JP4816363B2 - Correction necessity determination device, camera, and correction necessity determination program - Google Patents

Description

The present invention relates to a correction necessity determination device, a camera, and a correction necessity determination program .

2. Description of the Related Art Conventionally, it is known to detect the traveling state of the shutter front curtain and the rear curtain and adjust the traveling state to prevent the occurrence of uneven exposure (for example, Patent Document 1).
JP 2001-235777 A

  However, since the shutter front curtain and the rear curtain are moved without interfering with each other, they are arranged at a predetermined interval in the optical axis direction. Therefore, there is a problem that uneven exposure occurs due to the inter-curtain distance.

The correction necessity determination apparatus according to claim 1, wherein the image acquisition unit acquires an image captured by a camera having a focal plane shutter in which a front curtain and a rear curtain are disposed at a predetermined interval in the optical axis direction. And determining means for determining whether or not to correct the uneven exposure caused in the image due to the interval between the front curtain and the rear curtain based on the imaging sensitivity and the focal length when the image is captured. It is characterized by providing.
The correction necessity determination device according to claim 2 is the correction necessity determination device according to claim 1, wherein the determination unit determines whether the correction is necessary based on the imaging sensitivity, and subsequently the focus. The necessity of the correction is determined based on the distance.
A correction necessity determination device according to claim 3 is a correction for correcting the exposure unevenness of the image when the correction necessity determination device according to claim 1 or 2 determines that the correction is necessary. The apparatus further comprises means.
According to a fourth aspect of the present invention, there is provided a correction necessity determining apparatus according to the third aspect, wherein the correction necessity determination apparatus determines a correction processing content by the correction means based on the imaging sensitivity and the focal length. Is further provided.
According to a fifth aspect of the present invention, there is provided a correction necessity determination device according to the third or fourth aspect, further comprising a recording means for recording the image corrected by the correction means on a recording medium. It is characterized by.
The correction necessity determination device according to claim 6 is the correction necessity determination device according to claim 1 or 2, wherein the image is associated with the necessity of correction determined by the determination means. Recording means for recording on a recording medium.
The correction necessity determination device according to claim 7 is the correction necessity determination device according to any one of claims 1 to 6, wherein the determination means includes the imaging sensitivity, the focal length, and an aperture value. The necessity of the correction is determined by a combination of the above.
The camera according to claim 8 includes an image sensor and the correction necessity determination device according to any one of claims 1 to 7, wherein the image acquisition unit is imaged by the image sensor. An image is acquired as the image.
The correction necessity determination program according to claim 9 is an image acquisition process for acquiring an image photographed by a camera having a focal plane shutter in which a front curtain and a rear curtain are disposed at a predetermined interval in the optical axis direction. And a determination process for determining whether or not to correct exposure unevenness caused in the image due to an interval between the front curtain and the rear curtain based on an imaging sensitivity and a focal length when the image is captured. Let the computer run.

According to the onset bright, it is possible to determine the constant necessity of correction of exposure unevenness resulting from the interval in the optical axis direction of the front and rear curtains.

Hereinafter, a camera according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram for explaining a main configuration of an electronic camera according to an embodiment. A lens barrel 110 having a photographic lens 120 is attached to the camera body 10 in a replaceable manner. In the lens barrel 110, a photographing lens 120 including a lens group 120a to 120c and a diaphragm 140 are provided. The diaphragm 140 is driven by the diaphragm control device 130.

  Inside the camera body 10, an image sensor 20 for imaging a subject is provided. As the image sensor 20, a CCD, a CMOS, or the like is used. A quick return mirror 70 is provided between the photographing lens 120 and the image sensor 20 to reflect the subject light that has passed through the photographing lens 120 to the viewfinder optical system.

  The subject light reflected by the quick return mirror 70 forms an image on a focusing screen 90 provided at a position optically equivalent to the image sensor 20. The subject image formed on the focusing screen 90 is observed by the photographer through the eyepiece 50 from the pentaprism 30 and is formed on the light receiving surface of the photometric sensor 40 from the pentaprism 30.

  At the time of shooting, the quick return mirror 70 is moved from the optical path of the subject light to the outside of the optical path (broken line portion in FIG. 1) by the mirror driving device 201, and the subject image is formed on the image sensor 20. A shutter 19 is provided immediately before the image sensor 20. As shown in FIG. 2, the shutter 19 is a focal plane shutter having a front curtain 191 and a rear curtain 192. Before the release, the front curtain 191 unfolds on the aperture portion AP and light to the image sensor 20 is obtained. , The rear curtain 192 is folded over the aperture AP. When the front curtain 191 starts to travel after the release, the rear curtain 192 starts to travel after the time determined by the shutter speed. For example, in the case of a high shutter speed such as 1/8000 seconds, so-called slit traveling (slit exposure) in which the rear curtain 192 travels slightly behind the traveling of the front curtain 191.

  The image sensor 20 accumulates signal charges corresponding to the subject image formed on the imaging surface and sweeps out the accumulated charges. The A / D conversion circuit 203 converts the analog image signal output from the image sensor 20 into a digital image. The signal is converted into a signal and output to the image processing circuit 204. The image processing circuit 204 performs image processing such as white balance adjustment, sharpness adjustment, gamma correction, and gradation adjustment on the input digital image signal and outputs the processed image data to the control circuit 200.

  The control circuit 200 includes a CPU, ROM, RAM, and various peripheral circuits, and is a microcomputer that controls the electronic camera. The digital image signal input from the image processing circuit 204 is compressed by a method such as the JPEG format and displayed on a liquid crystal monitor 208 constituted by an LCD or the like.

  The photometric circuit 207 A / D converts the photometric signal obtained from the photometric sensor 40 and outputs it to the control circuit 200. The control circuit 200 calculates the shutter speed and the aperture value of the photographing lens 120 based on the luminance of the subject and the imaging sensitivity (ISO sensitivity) calculated based on the input photometric signal. The calculation result is output to the shutter 19 and the aperture controller 130 to control the shutter speed Tv and the aperture value Av.

  The camera is provided with a power switch 3, a release button 4, and a setting switch 5 for performing various settings. The half-press switch 47 and the full-press switch 48 that are turned on / off in conjunction with the pressing operation of the release button 4 output an on signal or an off signal to the control circuit 200, respectively.

  When the release button 4 is fully pressed and an ON signal is input from the full-press switch 48, the front curtain 191 travels like the front curtain travel curve 1 shown in FIG. Travel like this. FIG. 2 shows a case where the shutter speed is 1/8000 second, and the time t0 (0.122 ms) at the center of the photographing screen 193 is the desired exposure time at the shutter time 1/8000 seconds. The subject light Bp incident on the upper part of the photographing screen 193 is incident obliquely as shown in FIG. Therefore, when the front curtain 191 travels to Ya, the subject light Bp is incident on the imaging surface 194 and exposure is started. Further, when the rear curtain 192 travels to Yb, the incidence of the subject light Bp is blocked, and the exposure ends. Thus, since the exposure start and end positions are different in the height direction of the shooting screen 193, the exposure time is t1 (0.191 ms). Similarly, in the lower part of the shooting screen 193, since the subject light Bb is obliquely incident, exposure starts when the front curtain 191 travels to Yc, and exposure ends when the rear curtain 192 travels to Yd. Becomes t2 (0.089 ms).

  Accordingly, subject light from the photographing lens 120 is incident obliquely like Bp and Bb at the upper and lower portions of the photographing screen 193, and the front curtain 191 and the rear curtain 192 are spaced by Δd in the optical axis direction. Due to the arrangement, the exposure time is t1 in the upper part of the photographing screen 193, and the exposure time is t2 in the lower part, resulting in uneven exposure. In other words, the upper part of the image is overexposed and the lower part is underexposed with respect to the exposure time t0 at the center of the photographing screen 193. FIG. 2 shows the relationship between the exposure time and the front curtain 191 and the rear curtain 192 when a standard lens is used as the photographic lens 120.

  When the correction mode is selected by operating the setting switch 5 after shooting, the control circuit 200 reads the shot image data recorded on the recording medium 205 and corrects the exposure unevenness for the read shot image data. Do. At that time, correction is performed because the influence of exposure unevenness is significant based on the shooting conditions when the image is shot, which is recorded in association with the shot image data, that is, the data indicating the focal length and ISO sensitivity. Whether or not is necessary. If it is determined that correction is necessary, the captured image data is subjected to image processing by an optimal correction process among the correction processes A, B, and C according to the determination result. Recorded on the recording medium 205.

The correction processes A to C are determined based on exposure unevenness generated in a sample image obtained by photographing an achromatic subject such as white or gray under various photographing conditions.
In the sample image, as shown in FIG. 3, when a wide-angle lens with a short focal length is used, the exposure time is t3 at the upper part of the photographing screen 193, for example, 0.214 ms, and the exposure time is t4, for example, 0. Since the time is 076 ms, the influence of exposure unevenness at the top and bottom of the shooting screen 193 becomes more significant than in the case of FIG. As shown in FIG. 4, when a telephoto lens having a long focal length is used, the exposure time is t5 at the upper part of the photographing screen 193, for example, 0.140 ms, and the exposure time is t6, for example, 0.115 ms at the lower part. As a result, the influence of uneven exposure on the top and bottom of the photographing screen 193 is lower than in the case of FIG.

  Differences in ISO sensitivity also affect the occurrence of uneven exposure. FIG. 5 is a graph showing the relationship between the exposure time and the charge accumulated in the image sensor 20. The solid line indicates the ISO sensitivity 100, the alternate long and short dash line indicates the ISO sensitivity 400, and the alternate long and two short dashes line indicates the ISO sensitivity 1600. As shown in FIG. 5, in the range of the exposure time A, the charge amount C accumulated in the image sensor 20 when the ISO sensitivity is 1600 is larger than the charge amount B accumulated when the ISO sensitivity is 100. That is, the greater the ISO sensitivity, the more conspicuous the influence on the exposure unevenness (the larger the luminance difference on the image).

As described above, the correction formula for performing the correction process is determined based on the luminance in the sample image affected by the focal length and ISO sensitivity. The brightness of the sample image is as indicated by brightness curves A to C as shown in FIG. 6A, where the vertical axis represents the height Y in the vertical direction (shutter travel direction) of the shooting screen 193 and the horizontal axis represents the brightness I. Indicated. The luminance curve A is obtained when a sample image is taken under an imaging condition where the ISO sensitivity is 200 or less and the focal length is less than 35 mm. The luminance curve B is obtained when the ISO sensitivity is 400 or less and the focal length is less than 50 mm. The luminance curve C shows a case where the ISO sensitivity is 400 or more and the focal length is less than 85 mm. Both curves show a tendency that the luminance value increases toward the top of the screen. The luminance curve A is represented by a function f _1A (Y) of the screen height Y. Similarly, the luminance curves B and C are represented by Y functions f _1B (Y) and f _1C (Y), respectively. Such exposure unevenness has substantially uniform luminance values in the vertical direction of the screen as indicated by the luminance curves A, B, and C in FIG. 6A as the luminance curves Ah, Bh, and Ch in FIG. 6B, respectively. A distributed curve can be corrected as a target curve. That is, when the captured image is represented as I (X, Y), the captured image I (X, Y) is corrected by, for example, the following expressions (1) to (3), and the corrected image Ih _A (X, Y) is corrected. Y), Ih _B (X, Y), Ih _C (X, Y) are obtained.
Ih _A (X, Y) = I (X, Y) / f _1A (Y) (1)
Ih _B (X, Y) = I (X, Y) / f _1B (Y) (2)
Ih _C (X, Y) = I (X, Y) / f _1C (Y) (3)
Note that (X, Y) is the coordinates of each pixel on the imaging screen 193, and I (X, Y) is the luminance value at the coordinates (X, Y).

Note that the values of the points in the corrected images Ih _A (X, Y), Ih _B (X, Y), and Ih _C (X, Y) obtained by the equations (1) to (3) are the values of the captured image I ( Since (X, Y) is divided by f _1A (Y) to f _1C (Y), there may be a small value. In that case, an image CIh _A obtained by multiplying each point of the corrected images Ih _A (X, Y), Ih _B (X, Y), and Ih _C (X, Y) by one or more predetermined coefficients C. (X, Y), CIh _B (X, Y), and CIh _C (X, Y) may be used as corrected images. As the coefficient C, an average value of the luminance curve A or the like may be used.

  Expressions (1) to (3) set as described above are stored in a predetermined storage area as correction processes A, B, and C, respectively. When performing the correction process, an optimum correction formula is read out from these correction formulas.

The camera correction operation in the embodiment described above will be described with reference to the flowchart shown in FIG. A program for performing each process of FIG. 7 is stored in a memory (not shown) in the control circuit 200, and is activated when the correction mode is selected by the setting switch 5.
In step S110, the captured image data is read from the recording medium 205, and the process proceeds to step S111. In step S111, it is determined whether the ISO sensitivity of the captured image is 100 or less based on the captured image data. If the ISO sensitivity is 100 or less, an affirmative determination is made in step S111, and the process advances to step S120 without performing exposure unevenness correction processing. If the ISO sensitivity exceeds 100, a negative determination is made in step S111 and the process proceeds to step S112.

  In step S112, it is determined whether the ISO sensitivity of the captured image is 200 or less. If the ISO sensitivity is 200 or less, an affirmative determination is made in step S112 and the process proceeds to step S113.

  In step S113, it is determined whether or not the captured image is captured at a focal length of 35 mm or more. If the focal length is greater than or equal to 35 mm, an affirmative determination is made in step S113, and the process advances to step S120 without performing exposure unevenness correction processing. If it is less than 35 mm, a negative determination is made in step S113 and the process proceeds to step S117. In step S117, the captured image data is subjected to image processing by correction processing A, and the process proceeds to step S120.

  If the ISO sensitivity exceeds 200, a negative determination is made in step S112 and the process proceeds to step S114. In step S114, it is determined whether the ISO sensitivity of the captured image is 400 or less. If the ISO sensitivity is 400 or less, an affirmative determination is made in step S114 and the process proceeds to step S115.

  In step S115, it is determined whether or not the captured image is captured at a focal length of 50 mm or more. If it is 50 mm or more, an affirmative determination is made in step S115, and the process advances to step S120 without performing exposure unevenness correction processing. If it is less than 50 mm, a negative determination is made in step S115 and the process proceeds to step S118. In step S118, the captured image data is subjected to image processing by correction processing B, and the process proceeds to step S120.

  If the ISO sensitivity exceeds 400, a negative determination is made in step S114 and the process proceeds to step S116. In step S116, it is determined whether or not the captured image is captured at a focal length of 85 mm or more. If it is greater than 85 mm, an affirmative determination is made in step S116, and the process advances to step S120 without performing exposure unevenness correction processing. If it is less than 85 mm, a negative determination is made in step S116 and the process proceeds to step S119. In step S119, the captured image data is subjected to image processing by correction processing C, and the process proceeds to step S120.

  In step S120, when correction processing is performed in steps S117, 118, and 119, the corrected image is stored in the recording medium 205 together with the image before correction, and the corrected image is subjected to exposure unevenness correction. Attach the data and finish the series of processing.

According to the camera of the embodiment described above, the following effects can be obtained.
(1) The necessity of correcting exposure unevenness due to the distance Δd between the front curtain 191 and the rear curtain 192 of the shutter 19 in the optical axis direction is determined based on the shooting conditions of the captured image, and it is determined that correction is necessary. In such a case, exposure unevenness correction processing was performed. Accordingly, it is possible to correct exposure so that uniform exposure can be performed on the entire screen by suppressing exposure unevenness occurring in the captured image by the structure of the shutter 19.

(2) A correction process is selected from a plurality of correction processes A to C determined by the shooting conditions based on the shooting conditions, and exposure unevenness correction is performed using the selected correction process. Therefore, it is possible to perform the optimum correction process for the exposure unevenness that occurs depending on the photographing conditions, so that the accuracy of the exposure unevenness correction process can be improved.

(3) A combination of imaging sensitivity (ISO sensitivity) and focal length is used to determine whether correction is necessary based on shooting conditions. Therefore, it is possible to select a correction process that finely corresponds to the occurrence of exposure unevenness, so that the accuracy of the exposure unevenness correction process can be improved.

The camera of the embodiment described above can be modified as follows.
(1) Although it has been described that the necessity of correction is determined using the focal length and ISO sensitivity as imaging conditions, the imaging conditions may be any of focal length, ISO sensitivity, aperture value, lens type, or these It may be a combination. For example, it may be determined that the correction is necessary when the ISO sensitivity is 1600 or more, and that correction is not necessary when the sensitivity is less than 1600, or that correction is necessary when the focal length is less than 85 mm, and that correction is not necessary when the focal length is 85 mm or more.

(2) Although the determination based on the focal length is performed after the determination based on the ISO sensitivity, the determination based on the ISO sensitivity may be performed after the determination based on the focal length.

(3) Instead of the shutter 19 having the rear curtain 192 disposed on the subject side, the front curtain 191 may be disposed on the subject side. In this case, the positions of overexposure and underexposure occurring on the shooting screen 193 are reversed between the upper and lower portions of the shooting screen 193. The traveling direction of the front curtain 191 and the rear curtain 192 of the shutter 19 may move from the bottom to the top instead of moving from the top to the bottom. Also in this case, the positions of overexposure and underexposure occurring on the shooting screen 193 are reversed between the upper and lower portions of the shooting screen 193.

(4) The exposure unevenness correction process has been described as being performed using the correction formulas (1) to (3), but the correction process is limited to the methods represented by the formulas (1) to (3). It is not a thing. For example, using the luminance value at the center Y of the photographing screen 193 as a reference value and using the difference ΔI (Y) between the luminance I (Y) at the vertical height Y of the photographing screen 193 and the reference value, the following equation It may be a correction formula expressed in the form of (4).
Ih (X, Y) = I (X, Y) −f (Y, ΔI (Y)) (4)
Note that f is a value determined by the luminance difference between the height Y and the reference value at that height.

(5) Although the correction processes A to C have been described as correcting the entire captured image based on the luminance information, the correction processes A to C change the range of correction applied to the upper and lower parts of the captured image. Also good. That is, in the correction process A, correction is performed for the range indicated by the hatched portion at the top and the bottom of the photographed image in FIG. 8A, and in the correction process B, correction is performed for the range indicated by the hatched portion in FIG. In the correction process C, the correction may be performed in the range indicated by the hatched portion in FIG. When the shutter 19 travels, the exposure time t0 is adjusted to be the set shutter speed at the center of the shooting screen 193. Therefore, the brightness value at the center of the shot image is regarded as appropriate, and this appropriate brightness is set. With reference to the value, the size of the upper and lower correction areas of the photographed image may be changed according to the photographing condition. In this case, it is preferable to use the correction formula (4).

(6) When making the determination based on the shooting conditions, the ISO sensitivity is set to 100, 200, and 400, and the focal length is set to 35 mm, 50 mm, and 85 mm. Not. In addition, although the case division is described as being performed in three stages, the case division may be performed more finely.

(7) Although three types of correction processing A to C are used, the type of correction processing may be changed according to the number of cases in the shooting conditions. Further, the correction processes A to C may correct the same content depending on the situation of uneven exposure occurring on the shooting screen.

(8) The necessity of the correction process is determined for the captured image recorded on the recording medium 205 and the correction is performed. However, the necessity determination of the correction process and the correction process may be performed at the time of shooting. . In this case, whether or not correction is necessary and correction processing are performed on the image data that has been subjected to image processing by the image processing circuit 204 in the same manner as described above.

(9) Although the camera determines whether or not the correction process is necessary for the captured image and performs the correction process, only the necessity determination for the correction process is performed, and the determination result is recorded in the recording medium 205 in association with the captured image. Just be fine. In this case, the captured image is taken into a personal computer, and if correction is required, image processing for uneven exposure correction may be executed on the personal computer.

Next, a case where the above-described exposure unevenness correction process is performed by an image generation apparatus such as a computer will be described. In this case, an unevenness correction necessity determination result performed by the control circuit 200, one of the correction processes described above, and a captured image recorded on the recording medium 205 are read, and an image by an application operating on the computer is read. Exposure unevenness correction is performed by processing. FIG. 9 shows the flowchart.
In step S401, one image is read from the recording medium 205. In the image data of the read image, in addition to the image itself, shooting conditions, exposure unevenness correction necessity determination data, and correction processing type (any one of correction processing A, B, and C) are recorded in association with the image. Yes. In step S402, if the image read in step S401 requires exposure unevenness correction, the process proceeds to step S403, and correction processing is performed as described above based on the type of exposure unevenness correction processing. Thereafter, the process proceeds to step S404, where the uncorrected image and the corrected image are displayed side by side on the display monitor, and a message “Do you want to save the corrected image?” Is displayed on the display monitor. In step S405, when the user instructs the personal computer to store the corrected image, the corrected image is stored in the recording medium 205 in step S406. In this case, it is preferable to store the corrected image together with the image before correction. In addition, it is preferable to attach exposure unevenness corrected data to the corrected image. If the read image is non-uniform exposure correction or not stored, the correction process is not performed, and a message “No correction process required” is displayed on the display monitor in step S407, and the process ends.

  That is, when a captured image having a correction necessity determination result is taken into a personal computer, the personal computer corrects exposure unevenness by the following program. That is, this program includes a process for acquiring a captured image including exposure unevenness together with a result of determining whether exposure unevenness is necessary, and a correction process for correcting exposure unevenness of the captured image when exposure unevenness correction for the acquired captured image is necessary. Execute.

The image generation apparatus described above can be modified as follows.
(1) When exposure unevenness necessity determination data is not stored in a photographed image, exposure unevenness correction necessity may be determined by a personal computer as follows, and exposure unevenness correction may be performed based on the determination result. That is, when a captured image to which a shooting condition is added without having a correction necessity determination result is taken into a personal computer, the personal computer corrects exposure unevenness by the following program. This program requires processing for acquiring a captured image including exposure unevenness together with the shooting conditions, determination processing for determining whether exposure unevenness correction is necessary for the acquired captured image, and exposure unevenness correction. When the determination is made, correction processing for correcting exposure unevenness of the captured image is executed.

(2) If the correction processing type is not added to the captured image stored in the personal computer, the type of correction processing used in step S403 may be determined by the method described in the embodiment based on the image capturing conditions.

(3) The captured image recorded on the recording medium 205 is recorded with the shooting condition and the model (model) of the camera used. The correction processing method may be stored as a table. In this case, the recording medium 205 is set in a personal computer, an image is read, the camera model and shooting conditions are read together with the image data, and it is determined whether exposure unevenness correction is necessary or not. If correction is necessary, exposure unevenness correction is performed on the target image based on the correction processing method recorded in the table, and recording is performed on the recording medium as described above.

  For each of various shooting conditions, a standard pattern image obtained by shooting an achromatic standard pattern is stored in a personal computer, and the above correction formula is calculated each time based on the image to be corrected and the standard pattern image. May be.

  When the program is upgraded, support for existing camera users may be implemented via the Internet or a portable recording medium. Therefore, the program of FIG. 7 can be applied to such version-up software. That is, for example, a program that executes a correction process according to the flowchart of FIG. 7 on a computer mounted on a camera acquires a captured image including exposure unevenness together with the shooting conditions, and performs exposure unevenness correction on the acquired captured image. A determination process for determining whether or not it is necessary is performed, and a correction process for correcting exposure unevenness of a captured image when it is determined that exposure unevenness correction is necessary.

  In addition, the present invention is not limited to the above-described embodiment as long as the characteristics of the present invention are not impaired, and other forms conceivable within the scope of the technical idea of the present invention are also within the scope of the present invention. included.

It is a figure explaining the principal part structure of the camera by embodiment of this invention. It is a figure explaining the arrangement | positioning of the optical axis direction of a shutter front curtain and a rear curtain, and the relationship between the travel of the shutter in a standard lens, and exposure time. It is a figure explaining the arrangement | positioning of the optical axis direction of a shutter front curtain and a rear curtain, and the relationship between the travel of the shutter in a wide angle lens, and exposure time. It is a figure explaining the arrangement | positioning of the optical axis direction of a shutter front curtain and a rear curtain, and the relationship between the travel of the shutter in a telephoto lens, and exposure time. It is a graph which shows the exposure time in each ISO sensitivity, and the charge accumulation amount of an image pick-up element. It is a graph showing the relationship between the height in the vertical direction of the shooting screen and the luminance, (a) shows the luminance curve before correction, and (b) shows the luminance curve after correction. It is a flowchart explaining operation | movement of the camera by embodiment. It is a figure explaining the correction range in the case of changing a correction range according to a correction process, when correcting an imaging screen. It is a flowchart explaining operation | movement in image generation apparatuses, such as a computer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 19 Shutter 20 Image pick-up element 120 Shooting lens 191 Shutter front curtain 192 Shutter rear curtain 200 Control circuit

Claims (9)

Image acquisition means for acquiring an image taken by a camera having a focal plane shutter in which a front curtain and a rear curtain are disposed at a predetermined interval in the optical axis direction;
Determination means for determining whether or not to correct exposure unevenness caused in the image due to an interval between the front curtain and the rear curtain based on an imaging sensitivity and a focal length when the image is captured.
The necessity determination apparatus for correction characterized by this. In the correction necessity determination apparatus according to claim 1,
The determination unit determines whether the correction is necessary based on the imaging sensitivity, and subsequently determines whether the correction is necessary based on the focal length.
The necessity determination apparatus for correction characterized by this. In the correction necessity determination apparatus according to claim 1 or 2,
When it is determined that the correction is necessary, the image processing apparatus further includes correction means for correcting the exposure unevenness of the image.
The necessity determination apparatus for correction characterized by this. In the correction necessity determination apparatus according to claim 3,
A determination unit configured to determine a correction processing content by the correction unit based on the imaging sensitivity and the focal length;
The necessity determination apparatus for correction characterized by this. In the correction necessity determination device according to claim 3 or 4,
And further comprising recording means for recording the image corrected by the correcting means on a recording medium.
The necessity determination apparatus for correction characterized by this. In the correction necessity determination apparatus according to claim 1 or 2,
The image processing apparatus further comprises recording means for recording the image on the recording medium in association with the necessity of the correction determined by the determination means.
The necessity determination apparatus for correction characterized by this. In the correction necessity judgment device according to any one of claims 1 to 6,
The determination unit determines whether or not the correction is necessary based on a combination of the imaging sensitivity, the focal length, and an aperture value.
The necessity determination apparatus for correction characterized by this. An image sensor;
A correction necessity determination device according to any one of claims 1 to 7,
The image acquisition means acquires an image captured by the image sensor as the image.
Camera characterized by. An image acquisition process for acquiring an image taken by a camera having a focal plane shutter in which a front curtain and a rear curtain are disposed at a predetermined interval in the optical axis direction;
Based on the imaging sensitivity and focal length when the image was taken, a determination process for determining whether or not it is necessary to correct exposure unevenness occurring in the image due to the interval between the front curtain and the rear curtain Correction necessity determination program to be executed.

Images