JP2015080114A - Image-capturing device, control method therefor, program, and recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable accurate correction of dark shading in an image-capturing element capable of auto-focusing on an image-capturing surface, without causing a memory amount for storing a correction value to increase during a thinned readout.SOLUTION: An image-capturing device comprises: a pixel unit including a plurality of photoelectric conversion elements within one microlens and having a transfer unit for each of the photoelectric conversion elements; a row scanning circuit for selecting one row in order to transfer one row of pixel data; a column scanning circuit for reading out, for each column, the one row of data read out by the row scanning circuit; a thinning control circuit for controlling a readout thinning rate of the column scanning circuit; a correction value generation unit for generating a dark shading correction value on the basis of the readout data; a storage unit for storing the generated correction value; and a correction unit for correcting a pixel signal on the basis of the generated correction value. When reading out data from some of the photoelectric conversion elements corresponding to one microlens, the correction value generation unit generates, from the data read out with a small thinning amount or without thinning, the correction value that corresponds to the readout thinning rate.

Description

  The present invention relates to a technique for correcting data output from a solid-state imaging device capable of autofocusing on an imaging surface.

  In recent years, an image pickup element in a digital camera, a digital video camera, or the like has been used which can detect the focus of the pupil division method. For example, one pixel of the imaging element has two photodiodes, and each photodiode is configured to receive light that has passed through different pupil regions of the imaging lens by one microlens. Therefore, the focus detection by the imaging lens can be performed by comparing the output signals from the two photodiodes. Further, by adding the output signals from the two photodiodes, a captured image signal can be obtained.

  By the way, in general, when an image sensor such as a CMOS sensor is used, it is often necessary to correct the dark shading in the horizontal direction. In Patent Document 1, when shading data is used as a dark shading correction value, a correction value is created using data read out by thinning. This shortens the readout time required for creating the correction value.

JP 2012-39536 A

  This dark shading correction is the same in reading the focal length detection signal. When the thinning rate is changed in reading out a pixel signal, it is necessary to correct dark shading corresponding to the thinning rate. However, since the value of the correction value increases by the type of thinning-out reading, the memory capacity for storing the correction value increases. There is also a method to calculate correction values for other thinned out readings based on the thinned correction values in order to create correction values at high speed. However, if there are large variations in horizontal dark shading, accurate correction may not be possible. There is sex.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to increase the amount of memory for storing correction values when thinning readout is performed in an imaging device capable of autofocusing on an imaging surface. It is possible to correct dark shading accurately.

  An imaging apparatus according to the present invention includes a plurality of photoelectric conversion elements in one microlens, a pixel unit having a transfer unit for each photoelectric conversion element, and the one row for transferring pixel data of one row. A row scanning circuit for selecting, a column scanning circuit for reading out one row of data read by the row scanning circuit for each column, and a thinning control circuit for controlling a reading thinning rate of the column scanning circuit; Correction value generating means for generating a correction value for dark shading based on the read data; storage means for storing the generated correction value; and correcting a pixel signal based on the generated correction value A correction unit, and the correction value generation unit reads the data of a part of photoelectric conversion elements corresponding to one microlens with a small amount of thinning or without performing thinning. From over data, and generating a correction value corresponding to the thinning rate of reading.

  According to the present invention, it is possible to accurately correct dark shading without increasing the amount of memory for storing correction values when thinning-out reading is performed in an image pickup device capable of autofocus on the image pickup surface.

1 is a block diagram illustrating a configuration of an imaging apparatus according to a first embodiment of the present invention. 1 is a block diagram of an image sensor according to a first embodiment of the present invention. It is a conceptual diagram in which the light beam emitted from the exit pupil of the imaging lens enters the unit pixel. It is an equivalent circuit diagram of a pixel. It is a column circuit block diagram at the time of thinning-out reading in a 1st embodiment. It is a control signal timing diagram of the horizontal scanning circuit in the first embodiment. It is a figure which shows the one-dimensional data, correction value, and the output after correction | amendment in the case of no line thinning in 1st Embodiment. It is a figure which shows the one-dimensional data, correction value, and output after correction | amendment in the case of 1/3 pixel thinning-out in 1st Embodiment. It is the figure which showed the reading resolution at the time of changing the thinning-out rate of A image in 1st Embodiment. It is the figure which showed the example of generation | occurrence | production of the correction value at the time of carrying out 1/3 thinning out of the column 1 pixel addition average after a column 1/3 thinning out from the correction value without column thinning out in 1st Embodiment. . It is a flowchart which shows operation | movement of 1st Embodiment. It is a figure which shows the correction | amendment required range at the time of limiting the read-out area | region in the read-out which carried out 1/3 thinning out after 3 column addition in 2nd Embodiment. It is a flowchart which shows operation | movement of 2nd Embodiment. It is a figure which shows the difference in the horizontal dark shading by ISO sensitivity. It is the figure which showed the example of a generation | occurrence | production of the correction value for reading without a thinning | decimation out from the correction value thinned out by 1/3 in 3rd Embodiment. It is a flowchart which shows the operation | movement which produces | generates the correction value in 3rd Embodiment. It is a flowchart which shows the correction | amendment operation | movement in 3rd Embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

(First embodiment)
FIG. 1 is a block diagram showing a configuration of an imaging apparatus according to the first embodiment of the present invention. In FIG. 1, reference numeral 100 denotes an image pickup apparatus body, 200 denotes a recording medium such as a memory card or a hard disk, and 300 denotes a lens unit.

  Next, details of these blocks will be described. In the image pickup apparatus main body 100, a shutter 12 that controls the exposure amount of the image pickup element 1400 and an image pickup element 1400 that converts an optical image into an electric signal are arranged. Reference numerals 130 and 131 denote mirrors. Reference numeral 104 denotes an optical viewfinder. When the mirror 130 is on the optical axis, the incident light incident through the lens is imaged, and the composition of the still image taken by the user can be confirmed.

  Reference numeral 1700 denotes an analog front end (hereinafter referred to as AFE) incorporating an A / D converter that converts an analog signal output from the image sensor 1400 into a digital signal. Reference numeral 1800 denotes a timing generator (hereinafter referred to as TG) that supplies a clock signal and a control signal to the image sensor and the A / D converter, respectively.

  A liquid crystal monitor 1200 can display a live view image and a captured still image. Reference numeral 50 denotes a system control circuit (hereinafter referred to as “CPU”) that controls the entire operation of the imaging apparatus main body 100 including image processing.

  Reference numeral 61 denotes a shutter switch. The shutter switch 61 has two stages. Pressing the shutter button shallowly to the first level is called a half press, and pressing the button deeply to the second level is called a full press. When half-pressed, autofocus and shutter speed and aperture value are set by the automatic exposure mechanism in the state before shooting. When fully pressed, the shutter 12 operates and the photographing operation is performed.

  62 is a live view start / stop switch. The image data from the image sensor 1400 is displayed in accordance with the size of the liquid crystal monitor via the CPU 50. When the shutter switch 61 is pressed halfway during live view display, autofocus is performed using a focus detection output signal of the image sensor 1400 described later. Reference numeral 63 denotes a moving image recording start / stop switch. When an instruction to start recording is given, the moving image recording operation is continuously performed.

  Reference numeral 66 denotes a power switch that switches between power-on and power-off of the imaging apparatus main body 100. In addition, the power-on and power-off settings of various accessory devices such as the lens unit 300, the external strobe, and the recording medium 200 connected to the imaging device 100 can be switched.

  Reference numeral 70 denotes a volatile memory (hereinafter referred to as RAM) that temporarily records image data output from the image sensor 1400 and image data processed by the image processing unit 72. It also has a function as a work memory of the CPU 50. Reference numeral 71 denotes a nonvolatile memory (ROM) that stores a program used when the CPU 50 operates. An image processing unit 72 performs processing such as still image correction / compression. Reference numeral 73 denotes an arithmetic unit for calculating a position change amount of a lens 310 described later from a focal length detection signal for autofocus.

  A power control unit 80 includes a battery detection circuit, a DC-DC converter, a switch circuit that switches a block to be energized, and the like. Further, the presence / absence of a battery, the type of battery, the remaining battery level are detected, the DC-DC converter is controlled based on the detection result and the instruction of the system control circuit 50, and the necessary voltage is recorded for a necessary period. Supply to each part including Reference numerals 82 and 84 denote connectors, and 86 denotes a power supply unit including a primary battery such as an alkaline battery or a lithium battery, a secondary battery such as a Li ion battery, an AC adapter, or the like.

  Reference numeral 90 denotes an interface with a recording medium such as a memory card or hard disk, and reference numeral 92 denotes a connector for connecting to a recording medium such as a memory card or hard disk. Reference numeral 200 denotes a recording medium such as a memory card or a hard disk. The recording medium 200 includes a recording unit 230 configured by a semiconductor memory, a magnetic disk, and the like, and an interface 206 with the imaging apparatus main body 100.

  Reference numeral 300 denotes a lens unit, 310 denotes a photographing lens, 312 denotes an aperture, and 316 and 106 denote lens mounts for connecting the lenses. Reference numeral 320 denotes a lens control unit, and reference numeral 322 denotes a connector that electrically connects the lens unit 300 to the imaging apparatus main body 100. The lens control unit 320 receives a signal from the imaging apparatus main body 100 via the connectors 322 and 122. Then, the position of the imaging lens 310 on the optical axis is changed by the signal from the imaging apparatus main body 100 to control the focus. Similarly, the lens control unit 320 receives a signal from the imaging apparatus main body 100 and controls the size of the aperture of the diaphragm 312. Reference numeral 120 denotes an interface for communicating with the lens unit 300 using an electrical signal.

  FIG. 2 is a block diagram of the image sensor 1400. The pixels 203 are arranged in a matrix, and the vertical arrangement is called a “column” and the horizontal arrangement is called a “row”. A group of pixels 206 is a collection of all columns and rows of the pixels 203. The vertical scanning circuit 202 (row scanning circuit) outputs a signal necessary for row selection for reading the selected row and reading of electric charges of each row to the circuit of each pixel.

  The pixels in each column are connected to the vertical output line 410. The signals output to the vertical output line 410 are output to the horizontal scanning circuit 201 (column scanning circuit) via the column gain 204 and the column circuit 205, respectively. The horizontal scanning circuit 201 sequentially outputs the signal output for one row in the horizontal direction. Reference numeral 208 denotes a control circuit for the horizontal scanning circuit. A column thinning control unit 209 is one of the control circuits, and performs column thinning readout scanning depending on conditions. Reference numeral 210 denotes a column range designation control unit which reads only the set range. Reference numeral 211 denotes a horizontal pixel addition control unit that controls horizontal pixel addition.

  FIG. 3 is a conceptual diagram in which a light beam emitted from an exit pupil of a photographing lens enters a unit pixel. Reference numeral 203 denotes a unit pixel, and the unit pixel 203 includes a first photodiode 306A and a second photodiode 306B. 305 is a color filter, and 304 is a microlens. Reference numeral 300 denotes an exit pupil of the photographing lens. That is, the pixel portion includes a plurality of unit pixels 203, and the unit pixel 203 includes a plurality of photodiodes (photoelectric conversion elements) in the microlens.

  For the pixel having the microlens 304, the optical axis 303 is the center of the light beam emitted from the exit pupil. The light that has passed through the exit pupil enters the unit pixel 203 around the optical axis 303. Reference numerals 301 and 302 denote partial areas of the exit pupil of the photographing lens. As shown in FIG. 3, the light beam passing through the pupil region 301 is received by the photodiode 306A through the microlens 304, and the light beam passing through the pupil region 302 is received by the photodiode 306B through the microlens 304. Accordingly, each of the photodiodes 306A and 306B receives light from different areas of the exit pupil of the photographing lens. Therefore, the phase difference can be detected by comparing the signals of the photodiodes 306A and 306B.

  Here, a signal obtained from the photodiode 306A is defined as an A image signal, and a signal obtained from the photodiode 306B is defined as a B image signal. A signal obtained by adding the A image signal and the B image signal is an A + B image signal, and the A + B image signal can be used for a captured image.

  FIG. 4 shows an equivalent circuit diagram of one pixel 203. The charges generated and accumulated in the photodiodes 306A and 306B are transferred to the floating diffusion unit (hereinafter referred to as FD) 407 by controlling the transfer switch 405A by the transfer control signal 401 and the transfer switch 405B by the transfer control signal 402, respectively. . The source follower amplifier 408 amplifies a voltage signal based on the electric charge accumulated in the FD 407 and outputs it as a pixel signal. The row selection control signal 404 controls the row selection switch 409 to connect the output of the source follower amplifier to the vertical output line 410.

  When resetting unnecessary charges accumulated in the FD 407, the reset switch 406 is controlled by a reset control signal 403. Further, when resetting the photodiodes 306A and 306B, together with the reset switch 406, the transfer switch 405A is controlled by the transfer control signal 401, and the transfer switch 405B is controlled by the transfer control signal 402, respectively. The transfer control signals 401 and 402, the reset control signal 403, and the row selection control signal 404 are connected to the vertical scanning circuit 202, and the respective control signals are supplied to each row. The transfer control signals 401 and 402, the reset control signal 403, and the row selection control signal 404 are output by the CPU 50 controlling the vertical scanning circuit 202 via the TG 1800.

  The thinning-out reading control and the addition average control will be described with reference to FIGS. FIG. 5 shows the columns used in each reading method. The columns used are indicated by solid lines, and the columns not used are indicated by dotted lines. (A) shows a case where reading is performed without decimation, (b) shows a case where 1/3 decimation is read out, and (c) shows a state where 1/3 decimation is performed after averaging three pixels. The thinning-out reading when the averaging is not performed as in (b) is divided into a portion that is not used at all and a portion that is used. However, when reading is performed after the averaging, as shown in (c), columns that are not sent to the horizontal transfer circuit are also column circuits. The signals coming to 205 are averaged by the addition switch 500. Therefore, the signal read up to the column circuit 205 is not wasted.

  FIG. 6 shows a timing chart in each reading method. As shown in (a), at the time of reading without thinning, after transferring pixel data of one row, the CPU 50 sequentially transfers signals by setting the switch to HIGH from Φh1. In the case of 1/3 decimation reading as shown in (b), after transferring pixel data of one row, the CPU 50 transfers the switches every three columns to HIGH like Φh2, Φh5, and Φh8. When (3) horizontal three-pixel addition is performed and 1/3 thinning-out readout is performed as shown in (c), the CPU 50 sets ΦHADD to HIGH after transferring pixel data for one row, and then adds and averages signals for every three columns, and then Φh2, As in Φh5 and Φh8, the switches for every third column are set to HIGH and transferred. The CPU 50 controls the thinning control circuit 209 to read out every three columns.

  FIG. 7 is a diagram for explaining correction of dark horizontal shading. FIG. 7A shows a dark image read without being thinned out. (B) shows one-dimensional mapping data (hereinafter, horizontal dark shading) obtained by averaging the acquired images in the direction of each column. In order to correct this horizontal dark shading, the CPU 50 controls the image processor 72 to store the horizontal dark shading correction value as shown in (c) in the ROM 71 (correction value generation). When the image A is actually sent from the image sensor 1400 to the RAM 70, the CPU 50 controls the image processing unit 72 and develops the horizontal dark shading correction value from the ROM 71 to another area of the RAM 70. By performing correction with the developed data, the final A image horizontal dark shading result is (d).

  FIG. 8 is a diagram for explaining correction of dark horizontal shading of an image read out by thinning out three pixels. A column width of (1/3) · W is read with respect to the column width W when not thinned. Based on the data, (b) shows horizontal dark shading of the acquired image. In order to correct this dark shading, the CPU 50 controls the image processing unit 72 to store each column correction data (c) in the ROM 71. When an image of A image is actually sent from the image sensor 1400 to the RAM 70, the CPU 50 controls the image processing unit 72 and develops it from the ROM 71 to another area of the RAM 70. By performing correction with the developed data, the final A image horizontal dark shading result is (d).

  FIG. 9 is a diagram showing the readout resolution when the A + B image as the captured image output is read out without horizontal thinning and the thinning rate of the A image as the focal length detection output is changed. (A) shows no change in the A image, (b) shows readout of 1/3 of the A image, and (c) shows changes in the column width when readout of 1/5 of the A image is performed. The A + B image is fixed at the column width W, but the A image has a column width W when there is no decimation, (1/3) · W at 1/3 decimation readout, and (1/5) at 1/5 decimation readout. ) ・ It becomes like W. The total number of thinned readout pixels is reduced, and the readout speed can be increased.

  As described above, when reading with a thinning rate increased to 1/3, 1/5, 1/9 with no thinning reading and with thinning reading, each horizontal dark shading correction value is stored and corrected. There is a way. But doing so increases the memory capacity. As shown in FIGS. 7 and 8, the correction value when thinning is almost equivalent to the application column data of the correction value without thinning. Therefore, correction can be performed by selecting or calculating and applying the horizontal dark shading correction value when thinning is performed from the correction value without thinning or when thinning is performed after horizontal addition.

FIG. 10 shows an example of calculating a correction value when 1/3 thinning is performed from a correction value without thinning in the first embodiment, and an example of calculating a correction value when 1/3 thinning is performed by adding three horizontal pixels. Show. (A), (b) has shown the outline of the one-dimensional data of the correction value without thinning, and the correction value at the time of 1/3 thinning, respectively. (C) shows the dark output and the correction value when there is no decimation from -4 to +4 in the Nth column. The dark output offset level indicates data at 500. (D) shows a correction value to be applied when 1/3 decimation is performed. The correction value corresponding to the thinning-out reading is applied as it is. (E) shows the calculated value of the correction value in the case of reading out after thinning and averaging three horizontal pixels. In the case of addition, the correction values are also averaged. For example, the correction value from N-4 to N-2 is (5 + 3 + 4) / 3 = 4 [LSB] (1)
Calculate and correct as follows.

  FIG. 11 shows a flowchart of the operation in the first embodiment. First, a flowchart at the time of obtaining the horizontal dark shading correction value of the A image is shown in FIG. The CPU 50 drives and reads the image sensor 1400 without horizontal thinning (S1100). Since the image is a dark image, the mirror 130 and the shutter 12 can be captured with the light shielded while the initial state is maintained. Thereafter, the CPU 50 reads the image data to the RAM 70, and the image processing unit 72 creates one-dimensional data and a correction value corresponding to the one-dimensional data based on the data, and records it in the ROM 71 (S1101).

  Next, a flowchart for performing correction using the acquired correction value is shown in FIG. When an A image is read for AF, it is checked whether the A image is a horizontal thinning (or addition) reading (S1110). When thinning (or addition) reading is not performed, the CPU 50 reads the correction value from the ROM 71 via the image processing unit 72, and performs correction on the read A image (S1112). If the A image has been read out (or added), the CPU 50 reads out the correction value from the ROM 71, and the image processing unit 72 selects (calculates) the correction value according to the thinning rate (addition rate). Correction is performed (S1112). The AF calculation is performed using the image corrected with the changed correction value.

  In the first embodiment, it is assumed that the A image data for focus calculation is read by switching the shooting mode, switching the frame rate, or changing the thinning rate according to the current defocus amount. At that time, horizontal shading data corresponding to the thinning rate is necessary, but the correction value is acquired without thinning. The acquired correction value is selected (calculated) and applied according to the thinning rate. As a result, it is not necessary to have correction values corresponding to all the thinning rates, so that the amount of memory can be reduced and the correction accuracy can be maintained.

(Second Embodiment)
In the second embodiment, when the A image is read, correction when the thinning is performed after the horizontal addition and the horizontal range is selected and only a specific portion is read will be described with reference to FIG.

  In FIG. 12, the A image and the A + B elephant are read out by 1/3 thinning after adding three horizontal pixels. Further, the A image is read by selecting only a horizontal region having a horizontal width 1201 with respect to the total horizontal width 700. At this time, a region necessary for the correction value is a portion having a horizontal width 1201. As shown in FIG. 12B, only the portion of the horizontal width 1103 needs to be applied to the total horizontal width 1102 without thinning in the horizontal dark shading correction value. Therefore, it is possible to speed up the correction process.

  For example, if there is data with a horizontal width 1102 of 6000 columns, the horizontal width 700 is 2000 columns with 1/3 decimation, and the horizontal width 1201 that is a read specific portion is 1500 columns from the left end, the horizontal width 1103 applied to the correction value is 4500 columns. First, the data is expanded in the RAM 70. The correction values for 1500 columns are calculated and applied to the data read into the RAM 70 in correspondence with the 3-pixel addition average.

  FIG. 13 shows a flowchart of the operation of the second embodiment. When the A image is read out for AF, it is confirmed whether the A image is thinned out after horizontal addition (S1300). When the horizontal addition reading is not performed, correction is performed with the correction value stored in the ROM 71 as it is (S1302). If the horizontal addition reading is being performed, it is confirmed whether or not the horizontal region has been read out in the entire region (S1301). If the entire horizontal area has been read, the CPU 50 expands the correction value for the total horizontal width of the memory in the RAM 70 and calculates the correction value for addition reading (S1303). When only the specific area is read, the correction value corresponding to the portion read by the CPU 50 is expanded from the ROM 71 to the RAM 70, and the image processing unit 72 calculates and corrects the correction value for addition reading (S1304).

  In the second embodiment, the correction value calculation in the case where the A image is subjected to horizontal pixel addition averaging, the horizontal range is further selected, and only a specific portion is read has been described. Since only a necessary portion needs to be read from the storage area ROM 71, the reading speed increases as the reading area width is narrow, and the correction speed is further improved.

(Third embodiment)
In the third embodiment, a method for changing how to obtain the correction value of the A image according to the photographing condition will be described.

  FIG. 14A shows the read image size of the A image when horizontal pixel addition is not performed. (B) Horizontal dark shading at low ISO sensitivity (sensitivity below a predetermined value) read at low gain, (c) Horizontal dark shading at high ISO sensitivity (sensitivity greater than a predetermined value) read at high gain. Is shown. Since the level of horizontal dark shading is small at low ISO sensitivity compared to high ISO sensitivity, the correction value is also small. Therefore, in the case of low ISO sensitivity, there is a method of storing and applying the thinned correction value.

  FIG. 15 shows an example in which, when a correction value for horizontal dark shading of the A image is created by 1/3 thinning, the data without thinning is complemented and corrected. (A) shows an outline of 1/3 correction value data, and (b) shows correction values N-3 and N + 3 columns obtained by thinning out three pixels from the Nth column. When reading without thinning out of the A image is performed from here, the data of the N-2 column and the N-1 column are rounded from the weighted average value according to the position from the N-3 column and the N column. . Specifically, the calculation method for the N-2 column is obtained from the N-3 column and the N column as follows.

{(2 × 2) + (1 × 1)} / 3≈1.666≈2
A value obtained by weighted averaging in this way is used as a correction value.

  Note that the ISO sensitivity to be applied may be determined in advance, or may be applied from the ISO sensitivity in which the correction values MAX and MIN exceed predetermined values.

  FIG. 16 is a flowchart for obtaining a correction value for the A image in the third embodiment.

  First, it is determined whether or not the ISO sensitivity is greater than or equal to a predetermined value (S1600). If the ISO sensitivity is less than the predetermined value, the CPU 50 drives the image sensor 1400 without thinning out to generate a correction value as in the first embodiment (S1601). On the other hand, if the ISO sensitivity is equal to or higher than the predetermined value, the CPU 50 drives the image sensor 1400 with 1/3 pixel thinning to generate a correction value (S1602). The generated correction value is stored in the ROM 70 (S1603).

  FIG. 17 shows a flowchart for correcting the A image in the third embodiment.

  It is determined whether or not the A image is thinned out when the A image is read for the moving image AF (S1700). If the ISO sensitivity is smaller than a predetermined value when the A image is thinned out, the CPU 50 corrects the value written in the ROM 70 as a correction value (S1704). If the ISO sensitivity is equal to or higher than the predetermined value when the A image is thinned out, the CPU 50 selects the correction value stored in the ROM 70 for thinning out, develops it in the RAM 71, and corrects it (S1703). When the A image is not thinned out and the ISO sensitivity is smaller than the predetermined value, the CPU 50 reads out the correction value from the ROM 70 and corrects it by performing a complementary operation for reading without thinning out (S1705). When the A image is not thinned out and the ISO sensitivity is equal to or higher than a predetermined value, the CPU 50 corrects the value written in the ROM 70 as a correction value (S1704).

  Although ISO sensitivity is shown here, the ISO sensitivity is not limited as long as the level of the correction value changes.

  In the third embodiment, an example has been described in which the readout thinning rate is changed when the storage correction value is created according to the ISO sensitivity that is the imaging condition. When the one-dimensional correction value is small, the difference between the correction value and the correction value created with the data read without thinning is reduced. Therefore, the read correction value is created at a predetermined thinning rate. As a result, the amount of memory to be stored can be reduced.

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

Claims (13)

A pixel portion including a plurality of photoelectric conversion elements in one microlens, and having a transfer means for each photoelectric conversion element;
A row scanning circuit for selecting the one row in order to transfer pixel data of one row;
A column scanning circuit for reading out one row of data read out by the row scanning circuit for each column;
A decimation control circuit for controlling a read decimation rate of the column scanning circuit;
Correction value generation means for generating a dark shading correction value based on the read data;
Storage means for storing the generated correction value;
Correction means for correcting the signal of the pixel based on the generated correction value,
The correction value generating means corrects the data corresponding to one read-out thinning rate from the data read out with a small amount of thinning or without thinning out when reading data of a part of photoelectric conversion elements corresponding to one microlens. An imaging apparatus characterized by generating a value.   The imaging apparatus according to claim 1, wherein the correction value generation unit selects only a necessary portion from the storage unit according to a thinning rate and generates the correction value.   The addition average means for adding and averaging the signals of the pixels, and the correction value generation means generates the correction value according to an addition rate of the addition average means. Imaging device.   The image processing apparatus further comprises range specifying means for specifying the pixel range, and the correction value generating means reads only the read range specified by the range specifying means from the storage means and generates the correction value. The imaging device according to claim 3. A pixel portion including a plurality of photoelectric conversion elements in one microlens, and having a transfer means for each photoelectric conversion element;
A row scanning circuit for selecting the one row in order to transfer pixel data of one row;
A column scanning circuit for reading out one row of data read out by the row scanning circuit for each column;
A decimation control circuit for controlling a read decimation rate of the column scanning circuit;
Correction value generation means for generating a dark shading correction value based on the read data;
Storage means for storing the generated correction value;
Correction means for correcting the signal of the pixel based on the generated correction value,
When the correction value generation unit reads data of a part of photoelectric conversion elements corresponding to one microlens, the correction value is read at a thinning rate with a small thinning amount under an imaging condition in which the level of the correction value is larger than a predetermined value. The correction value is generated from data or data read without thinning out, and the correction value is generated from data read at a thinning rate with a large thinning amount under a photographing condition where the level of the correction value is a predetermined value or less. An imaging apparatus characterized by the above.   The imaging apparatus according to claim 5, wherein the correction value generation unit selects only a necessary portion from the storage unit according to a thinning rate and generates the correction value.   6. The addition average unit that adds and averages the signals of the pixels, and the correction value generation unit generates the correction value according to an addition rate of the addition average unit. Imaging device.   The image processing apparatus further comprises range specifying means for specifying the pixel range, and the correction value generating means reads only the read range specified by the range specifying means from the storage means and generates the correction value. The imaging device according to claim 7.   The imaging apparatus according to claim 5, wherein the predetermined value is an ISO sensitivity value. A pixel portion that includes a plurality of photoelectric conversion elements in one microlens and has a transfer means for each photoelectric conversion element, and a row scanning circuit for selecting the one row for transferring pixel data of one row And a column scanning circuit for reading out one row of data read out by the row scanning circuit for each column, and a method of controlling an imaging device comprising:
A decimation control step for controlling the read decimation rate of the column scanning circuit;
A correction value generation step for generating a correction value for dark shading based on the read data;
A storage step of storing the generated correction value;
A correction step of correcting a pixel signal based on the generated correction value,
In the correction value generation step, when data of a part of photoelectric conversion elements corresponding to one microlens is read, a correction corresponding to a reading thinning rate is performed from data read with little or no thinning. A method for controlling an imaging apparatus, characterized by generating a value. A pixel portion that includes a plurality of photoelectric conversion elements in one microlens and has a transfer means for each photoelectric conversion element, and a row scanning circuit for selecting the one row for transferring pixel data of one row And a column scanning circuit for reading out one row of data read out by the row scanning circuit for each column, and a method of controlling an imaging device comprising:
A decimation control step for controlling the read decimation rate of the column scanning circuit;
A correction value generation step for generating a correction value for dark shading based on the read data;
A storage step of storing the generated correction value;
A correction step of correcting a pixel signal based on the generated correction value,
In the correction value generation step, when data of a part of photoelectric conversion elements corresponding to one microlens is read, the reading is performed at a thinning rate with a small thinning amount under an imaging condition in which the level of the correction value is larger than a predetermined value. The correction value is generated from data or data read without thinning out, and the correction value is generated from data read at a thinning rate with a large thinning amount under a photographing condition where the level of the correction value is a predetermined value or less. A method for controlling an image pickup apparatus.   The program for making a computer perform each process of the control method of Claim 10 or 11.   A computer-readable storage medium storing a program for causing a computer to execute each step of the control method according to claim 10 or 11.

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