JP4875399B2 - Imaging apparatus, control method therefor, and imaging system - Google Patents

Description

  The present invention relates to an imaging apparatus having a photoelectric conversion element, a control method thereof, and an imaging system, and more particularly to an imaging apparatus using a CMOS image sensor, a control method thereof, and an imaging system.

  In imaging processing in an imaging device such as a digital camera or digital video camera, a signal output from the imaging device through a primary color filter is digitized by AD conversion and divided into blocks as shown in FIG. The However, each block is configured in units including one color signal R, G1, G2, B as shown in FIG. 7B. For each of these blocks, a color evaluation value, Formula 1, is calculated.

… （数式１）
また、図８に示すように、あらかじめ白色を高色温度下から低色温度下まで撮影して、色評価値Ｃｘ、Ｃｙをプロットすることによって、白軸を定めることができる（例えば、特許文献１参照）。実際の光源において白色には若干のばらつきが存在するため幅を持たせてある。これを白検出範囲と呼ぶ。このとき、各ブロックについてＣｘ、Ｃｙ軸にプロットして、白検出範囲に入った場合、そのブロックが白色であると仮定する。さらに、白検出範囲に入った色画素の積分値ＳｕｍＲ、ＳｕｍＧ１、ＳｕｍＧ２、ＳｕｍＢを算出して、数式２を用いることによってホワイトバランス係数を算出する。ただし、ＫＷＢ＿Ｒ、ＫＷＢ＿Ｇ１、ＫＷＢ＿Ｇ２、ＫＷＢ＿Ｂはそれぞれ色信号Ｒ、Ｇ１、Ｇ２、Ｂのホワイトバランス係数である。（以下、ホワイトバランスを「ＷＢ」という。）。

... (Formula 1)
Further, as shown in FIG. 8, the white axis can be determined by photographing white in advance from a high color temperature to a low color temperature and plotting the color evaluation values Cx and Cy (for example, Patent Documents). 1). In an actual light source, white has a width because of slight variations. This is called a white detection range. At this time, when each block is plotted on the Cx and Cy axes and enters the white detection range, it is assumed that the block is white. Further, the integral values SumR, SumG1, SumG2, and SumB of the color pixels that have entered the white detection range are calculated, and the white balance coefficient is calculated by using Equation 2. However, KWB_R, KWB_G1, KWB_G2, and KWB_B are white balance coefficients of the color signals R, G1, G2, and B, respectively. (Hereafter, white balance is referred to as “WB”).

… （数式２）
特開２００３−２４４７２３号公報

... (Formula 2)
JP 2003-244723 A

  However, in the above conventional method, when there are few whites in the screen, there are few colors that are determined to be in the white detection range, and the integrated value of the colors in the white detection range is close to zero. Is difficult to calculate. When shooting using the electronic zoom, the probability that white is present is lower than when the electronic zoom is not used, and in this case, it may be more difficult to specify the color temperature of the light source. For example, when a person's up is photographed by electronic zoom, the ratio of white to the screen decreases.

  In addition, when a person's up is photographed by electronic zoom, the following problems also occur. That is, under high color temperature, the color evaluation value is distributed in the vicinity of the region A in FIG. Therefore, it can be determined that the scene is a high color temperature light source. However, when the human skin is plotted on the Cx and Cy axes under this light source, it is distributed on the low color temperature side in the white detection range. Therefore, in a scene where the screen has little white and the human skin is up, the color evaluation values of the screen are distributed in the region B in FIG. In other words, since the skin color is mistakenly determined as white under a low color temperature, the human skin becomes pale. Therefore, there is a possibility that the image is not intended by the photographer.

  The present invention has been made in view of the problem of generating an image using a part of an imaging surface, such as the electronic zoom as described above, and performs appropriate WB processing even in such a case. With the goal.

A first aspect of the present invention relates to an imaging apparatus, wherein a plurality of photoelectric conversion elements are arranged on an imaging surface, and an image signal is received from a first photoelectric conversion element group arranged in a first region of the imaging surface. A first mode for reading, and a second mode for reading an image signal from a second photoelectric conversion element group disposed in a second area smaller than the first area of the imaging surface and included in the first area. An image pickup unit that can be driven in the first mode, a white balance correction value is calculated based on an image signal obtained by driving the image pickup unit in the first mode, and the image pickup is performed using the white balance correction value. A control unit that controls to perform white balance processing of an image signal obtained by driving the unit in the second mode, and the control unit is m every predetermined second (m is an integer of 2 or more). When reading frame image signals , In n (n is an integer greater than or equal to 1 smaller than m) of the m frames, the image pickup unit is driven in the first mode to read an image signal, and in the mn frames of the m frames In the second mode, the image pickup unit is driven to control to read an image signal .

  A second aspect of the present invention relates to an imaging system, and includes an optical system and the imaging device described above.

According to a third aspect of the present invention, there is provided a first mode in which a plurality of photoelectric conversion elements are arranged on the imaging surface, and an image signal is read from the first photoelectric conversion element group arranged in the first region of the imaging surface. Imaging that can be driven in a second mode that reads an image signal from a second photoelectric conversion element group that is arranged in a second region that is smaller than the first region of the imaging surface and included in the first region A white balance correction value based on an image signal obtained by driving the imaging unit in the first mode, and using the white balance correction value. When controlling to perform white balance processing of an image signal obtained by driving the imaging unit in the second mode, and reading out an image signal of m frames (m is an integer of 2 or more) every predetermined second And m In n frames (n is an integer of 1 or more smaller than m), the image pickup unit is driven in the first mode to read an image signal, and in the mn frames of the m frames, the first In the second mode, the image pickup unit is driven to control to read an image signal .

  ADVANTAGE OF THE INVENTION According to this invention, the imaging device which can perform suitable WB process, and its method can be provided.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The imaging apparatus according to the present embodiment includes an imaging unit 200 in which a photoelectric conversion element or the like is disposed on an imaging surface, and a control unit 509 (see FIG. 5) that controls the imaging unit 200 (see FIG. 2). . FIG. 2 is a diagram illustrating a configuration of the imaging unit 200 of the imaging apparatus using the XY address type scanning method.

  In the imaging unit 200, a unit pixel 201, a photoelectric conversion element 202, a transfer switch 203, a floating diffusion (FD) 204, an amplification transistor 205, a selection switch 206, and a reset switch 207 are arranged. Reference numeral 208 denotes a signal line, 209 denotes a constant current source serving as a load for the amplifying transistor 205, 210 denotes a selection switch, 211 denotes an output amplifier, 212 denotes a vertical scanning circuit, 213 denotes a readout circuit, and 214 denotes a horizontal scanning circuit. In FIG. 2, for simplification of the drawing, unit pixels 201 are arranged in 4 rows × 4 columns in the imaging unit 200, but the present invention is not limited to this, and an arbitrary number of unit pixels 201 are arranged. Can be done.

  The unit pixel 201 includes a photodiode (PD) PD 202 as a photoelectric conversion element, transfer switches 203 and FD 204, an amplification transistor 205 that functions as an increase source follower, a selection switch 206, and a reset switch 207. Light incident on the imaging device is converted into electric charge by the PD 202. The electric charge generated in the PD 202 is transferred by the transfer switch 203 in response to the transfer pulse φTX, and is temporarily stored in the FD 204. The FD 204, the amplification transistor 205, and the constant current source 209 constitute a floating diffusion amplifier. Then, the signal charge of the pixel selected by the selection switch 206 in accordance with the selection pulse φSEL is converted into a voltage and output to the readout circuit 213 through the signal output line 208. Further, the selection switch 210 driven by the horizontal scanning circuit 214 is selectively turned on so that an output signal is selected and output to the outside of the imaging apparatus via the output amplifier 211. The charge accumulated in the FD 204 is removed by the reset switch 207 in response to the reset pulse φRES. Further, the vertical scanning circuit 212 selects the transfer switch 203, the selection switch 206, and the reset switch 207.

  For each of the pulse signals φTX, φRES, and φSEL, the pulse signals applied to the nth (n is a natural number) scanning row selected by the vertical scanning circuit 212 are described as φTXn, φRESn, and φSELn.

  FIG. 3 is a diagram illustrating the operation of the imaging apparatus according to the present embodiment. FIG. 3A shows the operation in the first mode, and FIG. 3B shows the operation in the second mode.

  As shown in FIG. 3A, in the first mode, the control unit 509 in FIG. 5 reads the image signal from the group of photoelectric conversion elements 202 arranged in the first region 301 of the imaging surface. 200 is controlled. The first mode is used when calculating a correction value for use in white balance processing from the read image signal.

  On the other hand, as shown in FIG. 3B, in the second mode, the control unit 509 reads the image signal from the photoelectric conversion element 202 group arranged in the second region 302 of the imaging surface. To control. The second mode is used when an image is recorded or displayed.

  The first region 301 may be larger than the second region 302, but preferably includes the second region 302, and more preferably includes all photoelectric conversion elements arranged on the imaging surface. In addition, the imaging apparatus according to the present embodiment includes an adder (not shown) for adding a part of a plurality of signals read from the first photoelectric conversion element group in the first mode. It is preferable to prepare for. In this case, the control unit 509 ensures that the frame rates of the first mode and the second mode are the same (the number of signals read from the imaging unit 200 is the same in the first mode and the second mode). Therefore, it is preferable to set the number of signals to be added by the adding unit. By adding and outputting a part of the plurality of signals read from the first photoelectric conversion element group, the number of signals read from the horizontal scanning circuit 214 can be reduced.

  Further, the control unit 509 may perform thinning readout for the first photoelectric conversion element group in the first mode. In this case, the control unit 509 ensures that the frame rates of the first mode and the second mode are the same (the number of signals read from the imaging unit 200 is the same in the first mode and the second mode). Therefore, it is preferable to set a thinning rate for thinning readout.

  With such a configuration, it is possible to use the WB coefficient calculated from the image of the first region 301 in which white is likely to exist even when using the electronic zoom in which the white ratio is likely to decrease. Therefore, it is possible to perform appropriate WB processing. For example, even when the number of whites is small and the ratio of chromatic colors is high, such as when a person is increased by zoom shooting, the color temperature specified from the image of the first region 301 having a high probability of white is used, and an appropriate WB processing is possible.

  FIG. 4 is a diagram showing a part of a color filter array used in the imaging apparatus of FIG. A case is shown in which the first color filter is red (R), the second color filter is green (G), the third color filter is green (G), and the fourth color filter is blue (B). . This array of color filter arrays is called a Bayer array, among the primary color filter arrays, and is a color filter array having high resolution and excellent color reproducibility.

  FIG. 5 is a diagram showing an outline of an imaging system using the imaging apparatus of FIG. Reference numeral 501 denotes a lens portion (referred to as “lens” in FIG. 5) as an optical system, 502 denotes a lens driving portion, 503 denotes a mechanical shutter (noted as mechanical shutter), and 504 denotes a mechanical shutter driving portion (“shutter driving portion” in FIG. 5). 505) denotes an A / D converter. Reference numeral 200 denotes an imaging unit having the configuration shown in FIG.

  Reference numeral 506 denotes an imaging signal processing circuit, 507 denotes a timing generation unit, 508 denotes a memory unit, 509 denotes a control unit, 510 denotes a recording medium control interface unit (indicated as “recording medium control I / F unit” in FIG. 5), 511. Indicates a display. Reference numeral 512 denotes a recording medium, 513 denotes an external interface unit (indicated as “external I / F unit” in FIG. 5), 514 denotes a photometric unit, and 515 denotes a distance measuring unit.

  The subject image that has passed through the lens unit 501 is formed on the imaging unit 200. The subject image formed on the imaging unit 200 is captured as an image signal. The imaging signal processing circuit 506 amplifies the image signal, converts the image signal from an analog signal to a digital signal, and obtains R, G1, G2, and B signals after A / D conversion and A / D conversion. Further, the imaging signal processing circuit 506 performs various corrections, compression of image data, and the like.

  The lens unit 501 is driven and controlled by a lens driving unit 502 such as zoom, focus, and diaphragm. The mechanical shutter 503 is a shutter mechanism having only a curtain corresponding to the rear curtain of a focal plane type shutter used in a single-lens reflex camera. The mechanical shutter 503 is driven and controlled by a shutter driving unit 504. The timing generation unit 507 outputs various timing signals to the imaging unit 200 and the imaging signal processing circuit 506. A control unit 509 controls the entire imaging apparatus and performs various calculations. The memory unit 508 temporarily stores image data. The recording medium control interface unit 510 records image data on the recording medium 512 and reads or reads image data from the recording medium 512. The display unit 511 displays image data. The recording medium 512 is a detachable storage medium such as a semiconductor memory, and records image data. The external interface unit 513 is an interface for communicating with an external computer or the like. The photometry unit 514 detects the brightness information of the subject, and the distance measurement unit 515 detects the distance information to the subject.

  FIG. 6 illustrates a WB processing circuit 601 that performs processing based on signals R, G1, G2, and B from the A / D converter 505 in the imaging signal processing circuit 506 in FIG. 5 and WB circuit control of the signal processing control unit 605. It is the block diagram which showed the example of a structure concerning in detail.

  Reference numeral 601 denotes a WB processing circuit (indicated as “WB” in FIG. 6), 602 denotes a color signal generation circuit, 603 denotes a luminance signal generation circuit, 604 denotes an APC (Automatic Power Control) circuit as a correction unit, and 605 denotes a signal processing control unit. It is. Reference numeral 606 denotes a CPU, 607 denotes a ROM, and 608 denotes a RAM. The ROM 607 includes a WB control program 607a, a WB coefficient calculation program 607b, and a white detection range table 607c. The RAM 608 includes an image data storage area 608a, a color evaluation value storage area 608b, and a calculated WB coefficient storage area 608c.

  Digital image signals R, G1, G2, and B are input to the WB processing circuit 601 and the signal processing control unit 605 in units of blocks. The signal processing control unit 605 provides the WB coefficient determined based on the input digital image signals R, G1, G2, and B to the WB processing circuit 601, and the WB processing circuit 601 executes WB processing. The

  The signal processing control unit 605 includes an arithmetic control CPU 606, a ROM 607 for storing fixed programs and data, and a RAM 608 for primary storage. In the present embodiment, it is assumed that the WB process is fixed in advance, and a processing program, a table, and the like are stored in the ROM 607. However, these may be stored in a rewritable nonvolatile RAM so as to be changeable.

  The ROM 607 has a program storage area and a data storage area. In the present embodiment, the program storage area has a WB control program 607a containing the procedure of WB processing, a WB coefficient calculation program 607b for obtaining a WB coefficient as shown in the background art, and the data storage area is shown in FIG. A white detection range table 607c as shown in FIG.

  The RAM 608 stores an image data storage area 608a for storing the amount of data necessary for WB processing, input color data, a color evaluation value storage area 608b for storing color evaluation values, and a WB coefficient calculated in real time. It has a calculated WB coefficient storage area 608c.

  In this embodiment, the data is used according to the program stored in the ROM 607. Then, based on the digital image data R, G1, G2, and B input by the CPU 606, the determination is performed by calculating and selecting the WB coefficient while using the area of the RAM 608. The determined WB coefficient is sent to the WB processing circuit 601, and the WB processing circuit 601 executes appropriate WB processing.

  After the WB processing is performed by the WB processing circuit 601, the color signal generation circuit 602 generates the color difference signals U and V. On the other hand, a luminance signal Y is generated through a luminance signal generation circuit 603 that generates a luminance signal and an APC circuit 604 that amplifies a high-frequency component of the luminance signal. A color image is obtained from the color difference signals U and V and the luminance signal Y.

  Note that how the generated color difference signals U and V and the luminance signal Y are processed differs depending on the purpose and application of each imaging apparatus, but these various processing methods can also be applied to this embodiment. Is possible.

  FIG. 1 shows a conceptual diagram of the operation in the present embodiment. An operation example of an imaging apparatus that is driven in a moving image mode that is set to 4 × electronic zoom will be described as this embodiment.

  FIG. 1 is a diagram showing a state where moving image output data is arranged in time series from frame M-3 to frame N + 3 (where N> M, and M and N are integers). When an image signal is read out at m (m is an integer of 2 or more) frames per second, out of m frames, n (n is an integer of 1 or more smaller than m) is read out in the first mode. Of these, mn frames are read in the second mode. A frame M-3 is a frame that is driven and read in the first mode in a state in which the electronic zoom is set to OFF before the electronic zoom is set. The frame M-2 and subsequent frames show the state set to the electronic zoom ON state, and are frames that are driven and read in the first mode or the second mode. In the first mode, the effective pixel region 901 shown in FIG. 9 is read in the vertical direction in the imaging unit 200, for example, every two lines. In the second mode, the imaging unit 200 reads out the area 902 shown in FIG. The effective pixel region 901 corresponds to the first region 301 in FIG. 3, and the region 902 corresponds to the second region 302 in FIG. The region 902 is, for example, a region up to 50% diagonally from the center of the effective pixel region 901, and is in a state where electronic zoom is performed four times as compared with the case where the effective pixel region 901 is read. Note that the frame rate when the imaging unit 200 is driven in the first mode and the frame rate when the imaging unit 200 is operated in the second mode are preferably set to be the same.

  Before the frame M-3, the imaging unit 200 is driven in the first mode, and after the frame M-2, the imaging unit 200 is driven in the first mode or the second mode. As shown in the frame M and the frame N, the imaging unit 200 is driven in the first mode at a rate of one frame for every fixed frame. For example, if one frame is set every 10 seconds, the first mode is set at a rate of one frame every 300 frames when the frame rate is 30 frames / second. Then, in the frames M and N read when driven in the first mode, the correction values for the WB processing are calculated, and the correction values are reflected in the frames M + 1 and N + 1 and later, respectively. In frames M and N that are driven and read in the first mode, an area smaller than the angle of view of the read frame is cut out, and the cut out image is resized to be an output image. Preferably, the imaging signal processing circuit 507 cuts out a region having the same angle of view as the frame read in the second mode, and resizes the image to obtain an output image. Thus, the frame rate can be kept constant by using the image read in the first mode as the output image. In this case, since the resized image read in the first mode has a lower resolution than the image read in the second mode, the APC circuit 604 serving as a correction unit performs correction for suppressing the difference in resolution. Preferably it is done. Specifically, APC processing is performed so as to increase the amplification factor of the high-frequency luminance signal.

  By using the above method, it is possible to perform appropriate WB processing even when the white ratio is likely to decrease, such as when moving pictures are shot using electronic zoom. In addition, by setting the frame rates of the two different modes to be the same, a smooth moving image can be realized.

  In the above method, a frame read in the first mode is used as an output image. However, if the frame read out in the first mode is resized to the same angle of view as the image read out in the second mode, the information amount is less than that of the image read out in the second mode, and the resolution is lowered. to degrade.

  Therefore, only the frames read in the second mode are read at a constant frame interval, and the frames that are driven and read in the first mode for performing the WB process are read between the frames that are driven and read in the second mode. As an output image, only a frame read in the second mode may be used. In this case, since the image data of the frame read in the first mode is not used, the image quality is not deteriorated by using the frame read in the first mode as the output image. In addition, since the frames read out in the second mode are read out at a constant frame interval, a smooth moving image can be realized.

  FIG. 10 shows a conceptual diagram of another operation in the present embodiment. In the present embodiment, an example of the operation of the imaging apparatus in the case of taking a still image with the electronic zoom set to 4 times is shown.

  FIG. 10 is a diagram illustrating a state in which frames read from the imaging device are arranged in time series from left to right until a still image is captured from several frames immediately before SW2. The frames P-3 to P-1 are driven in the first mode, and the second mode is switched by SW2 to read the frame P. At this time, the first mode is a mode in which the imaging unit 200 reads out the effective pixel region 901 shown in FIG. 9 every two lines in the vertical direction, and the second mode is a mode in which the imaging unit 200 reads out the region 902 shown in FIG. Mode. The region 902 is a region up to 50% diagonally from the center in the effective pixel region 901, and is in a state in which electronic zoom is performed four times as compared with the case where the effective pixel region 901 is read. The image data from the frame P-3 to the frame P-1 is displayed on the display unit 512 as a resized image obtained by cutting out a predetermined area so as to have the same angle of view as the frame P in the imaging signal processing circuit 507. Is done. At the same time, the imaging signal processing circuit 507 performs WB processing from the image data of the frame P-1, and creates a still image based on the WB coefficient obtained as a result and the image data of the frame P. At this time, the image data obtained from the frame P-3 to the frame P-1 is APC processed so that the amplification factor of the high-frequency luminance signal in the APC circuit 604 is higher than the image data obtained from the frame P (where P is an integer). It is desirable to do.

  As described above, by using the above method, it is possible to perform appropriate WB processing even when the white ratio is highly likely to decrease, such as when still image shooting is performed using electronic zoom. .

  Although the above embodiment has been described by taking a digital camera as an example, the present invention is not limited to a digital camera. Also included are digital video cameras, mobile phones with digital cameras, and scanners. Also included are those that perform imaging by remote operation in which a release instruction is issued from the PC while the camera and the PC are connected by wire or wirelessly. What supplied the program code of the software for implement | achieving the function of the above-mentioned embodiment with respect to the computer in the apparatus or system connected with various devices is also contained under the category of this invention. In addition, those implemented by operating the various devices in accordance with a program stored in a computer (CPU or MPU) of the system or apparatus are also included in the scope of the present invention.

  In this case, the program code of the software itself realizes the functions of the above-described embodiment. That is, the program code itself and means for supplying the program code to the computer, for example, a recording medium storing the program code constitutes the present invention. As a recording medium for storing the program code, for example, a flexible disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used.

  Further, by executing the program code supplied by the computer, not only the functions of the above-described embodiments are realized, but also an OS (operating system) in which the program code is operating in the computer falls within the scope of the present invention. included. Alternatively, it goes without saying that the program code is also included in the embodiment of the present invention when the functions of the above-described embodiment are realized in cooperation with other application software.

  Further, after the supplied program code is stored in the memory provided in the function expansion board of the computer or the function expansion unit connected to the computer, the CPU provided in the function expansion board or function expansion unit based on the instruction of the program code Is also included. Needless to say, the present invention also includes a case where the CPU or the like performs part or all of the actual processing and the functions of the above-described embodiments are realized by the processing.

It is a conceptual diagram of operation | movement of the imaging device which concerns on suitable embodiment of this invention. 1 is a schematic diagram of an imaging apparatus according to a preferred embodiment of the present invention. 1 is a schematic diagram of an imaging apparatus according to a preferred embodiment of the present invention. It is a figure which shows the color filter used for the imaging device which concerns on suitable embodiment of this invention. 1 is a schematic diagram of an imaging system according to a preferred embodiment of the present invention. It is a block diagram which shows the structural example of the part regarding the white balance process which concerns on suitable embodiment of this invention. It is a figure which shows the example of the color temperature detection block which concerns on suitable embodiment of this invention. It is a figure which shows the example of a white detection range. It is a figure which shows the example of the effective pixel area | region of the imaging device which concerns on suitable embodiment of this invention. It is a conceptual diagram of operation | movement of the imaging device which concerns on suitable embodiment of this invention.

Explanation of symbols

200 Image pickup unit 202 Photoelectric conversion element 301 First region 302 Second region

Claims (9)

A first mode in which a plurality of photoelectric conversion elements are disposed on the imaging surface, and an image signal is read from a first photoelectric conversion element group disposed in a first region of the imaging surface, and the first of the imaging surface An image pickup unit that can be driven in a second mode for reading out an image signal from a second photoelectric conversion element group disposed in a second region included in the first region smaller than the first region;
A white balance correction value is calculated based on an image signal obtained by driving the imaging unit in the first mode, and the imaging unit is driven in the second mode using the white balance correction value. and a control unit for controlling to perform white balance processing of the image signal obtained by,
When the control unit reads out an image signal of m (m is an integer of 2 or more) frames every predetermined second, the control unit performs the operation in the n (n is an integer of 1 or more smaller than m) of the m frames. Driving the image pickup unit in the first mode to read an image signal, and controlling to drive the image pickup unit in the second mode to read the image signal in the mn frames out of the m frames. An imaging device that is characterized. The imaging apparatus according to claim 1 , wherein the control unit drives the imaging unit in the first mode every predetermined frame. The imaging unit includes an adding unit that adds image signals read from the photoelectric conversion elements, and the control unit is configured so that the frame rate is the same in the first mode and the second mode. the imaging apparatus according to claim 1 or 2, characterized in that to set the number of the image signal to be added by the addition section. Wherein, when driving the imaging unit in the first mode, according to claim 1 or 2, characterized in that the control from the first photoelectric conversion element group so as to perform thinning-out reading of the image signals The imaging device described in 1. The imaging apparatus according to claim 4 , wherein the control unit sets the thinning rate of the thinning readout so that a frame rate is the same between the first mode and the second mode. The control unit cuts out an image having the same angle of view as an image obtained in the second mode from an image obtained by driving the imaging unit in the first mode, and resizes the cut-out image. the imaging apparatus according to any one of claims 1 to 5 and. The imaging apparatus according to claim 6 , further comprising a correction unit that corrects a difference in resolution between the resized image and an image obtained by driving the imaging unit in the second mode. An imaging system comprising: an optical system; and the imaging apparatus according to any one of claims 1 to 7 . A first mode in which a plurality of photoelectric conversion elements are disposed on the imaging surface, and an image signal is read from a first photoelectric conversion element group disposed in a first region of the imaging surface; and the first mode of the imaging surface Control method for an imaging apparatus including an imaging unit that can be driven in a second mode that reads an image signal from a second photoelectric conversion element group that is arranged in a second area that is smaller than the area and included in the first area Because
A white balance correction value is calculated based on an image signal obtained by driving the imaging unit in the first mode, and the imaging unit is driven in the second mode using the white balance correction value. When the image signal of m (where m is an integer of 2 or more) frames are read out every predetermined second, n (n is m) of the m frames. In the first frame), the image pickup unit is driven to read the image signal in the first mode, and the image pickup unit is operated in the second mode in the mn frame among the m frames. A control method for an imaging apparatus, wherein the control is performed so as to drive and read an image signal .

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