JP2013222980A - Image-pickup device and image-pickup method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image pick-up device which can maintain or enhance sensitivity without deteriorating the resolution and S/N ratio of a captured image.SOLUTION: An image pick-up device includes an exposure control unit for controlling the level of a signal input from an image sensor, a noise removal unit for performing noise reduction processing of an image thus captured, and an image size change unit for scaling an image thus captured by performing interpolation according to a set output image size. The upper limit of gain used for exposure control by the exposure control unit is set according to the output image size, and the intensity of noise reduction processing by the noise removal unit is changed according to the output image size, thus maintaining or enhancing the sensitivity without deteriorating the resolution and S/N ratio of a captured image.

Description

  The present invention relates to an imaging apparatus and an imaging method, and relates to an image processing technique for improving sensitivity related to a captured image.

  In recent years, an imaging apparatus having an imaging element such as a CCD has been increased in number of pixels. On the other hand, downsizing of the main body of the imaging device is progressing. With the downsizing of the image pickup apparatus, the image pickup device has to be downsized, and in order to increase the number of pixels, there is a current situation that the size of the pixel in the image pickup device has to be reduced. However, if the pixel size is reduced, the amount of light received per unit pixel is reduced, which causes a decrease in sensitivity when the exposure time is increased or the amount of noise at low illuminance is increased. In imaging devices that shoot darkness, such as surveillance cameras, shooting performance at low illuminance is an important factor, and technologies such as noise reduction, image reduction processing, and pixel addition are required to meet the desired shooting performance at low illuminance. It has penetrated.

  For example, Patent Literature 1 discloses a technique for setting a gain according to an image size enlargement / reduction ratio and increasing the sensitivity of a captured image. Patent Document 2 discloses a technique for obtaining an image having a pixel addition mode composed of a plurality of stages and having a balance between resolution and image quality expected by the user.

JP 2006-245709 A JP 2009-118247 A

  However, although the technique disclosed in Patent Document 1 sets the gain according to the image size and noise level, a sufficient signal-to-noise ratio (S / N) cannot be obtained. In the technique disclosed in Patent Document 2, the sensitivity is improved by using pixel addition. However, even if the sensitivity can be improved with respect to an image taken by a multi-pixel imaging device, the resolution is lowered. There was a problem that jaggy was conspicuous.

  An object of the present invention is to provide an imaging apparatus and an imaging method capable of maintaining or improving sensitivity without degrading the resolution and S / N of a captured image.

  An imaging apparatus according to the present invention is obtained by an imaging device that photoelectrically converts light from a subject to generate an image signal, an exposure control unit that controls a level of a signal input from the imaging device, and the imaging device. First image processing means for performing noise reduction processing on the captured image, and second processing for performing interpolation processing in accordance with the set enlargement / reduction ratio and performing enlargement / reduction of the captured image obtained by the image sensor Image processing means, and sets an upper limit of the gain in the exposure control means according to the enlargement / reduction ratio, and changes the intensity of noise reduction processing by the first image processing means according to the enlargement / reduction ratio. It is characterized by that.

  According to the present invention, the resolution and S / N of a captured image are degraded by changing the upper limit of the gain related to exposure control and the intensity of noise reduction processing according to the enlargement / reduction ratio of the captured image. Sensitivity can be maintained or improved.

It is a figure which shows the structural example of the imaging device which concerns on the 1st Embodiment of this invention. 5 is a flowchart illustrating an example of a method for determining a maximum gain and an NR level according to an output image size in the first embodiment. It is a flowchart which shows the example of the upper limit setting of NR intensity | strength according to AE mode and shutter speed in 1st Embodiment. It is a flowchart which shows the example of the determination method of the image size according to exposure of the picked-up image in 1st Embodiment. It is a figure which shows the structural example of the imaging device which concerns on the 2nd Embodiment of this invention. 10 is a flowchart illustrating an example of a method for determining a maximum gain according to an output image size and a shooting mode according to the second embodiment. It is a flowchart which shows the example of the determination method of NR level in 2nd Embodiment. It is a figure which shows the computer function which can perform the process in this embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
A first embodiment of the present invention will be described.
FIG. 1 is a block diagram illustrating a configuration example of the imaging apparatus according to the first embodiment.

  In the imaging apparatus shown in FIG. 1, the optical imaging system 100 includes an imaging lens and an aperture for imaging incident light. The image sensor 101 photoelectrically converts light from the subject imaged on the imaging surface by the optical imaging system 100 to generate an image signal of the subject. A CDS (Correlated Double Sampling) circuit 102 removes amplifier noise and reset noise included in an image signal read from the image sensor 101. An AGC (Auto Gain Control) circuit 103 amplifies the input signal. The A / D conversion circuit 104 performs analog-to-digital conversion (A / D conversion) on an analog image signal from the image sensor 101 input via the CDS circuit 102 and the AGC circuit 103 to convert it into a digital image signal.

  The exposure control unit 105 performs exposure control (AE: Auto Exposure). For example, the exposure control unit 105 controls the level of the input signal by controlling at least one of the gain, shutter speed, and aperture value so as to achieve an appropriate exposure. The exposure control unit 105 also determines whether the exposure is under (light quantity is insufficient) or over (light quantity is excessive). The maximum gain setting unit 106 sets a maximum gain that is an upper limit of a gain used in exposure control according to the output image size determined by the image size determination unit 108, in other words, the image enlargement / reduction ratio.

  The noise removing unit 107 performs noise reduction processing as a first image processing unit to reduce noise in the captured image. For example, the noise removal unit 107 includes two filters: an ε filter that uniformly removes random noise from the entire photographed image, and a cyclic filter that removes noise from a motion portion in the photographed image. The noise removal unit 107 can change the processing intensity related to noise removal. The image size determination unit 108 determines the output size of the captured image.

  The image size changing unit 109 enlarges / reduces the captured image by performing an interpolation process as a second image processing unit, and changes the captured image to an image having a desired image size. The image size changing unit 109 can change the enlargement / reduction ratio of the captured image, and can enlarge or reduce the captured image to an arbitrary size. In addition, the image size changing unit 109 can remove noise by filter processing such as LPF (Low Pass Filter) or interpolation processing when enlarging or reducing a captured image. The image output unit 110 outputs a captured image that has been subjected to various types of image processing. Note that the image output unit 110 may externally output a captured image on which image processing has been performed outside the imaging apparatus.

  In the imaging apparatus illustrated in FIG. 1, an analog image signal output from the imaging element 101 is input to the A / D conversion circuit 104 via the CDS circuit 102 and the AGC circuit 103, and the digital image is output from the A / D conversion circuit 104. A / D converted into a signal. The digital image signal is subjected to image processing such as noise reduction processing (NR processing) for reducing noise and enlargement / reduction processing using interpolation processing by the noise removing unit 107 and the image size changing unit 109. Is output to the image output unit 110. In the image processing in the imaging apparatus according to the present embodiment, the processing strength (NR level) in the NR processing is controlled according to the output image size and the shutter speed. Further, the enlargement / reduction ratio of the photographed image, that is, the output image size is appropriately changed according to the exposure (luminance) of the photographed image.

  A method for determining the maximum gain and the intensity (NR level) of NR processing according to the output image size will be described below. FIG. 2 is a flowchart illustrating an example of a method for determining the maximum gain and the NR level according to the output image size in the first embodiment. Here, in this embodiment, the value of the maximum gain decreases as the number increases for the maximum gain (1 to 3), and the effect of the NR processing increases as the number increases for the NR level (1 to 3). Shall be. That is, in the example shown in FIG. 2, the maximum gain value is the largest and the maximum gain 3 is the smallest. The processing strength of NR processing is the weakest at NR level 1 and the strongest at NR level 3.

  In the example shown in FIG. 2, the output image size is shown in three patterns of SMALL, MIDDLE, and LARGE. Although the MIDDLE is set to the full size, the enlargement process is expressed as LARGE, and the reduction process is expressed as SMALL. However, the image may be classified into three or more pattern sizes regardless of the form. The same applies to the output image size in the following description.

  First, the image size determination unit 108 determines the output image size (S101). As a result of the determination, when the output image size is smaller than the full size (S101; SMALL), the S / N is improved in the reduction process. Therefore, the maximum gain setting unit 106 sets the maximum gain 1 as the maximum gain used in the exposure control. Is selected (S102). At this time, since the random noise is averaged by the reduction process, the noise removing unit 107 selects NR level 1 having a relatively weak effect as the processing intensity of the NR process (S103).

  When the output image size is the same as the full size as a result of the determination (S101; MIDDLE), the maximum gain setting unit 106 selects the maximum gain 2 as the maximum gain used for exposure control (S104). At this time, the noise removing unit 107 selects NR level 2 which is a normal level effect as the processing intensity of the NR processing (S105). As a result of the determination, when the output image size is larger than the full size (S101; LARGE), the maximum gain setting unit 106 selects the maximum gain 3 as the maximum gain used in the exposure control (S106). At this time, since noise increases due to the enlargement process, the noise removal unit 107 selects NR level 3 that is relatively effective as the processing intensity of the NR process (S107).

  As described above, the maximum gain used in exposure control is set according to the output size of the image, and the NR level corresponding to the amount of noise at that time is appropriately selected. As a result, it is possible to minimize degradation of resolution and S / N degradation of a captured image, and it is possible to suppress a decrease in sensitivity. As the output image size decreases, an image with improved sensitivity can be obtained.

  Next, a method for setting the upper limit of the intensity of NR processing according to the AE mode and the shutter speed related to exposure control will be described. FIG. 3 is a flowchart illustrating an example of setting the upper limit of the intensity of the NR process according to the AE mode and the shutter speed in the first embodiment. In the example shown in FIG. 3, the shutter priority AE mode is one of exposure control modes in which the shutter speed is arbitrarily set to automatically set an appropriate exposure. As for the shutter speed, a slow shutter is used when the shutter speed is slower than a predetermined speed (in this embodiment, 1/30 second), and a high-speed shutter is used when the shutter speed is faster than the predetermined speed. And When the shutter speed is a high-speed shutter, a fast-moving subject can be photographed without blur.

  First, the exposure control unit 105 determines whether or not the exposure control mode is the shutter priority AE mode (S201). As a result of the determination, when the shutter priority AE mode is set and the shutter speed is the high shutter speed (S202; YES), since the recognition of moving subjects is emphasized, the upper limit of the strength of NR processing in the noise removal unit 107 is set. Lower (S203). In this way, when the shutter priority AE mode is set and the shutter speed is a high-speed shutter, the upper limit of the intensity of the NR process in the noise removal unit 107 is suppressed to the extent that the subject is not blurred.

  In addition, as a result of the determination, when the shutter priority AE mode is set and the shutter speed is slow shutter (S202; NO), the upper limit of the strength of the NR processing in the noise removal unit 107 for the purpose of placing importance on detection of a stationary subject. Is increased (S204). This is because the moving subject has already imaged and it is difficult to recognize the moving subject. If the result of determination is that the exposure control mode is not the shutter priority AE mode, the upper limit of the intensity of NR processing in the noise removal unit 107 is not changed.

  Thus, by setting the upper limit of the intensity of NR processing according to the AE mode and the shutter speed related to exposure control, it is possible to perform image processing by separating the priority between detection of a moving subject and detection of a stationary subject. The image according to the needs of the shooting scene can be obtained.

  Next, a method for changing the output image size (enlargement / reduction ratio) according to the exposure (luminance) of the captured image for each output image size will be described. FIG. 4 is a flowchart illustrating an example of a method for determining an image size according to exposure of a captured image in the first embodiment. In the example shown in FIG. 4, the image size is assumed to increase in the order of EXTRA SMALL, SMALL, MIDDLE, and LARGE.

  First, the image size determination unit 108 determines the output image size (S301). Further, the exposure control unit 105 determines the exposure of the captured image (S302, S305, S307). As a result of the determination, when the output image size is larger than the full size and the exposure of the photographed image is under (S301; LARGE, S302; YES), the output image size is equivalent to the full size in order to increase sensitivity. It is reduced (S303). In other words, when the output image size is larger than the full size and the luminance of the captured image is smaller than the predetermined value, the output image size is reduced to the full size. When the captured image is not underexposed, that is, when the proper exposure or overexposure is over (S302; NO), the output image size is not changed and remains larger than the full size (S304).

  Further, if the result of determination is that the output image size is equivalent to the full size and the exposure of the captured image is under (S301; MIDDLE, S305; YES), the output image size is larger than the full size in order to increase sensitivity. Is also reduced to a small size (S306). In other words, when the output image size is equivalent to the full size and the luminance of the captured image is smaller than the predetermined value, the output image size is reduced to be smaller than the full size. When the exposure of the captured image is not under (S305; NO), the output image size is not changed and remains equivalent to the full size (S303).

  When the output image size is smaller than the full size as a result of the determination and the exposure of the captured image is under (S301; SMALL, S307; YES), the output image size is further reduced to increase sensitivity. The image is reduced (S308). In other words, when the output image size is smaller than the full size and the brightness of the captured image is smaller than the predetermined value, the output image size is further reduced. Note that when the exposure of the captured image is not under (S307; NO), the output image size is not changed (S306).

  As described above, when the captured image is underexposed, the amount of light is insufficient and the entire image becomes dark. Therefore, by performing a reduction process at each image size, sensitivity can be increased and S / N can be reduced. Can be improved.

(Second Embodiment)
Next, a second embodiment of the present invention will be described.
FIG. 5 is a block diagram illustrating a configuration example of an imaging apparatus according to the second embodiment. 5, components having the same functions as those shown in FIG. 1 are denoted by the same reference numerals, and redundant description is omitted.

  The imaging apparatus according to the second embodiment has an infrared cut filter (hereinafter referred to as IRCF) insertion / extraction function. The IRCF 200 is used for the purpose of preventing light in the near-infrared region from passing through the image sensor 101 in order to match color reproducibility with human color vision characteristics. The IRCF control unit 201 controls insertion / removal of the IRCF 200. Under the control of the IRCF control unit 201, the IRCF 200 is inserted into and removed from the optical path between the optical imaging system 100 and the image sensor 101. The IRCF insertion / extraction determination unit 202 acquires the current insertion / removal state of the IRCF 200 and determines whether the mode is the day mode or the night mode. The maximum gain determination unit 203 determines whether or not the gain in exposure control is the maximum gain.

  Here, the use environment of the day mode and the night mode in the imaging apparatus according to the second embodiment will be described. In an imaging device that is used day or night like a surveillance camera, the IRCF control unit 201 inserts the IRCF 200 into the optical path (day mode) when there is sufficient illuminance such as during the daytime. Output. On the other hand, at low illuminance such as at night, sensitivity is more important than color reproducibility due to the effect of noise due to gain. In that case, in order to use near-infrared light in addition to visible light, the IRCF controller 201 retracts the IRCF 200 to the outside of the optical path (night mode), and the visible light and near-infrared light are sent to the image sensor 101. Receive light.

  The processing in the imaging apparatus according to the second embodiment is the same as the processing in the imaging apparatus according to the first embodiment, except for the processing related to insertion / extraction of the IRCF 200 with respect to the optical path between the optical imaging system 100 and the imaging element 101. The same effects as those of the first embodiment are obtained. Hereinafter, image processing in the imaging apparatus according to the second embodiment and processing executed by the IRCF control unit 201 including the IRCF insertion / extraction determination unit 202 will be described.

  First, a method for determining the maximum gain according to the output image size and the shooting mode will be described. FIG. 6 is a flowchart illustrating an example of a method for determining the maximum gain according to the output image size and the shooting mode in the second embodiment. In the present embodiment, the maximum gain (1 to 4) is assumed to decrease as the number increases. That is, in the example shown in FIG. 6, the maximum gain value decreases in the order of maximum gain 1, maximum gain 2, maximum gain 3, and maximum gain 4, with maximum gain 1 being the largest and maximum gain 4 being the smallest.

  First, the image size determination unit 108 determines the output image size (S401). Further, the IRCF insertion / extraction determination unit 202 determines whether the shooting mode is the day mode or the night mode based on the current state of the IRCF 200 (S402, S405, S407).

  As a result of the determination, when the output image size is smaller than the full size (S401; SMALL) and when the shooting mode is the day mode (S402; NO), the maximum gain setting unit 106 uses the maximum gain used in the exposure control. Then, the maximum gain 1 is set (S403). On the other hand, when the shooting mode is the night mode (S402; YES), the maximum gain setting unit 106 sets the maximum gain 2 as the maximum gain used in the exposure control (S404).

  When the output image size is equivalent to the full size (S401; MIDDLE) and when the shooting mode is the day mode (S405; NO), the maximum gain setting unit 106 uses the maximum gain as the maximum gain used in the exposure control. 2 is set (S404). On the other hand, when the shooting mode is the night mode (S405; YES), the maximum gain setting unit 106 sets the maximum gain 3 as the maximum gain used in the exposure control (S406).

  When the output image size is larger than the full size (S401; LARGE), and when the shooting mode is the day mode (S407; NO), the maximum gain setting unit 106 sets the maximum gain used in the exposure control as the maximum gain. Gain 3 is set (S406). On the other hand, when the shooting mode is the night mode (S407; YES), the maximum gain setting unit 106 sets the maximum gain 4 as the maximum gain used in the exposure control (S408).

  As described above, for each output image size, it is determined whether the shooting mode is the day mode or the night mode, and the maximum gain used in the exposure control is set. As a result, when the shooting mode is the day mode, the maximum gain can be set higher than when the shooting mode is the night mode, and the sensitivity of the shot image in the day mode can be improved.

  Next, a method for determining the strength (NR level) of NR processing in the second embodiment will be described. FIG. 7 is a flowchart illustrating an example of an NR level determination method according to the second embodiment. In the present embodiment, it is assumed that the effect of NR processing increases as the number increases for NR levels (1 to 5). That is, in the example shown in FIG. 7, the processing strength of NR processing increases in the order of NR level 1, NR level 2, NR level 3, NR level 4, and NR level 5, NR level 1 is the weakest, and NR level 5 Is the strongest.

  First, the image size determination unit 108 determines the output image size (S501). Further, the maximum gain determination unit 203 determines whether the gain in exposure control is the maximum gain (S502, S506, S511). Further, the IRCF insertion / extraction determination unit 202 determines whether the shooting mode is the day mode or the night mode (S503, S507, S509, S512).

  As a result of the determination, when the output image size is smaller than the full size (S501; SMALL), the noise removing unit 107 selects the processing strength of the NR process as follows. When the gain in the exposure control is not the maximum gain (S502; NO) and the shooting mode is the day mode (S503; NO), NR level 1 is selected as the processing intensity of the NR process (S504). On the other hand, when the gain in exposure control is not the maximum gain (S502; NO) and the shooting mode is the night mode (S503; YES), NR level 2 is selected as the processing intensity of the NR process (S505). When the gain in exposure control is the maximum gain (S502; YES) and the shooting mode is the day mode (S507; NO), NR level 2 is selected as the processing intensity of the NR process (S505). On the other hand, when the gain in exposure control is the maximum gain (S502; YES) and the shooting mode is the night mode (S507; YES), NR level 3 is selected as the processing intensity of the NR process (S508).

  If the output image size is equivalent to the full size as a result of the determination (S501; MIDDLE), the noise removing unit 107 selects the processing strength of the NR process as follows. When the gain in the exposure control is not the maximum gain (S506; NO) and the shooting mode is the day mode (S507; NO), NR level 2 is selected as the processing intensity of the NR process (S505). On the other hand, when the gain in exposure control is not the maximum gain (S506; NO) and the shooting mode is the night mode (S507; YES), NR level 3 is selected as the processing intensity of the NR process (S508). When the gain in exposure control is the maximum gain (S506; YES) and the shooting mode is the day mode (S509; NO), NR level 3 is selected as the processing intensity of the NR process (S508). On the other hand, when the gain in exposure control is the maximum gain (S506; YES) and the shooting mode is the night mode (S509; YES), NR level 4 is selected as the processing intensity of the NR process (S510).

  If the output image size is larger than the full size as a result of the determination (S501; LARGE), the noise removing unit 107 selects the processing strength of the NR process as follows. When the gain in exposure control is not the maximum gain (S511; NO) and the shooting mode is the day mode (S509; NO), NR level 3 is selected as the processing intensity of the NR process (S508). On the other hand, when the gain in exposure control is not the maximum gain (S511; NO) and the shooting mode is the night mode (S509; YES), NR level 4 is selected as the processing intensity of the NR process (S510). When the gain in exposure control is the maximum gain (S511; YES) and the shooting mode is the day mode (S512; NO), NR level 4 is selected as the processing intensity of the NR process (S510). On the other hand, when the gain in the exposure control is the maximum gain (S511; YES) and the shooting mode is the night mode (S512; YES), NR level 5 is selected as the processing intensity of the NR process (S513).

  As described above, for each output image size, it is determined whether the gain in exposure control is the maximum gain, and whether the shooting mode is the day mode or the night mode, and the NR processing is performed. Determine the processing intensity. As a result, it is possible to prevent degradation of resolution and S / N of captured images and improve sensitivity.

(Other embodiments of the present invention)
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.

  For example, the image processing in the imaging apparatus shown in the first and second embodiments has a computer function 800 as shown in FIG. 8, and the CPU 801 performs the operations in the first and second embodiments. The As shown in FIG. 8, the computer function 800 includes a CPU 801, a ROM 802, and a RAM 803. Further, a controller (CONSC) 805 of the operation unit (CONS) 809 and a display controller (DISPC) 806 of a display (DISP) 810 as a display unit are provided. Furthermore, a hard disk (HD) 811, a controller (DCONT) 807 of a storage device (STD) 812 such as various storage media, and a network interface card (NIC) 808 are provided. The functional units 801, 802, 803, 805, 806, 807, and 808 are configured to be communicably connected to each other via a system bus 804.

  The CPU 801 generally controls each component connected to the system bus 804 by executing software stored in the ROM 802 or the HD 811 or software supplied from the STD 812. That is, the CPU 801 reads out and executes a processing program for performing the operation as described above from the ROM 802, HD 811, or STD 812, thereby performing control for realizing the operation in the first and second embodiments. Do. The RAM 803 functions as a main memory or work area for the CPU 801. The CONSC 805 controls an instruction input from the CONS 809. The DISPC 806 controls the display of the DISP 810. The DCONT 807 controls access to the HD 811 and the STD 812 that store a boot program, various applications, user files, a network management program, and the processing programs in the first and second embodiments. The NIC 808 exchanges data with other devices on the network 813 in both directions.

  The above-described embodiments are merely examples of implementation in carrying out the present invention, and the technical scope of the present invention should not be construed as being limited thereto. That is, the present invention can be implemented in various forms without departing from the technical idea or the main features thereof.

DESCRIPTION OF SYMBOLS 101 Image sensor, 105 Exposure control part, 106 Maximum gain setting part, 107 Noise removal part, 108 Image size determination part, 109 Image size change part, 200 Infrared cut filter (IRCF), 201 IRCF control part, 202 IRCF insertion / extraction determination part , 203 Maximum gain determination unit

Claims (9)

An image sensor that photoelectrically converts light from a subject to generate an image signal;
Exposure control means for controlling the level of a signal input from the image sensor;
First image processing means for performing noise reduction processing on a captured image obtained by the imaging element;
A second image processing unit that performs an interpolation process according to a set enlargement / reduction ratio and enlarges / reduces the captured image obtained by the image sensor;
The upper limit of the gain in the exposure control means is set according to the enlargement / reduction ratio, and the intensity of noise reduction processing by the first image processing means is changed according to the enlargement / reduction ratio. .   The imaging apparatus according to claim 1, wherein the upper limit of the gain in the exposure control unit is set to be larger as the image size after being enlarged / reduced by the second image processing unit is smaller.   The imaging apparatus according to claim 1, wherein when the shutter speed is faster than a predetermined speed, the upper limit of the intensity of noise reduction processing by the first image processing unit is lowered.   The imaging apparatus according to claim 1, wherein when the shutter speed is slower than a predetermined speed, the upper limit of the intensity of noise reduction processing by the first image processing unit is increased.   5. The imaging apparatus according to claim 1, wherein the enlargement / reduction ratio in the second image processing unit is changed according to the luminance of the captured image.   6. The image pickup apparatus according to claim 5, wherein when the luminance of the photographed image is smaller than a predetermined value, the second image processing unit changes an image size that is enlarged or reduced to a smaller image size. An infrared cut filter that is inserted into and removed from an optical path through which light from the subject is incident on the image sensor;
In the state where the infrared cut filter is inserted, the upper limit of the gain in the exposure control means is set larger than the state where the infrared cut filter is removed,
The imaging apparatus according to claim 1, wherein the intensity of noise reduction processing by the first image processing unit is changed according to an insertion / extraction state of the infrared cut filter. An exposure control process for controlling the level of a signal input from an image sensor that photoelectrically converts light from a subject;
A first image processing step of performing noise reduction processing on a captured image obtained by the imaging element;
A second image processing step of performing an interpolation process according to a set enlargement / reduction ratio and enlarging / reducing the photographed image obtained by the imaging device,
An imaging method comprising: setting an upper limit of gain in the exposure control step according to the enlargement / reduction ratio; and changing an intensity of noise reduction processing by the first image processing step according to the enlargement / reduction ratio. . An exposure control step for controlling the level of a signal input from an image sensor that photoelectrically converts light from a subject;
A first image processing step of performing noise reduction processing on a captured image obtained by the imaging element;
Performing an interpolation process according to the set enlargement / reduction ratio, and causing the computer to execute a second image processing step for enlarging / reducing the captured image obtained by the imaging element;
An upper limit of the gain in the exposure control step is set according to the enlargement / reduction ratio, and the intensity of the noise reduction process in the first image processing step is changed according to the enlargement / reduction ratio. .

Images