the imaging device,
The correction means corrects a peripheral light amount drop caused by illumination by the illumination means in accordance with a peripheral light amount drop correction pattern derived from illumination according to a light distribution characteristic at the time of lighting for each type of the illumination means. The imaging apparatus according to claim 2, wherein a peripheral light amount drop caused by the lens unit is corrected according to an optically derived peripheral light amount drop correction pattern determined for each type of the lens unit. An imaging device control method comprising an illuminating means for illuminating a subject and capturing the subject through an imaging optical system to obtain an image,
A correction step for correcting a peripheral light amount drop that is a decrease in the light amount generated in the peripheral portion of the image;
A determination step of determining whether or not the subject is illuminated by the illumination means;
In accordance with the determination result in the determination step, a determination step for determining whether or not to correct the decrease in peripheral light amount caused by illumination by the illumination unit in the correction step;
A control method characterized by comprising: A control program used in an imaging apparatus that includes an illuminating unit that illuminates a subject and obtains an image by photographing the subject via an imaging optical system,
In the computer provided in the imaging device,
A correction step for correcting a peripheral light amount drop that is a decrease in the light amount generated in the peripheral portion of the image;
A determination step of determining whether or not the subject is illuminated by the illumination means;
In accordance with the determination result in the determination step, a determination step for determining whether or not to correct the decrease in peripheral light amount caused by illumination by the illumination unit in the correction step;
A control program characterized by causing