JP2011135379A - Imaging apparatus, imaging method and program - Google Patents

Abstract

When photographing with a flash, the entire image including a main subject is photographed with a desired luminance without degrading image quality.
A main subject luminance difference calculating unit 131 that calculates a luminance difference of a main subject region between a first image capturing that emits a flash and a second image that is captured without emitting a flash; Based on the pixel luminance difference calculation unit 132 that calculates the luminance difference of each pixel in the shooting and the second shooting, the luminance difference of the main subject region, and the pixel luminance difference of each pixel, the luminance amplification amount of each pixel is calculated. An amplification amount calculation unit 133 for calculating.
[Selection] Figure 1

Description

  The present invention relates to an imaging apparatus, an imaging method, and a program.

  Conventionally, in photographing in a dark place scene, there is known a method called slow sync photographing in which exposure of a main subject is made appropriate by flash emission and exposure of a background is made appropriate by long-time exposure. However, in slow sync photography, there is a problem that a so-called camera shake image is photographed unless the imaging device is fixed with a tripod. In addition, in slow sync photography, since long exposure is performed, there is a problem that a blurred image is photographed when the subject is moving.

  Japanese Patent Application Laid-Open No. 2004-228688 describes a method of setting a high shutter speed by compensating for the amount of light obtained by long-time exposure after flash emission during exposure, thereby preventing a camera shake image or a subject image from being shot. Is disclosed. Patent Document 2 discloses a method for reducing the exposure time and flash emission amount, and compensating for the amount of light that is insufficient after exposure with a gain, thereby preventing blurring images and making the main subject and background brightness appropriate. Has been.

JP 2004-32681 A JP 7-2222049 A

  However, in the technique described in Patent Document 1, the same amount of light as that obtained during long-time exposure is obtained by performing gain increase during exposure. However, in actuality, image data transferred after exposure is obtained. Therefore, there is a problem that the gain increase is not reflected in the original image. As a result, there is a problem that only the shutter speed becomes faster than before and the background is still taken dark. Further, in the technique described in Patent Document 2, the background where the flash light does not reach is compensated for by an increase in gain after exposure. However, the increase in gain causes a problem that noise in the entire image including the main subject increases. . Furthermore, if the gain is increased while the main subject is still exposed, the main subject will be overexposed, so it will be necessary to shoot with the flash emission level lower than the appropriate emission level. There arises a problem that the flash performance cannot be maximized.

  Accordingly, the present invention has been made in view of the above problems, and an object of the present invention is to make an entire image including a main subject without degrading image quality when shooting with a flash. It is an object of the present invention to provide a new and improved imaging apparatus, imaging method, and program capable of taking a picture with a desired luminance.

  In order to solve the above-described problem, according to an aspect of the present invention, a luminance difference of a main subject region between a first shooting that is shot with a flash and a second shooting that is shot without a flash is calculated. A main subject luminance difference calculating unit, a pixel luminance difference calculating unit for calculating a luminance difference between the pixels in the first shooting and the second shooting, a luminance difference in the main subject region, and a pixel of each pixel An imaging device is provided that includes an amplification amount calculation unit that calculates a luminance amplification amount of each pixel based on the luminance difference.

  The main subject area is a predetermined area including a pixel having a maximum luminance difference between the first shooting and the second shooting.

  The amplification amount calculation unit calculates the luminance amplification amount based on a necessary light amount of each pixel obtained from a difference between a luminance difference of the main subject region and a pixel luminance difference of each pixel.

  The amplification amount calculation unit includes a correction unit that corrects the necessary light amount of each pixel with a coefficient corresponding to the luminance of each pixel.

  In addition, an appropriate AE calculation unit that calculates an appropriate exposure amount from an image signal obtained from the image sensor, and a flash emission when the subject area is determined to be lower than a specific brightness by the appropriate AE calculation unit. When a shooting control is performed and it is determined that the subject area has a higher brightness than the specific brightness, a flash control unit is provided that controls the flash emission so as to perform a shooting control that does not emit the flash.

  The flash control unit includes a dimming sensor unit that determines whether flash light reaches the subject, and the flash control unit determines that the subject region has a lower luminance than a specific luminance by the appropriate AE calculation unit, and the dimming control unit. When it is determined by the optical sensor unit that flash light reaches the subject, shooting control with flash emission is performed, the subject area is determined to be higher than a specific luminance by the appropriate AE calculation means, and the light control sensor When it is determined by the unit that the flash light does not reach the subject, shooting control is performed so that the flash is not emitted.

  In order to solve the above-described problem, according to another aspect of the present invention, the luminance of the main subject region in the first shooting for shooting with flash emission and the second shooting for shooting without flash emission A step of calculating a difference; a step of calculating a luminance difference of each pixel in the first shooting and the second shooting; a luminance difference of the main subject region; and a pixel luminance difference of the pixels. And a step of calculating a luminance amplification amount of each pixel.

  In order to solve the above-described problem, according to another aspect of the present invention, the luminance of the main subject region in the first shooting for shooting with flash emission and the second shooting for shooting without flash emission Based on the means for calculating the difference, the means for calculating the luminance difference of each pixel in the first imaging and the second imaging, the luminance difference of the main subject area, and the pixel luminance difference of the pixels, A program for causing a computer to function as a means for calculating the luminance amplification amount of a pixel is provided.

  According to the present invention, it is possible to shoot an entire image including a main subject with a desired luminance without degrading image quality when shooting with a flash.

1 is a schematic diagram illustrating a configuration of an imaging apparatus according to an embodiment of the present invention. It is a figure which shows typically the effect which this embodiment realizes. It is a schematic diagram for demonstrating the calculation method of the gain for every pixel which concerns on this embodiment. It is a schematic diagram for demonstrating the calculation method of the gain for every pixel which concerns on this embodiment. It is a schematic diagram for demonstrating the calculation method of the gain for every pixel which concerns on this embodiment. It is a schematic diagram for demonstrating the calculation method of the gain for every pixel which concerns on this embodiment. It is a schematic diagram which shows the coefficient reference table for correct | amending a gain. It is a flowchart which shows the procedure of the process by the imaging device of this embodiment.

  Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In addition, in this specification and drawing, about the component which has the substantially same function structure, duplication description is abbreviate | omitted by attaching | subjecting the same code | symbol.

  FIG. 1 is a schematic diagram showing a configuration of an imaging apparatus 100 according to an embodiment of the present invention. FIG. 1 is a block diagram mainly related to an image processing pipeline (Pipe Line) in a digital still camera according to the present embodiment. As shown in FIG. 1, an imaging apparatus 100 according to an embodiment of the present invention includes a zoom lens (group) 102, a diaphragm / shutter 104, a focus lens (group) 108, and a CCD (Charge Coupled) as an imaging device. Devices) element 110, amplifier-integrated CDS (Correlated Double Sampling) circuit 112, A / D converter 114, image input controller 116, AE evaluation value calculation circuit 118, image processing circuit 120, and compression processing Unit 122, LCD (Liquid Crystal Display) driver 124, LCD 126, timing generator 128, pixel amplification unit 130, CPU (Central Processing Unit) 150, memory 134, and VRAM (Video Random Access Memory) 136 , Media controller 138, recording medium 140, motor 142, driver 144, dimming sensor 1 0 and is configured to have a flash portion 170, a.

  The zoom lens 102, the iris / shutter 104, and the focus lens 108 are driven via an actuator 142 controlled by each driver 144. The zoom lens 102 is a lens that is moved back and forth in the optical axis direction and continuously changes the focal length. The diaphragm shutter 104 controls the exposure time for the CCD element 110 and adjusts the amount of light incident on the CCD element 110 when an image is captured. The focus lens 108 is moved back and forth in the optical axis direction, and adjusts the focus of the subject image formed on the CCD element 110.

  The CCD element 110 is an element for converting light incident through the zoom lens 102, the diaphragm shutter 104 and the focus lens 108 into an electrical signal.

  In the present embodiment, the CCD element 110 is used as the imaging element. However, the present invention is not limited to this example, and a CMOS (Complementary Metal Oxide Semiconductor) element may be used instead of the CCD element 110. Other image sensors may be used. Since the CMOS element can convert the image light of the subject into an electric signal at a higher speed than the CCD element, it is possible to shorten the time from when the subject is imaged to when the image is combined.

  The CDS circuit 112 is a circuit in which a CDS circuit that is a kind of sampling circuit that removes noise from the electrical signal output from the CCD element 110 and an amplifier that amplifies the electrical signal after removing the noise are integrated. . In the present embodiment, a circuit in which the CDS circuit and the amplifier are integrated is used. However, the CDS circuit and the amplifier may be configured as separate circuits.

  The A / D converter 114 converts the electrical signal generated by the CCD element 110 into a digital signal, and generates raw image data (raw data, image data). The image input controller 116 controls input of raw image data (image data) generated by the A / D converter 114 to the memory 134.

  The AE evaluation value calculation circuit 118 calculates an AE evaluation value as road light amount information from the image data output from the CCD element 110. Further, the image processing circuit 120 performs processing such as light amount gain correction, image edge processing (outline enhancement processing), white balance adjustment, and the like on the image data output from the CCD element 110.

  The compression processing unit 122 performs compression processing for compressing the image data output from the CCD element 110 into image data in an appropriate format. The image compression format may be a reversible format or an irreversible format. As an example of an appropriate format, it may be converted into a JPEG (Joint Photographic Experts Group) format or JPEG2000 format.

  The LCD 126 performs live view display before performing an imaging operation, various setting screens of the imaging apparatus 100, display of captured images, and the like. Display of image data and various information of the imaging apparatus 100 on the LCD 126 is performed via the LCD driver 124.

  The timing generator 128 inputs a timing signal to the CCD element 110. That is, the drive of the CCD element 110 is controlled by the timing signal from the timing generator 128. The timing generator 128 can cause the CCD element 110 to have an electronic shutter function by causing the image light from the subject to enter during the time that the CCD element 110 is driven.

  The memory 134 temporarily stores captured images. The memory 134 has a storage capacity sufficient to store a plurality of images. Reading and writing of images to and from the memory 134 is controlled by the image input controller 116.

  The pixel amplification unit 130 is a component that calculates the amplification amount (gain) of the pixel. As will be described later, the first imaging that causes the flash unit 170 to emit light and the second imaging that does not cause the flash unit 170 to emit light. From the result, the luminance amplification amount of each pixel is calculated. The pixel amplification unit 130 includes a main subject luminance difference calculation unit 131 that calculates a luminance difference in the main subject region and a pixel luminance difference calculation unit 132 that calculates a luminance difference between the pixels in the first shooting and the second shooting. Prepare. In addition, an amplification amount calculation unit 133 that calculates a luminance amplification amount (gain) of each pixel based on the calculated luminance difference of the main subject region and the pixel luminance difference of each pixel is provided.

  The VRAM 136 holds contents to be displayed on the LCD 126, and the resolution and the maximum number of colors of the LCD 126 depend on the capacity of the VRAM 136.

  The recording medium 140 records the captured image. Input / output to / from the recording medium 140 is controlled by the media controller 138. As the recording medium 140, a memory card which is a card-type storage device that records data in a flash memory can be used.

  The CPU 150 issues a signal-related command to the CCD element 110, the CDS circuit 112, and the like, and issues an operating-system command according to the operation of the operation unit and the shutter button. In the present embodiment, only one CPU is included, but a signal-related command and an operation-related command may be executed by separate CPUs.

  The CPU 150 includes a proper AE calculation unit 152 and a flash control unit 154. The appropriate AE calculation unit 152 performs automatic exposure with the imaging apparatus 100 and acquires an EV (Exposure Value) value. The appropriate AE calculation unit 152 calculates an AE (Auto Exposure) evaluation value of the photographed image. As described above, the AE evaluation value can also be calculated by the AE evaluation value calculation circuit 118. Further, the appropriate AE calculation unit 152 calculates an AE evaluation value according to the detection value of the light control sensor 160.

  The flash control unit 154 controls the light emission of the flash 170 based on the AE evaluation value calculated by the appropriate AE calculation unit 152. In addition, the appropriate AE calculation unit 152 determines an aperture value and a shutter speed when photographing the subject based on the AE evaluation value. The driver 144 is controlled based on the determined aperture value and shutter speed, and drives the motor 142. As a result, the diaphragm / shutter included in the lens optical system is driven.

  The light control sensor 160 is a block that determines whether flash light from the flash unit 170 reaches the subject. If the appropriate AE calculation unit 152 determines that the subject area is lower than the specific luminance, and the light control sensor 160 determines that the flash light reaches the subject, the CPU 150 controls the flash unit under the control of the flash control unit 154. 170 is caused to emit light. On the other hand, when the appropriate AE calculation unit 152 determines that the subject area is lower than the specific luminance and the light control sensor 160 determines that the flash light does not reach the subject, the CPU 150 controls the flash control unit 154. Therefore, the flash unit 170 does not emit light.

  An RGB image signal obtained from an analog front end (AFE) including an image sensor 110 such as CCD or CMOS shown in FIG. 1 is mainly processed by an image processing circuit 120 in an image front process such as defective pixel correction and black level correction. (Image front process) processing is performed, and further, electronic processing such as white balance correction processing, Bayer color interpolation (Demosaic) processing, color correction processing, and gamma correction processing is performed, and image recording is performed. Is done. Each functional block shown in FIG. 1 can be configured by a circuit (hardware) or a CPU 150 and a program (software) for causing the CPU 150 to function. The program is a memory included in the imaging apparatus 100 or an external device. Can be stored in a recording medium such as a memory.

  In the present embodiment, by calculating an appropriate gain (Gain) for each pixel with respect to a captured image at the time of flash emission, even a subject to which light by the flash unit 170 does not reach can be captured at a desired luminance. enable. FIG. 2 is a diagram schematically showing the effect realized by the present embodiment, and shows the scenery in a state where the “sky” is getting darker, such as at dusk.

  Here, the upper left figure of FIG. 2 shows the scenery that can be seen with the naked eye. In this way, even with the naked eye, even at dusk, the person located in front of the right side and the background “lawn” and “tree” behind it are recognized as having relatively high luminance.

  Further, the lower left diagram in FIG. 2 shows an image obtained by flash photography in which long exposure is performed. In this case, the “person” on the right side is photographed in a state where the brightness is high because the flash is irradiated. In addition, the background “lawn” and “tree” are photographed in a state where the brightness is high by long-time exposure, although the flash light does not reach sufficiently.

  The upper right diagram in FIG. 2 shows an image obtained by flash photography without long exposure. In this case, the “person” on the right side is photographed in a state where the brightness is high because the flash is irradiated. On the other hand, “grass” and “trees” in the background are photographed with very low brightness because the flash light does not reach them. Therefore, most of the background becomes dark, resulting in an image in which “lawn”, “tree” and the like cannot be recognized.

  On the other hand, the lower right diagram of FIG. 2 shows an image obtained by flash photography without long exposure according to the present embodiment. As described above, in the present embodiment, by calculating an appropriate gain for each pixel with respect to a captured image at the time of flash emission, it is equivalent to a case where a long-time exposure is performed even on a subject that does not reach the flash light. Shooting at a desired luminance is possible.

  Hereinafter, a method for calculating the gain for each pixel according to the present embodiment will be described with reference to FIGS. 3A to 3D. FIG. 3A shows the positions of the areas “3B”, “3C”, and “3D” when the subject described in FIG. 2 is photographed. As will be described later, the processing according to FIG. 3B is performed for the main subject region “3B”, the processing according to FIG. 3C is performed for the region “3C”, and the processing according to FIG. 3D is performed for the region “3D”.

  3B to 3D are diagrams schematically illustrating processing of the pixel amplification unit 130 that calculates the amplification amount (gain) of the pixel in the present embodiment. First, based on the image signal (AE evaluation value) obtained from the image sensor 110, when the appropriate AE calculation unit 152 determines that the light amount is insufficient, it sets a shutter (Shutter) speed at which camera shake and subject shake do not occur. . Further, the flash control unit 154 determines a flash light amount that provides proper exposure for the entire image. Then, the flash control unit 154 causes the flash unit 170 to emit light based on the determined flash light amount. As a result, the first shooting is performed in which the flash is emitted for shooting.

  Next, the second shooting is performed under the above exposure conditions without shooting the flash. Then, the pixel having the largest difference in flash reflection amount is specified from the raw data (Raw Data) obtained in the first photographing and the second photographing at this time.

  Here, it is assumed that the luminance of a specific pixel in the first shooting is An, and the luminance of a specific pixel in the second shooting is Bn. Further, as shown in the following (Expression 1), the difference between An (logarithmically converted value) and Bn (logarithmically converted value) is ΔYn. Here, n is a value that changes for each pixel. If RawData has 100 pixels, n changes from 0 to 99.

  Based on RawData of the first imaging, an area having a pixel where ΔYn is the maximum value as a central coordinate is M1, and the luminance of each pixel in the area M1 is averaged by the following (Equation 2) to obtain the first average luminance YA1 is obtained. Here, the width of the region M1 is w and the height is h. Further, the size (Size) of the region M1 is not particularly limited, but can be a value of about 5 × 5 = 25 pixels as an example.

  From the raw data of the second imaging, an area having the pixel where ΔYn is the maximum value as the center coordinate is M2, and YA2, which is the second average luminance, is obtained from the area M2. Note that the size (size) of the region is set to be the same size as (Expression 2), and the regions M1 and M2 are the same region.

  Here, as in the following (Equation 4) and (Equation 5), a value obtained by logarithmically transforming the calculated YA1 is denoted by YF, and a value obtained by logarithmically transforming YA2 is denoted by YN.

  Here, as shown in the drawing of the main subject area in FIG. 3B, the amount of light YF in the flash emission is increased by the amount of flash emission compared to the luminance YN in flash emission.

  Next, the subject luminance difference YG between the first shooting and the second shooting is obtained from the following (Equation 6) from YN and YF obtained by (Equation 4) and (Equation 5). Further, the condition at this time is YF> YN. If this condition is true, (Equation 6) is satisfied, and if it is false, YG = 0.

  As shown in FIG. 3B, the value of YG corresponds to the amount of light increased by the flash, and this value is the reference. The calculation of the subject luminance difference YG as described above is performed by the main subject luminance difference calculation unit 131 of the pixel amplification unit 130.

  Next, for all pixels, luminance values obtained by the first photographing and the second photographing are obtained. The brightness value of the specific pixel of the first photographing calculated here is P1, and a value obtained by logarithmically converting this value is PF. In addition, the luminance value of the specific pixel in the second photographing is P2, and a value obtained by logarithmically converting this value is PN.

  Next, the pixel luminance difference between the first photographing and the second photographing of the specific pixel is obtained from the PF and PN obtained by (Expression 7) and (Expression 8). This pixel luminance difference is defined as PG, and is obtained from the following (Equation 9). Further, the condition at this time is PF> PN, (Equation 9) is satisfied if true, and PG = 0 if false.

  The value of PG is calculated for each of all pixels. The calculation of the pixel luminance difference PG is performed by the pixel luminance difference calculation unit 132 of the pixel amplification unit 130. When the pixel luminance difference PG is obtained for all the pixels, next, the necessary light amount of the specific pixel is obtained from (Expression 6) and (Expression 9). The required light quantity of the specific pixel calculated here is FG, and is obtained from the following (Equation 10). Further, the condition at this time is YG> PG, (Equation 10) is satisfied if true, and FG = 0 if false.

  Here, as described above, the value of PG is a value obtained for each pixel, while the value of YG is a value obtained for the main subject region. Therefore, FG, which is the difference between YG and PG, represents an insufficient amount of light for the area other than the main subject area.

  Referring to FIG. 3A, the flash light reaches the “tree” in the region “3C” that appears in the background on the left side of the main subject (right person's face). This is a medium distance subject. As for the pixel corresponding to such a subject, as shown in FIG. 3C, the luminance PN when the flash is not emitted and the luminance PF when the flash is emitted are both lower than the luminance YN and YF of the main subject area, and the flash emission. The amount of increase in luminance (pixel luminance difference PG) due to is also lower than YG. For this reason, by calculating the difference between YG and PG, the required light amount FG of the medium-distance subject can be obtained, and the amplification amount (gain) of the pixel corresponding to the medium-distance subject can be obtained based on this. . Then, by correcting the luminance of the pixels of the medium-distance subject based on this gain, the luminance of the medium-distance subject can be increased to the same level as the luminance of the main subject area.

  Similar processing is performed for pixels corresponding to a long-distance subject. In the image shown in FIG. 3A, the flash light does not reach the “cloud” in the region “3D” that is visible in the upper right of the main subject (right person's face). There is no far-distance subject. For pixels corresponding to such a subject, as shown in FIG. 3D, the luminance PN when the flash is not emitted and the luminance PF when the flash is emitted are both lower than the luminances YN and YF of the main subject region, and the flash light Therefore, the amount of increase in luminance (pixel luminance difference PG) is zero due to flash emission. Therefore, by calculating the difference between YG and PG (= 0), the gain corresponding to the required light amount FG of the subject at a long distance can be obtained, and the luminance of the pixel of the subject at a long distance is corrected based on this. As a result, the luminance of the subject at a long distance can be increased to the same level as the luminance of the main subject area.

  As described above, the required amount of light FG of each pixel is obtained based on the main subject luminance difference, and the luminance of each pixel is corrected with a gain corresponding to the required amount of light FG, so that the main distance can also be obtained for subjects at medium and long distances. The same luminance as the subject can be ensured. The calculation of the required light amount FG and the calculation of the gain corresponding to the required light amount FG are performed by the amplification amount calculation unit 133 of the pixel amplification unit 130. As a result, as described with reference to FIG. 2, it is possible to increase the luminance even in regions other than the main subject region.

  Next, a coefficient reference table for correcting the gain will be described with reference to FIG. FIG. 4 is a schematic diagram illustrating an example of a coefficient reference table for luminance values of specific pixels. When the luminance is corrected for each pixel based on the required light amount FG, it is assumed that the image becomes unnatural when the gain is increased and the luminance is increased in the dark luminance pixel originally close to “black”. Therefore, a coefficient k for adjusting the balance between the low luminance pixel and the appropriate gain is obtained from the table shown in FIG. 4, and a final gain (FinalGain) that is a multiplier for final amplification by the pixel amplifying unit 130 is expressed by the following ( It is obtained from equation 11). Further, the condition at this time is FG> 0, and when this condition G is true, (Equation 11) is satisfied, and when it is false, k = 1.

  Then, the final gain obtained in (Equation 11) is applied to all the pixels of the image signal obtained in the first shooting by the pixel amplifying unit 130, thereby obtaining an image with optimum brightness. It becomes possible. The correction of the gain using the coefficient k is performed by a correction unit provided in the amplification amount calculation unit 133.

  Next, a processing procedure according to the present embodiment will be described with reference to the flowchart of FIG. First, in step S10, it is determined whether or not the user has performed a shutter operation. If the shutter operation has been performed, the process proceeds to step S12. If no shutter operation is performed, the process waits in step S10.

  Next, in step S12, the appropriate AE calculation unit 152 sets a shutter speed at which camera shake and subject blur do not occur. Next, in step S14, the flash unit 170 is caused to emit light to perform first photographing. Next, in step S16, the second photographing is performed without causing the flash unit 172 to emit light.

  Next, in step S18, a pixel having the maximum flash reflection amount is detected from the first shooting and the second shooting. At this time, as described above, ΔYn is calculated for all the pixels, and the pixel having the maximum ΔYn is found. Next, in step S20, the main subject luminance difference YG is calculated from the pixel region centered on the pixel detected in step S18.

  Thereafter, the loop of steps S22 to S32 is processed for all pixels. First, in step S24, a pixel luminance difference PG between the first shooting and the second shooting is calculated for a specific pixel. In the next step S26, the necessary light amount FG of this specific pixel is calculated from the main subject luminance difference YG and the pixel luminance difference PG. In the next step S28, the necessary light amount FG is converted into a gain. Here, the final gain is calculated from (Equation 11) described above. In the next step S30, pixel amplification is performed by multiplying the luminance value of the specific pixel by the final gain obtained in step S28. When the loop processing of steps S22 to S32 is completed for one pixel, the loop processing is performed for the next specific pixel, and pixel amplification is performed on all the pixels.

  As described above, according to the present embodiment, it is possible to eliminate camera shake and subject blur due to long exposure by shooting at a shutter speed at which camera shake and subject blur do not occur. It is possible to solve the problem of shooting a dark background by calculating the luminance difference of the main subject and the luminance difference for each pixel in the non-luminous image, and calculating and applying the Gain value for each pixel. become. Furthermore, according to the present embodiment, it is possible to shoot without degrading the image quality of the main subject without impairing the flash performance and by applying the gain calculated for other than the main subject. An image in which the brightness of the subject and the background is appropriate can be provided.

  The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious that a person having ordinary knowledge in the technical field to which the present invention pertains can come up with various changes or modifications within the scope of the technical idea described in the claims. Of course, it is understood that these also belong to the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 100 Imaging device 130 Pixel amplification part 131 Main subject luminance difference calculation part 132 Pixel luminance difference calculation part 133 Amplification amount calculation part

Claims (8)

A main subject luminance difference calculation unit for calculating a luminance difference of the main subject region between the first shooting for shooting with flash emission and the second shooting for shooting without flash emission;
A pixel luminance difference calculating unit that calculates a luminance difference between the pixels in the first imaging and the second imaging;
An amplification amount calculation unit that calculates a luminance amplification amount of each pixel based on the luminance difference of the main subject region and the pixel luminance difference of each pixel;
An imaging apparatus comprising:   The imaging apparatus according to claim 1, wherein the main subject area is a predetermined area including a pixel having a maximum luminance difference between the first shooting and the second shooting.   The amplification amount calculation unit calculates the luminance amplification amount based on a necessary light amount of each pixel obtained from a difference between a luminance difference of the main subject region and a pixel luminance difference of the pixels. The imaging device according to claim 1.   The imaging apparatus according to claim 3, wherein the amplification amount calculation unit includes a correction unit that corrects a necessary light amount of each pixel with a coefficient corresponding to a luminance of each pixel. An appropriate AE calculation unit for calculating an appropriate exposure amount from an image signal obtained from the image sensor;
When the subject area is determined to be lower than the specific brightness by the appropriate AE calculation means, shooting control with flash emission is performed, and when the subject area is determined to be higher than the specific brightness, flash emission is performed. The imaging apparatus according to claim 1, further comprising: a flash control unit that controls flash emission so as to perform shooting control that is not performed. A light control sensor unit for determining whether flash light reaches the subject;
The flash controller is
When the appropriate AE calculation means determines that the subject area is lower than the specific brightness, and the light control sensor unit determines that flash light reaches the subject, performs shooting control with flash emission,
6. When the appropriate AE calculation means determines that the subject area has a higher brightness than a specific brightness, and the light control sensor unit determines that flash light does not reach the subject, shooting control that does not emit flash is performed. The imaging device described in 1. Calculating a luminance difference of the main subject region between the first shooting for shooting with flash emission and the second shooting for shooting without flash emission;
Calculating a luminance difference of each pixel in the first photographing and the second photographing;
Calculating a luminance amplification amount of each pixel based on a luminance difference of the main subject region and a pixel luminance difference of each pixel;
An imaging method comprising: Means for calculating a luminance difference of the main subject area between the first shooting for shooting with flash emission and the second shooting for shooting without flash emission;
Means for calculating a luminance difference of each pixel in the first photographing and the second photographing;
Means for calculating a luminance amplification amount of each pixel based on a luminance difference of the main subject region and a pixel luminance difference of the pixels;
As a program to make the computer function.

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