JP2009038439A - Imaging method performing spatial filtering and its imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging apparatus in which the cut-off frequency when the low frequency components of a captured image are removed is set such that the high frequency noise, e.g. an quantization error, can be reduced effectively and surely. <P>SOLUTION: An image processing means for picking up an image by receiving the light from an optical system and processing the imaging output, i.e. image data, performs spatial filtering for removing the components of higher frequency than a cut-off frequency dependent on the numerical aperture of an optical system from the image data. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an imaging method suitable for high-magnification imaging such as a microscope and an imaging apparatus thereof, and in particular, to perform spatial filter processing for removing frequency components higher than a cutoff spatial frequency determined from the numerical aperture NA of an optical system. The present invention relates to an imaging method and an imaging apparatus thereof.

  2. Description of the Related Art Conventionally, as an imaging device, a device that photoelectrically converts light incident through an imaging optical system using a CCD (charge-coupled device) and outputs the same is known. For example, Japanese Unexamined Patent Application Publication No. 2004-289786 (Patent Document 1) discloses an imaging apparatus 100 including an imaging unit 101 and an image processing unit 110 as shown in FIG. The imaging unit 101 functions as an imaging unit that receives incident light from an imaging target and performs photoelectric conversion, and for example, a CCD camera is used. The imaging unit 101 uses a CCD as an imaging element, and an imaging optical system is installed in front of the CCD.

  The image processing unit 110 has a function as an image processing unit that performs image processing on a captured image output from the imaging unit 101, and includes a spatial filter 111 and a D / A conversion unit 112. The spatial filter 111 is a spatial filter that removes a predetermined low-frequency component in the spatial frequency of the photographic signal and reduces halation around the high-luminance portion in the photographic image. The D / A conversion unit 112 converts the output signal of the spatial filter 111 from a digital signal to an analog signal and outputs it as a video signal.

  The spatial filter 111 performs a discrete Fourier transform process, a low-frequency removal process, and an inverse discrete Fourier transform process, or removes a low-frequency component in the spatial frequency of a captured image using a one-dimensional digital filter or a two-dimensional digital filter. Things are used.

The imaging device described in Patent Document 1 described above removes a predetermined low-frequency component in the spatial frequency of a photographic signal in order to reduce halation around a high-luminance portion in a photographic image. An imaging apparatus that removes a high-frequency component of a photographic signal is also known in order to reduce a quantization error mixed during digital conversion.
JP 2004-289786 A

  In the image pickup apparatus that removes the low-frequency component of the photographed image described in Patent Document 1 described above or the image pickup apparatus that removes the high-frequency component of the photographed image in order to reduce the quantization error, The cut-off spatial frequency is often determined based on experience and intuition. Thus, if the cut-off spatial frequency is determined based on experience and intuition, the quantization error cannot be effectively reduced, and there is a problem that appropriate photographing cannot be performed.

  The present invention has been made for the above-described circumstances, and an object of the present invention is to effectively and reliably reduce a cutoff spatial frequency when removing a low-frequency component of a captured image and a high-frequency noise such as a quantization error. It is an object of the present invention to provide an imaging method and an imaging apparatus for performing a spatial filter process that is set so as to be reduced.

  The present invention relates to an imaging method for receiving and imaging light from an optical system and performing image processing on image data as an imaging output. The object of the present invention is a cutoff spatial frequency determined by the numerical aperture NA of the optical system. This is achieved by removing higher frequency components from the image data and performing spatial filtering.

  The present invention relates to an imaging method for receiving and imaging light from an optical system and performing image processing on image data which is an imaging output. The object of the present invention is to perform first Fourier transform on the image data by performing a discrete Fourier transform. The second image data is generated by removing a frequency component higher than the cutoff spatial frequency determined by the numerical aperture NA of the optical system from the first image data, and the second image data is subjected to inverse discrete Fourier transform. Generating a third image data and outputting it, or performing a spatial filtering process, or performing a one-dimensional digital filtering process on the image data, and a frequency higher than a cutoff spatial frequency determined by the numerical aperture NA of the optical system Spatial filtering is performed by removing components from the image data, or two-dimensional digital filtering is applied to the image data. And performing spatial filtering by removing a frequency component higher than a cutoff spatial frequency determined by the numerical aperture NA of the optical system from the image data, or performing the imaging with a plurality of imaging elements, and performing the plurality of imaging The elements are arranged such that the mutual distance is twice the cutoff spatial frequency determined by the numerical aperture NA of the optical system, and spatial filtering is performed by removing frequency components higher than the cutoff spatial frequency from the image data. Or by scanning the image sensor so that the distance between the points received by the image sensor is twice the cut-off spatial frequency determined by the numerical aperture NA of the optical system. In addition, a scanning speed of the image sensor and a time interval of light reception of the image sensor are set, and the image data is It is achieved by performing spatial filtering to be free of frequency components higher than-off spatial frequency.

The present invention also relates to an imaging method for receiving and imaging light from an optical system and performing image processing on first image data that is an imaging output. The object of the present invention is to perform the first by scanning an imaging device. One image data is generated, a cutoff spatial frequency is determined based on the numerical aperture NA of the optical system, and data in which a distance between points received by the image sensor is twice the cutoff spatial frequency is the first data. The second image data is generated by decimating from one image data, and the second image data does not contain a frequency component higher than the cutoff frequency, and is subjected to a spatial filter process, and the numerical aperture NA is further reduced. The spot image is formed by inputting from the outside, or a position where the light intensity of the image data or the first image data is approximately half of the peak value, and the spot image Calculating the diameter d of the spot image from the numerical aperture NA
NA = cλ / πd
(Where c is (2J ₁ (x)) ² = 0.5 (J ₁ (x) is the smallest solution of the first type Bessel function, a constant of about 1.61634, and λ is the wavelength of light. is there.)
Or the first dark ring of the spot image of the image data or the first image data is extracted by an edge extraction method or the like, the diameter d of the first dark ring is obtained, and the numerical aperture NA is determined.
NA = cλ / πd
Where c is the minimum solution of (2J ₁ (x)) ² = 0 (J ₁ (x) is the first kind Bessel function), a constant of about 3.832, and λ is the wavelength of light. )
Is achieved more effectively.

  Furthermore, the present invention relates to an imaging apparatus including an imaging unit that receives and captures light from an optical system, and an image processing unit that performs image processing on image data output from the imaging unit. The image processing means comprises a spatial filter that removes from the image data a frequency component higher than a cutoff spatial frequency determined by the numerical aperture NA of the optical system, or the image processing means comprises the image data A Fourier transform unit for generating a first image data by performing a discrete Fourier transform on the second image by removing a frequency component higher than a cutoff spatial frequency determined based on a numerical aperture NA of the optical system from the first image data. A spatial filter for generating data, and inverse Fourier transform for generating and outputting third image data by performing inverse discrete Fourier transform on the second image data. Or the image processing means performs one-dimensional digital filter processing on the image data, and removes a frequency component higher than a cutoff spatial frequency determined by the numerical aperture NA of the optical system from the image data. A function of removing a frequency component higher than a cutoff spatial frequency determined by a numerical aperture NA of the optical system from the image data by providing a function or by the image processing means performing two-dimensional digital filter processing on the image data Or the imaging means comprises a plurality of imaging devices, and the plurality of imaging devices are arranged such that the distance between them is twice the cutoff spatial frequency determined by the numerical aperture NA of the optical system. A frequency component higher than the cut-off spatial frequency is removed from the image data. Or the imaging means comprises an imaging device, and the image data is generated by scanning the imaging device, and the distance between points received by the imaging device is determined by the numerical aperture NA of the optical system. The scanning is performed by setting the scanning speed of the image sensor and the light reception time interval of the image sensor so as to be twice the cut-off spatial frequency, and the image data has a frequency component higher than the cut-off spatial frequency. The image processing means includes means for generating and outputting the first image data by scanning the image sensor, or the image processing means is configured to adjust the numerical aperture NA of the optical system. A function for determining a cut-off spatial frequency based on the data, and data in which a distance between points at which the image sensor receives light is twice the cut-off spatial frequency. And the second image data is generated by thinning out from one image data, and the second image data does not include a frequency component higher than the cut-off spatial frequency.

  According to the present invention, the cut-off spatial frequency for removing high-frequency components from the photographed image is determined by an objective mathematical expression based on the numerical aperture NA of the optical system, so that information on the light passing through the optical system is obtained. Can be maintained, various high-frequency noises mixed in downstream can be effectively and reliably reduced, and an appropriate photographed image can be generated.

In the present invention, since the light imaged on the image sensor such as a CCD does not include a spatial frequency higher than the cutoff spatial frequency determined from the numerical aperture NA of the optical system, a spatial frequency component higher than the cutoff spatial frequency is included. We focus on the fact that the signal can be regarded as noise.
In the present invention, in order to effectively and reliably reduce high-frequency noise such as quantization error, in image processing of image data picked up by receiving light from the optical system, a cutoff determined by the numerical aperture NA of the optical system Spatial filtering is performed by removing frequency components higher than the spatial frequency from the image data. Spatial filter processing is performed by setting one-dimensional or two-dimensional digital filter processing, scanning speed of the image sensor, and time interval of light reception.

  Embodiments of the present invention will be described below with reference to the drawings.

  As shown in FIG. 1, the imaging apparatus according to the present invention includes an imaging unit 2 that receives incident light from the optical system 1 and an image processing unit 3 that processes image data IM1 output from the imaging unit 2. Thus, the image data IM2 output from the image processing unit 3 has frequency components higher than the cutoff spatial frequency determined by the numerical aperture NA of the optical system 1 removed. The optical system 1 is an optical system for forming a high-magnification image such as a microscope, for example. Incident. The imaging unit 2 is provided with an imaging device as an imaging means for receiving and photoelectrically converting incident light from the optical system. As the imaging device, for example, a one-dimensional or two-dimensional CCD camera is used.

The image processing unit 3 includes a spatial filter unit 31 that receives the image data IM1 output from the imaging unit 2, and outputs the image data IM2 that has been subjected to image processing and from which frequency components higher than the cutoff spatial frequency have been removed. It has become. The spatial filter unit 31 removes a frequency component higher than the cutoff spatial frequency of the input image data IM1, and in order to effectively reduce high frequency noise such as a quantization error, the spatial filter unit 31 according to the present invention has a cutoff spatial frequency. Uses the maximum spatial frequency determined based on the numerical aperture NA of the optical system 1. That is, assuming that the wavelength of light is λ, the maximum spatial frequency f _m is given by the following equation (1).
(Equation 1)
f _m = 2NA / λ
As shown in FIG. 2, in order to convert an output signal IMS from the spatial filter unit 31, that is, a digital signal in which a frequency component higher than the cutoff spatial frequency (f _m ) is removed from the image data IM1, into an analog signal, The image processing unit 3 may include a D / A conversion unit 32. In the embodiment shown in FIG. 2, the digital signal image data IM1 is processed by the spatial filter unit 31 and then converted to an analog signal by the D / A conversion unit 32. However, the image data IM1 is analog. When the spatial filter processing in the spatial filter unit 31 is performed with a digital signal, the A / D conversion unit is inserted before the spatial filter unit 31 to convert the image data IM1 into a digital signal, and then the spatial filter unit 31 In this case, the image data may be processed. Further, the D / A conversion unit and the A / D conversion unit are not essential to the present invention, depending on the form of the image data IM1 from the imaging unit 2 or the usage form of the image data IM2 that is the output of the image processing unit 3. May be provided as appropriate.

  In the first embodiment of the present invention, as shown in FIG. 3, the spatial filter unit 31 includes a Fourier transform unit 311 that performs discrete Fourier transform on the image data IM1 from the imaging unit 2, and a cut from the image data IMS1 that has been subjected to discrete Fourier transform. A spatial filter 312 that removes frequency components higher than the off-spatial frequency, and an inverse Fourier transform unit 313 that performs inverse discrete Fourier transform on the image data IMS2 from which the high frequency component has been removed by the spatial filter 312 and outputs the image data IMS. It is configured.

4A to 4D show the process of such spatial filter processing, and images in each process are shown. First, the original image 10 from the imaging unit 2 shown in FIG. 4A is subjected to discrete Fourier transform by the Fourier transform unit 331 to become an image 11 shown in FIG. 4B, and the spot 10A in the original image 10 is a discrete Fourier transform. The image 11 is separated into four corners and becomes the encoding unit 11A shown in FIG. Then, when the spatial filter 312 removes high frequency components from the image 11, an image 12 as shown in FIG. 4C is obtained, and noise appearing at reference numeral 11B in FIG. 4B is reduced. , As indicated by reference numeral 12B in FIG. When this image 12 is subjected to inverse discrete Fourier transform by the Fourier transform unit 313, an image 13 as shown in FIG. 4D from which high-frequency component noise has been removed is obtained. Here, the cutoff frequency of the high frequency components removed is the maximum spatial frequency f _m given by the number 1.

  On the other hand, the spatial filter unit 31 may perform one-dimensional digital filter processing or two-dimensional digital filter processing (second embodiment).

In the one-dimensional digital filter processing, for example, a three-pixel operator (mask) as shown in FIG. 5 is used, and in the two-dimensional digital filter processing, a nine-pixel operator (mask) as shown in FIG. 6 is used. Both perform smoothing of the image data, the frequency components higher than the maximum spatial frequency f _m given by the number 1 may be removed. The number of taps of the filter of FIGS. 5 and 6 is “3”, but it is preferable to increase the number of taps of this filter as much as possible.

In the third embodiment shown in FIG. 7, a large number of imaging elements 2A constituting the imaging unit 2 are arranged at a plurality of locations, and the distance between the imaging elements 2A is 2 at the maximum spatial frequency f _m given by the above equation 1. by approximately doubled, frequency components higher than the maximum spatial frequency f _m is to be removed with respect to the image data IM3 generated by an imaging element 2A. The imaging element 2A may be a two-dimensional area element or a linear linear element. In the case of a linear element, it is necessary to scan spatially or temporally. The image sensor 2A may be a CCD.

Imaging element 2A is disposed in a two-dimensional plane for receiving incident light from the optical system 1 is arranged such that the distance therebetween is 2 times the maximum spatial frequency f _m. By doing so, the image data sent to the image processing unit 3, can be prevented contain frequency components higher than the maximum spatial frequency f _m.

  In the fourth embodiment shown in FIG. 8, the single image sensor 2A scans the two-dimensional plane in order to receive the incident light from the optical system 1, whereby the image processing unit 3 receives image data. IM4 is sent. Scanning in a two-dimensional plane can be realized by repeatedly performing linear scanning with a slight shift in space or time.

In this embodiment, as the image pickup device 2A is 2 times the maximum spatial frequency f _m of distance between a point for receiving incident light is given by the number 1 from the optical system 1, and the scanning speed of the image pickup device 2A A time interval (sampling interval) at which the image sensor 2A receives light is set. As in the Nyquist Shannon sampling theorem, the image data IM4 generated by the imaging element 2A by doing so it can be made to not contain frequency components higher than the maximum spatial frequency f _m.

Further, even when the scanning speed and the imaging device 2A of the imaging element 2A was arbitrarily set the time interval of light receiving, in the image processing unit 3, the distance between the light receiving been points is 2 times the maximum spatial frequency f _m The image data IM2 may not include a frequency component higher than the maximum spatial frequency f _m by generating only the data and generating the image data IM2 from only the thinned data.

  The numerical aperture NA of the optical system 1 may be set in the imaging unit 2 in advance. However, since the numerical aperture NA varies depending on conditions such as the diaphragm of the optical system 1, the numerical aperture NA obtained by calculation is externally applied. You may make it input each time. When the numerical aperture NA of the optical system is not completely known, the cutoff spatial frequency may be determined using the maximum numerical aperture NA among the possible numerical apertures NA. For example, when the numerical aperture NA1 of the light to be observed is unknown and the maximum effective numerical aperture NA2 in the imaging unit of the optical system of the measuring device such as a microscope is known, the numerical aperture NA1 is sufficiently large. An effective numerical aperture NA0 in the imaging unit is calculated, and a cutoff spatial frequency is determined using the effective numerical aperture NA0.

  Furthermore, the numerical aperture NA under the desired conditions of the optical system 1 is set in the imaging unit 2 by calculating the numerical aperture NA from the spot image by providing the imaging unit 2 with a spot image analysis unit. be able to.

The numerical aperture NA of the optical system 1 can be obtained from the spot image. That is, as shown in FIG. 9, when the incident angle of incident light is θ and the refractive index of the medium is n with respect to the spot image formed on the image plane 6 from the optical system 1, the numerical aperture NA is the following number. Defined by 2.
(Equation 2)
NA = n × sin θ

For example, the spot image analysis unit obtains the area s of the spot image by setting the spot image to a position where the light intensity of the spot image is approximately half from the peak value. Then, the diameter d of the spot image is calculated from the area s of the spot image by the following formula 3.
(Equation 3)
d = √ (4 s / π)

When the diameter d of the spot image is obtained by the above equation 3, the numerical aperture NA can be obtained by the following equation 4.
(Equation 4)
NA = cλ / πd
Where c is the minimum solution of (2J ₁ (x)) ² = 0.5 (J ₁ (x) is the first kind Bessel function), a constant of about 1.61634, and λ is the wavelength of light .
The diameter d of the spot image may be obtained directly from the diameter of the spot image rather than from the area s of the spot image.

Also, there is a method in which the spot image analysis unit extracts the first dark ring of the spot image by an edge extraction method or the like and obtains the diameter d of the extracted first dark ring. In this case, after obtaining the diameter d, the numerical aperture NA can be obtained by the following equation (5).
(Equation 5)
NA = cλ / πd
However, c is the minimum solution of (2J ₁ (x)) ² = 0 (J ₁ (x) is the first kind Bessel function), and is a constant of about 3.832.

In the case where it is assumed that an error is included in the numerical aperture NA determines the cut-off spatial frequency f _m by the following Equation 6 is multiplied by a safety factor beta.
(Equation 6)
f _m = 2β · NA / λ

For example, when an error of 20% is assumed in the numerical aperture NA, the safety coefficient β is set to “1.2”.

  As mentioned above, although embodiment of this invention was described concretely, this invention is not limited to these embodiment, In the range which does not deviate from the meaning, it can change suitably. Particularly for the pupil of the optical system, the embodiments of the present invention can be applied to any pupil shape. For example, the spatial frequency signal of the autocorrelation function platform (region in which the function has a value) of the pupil mask function f (x, y) having “1” in the pupil opening and “0” in the other regions is obtained. The present invention can be applied to an arbitrary pupil shape by configuring a low-pass filter that passes and cuts signals in bands other than the table.

It is a block diagram which shows the structural example of the imaging device which concerns on this invention. It is a block diagram which shows the structural example at the time of making it comprise a D / A conversion part in the image processing part of the imaging device which concerns on this invention. It is a block diagram which shows the structural example of the spatial filter part of this invention. It is a figure for demonstrating the image processing of this invention (1st Embodiment). It is a figure which shows the example of the operator of the one-dimensional digital filter process performed by this invention (2nd Embodiment). It is a figure which shows the example of the operator of the two-dimensional digital filter process performed by this invention (2nd Embodiment). It is a block diagram which shows the structural example of the imaging device (3rd Embodiment) which has arrange | positioned several image pick-up element by the space | interval twice as large as the maximum spatial frequency. It is a block diagram which shows the structural example of the imaging device (4th Embodiment) which produces | generates image data by scanning an imaging device. It is a figure for demonstrating the definition by the spot image of the numerical aperture of an optical system. It is a block diagram which shows the structural example of the conventional imaging device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical system 2 Image pick-up part 2A Image pick-up element 3 Image processing part 31 Spatial filter part 32 D / A conversion part 311 Fourier transform part 312 Spatial filter 313 Inverse Fourier transform part 6 Image surface

Claims (20)

In an imaging method in which light from an optical system is received and imaged, and image data as an imaging output is processed, a frequency component higher than a cutoff spatial frequency determined by the numerical aperture NA of the optical system is removed from the image data. An imaging method for performing spatial filter processing characterized by the above. In an imaging method in which light from an optical system is received and imaged, and image data that is an imaging output is image-processed, first image data is generated by performing discrete Fourier transform on the image data, and the first image data is used to generate the first image data. The second image data is generated by removing frequency components higher than the cutoff spatial frequency determined by the numerical aperture NA of the optical system, and the second image data is subjected to inverse discrete Fourier transform to generate and output third image data. An imaging method for performing spatial filter processing characterized by the above. In an imaging method in which light from an optical system is received and imaged, and image data that is an imaging output is image-processed, a one-dimensional digital filter process is performed on the image data, and a cutoff space determined by a numerical aperture NA of the optical system An imaging method for performing spatial filtering, wherein a frequency component higher than a frequency is removed from the image data. In an imaging method in which light from an optical system is received and imaged, and image data that is an imaging output is image-processed, a two-dimensional digital filter process is performed on the image data, and a cut-off space determined by a numerical aperture NA of the optical system An imaging method for performing spatial filtering, wherein a frequency component higher than a frequency is removed from the image data. In an imaging method in which light from an optical system is received and imaged, and image data that is an imaging output is image-processed, the imaging is performed by a plurality of imaging elements, and the plurality of imaging elements are spaced apart from each other by the optical system. An imaging method for performing spatial filter processing, characterized in that a frequency component higher than the cut-off spatial frequency is removed from the image data, which is arranged so as to be twice the cut-off spatial frequency determined by the numerical aperture NA. In an imaging method in which light from an optical system is received and imaged, and image data that is an imaging output is image-processed, the image data is generated by scanning the image sensor, and the distance between points received by the image sensor Is set to be twice the cutoff spatial frequency determined by the numerical aperture NA of the optical system, the scanning speed of the imaging element and the time interval of light reception of the imaging element are set, and the image data is the cutoff spatial frequency An imaging method for performing spatial filtering, characterized by not including a higher frequency component. In an imaging method in which light from an optical system is received and imaged and image processing is performed on first image data that is an imaging output, the first image data is generated by scanning an image sensor, and the numerical aperture of the optical system Cut-off spatial frequency is determined based on NA, and second image data is generated by thinning out data from which the distance between the points received by the image sensor is twice the cut-off spatial frequency from the first image data. An imaging method for performing spatial filtering, wherein the second image data does not include a frequency component higher than the cutoff frequency. The imaging method for performing spatial filter processing according to claim 1, wherein the numerical aperture NA is input from the outside. A spot image is defined as a spot image where the light intensity of the image data or the first image data is approximately half of the peak value, the diameter d of the spot image is calculated from the spot image, and the numerical aperture NA is calculated.
NA = cλ / πd
Where c is the minimum solution of (2J ₁ (x)) ² = 0.5 (J ₁ (x) is the first type Bessel function), a constant of about 1.61634, and λ is the wavelength of light .)
The imaging method which performs the spatial filter process in any one of Claims 1 thru | or 7 calculated | required as. A first dark ring of the image data or the spot image of the first image data is extracted by an edge extraction method or the like to obtain a diameter d of the first dark ring, and the numerical aperture NA is calculated.
NA = cλ / πd
(However, c is the smallest solution of ^{_{(2J 1 (x)) 2}} = 0 (J 1 (x) is the first kind Bessel function), about 3.832 constants, lambda is the wavelength of light. )
The imaging method which performs the spatial filter process in any one of Claims 1 thru | or 7 calculated | required as. An imaging apparatus comprising: an imaging unit that receives and captures light from an optical system; and an image processing unit that performs image processing on image data output from the imaging unit. The image processing unit includes an opening of the optical system. An imaging apparatus for performing spatial filter processing, comprising: a spatial filter that removes a frequency component higher than a cutoff spatial frequency determined by a number NA from the image data. An imaging apparatus comprising: an imaging unit that receives light from an optical system to capture an image; and an image processing unit that performs image processing on image data output from the imaging unit. The image processing unit discretely processes the image data. A Fourier transform unit that generates first image data by performing Fourier transform, and removes a frequency component higher than a cutoff spatial frequency determined based on the numerical aperture NA of the optical system from the first image data to obtain second image data. An imaging apparatus for performing spatial filter processing, comprising: a spatial filter to be generated; and an inverse Fourier transform unit configured to generate and output third image data by performing inverse discrete Fourier transform on the second image data . An image pickup apparatus including an image pickup unit that receives light from an optical system and picks up an image and an image processing unit that performs image processing on image data output from the image pickup unit. An imaging apparatus for performing spatial filter processing, comprising a function of performing digital filter processing and removing a frequency component higher than a cutoff spatial frequency determined by a numerical aperture NA of the optical system from the image data. An imaging apparatus comprising: an imaging unit that receives light from an optical system to capture an image; and an image processing unit that performs image processing on image data output from the imaging unit. An imaging apparatus for performing spatial filter processing, comprising a function of performing digital filter processing and removing a frequency component higher than a cutoff spatial frequency determined by a numerical aperture NA of the optical system from the image data. An imaging apparatus comprising: an imaging unit that receives and captures light from an optical system; and an image processing unit that performs image processing on image data obtained by the imaging unit. The imaging unit includes a plurality of imaging elements, and The imaging elements are arranged such that the mutual distance is twice the cutoff spatial frequency determined by the numerical aperture NA of the optical system, and frequency components higher than the cutoff spatial frequency are removed from the image data. An imaging apparatus that performs spatial filter processing. An imaging apparatus comprising: an imaging unit that receives light from an optical system to capture an image; and an image processing unit that performs image processing on image data obtained by the imaging unit. The imaging unit includes an imaging element, and scans the imaging element. The image data is generated, and the scanning speed of the image sensor and the distance between the points received by the image sensor are twice the cutoff spatial frequency determined by the numerical aperture NA of the optical system. An imaging apparatus for performing spatial filtering, wherein the scanning is performed by setting a time interval of light reception of the imaging element so that the image data does not include a frequency component higher than the cutoff spatial frequency. In an imaging apparatus including an imaging unit that receives light from an optical system and captures an image, and an image processing unit that performs image processing on the first image data by the imaging unit, the imaging unit scans the imaging element. The first image data is generated and output. The image processing unit has a function of determining a cutoff spatial frequency based on a numerical aperture NA of the optical system, and a point where the image sensor receives light. The second image data is generated by thinning out data from which the distance is twice the cut-off spatial frequency from the first image data, and the second image data has a frequency higher than the cut-off spatial frequency. An imaging apparatus that performs spatial filter processing characterized by not including a component. The imaging device for performing spatial filter processing according to claim 11, wherein the numerical aperture NA is input from the outside. A spot image is defined as a spot image where the light intensity of the image data or the first image data is approximately half of the peak value, the diameter d of the spot image is calculated from the spot image, and the numerical aperture NA is calculated.
NA = cλ / πd
(Where c is the minimum solution of (2J ₁ (x)) ² = 0.5, a constant of about 1.61634, and λ is the wavelength of light.)
An imaging apparatus for performing spatial filter processing according to claim 11, wherein the imaging apparatus performs spatial filter processing according to claim 11. The first dark ring of the spot image of the image data is extracted by an edge extraction method or the like, the diameter d of the first dark ring is obtained, and the numerical aperture NA is calculated.
NA = cλ / πd
(However, the constant c is the minimum solution of (2J ₁ (x)) ² = 0, a constant of about 3.832, and λ is the wavelength of light.)
The imaging device according to claim 11, wherein the imaging device is obtained as follows.

Images