JP5589284B2 - Imaging apparatus and correction amount calculation program - Google Patents

Description

  The present invention relates to an imaging apparatus that corrects a captured image and a correction amount calculation program.

  2. Description of the Related Art Conventionally, there has been provided an imaging device such as a digital camera that acquires image data by photoelectrically converting subject light using an imaging element such as a CCD or a CMOS. In such an image pickup apparatus, in addition to an image pickup element, a mechanism for performing focus adjustment and exposure adjustment, a processing circuit for performing image processing on image data, a power supply apparatus for supplying power to these mechanisms and circuits, and the like Is installed.

  In such an image pickup apparatus, image data (dark image data) composed of image signals accumulated by the image sensor in a state where exposure is not performed, and image data (main image) composed of image signals accumulated by the image sensor at the time of actual photographing. Data) and correcting the main image data using the dark image data to perform image correction for dark current noise has been proposed.

  At the time of photographing, a power feeding operation is performed at a predetermined timing to the above-described mechanism or circuit. If these power feeding operations are performed at the time of reading the signal charges accumulated in the image sensor, the image sensor is affected by the voltage fluctuation due to the power feeding operation described above. That is, since a noise component is added to the signal charge to be read, streak noise is generated in the obtained image. In order to prevent the influence of such voltage fluctuations from being exerted on the image sensor, it is necessary to mount a new mechanism or device inside the image pickup apparatus. Such manufacturing costs are increased.

  An object of the present invention is to provide an imaging apparatus and a correction amount calculation program capable of correcting streak noise generated due to voltage fluctuation or the like with an easy configuration.

An image pickup apparatus according to a first aspect of the present invention includes an image pickup device including an effective pixel region for accumulating charges generated according to incident light and a light-shielded pixel region for blocking incident light, and the effective pixel region and the light-shielded pixel region Storage means for storing pixel values of pixels included in each pixel, first calculation means for calculating an average pixel value of pixels included in a predetermined area in the light-shielded pixel area, and pixels of pixels included in the light-shielded pixel area Among the effective pixel areas, second calculation means for obtaining an average pixel value for each of a plurality of pixels arranged in the same line for each line, and an average pixel value for the predetermined area and an average pixel value for each line are included in the effective pixel area. A correction amount calculating means for obtaining a correction amount for the pixel value of each pixel to be calculated for each line, and a correction amount for each line calculated by the correction amount calculating means for the pixels included in the effective pixel region. By multiplying the pixel value of the pixel to be down and the same line, characterized in that and a correcting means for correcting the pixel value of pixels in the effective pixel region.
According to a second invention, in the first invention, there is provided switching means for switching whether or not to perform the correction processing of the pixel value by the correction processing means according to the photographing sensitivity set at the time of photographing. And

According to a third invention, in the first invention, the pixel value correction processing by the correction processing means is performed according to a signal gain value at the time of signal amplification applied to an output signal output from the image sensor. Switching means for switching whether to perform or not is provided.

According to a fourth invention, in the first invention, there is provided switching means for switching whether or not to perform the correction processing of the pixel value by the correction processing means in accordance with an exposure time at the time of photographing. .

According to a fifth invention, in any one of the first to fourth inventions, a plurality of pixel ranges that can be taken as the predetermined region are provided, and any one of the plurality of pixel ranges is set as the predetermined region according to an imaging condition. It is characterized by selecting.

According to a sixth aspect of the present invention, there is provided a correction amount calculation program including, among each pixel output from an imaging device including an effective pixel region for accumulating charges generated according to incident light and a light-shielding pixel region for blocking incident light. A storage step of storing pixel values of pixels included in each of the effective pixel region and the light-shielding pixel region for each pixel, and a first calculation step of obtaining an average pixel value of pixels included in a predetermined region in the light-shielding pixel region A second calculation step of obtaining, for each line, an average pixel value in a plurality of pixels arranged in the same line among the pixels included in the light-shielding pixel area, and the average pixel value in the predetermined area and the average for each line A correction amount calculating step for obtaining a correction amount for each pixel of the pixel value of the pixel included in the effective pixel region from the pixel value, and a correction amount for each line calculated by the correction amount calculating step A correction processing step of correcting the pixel value of the pixel included in the effective pixel region by multiplying the pixel value of the pixel that is the same line as the line among the pixels included in the effective pixel region; Can be executed.

  According to the present invention, the correction of the pixel value of the pixel included in the effective pixel region from the average pixel value of the plurality of pixels arranged in the same column as the average pixel value of the pixel included in the predetermined region within the light-shielding pixel region. By obtaining the amount for each column, even if voltage fluctuation occurs when reading the pixel value of each pixel from the image sensor, the influence on the voltage fluctuation can be corrected by the correction amount obtained for each column. Thereby, it is possible to suppress the occurrence of streak noise in the image.

It is a figure which shows the structure of a digital camera. It is a figure which shows the structure of the light-receiving surface of an image pick-up element. It is a flowchart which shows the flow of the process at the time of imaging. It is a flowchart which shows the flow of a process of image correction.

  FIG. 1 is a functional block diagram showing the configuration of the digital camera. As is well known, the digital camera 10 photoelectrically converts the subject light captured by the imaging optical system 15 by the imaging device 16 and acquires image data from the image signal after the photoelectric conversion.

  The imaging optical system 15 includes a lens group including a photographing lens 21, a zoom lens 22, a focus lens 23, and the like. The zoom lens 22 moves along the optical axis L so as to obtain the selected photographing magnification. Further, the focus lens 23 slightly moves along the optical axis L when adjusting the focus of the subject image. The zoom lens 22 and the focus lens 23 that constitute the lens group are driven and controlled by a lens driving mechanism 25.

  The image pickup device 16 is configured by, for example, a charge coupled device (CCD), a complementary metal-oxide semiconductor (CMOS), or the like. The image sensor 16 receives subject light captured by the imaging optical system 15, converts the received light amount into signal charges (photoelectric conversion), and accumulates the converted signal charges.

As shown in FIG. 2, pixels made of photodiodes and the like are arranged in a two-dimensional matrix on the light receiving surface 16a of the image sensor 16. Among the light receiving surface 16a, m pixels (the number of pixels in the x direction) × n pixels (the number of pixels in the y direction) shifted from the center C to the left in FIG. 2 (pixels P _{11 to} P _{mn in the} drawing). This area is set as the effective pixel area 31. The effective pixel region 31 is a region of pixels that receive subject light captured via the imaging optical system 15, and image data is acquired by collecting image signals output from the pixels of the effective pixel region 31. The

In the light receiving surface 16a, the area excluding the effective pixel area 31 is a pixel area where the subject light is shielded, that is, a so-called optical black (OB) area 32. Of the OB region 32, q (the number of pixels in the x direction) × n (the number of pixels in the y direction) pixels (pixels P ₁₁ ′ to P in the drawing) arranged to the right of the effective pixel region 31 in FIG. The area _qn ′) is set as the horizontal OB area 33. Hereinafter, the direction in which signal charges accumulated by each pixel are read (transferred) is referred to as an x direction, and this x direction is referred to as a horizontal line. Each region is set so that the number of pixels in the y direction in the effective pixel region 31 and the number of pixels in the y direction in the horizontal OB region 33 are the same.

  In addition to the plurality of pixels described above, the imaging element 16 is not shown in detail, but a transistor that accumulates signal charges photoelectrically converted in each pixel arranged on the light receiving surface 16a of the imaging element, A horizontal transfer path for transferring the accumulated signal charge for each horizontal line, a vertical transfer path for transferring the signal charge transferred by the horizontal transfer path in the y direction, and a signal charge transferred by the vertical transfer path as a voltage signal An output unit for outputting to the outside is provided.

  Returning to FIG. 1, the driver 35 controls the driving of the image sensor 16. Controlling the driving of the image sensor 16 means that in addition to controlling the accumulation of signal charges in each pixel of the image sensor 16 and the output of the accumulated signal charges, the pixels that receive subject light and the pixels that do not receive light. For example, so-called thinning-out control is performed. Note that the image data obtained by performing the thinning control is used when a through image is displayed on the LCD 54 described later. Hereinafter, the voltage signal output from the image sensor 16 will be described as an image signal.

  The AFE circuit 36 includes an AGC circuit and a CDS circuit (not shown). The AFE circuit 36 performs analog processing such as gain control and noise removal on the input image signal. The analog-processed image signal is output to the DFE circuit 37.

  A DFE (Digital Front End) circuit 37 converts an image signal subjected to analog processing by the AFE circuit 36 into a digital signal. Reference numeral 38 denotes a timing generator (TG), and the driving timing of the driver 35, the AFE circuit 36, and the DFE circuit 37 is controlled by the TG 38.

  The buffer memory 40 stores the image signals digitized by the DFE circuit 37 for each frame. That is, the buffer memory 40 stores image signal values (hereinafter referred to as pixel values) corresponding to signal charges accumulated by all the pixels arranged on the light receiving surface 16a of the image sensor 16. The buffer memory 40 stores the pixel values of all the pixels arranged on the light receiving surface 16a of the image sensor 16. However, the present invention is not limited to this, and the effective pixel region 31 and the horizontal OB region 33 are not limited thereto. It is also possible to store only the pixel values of the pixels included in each. For example, since the signal charge accumulated by the image sensor 16 represents the brightness (luminance) of the subject light, the pixel value described above includes a luminance value.

  The image processing circuit 41 performs image processing on image-corrected image data in addition to processing for correcting the pixel value of each pixel in the effective pixel region 31 using the horizontal OB region 33 (hereinafter referred to as image correction). To do. The image processing is well known and will not be described in detail, but includes Bayer interpolation processing, white balance processing (hereinafter referred to as WB processing), contour compensation processing, gamma processing, and the like. The image processing circuit 41 has functions of a calculation unit 45, a correction amount calculation unit 46, and an image correction unit 47 when performing the above-described image correction.

Calculation unit 45, among the pixels included in the horizontal OB region 33, (in FIG. 2, for example, pixels included in the area A ₁₎ pixels arranged along a horizontal line an average pixel value S _n of the horizontal lines per the (in each region a ₁ to a _n other words) is calculated. In addition, the calculation unit 45 obtains an average pixel value S _typ of pixels included in the reference region (reference numeral 50 in FIG. 2) in the horizontal OB region 33.

  In the reference region 50, for example, when reading out signal charges accumulated in each pixel of the image sensor 16, various mechanisms provided in the digital camera 10 do not operate, in other words, power supply operation in the power supply device 68. A range of pixels that is not affected by voltage fluctuations associated with is set. In FIG. 2, the range of the pixels arranged in the center of the horizontal OB area 33 is the reference area 50. However, the present invention is not limited to this, and shooting conditions at the time of shooting in the digital camera 10 and control timings of various mechanisms are not limited. In some cases, the range of pixels that are not affected by voltage fluctuations in the power supply device 63 changes. Therefore, a plurality of pixel ranges that can be taken as the reference region 50 are prepared in advance, and are matched to the shooting conditions set at the time of shooting. It suffices to be able to select a pixel range to be the reference region.

Correction amount calculation unit 46, correction from the average pixel value S _n of pixels in the horizontal line for each calculated by calculation unit 45, among the horizontal OB region 33, the average pixel value S _typ of pixels included in the reference area 50 calculating a coefficient R _n. The correction factor R _n is calculated from _{R n = S n / S typ} .

The image correction unit 47 corrects the pixel value of each pixel in the effective pixel region 31 using the correction coefficient R _n for each horizontal line calculated by the correction amount calculation unit 46. For example, when the image value before correction at the pixel P _mn is T _mn and the image value after correction is T _mn ′, the corrected image value T _mn ′ is calculated from T _mn ′ = T _mn / R _n. Desired.

As described above, since the horizontal OB area 33 is an area in which subject light is shielded, it is desirable that the signal charge amount accumulated at the time of shooting is constant in each pixel included in the horizontal OB area 33. However, since the pixel value of a pixel that is affected by voltage fluctuation varies, the correction coefficient R _n described above is obtained and the pixels in the effective pixel region 31 are corrected to thereby influence the voltage fluctuation. Can be deterred.

  The image processing unit 41 performs format processing (image post-processing) for compressing the image data subjected to the above-described image correction processing and image processing by a storage method such as a JPEG method. After this processing, the image processing circuit 41 generates thumbnail image data or, for example, JPEG compressed image data compressed using a preset compression rate. In addition to being temporarily stored in the built-in memory 52, these image data are stored in memory cards, magnetic disks, optical disks, and the like as image files that include model information of the digital camera 10 and shooting information at the time of shooting. It is written on the medium 53. The above-described thumbnail image data is used, for example, when an image taken at the time of shooting is displayed on the LCD 54. Reference numeral 55 denotes a media slot in which a storage medium is mounted, and reference numeral 56 denotes a display control circuit that performs display control of the LCD 54.

  The CPU 60 comprehensively controls each unit of the digital camera 10. For example, when the setting operation unit 61 is operated, the CPU 60 causes the LCD 54 to display, for example, a prompt for setting of shooting conditions such as basic settings and shooting modes of the digital camera 10 via the display control circuit 56. Examples of the setting operation unit 61 include a menu button and a cross key. When the release button 62 is operated, the CPU 60 performs automatic focus adjustment (AF) control, automatic exposure (AE) control, auto white balance (AWB) control, and the like. Since these controls are well known, the details are omitted here. Reference numeral 63 denotes a power supply device, which is provided to supply power to each part of the digital camera 10.

  Next, the flow of processing during imaging will be described based on the flowchart of FIG.

  Step S101: Imaging processing. For example, when the release button 62 is pressed halfway, the CPU 60 executes AE processing, AF control, and AWB control based on the set shooting conditions. In the AE process, for example, when only ISO sensitivity is set, the shutter speed (in other words, the charge accumulation time in the image sensor 16) is determined according to the luminance value of the subject light captured when the release button 62 is half-pressed. ) And aperture value are determined. If the shutter speed is set in advance, the ISO sensitivity and aperture value are determined. Further, if the ISO sensitivity and the shutter speed are set in advance, the aperture value is determined. Thus, in the AE process, the exposure condition at the time of shooting is determined. In the AF process, a focus evaluation value obtained by minutely moving the focus lens 23 in the optical axis (L) direction is obtained, and the position of the focus lens 23 is determined so that the focus evaluation value is maximized. When the release button 62 is pressed fully, the position of the focus lens 23 is readjusted again, and then imaging using the determined exposure condition is executed. With this imaging, signal charges are accumulated in each pixel of the image sensor 16 based on the charge accumulation time corresponding to the determined shutter speed.

  Step S102: Processing for recording an image signal in the buffer memory 52. Through the processing in step S101, each pixel in the image sensor 16 accumulates signal charges based on the charge accumulation time corresponding to the determined shutter speed. The driver 35 reads the signal charges accumulated in each pixel of the image sensor 16 for each horizontal line. The read signal charges for each horizontal line are converted into voltage signals (image signals) and output to the AFE circuit 36. The image signal that has been subjected to analog processing by the AFE circuit 36 is digitally processed by the DFE circuit 37 and is recorded in the buffer memory 40 for each horizontal line.

Step S103: a process for performing image correction. Since this image correction will be described later, the details are omitted here. By executing this step S103, the correction coefficient R _{n for} each horizontal line for the pixel value of the pixel included in the effective pixel area is calculated, and the pixel value of the pixel in the effective pixel area 31 is calculated using this correction coefficient R _n. In a case where correction is performed, that is, when the image value before correction in the pixel P _mn is T _mn and the image value after correction is T _mn ′, the image value T _mn ′ after correction is T _mn ′ = T _mn / consisting of R _n. As a result, even when the signal charge accumulated in each pixel of the image sensor 16 is read out for each horizontal line, even if it is affected by voltage fluctuations, the voltage is corrected by using the correction coefficient R _n described above. The effects of fluctuations can be suppressed. That is, it is possible to suppress streak noise generated by the influence of voltage fluctuation in the obtained image.

  Step S104: This is a step of performing image processing on image-corrected image data. The processing in step S104 is also executed by the image processing unit 41 as in step S103. Bayer interpolation processing, WB processing, contour compensation processing, gamma processing, and the like are performed on the image data that has been subjected to image correction in step S103. For example, format processing (image post-processing) for compression by a storage method such as the JPEG method is performed.

  Step S105: This is a process for recording image data in a storage medium. The image processing unit 41 generates thumbnail image data and compressed image data from the image data subjected to the formatting process in step S104 and writes the thumbnail image data and the compressed image data in the built-in memory 52. The CPU 60 reads shooting information such as shooting conditions, model information of the digital camera 10, and the like, and writes these information and an image file including thumbnail image data and compressed image data in a storage medium. As a result, the image file having the shooting information and the model information of the digital camera 10 as supplementary information is stored in the storage medium 53.

  Hereinafter, the process of step S103, that is, the flow of the image correction process will be described with reference to the flowchart of FIG.

  Step S201: A process of initializing a value n indicating the target horizontal line. When starting the image correction, the image processing circuit 41 initializes a history of image correction performed in the past by performing the process of step S201. By initializing the value n indicating the target horizontal line, n = 1 is set as the number n indicating the target horizontal line. That is, when n = 1, the first horizontal line (A1 area in FIG. 2) is the target horizontal line.

  Step S202: A process of determining whether or not the value n of the target horizontal line exceeds the maximum value. Note that the maximum value shown here is the total number of horizontal lines included in the horizontal OB area 33. If the process of step S202 is performed immediately after the process of step S201 is performed, the value n indicating the target horizontal line is n = 1, so the determination of step S202 is Yes. Become. In this case, the process proceeds to step S203.

  Step S203: A process of adding 1 to the value n indicating the target horizontal line.

Step S204: This is a process corresponding to the value n of the horizontal line, that is, the average pixel value Sn of the nth horizontal line. As shown in FIG. 2, for example, when n = 1, an average pixel value S ₁ of pixels included in the region A1 is obtained. When the process of step S204 ends, the process returns to step S202. That is, until the value n indicating the target horizontal line reaches the maximum value, the processing from step S202 to step S204 is repeatedly executed, and the average pixel value for all horizontal lines included in the horizontal OB area 33 (in other words, A average pixel value) S _n of pixels included in each of the ₁ a _y is determined for each horizontal line.

  If it is determined in step S202 that the value n of the target horizontal line has exceeded the value y of the final horizontal line, the process proceeds to step S210.

Step S210: A process of calculating the average pixel value S _typ of the reference area. Since the reference area 50 is set in advance according to shooting conditions and the like, the average pixel value S _typ is obtained using the pixel values of the pixels included in the set reference area 50.

  Step S211: A process of initializing a value n indicating the target horizontal line. By initializing a value n indicating the target horizontal line, n = 1 is set as the number n of target horizontal lines. That is, when n = 1, the first horizontal line (A1 area in FIG. 2) is the target horizontal line.

  Step S212: This is a process for determining whether or not the value n of the target horizontal line exceeds the maximum value. If the process of step S212 is executed immediately after the process of step S211, the value n indicating the target horizontal line is n = 1, so the determination of step S212 is Yes. Become. In this case, the process proceeds to step S213.

  Step S213: This is a process of adding 1 to the value n indicating the target horizontal line.

Step S214: This is a process for calculating the correction coefficient R _n for the horizontal line to be processed. After the value n indicating the target horizontal line is initialized in step S211, since n = 1, the correction coefficient R1 for the first horizontal line is obtained. In this case, the correction coefficient R ₁ is calculated from R ₁ = S ₁ / S _typ .

Step S215: A process of correcting the pixel value of each pixel of the target horizontal line using the calculated correction coefficient R _n . When the value n indicating the target horizontal line is n = 1, the image processing unit 41 uses the correction coefficient R ₁ to select the first horizontal line among the pixels included in the effective pixel region 31. The pixel value of the pixel is corrected. For example, when the image value before correction in the pixel P ₁₁ is T ₁₁ and the image value after correction is T ₁₁ ′, the image value T ₁₁ ′ after correction is T ₁₁ ′ = T ₁₁ / R ₁ . This correction is performed on all pixels included in the same horizontal line. When this process is executed, the process returns to step S212. That is, the processing from step S212 to step S215 is repeatedly executed until the value n indicating the target horizontal line reaches the maximum value, and all the pixels included in the effective pixel region are corrected for each horizontal line.

  When it is determined in step S212 that the value n of the target horizontal line has exceeded the value y that is the final horizontal line, the image correction for all the pixels included in the effective pixel region is completed. The image correction is finished. As a result, the pixel values of all the pixels are corrected in accordance with the reference area, so that the influence due to voltage fluctuation can be suppressed.

  In the present embodiment, the image correction is performed at the time of imaging. However, the present invention is not limited to this, and it may be possible to select whether to perform the image correction according to the shooting conditions. As a method for selecting whether or not to perform the image correction, the user can select the image by operating the setting operation unit, or can select according to the shooting conditions. good.

  An example of the shooting condition when selecting whether to perform image correction according to the shooting condition is a shooting sensitivity (ISO sensitivity). When the ISO sensitivity is high, the signal charge to be obtained is small, so it is necessary to increase the amplification amount when outputting the signal charge. In such a case, when the signal charge is amplified, the noise component due to the voltage fluctuation is also amplified at the same rate as the signal charge, so that the influence of the noise is increased. In such a case, the image correction described above may be performed. On the other hand, when the ISO sensitivity is low, the amount of signal charge to be obtained is large, so that the amount of amplification at the time of outputting the signal charge can be small, so the influence of noise components is small. In such a case, image correction may not be performed. Note that ISO800 can be cited as the shooting sensitivity when selecting whether or not to perform image correction depending on the shooting sensitivity. When the image sensitivity is less than ISO800, the above-described image correction is not performed. Should be done. Note that the above description is an example, and it is only necessary to set shooting sensitivity for determining whether or not to perform image correction in accordance with the control method of the digital camera.

  Further, in addition to the photographing sensitivity, it is also possible to change depending on the signal gain value (gain value) when the image signal is amplified. For example, when a CCD is used as the imaging device, the signal gain value includes, for example, a signal gain value when an analog image signal is amplified in the AFE circuit. On the other hand, when a CMOS is used as the image sensor, an amplifier is provided for each pixel. Therefore, for example, a signal in an apparatus called an attenuator that adjusts the output level of an image signal output from the image sensor Gain value. In the case of CMOS, since a digital image signal may be output, a signal gain value when a digital image signal is amplified can be mentioned.

  When selecting whether or not to perform image correction based on a gain value when amplifying an image signal, a signal gain value corresponding to the shooting sensitivity set at the time of shooting is used to amplify the obtained image signal. In some cases, the signal gain value is too small or too large. In such a case, it is only necessary to select whether or not to perform image correction according to the signal gain value used when the actually obtained image signal is amplified.

  Further, the shooting conditions include exposure time (shutter speed) in addition to shooting sensitivity and signal gain value. For example, as the exposure time is shorter, the operation of each mechanism of the digital camera is performed in a shorter time. Therefore, the signal charge read from the image sensor is likely to be affected by voltage fluctuations and easily has noise components. That is, the image correction according to this embodiment may be performed when the exposure time is short, and the image correction may not be performed when the exposure time is long. Examples of the exposure time when performing image correction include a case where the Tv value is 1 or more.

  Although shooting sensitivity and exposure time are taken up as shooting conditions used when determining whether or not to perform image correction, and they are used individually, they may be used in combination. That is, for example, when the shooting sensitivity is less than ISO 800 and the TV value is less than 1, it is determined that image correction is not performed, and in other cases, it is determined that image correction is performed.

  In this embodiment, an example of a digital camera having an image correction function has been described. However, an image processing apparatus having an image correction function may be used. In this case, a correction coefficient is calculated inside the digital camera, and the image data obtained from the pixels in the effective pixel region and the correction coefficient are stored in association with each other, and these are read by the image processing device to perform image correction on the image data. Or the image signal obtained from all the pixels of the image sensor is stored in a storage medium as it is, and the correction coefficient is calculated from the horizontal OB area in the image processing apparatus and included in the effective pixel area. It is also possible to correct the pixel value of the pixel to be corrected.

  In addition to this, a program that can cause a computer to execute the function of the image processing unit illustrated in FIG. 1 or the processing of the flowchart illustrated in FIG. 4 may be used. In this case, the program is preferably stored in a computer-readable storage medium such as a memory card, a magnetic disk, or an optical disk.

  DESCRIPTION OF SYMBOLS 10 ... Digital camera, 16 ... Image sensor, 31 ... Effective pixel area, 33 ... Horizontal OB area | region, 40 ... Buffer memory, 41 ... Image processing circuit, 45 ... Calculation part, 46 ... Correction amount calculation part, 47 ... Image correction part

JP 2005-57691 A

Claims (6)

An image pickup device including an effective pixel region for accumulating charges generated according to incident light and a light-shielding pixel region for blocking incident light;
Storage means for storing pixel values of pixels included in the effective pixel region and the light-shielding pixel region for each pixel;
First calculating means for obtaining an average pixel value of pixels included in a predetermined area in the light-shielding pixel area;
Second calculating means for obtaining an average pixel value for each of a plurality of pixels arranged in the same line among the pixels included in the light-shielding pixel region;
A correction amount calculating means for obtaining, for each line, a correction amount for a pixel value of a pixel included in the effective pixel region from the average pixel value in the predetermined region and the average pixel value for each line;
The correction amount for each line calculated by the correction amount calculation means is included in the effective pixel region by multiplying the pixel value of the pixel that is the same line as the line among the pixels included in the effective pixel region. Correction processing means for correcting the pixel value of the pixel to be
An imaging apparatus comprising: The imaging device according to claim 1 ,
An image pickup apparatus comprising: a switching unit that switches whether or not to perform the correction processing of the pixel value by the correction processing unit in accordance with shooting sensitivity set at the time of shooting . The imaging device according to claim 1,
There is provided switching means for switching whether or not to perform the correction processing of the pixel value by the correction processing means in accordance with a signal gain value at the time of signal amplification performed on the output signal output from the imaging element. An imaging apparatus characterized by that. The imaging device according to claim 1 ,
An image pickup apparatus comprising: a switching unit that switches whether to perform the correction processing of the pixel value by the correction processing unit according to an exposure time at the time of shooting . In the imaging device according to any one of claims 1 to 4 ,
An imaging apparatus comprising: a plurality of pixel ranges that can be taken as the predetermined region; and selecting one of the plurality of pixel ranges as the predetermined region according to an imaging condition . Of each pixel output from an imaging device having an effective pixel area for accumulating charges generated according to incident light and a light-shielding pixel area for shielding incident light, each of the effective pixel area and the light-shielding pixel area Storing a pixel value of a pixel included in each pixel;
  A first calculation step of obtaining an average pixel value of pixels included in a predetermined area in the light-shielding pixel area;
  A second calculation step of obtaining an average pixel value for each of a plurality of pixels arranged in the same line among the pixels included in the light-shielding pixel region;
  A correction amount calculating step for obtaining, for each line, a correction amount for a pixel value of a pixel included in the effective pixel region from the average pixel value in the predetermined region and the average pixel value for each line;
  The correction amount for each line calculated in the correction amount calculation step is included in the effective pixel region by multiplying the pixel value of the pixel that is the same line as the line among the pixels included in the effective pixel region. Correction processing step of correcting the pixel value of the pixel to be
  Correction amount calculation program capable of causing a computer to execute.

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