JP6277695B2 - Imaging device, adjustment device, and adjustment method - Google Patents

Description

  The present invention relates to an imaging device having a function of detecting the color of a subject, an adjustment device for adjusting the imaging device, and an adjustment method.

  2. Description of the Related Art Conventionally, there is known an imaging device that receives light from a subject spatially separated into a plurality of lights having different wavelength characteristics, and outputs an image including a plurality of regions corresponding to the separated lights ( For example, see Patent Document 1). In the imaging apparatus described in Patent Document 1, in the configuration of the plenoptic camera, a filter unit having a plurality of filter regions each having a different wavelength selectivity is arranged in front of the microlens array. A light field image in which partial light images (hereinafter referred to as macropixels) corresponding to each microlens constituting the microlens array are arranged by receiving light sequentially transmitted through the filter unit and the microlens array by the light receiving element array. Is output.

  Each macro pixel in the light field image has a plurality of image areas corresponding to the plurality of filter areas of the filter unit. By extracting and rearranging the output values of the image areas corresponding to the same filter area from these macro pixels, it is possible to generate a plurality of images according to the intensity of light transmitted through each filter area. The plurality of images can be used, for example, for detecting the color of the subject.

  However, in the imaging device described in Patent Document 1, it is difficult to accurately specify which position corresponds to which filter region in each macro pixel in the light field image. There is a concern that it may interfere with the detection of the problem.

  The present invention has been made in view of the above, and an object of the present invention is to provide an imaging device, an adjustment device, and an adjustment method that can accurately specify a position in an image corresponding to each filter region of a filter unit. And

  In order to solve the above-described problems and achieve the object, an imaging apparatus according to the present invention receives a filter unit having a plurality of filter regions each having a different wavelength selectivity, and light transmitted through the filter unit. A light receiving element array that outputs an image, a storage unit that stores position information indicating a position on the light receiving element array that receives light transmitted through each filter region, for each of a plurality of filter regions of the filter unit; Area detection for detecting an image area corresponding to light transmitted through each filter area of the filter section from an image output from the light receiving element array when light from a subject enters the filter section based on position information And a color detection unit that detects the color of the subject based on the detected output value of the image region, and includes one of the plurality of filter regions of the filter unit. The position information corresponding to the target region is output by the light receiving element array when inspection light having a wavelength characteristic corresponding to the wavelength selectivity of the target region is incident on the filter unit. It is the information which shows the position on the said light receiving element array specified using the binarized image obtained by binarizing with respect to the image to do.

  According to the present invention, it is possible to accurately specify the position in the image corresponding to each filter region of the filter unit.

FIG. 1 is a conceptual diagram of an optical system in the imaging apparatus of the embodiment. FIG. 2 is a diagram illustrating a geometric design example of the filter unit. FIG. 3 is a diagram illustrating the spectral transmittance of the filter unit. FIG. 4 is a plan view of the microlens array as seen from the direction along the optical axis. FIG. 5 is a diagram illustrating a light field image captured by the imaging apparatus. FIG. 6 is an enlarged view of a macro pixel. FIG. 7 is a diagram illustrating a specific configuration example of the imaging apparatus according to the first embodiment. FIG. 8 is a diagram illustrating the difference in spectral transmittance between the three filter regions of the filter unit and the maximum value thereof. FIG. 9 is a diagram showing the spectral transmittance of the bandpass filter. FIG. 10 is an enlarged view of macro pixels included in the light field image output from the light receiving element array when the inspection light is incident on the filter unit. FIG. 11 is a diagram illustrating a specific configuration example of the imaging apparatus according to the second embodiment. FIG. 12 is a flowchart illustrating a processing procedure of the adjusting device when adjusting the imaging device.

  Exemplary embodiments of an imaging device, an adjustment device, and an adjustment method according to the present invention will be described below in detail with reference to the accompanying drawings. In addition, although embodiment described below is an example which applied this invention with respect to the imaging device which has the structure of a plenoptic camera, the imaging device which can be applied is not restricted to this. The present invention is widely applied to an imaging device that receives light from a subject spatially separated into a plurality of lights having different wavelength characteristics and outputs an image including a plurality of regions corresponding to the separated lights. Applicable.

<First Embodiment>
FIG. 1 is a conceptual diagram of an optical system in the imaging apparatus of the present embodiment. In FIG. 1, for easy understanding, the main lens 1 functioning as an imaging lens is shown as a single lens, and the aperture position of the main lens 1 is the center of the single lens.

  A filter unit 2 is disposed at the stop position of the main lens 1. In FIG. 1, the filter unit 2 is illustrated as being disposed in the main lens 1 shown as a single lens, but the filter unit 2 is not actually disposed inside the lens.

  The filter unit 2 has a plurality of filter regions each having a different wavelength selectivity. In the present embodiment, a color filter corresponding to the tristimulus value of the color having the spectral transmittance based on the color matching function of the XYZ color system defined by the CIE is used as the filter unit 2.

FIG. 2 is a diagram illustrating a geometric design example of the filter unit 2 of the present embodiment. As shown in FIG. 2, the filter unit 2 of the present embodiment includes three filter regions F _X , F _Y , and F _Z designed based on the color matching functions of the XYZ color system.

FIG. 3 is a diagram showing the spectral transmittance of the filter unit 2 of the present embodiment. The solid line in FIG. 3 indicates the spectral transmittance T _X (λ) of the filter region F _X , the alternate long and short dash line indicates the spectral transmittance T _Y (λ) of the filter region F _Y , and the broken line indicates the spectral transmittance of the filter region F _Z. The rate T _Z (λ) is shown. These T _X (λ), T _Y (λ), and T _Z (λ) are obtained by replacing the color matching function of the XYZ color system with transmittance. As described above, the filter regions F _X , F _Y , and F _Z of the filter unit 2 have different wavelength selectivity. 2 and FIG. 3 is an example, and the present invention is not limited to this. The filter unit 2 may be configured to have a plurality of filter regions having different wavelength selectivity, and the number of filter regions may be two, or four or more.

  A microlens array 3 composed of a plurality of microlenses (small lenses) is disposed near the condensing position of the main lens 1. A light receiving element array 4 that receives light transmitted through the filter unit 2 and the microlens array 3 and outputs an image is disposed on the image surface of the optical system. The light receiving element array 4 is a monochrome sensor in which a color filter for each pixel is not mounted, and each light receiving element corresponds to one pixel of an image. The diameter of each microlens constituting the microlens array 3 and the size of each light receiving element constituting the light receiving element array 4 are approximately in a ratio of 30: 1 to 2: 1.

  FIG. 4 is a plan view of the microlens array 3 viewed from a direction along the optical axis P (see FIG. 1). In FIG. 4, the portions shown in white are the microlenses, and the portions shown in black are the light shielding portions. The light shielding portion is a flat portion having no curvature or a region where the curvature does not satisfy the design value specification in terms of manufacturing. Since the light from these regions may cause an unintended light beam to reach the light receiving element, the electrical signal assumed from the design can be obtained by shielding the light. This is important for obtaining accurate measurements.

In the imaging apparatus of the present embodiment, among the light emitted from the object (subject) Ob, the light beam that enters the aperture of the main lens 1 and passes through the aperture is transmitted through the microlens array 3 and received by the light receiving element array 4. The The light beam incident on the main lens 1 is a collection of innumerable light beams, and each light beam passes through different positions of the stop of the main lens 1. In the imaging apparatus of the present embodiment, the filter unit 2 having three filter regions F _X , F _Y , and F _Z is disposed at the stop position of the main lens 1. Accordingly, each light beam that passes through different positions of the stop of the main lens 1 passes through the three filter regions F _X , F _Y , and F _Z having different spectral transmittances (wavelength selectivity), and thereby the wavelength characteristics. Are three types of light beams.

The light beam that has passed through the filter unit 2 forms an image once in the vicinity of the micro lens array 3, but is then diffused by the action of the micro lens array 2 and transmitted through the three filter regions F _X , F _Y , and F _Z of the filter unit 2. The received light beams reach different positions of the light receiving element array 4. That is, the light beam that passes through the stop position of the main lens 1 passes through the filter region F _X , F _Y , F _Z of the filter unit 2 according to which filter region is transmitted through the light receiving element array 4. The light receiving position on the sensor surface is different. For this reason, in the imaging apparatus of the present embodiment, it is possible to measure a value obtained by decomposing light emitted from one point of the object (subject) Ob into tristimulus values X, Y, and Z in terms of wavelength.

  FIG. 5 is a diagram illustrating a light field image captured by the imaging apparatus of the present embodiment. When an image is picked up by the image pickup apparatus of this embodiment, a light field image in which small circular partial images are arranged is obtained as shown in FIG. The partial image included in the light field image is a circle because the aperture shape of the main lens 1 is a circle. Each small circle partial image included in the light field image is called a “macro pixel”. Each macro pixel is formed immediately below each micro lens constituting the micro lens array 3.

FIG. 6 is an enlarged view of a macro pixel. The internal structure of the macro pixel corresponds to the structure of the filter unit 2 arranged at the stop position of the main lens 1 (see FIG. 2). In other words, each macro pixel included in the light field image captured by the imaging device of the present embodiment, as shown in FIG. 6, an image area M _X corresponding to the filter region F _X of the filter section 2, filter region F _The image area M _Y corresponding to _Y and the image area M _Z corresponding to the filter area F _Z are included. The image areas M _X , M _Y , and M _Z in the macro pixel are obtained by receiving light that has passed through the filter areas F _X , F _Y , and F _Z of the filter unit 2, respectively. The reason why the internal structure of the macro pixel shown in FIG. 6 is inverted upside down with respect to the structure of the filter unit 2 shown in FIG. 2 is that it has passed through the optical system. However, since this correspondence depends on the optical system, it is not limited to this example.

In the imaging apparatus of the present embodiment, the spectral energy at the object position corresponding to the macro pixel can be measured from the output values of the image areas M _X , M _Y , and M _Z of the macro pixel. _Assume that the output values of the image areas M _X , M _Y , and M _Z of the macro pixel are v = [v _X , v _Y , v _Z ] ^t . t means transposition of the matrix. How to take the output value, the image area M _X, M _Y, may take the average value of the output of the light receiving element for each M _Z, the image region M _X, M _Y, then select one light receiving element for each M _Z thereof The output value may be adopted as the representative value. However, the image area M _X, M _Y, each of the image areas the average value of the output of the light receiving element for each M _Z M _X, M _Y, by the output value of the M _Z, suppress the influence of electrical random noise In addition, a signal robust against noise can be obtained.

The output values of the image areas M _X , M _Y , and M _Z of the macro pixel are obtained by dividing the light emitted from the object (subject) Ob into the tristimulus values X, Y, and Z in terms of wavelength. 4 multiplied by the spectral sensitivity. Since the spectral sensitivity of the light receiving element array 4 is known at the time of design, by dividing the output value by the spectral sensitivity of the light receiving element array 4, the tristimulus values X, Y, and Z of light emitted from the object (subject) Ob are obtained. Can be sought. The color of the object (subject) Ob (the color value in the XYZ color space) can be detected from the tristimulus values X, Y, and Z.

Here, in the imaging apparatus of the present embodiment, in order to detect the color of the object (subject) Ob from the output values of the image areas M _X , M _Y , and M _Z of the macro pixel, the light is received by the actual machine actually manufactured. It is necessary to specify which light receiving element of the element array 4 corresponds to each image area M _X , M _Y , M _Z of the macro pixel. That is, in the actual machine, for example, there is a manufacturing error such as an alignment error of the optical system, and therefore the light receiving elements of the light receiving element array 4 corresponding to the image regions M _X , M _Y , and M _Z of the macro pixel are different for each individual. There is.

Therefore, in the imaging apparatus of the present embodiment, the position of the light receiving element of the light receiving element array 4 corresponding to each image area M _X , M _Y , M _Z of the macro pixel, that is, each filter area F _X , F of the filter unit 2. A position on the light receiving element array 4 that receives the light transmitted through _{Y 1} and F _Z is specified by a method described later, and position information indicating the position is stored in the storage unit. Then, using the position information stored in the storage unit, each image area M _X , M _Y , M _Z of the macro pixel is detected from the light field image output from the light receiving element array 4, and each detected image area M Based on the output values of _{X 1} , M _Y , and M _Z , the color of the object (subject) Ob is detected.

  FIG. 7 is a diagram illustrating a specific configuration example of the imaging apparatus according to the present embodiment. The imaging device 10 illustrated in FIG. 7 includes a lens module 20, a camera unit 30, a calculation device 40, and a storage unit 50.

  The lens module 20 includes the first lens 1a and the second lens 1b, and the filter unit 2 described above. The first lens 1a and the second lens 1b constitute the main lens 1 described above. However, this configuration is merely an example, and any configuration may be used as long as the filter unit 2 is disposed at the stop position of the optical element constituting the main lens 1.

  The camera unit 30 includes the microlens array 3 described above, the light receiving element array 4 described above, and a frame memory 31. The frame memory 31 temporarily holds a light field image output from the light receiving element array 4.

  The arithmetic device 40 is configured using, for example, a microcomputer including a CPU, a ROM, a RAM, an input / output interface, and the like. For example, as shown in FIG. 7, the arithmetic device 40 executes a predetermined program stored in the ROM using the RAM as a work area, whereby the binarization processing unit 41, the position specifying unit 42, and the region detection unit 43 and the color detecting unit 44 are realized. Among these, the binarization processing unit 41 and the position specifying unit 42 are functional configurations for storing the above-described position information in the storage unit 50. For example, any timing before shipping the actual machine or after shipping Called in response to a predetermined operation by the adjustment operator at the time of adjustment carried out in (1). On the other hand, the area detection unit 43 and the color detection unit 44 have a functional configuration for actually detecting the color of the subject using the light field image, and each time the light receiving element array 4 outputs the light field image during imaging of the subject. Called.

At the time of adjustment of the imaging device 10, the light emitted from the light source 61 shown in FIG. 7 and transmitted through the bandpass filter 62 is incident on the filter unit 2 of the optical system as inspection light. The inspection light is light having wavelength characteristics corresponding to a filter region (hereinafter, referred to as a target region) whose position is to be specified among the three filter regions F _X , F _Y , and F _Z of the filter unit 2. Set for each target area. At the time of adjustment of the imaging device 10, the inspection light corresponding to each of the three filter regions F _X , F _Y , and F _Z of the filter unit 2 is sequentially applied to the filter unit 2 by switching the bandpass filter 62 according to the target region. Incident light (inspection light generating means). Details of the inspection light will be described later.

  The binarization processing unit 41 performs binarization processing on the light field image output from the light receiving element array 4 when the above-described inspection light enters the filter unit 2, and the bright pixels are white and the other pixels Generates a binary image that is black.

The position specifying unit 42 specifies the coordinates of the white pixels using the binarized image generated by the binarization processing unit 41 and specifies the position of the “chunk” (connected portion) where the white pixels are connected. Thus, the position of the image region in the macro pixel corresponding to the target region of the filter unit 2 is specified. For example, when the filter area F _X of the filter unit 2 is the target area, the image area M _X in the i-th macro pixel in the horizontal direction and the j-th macro pixel in the vertical direction is M _X (i, j) in the light field image. Then, M _X (i, j) usually consists of a plurality of pixels. The position specifying unit 42 specifies the coordinates of each pixel belonging to M _X (i, j) in association with i, j, and stores these in the storage unit 50 as position information of the image area M _X.

  The storage unit 50 is a non-volatile memory that stores the position information specified by the position specifying unit 42. The storage unit 50 can hold the position information specified by the position specifying unit 42 in the form of a lookup table, for example.

Based on the position information stored in the storage unit 50, the region detection unit 43 calculates from the light field image output from the light receiving element array 4 when the subject is imaged, that is, when light from the subject enters the filter unit 2. Image areas M _X , M _Y , and M _Z of each macro pixel are detected. In addition, the area detection unit 43 of the present embodiment generates an intermediate image by rearranging the output values of the detected image areas M _X , M _Y , and M _Z according to the positions of the macro pixels.

Pixel Specifically, the region detecting unit 43 detects the image region M _X within each macro-pixel included in the light field image, which constitutes the output value of the detected image area M _X (e.g., an image region M _X position i of the average value) each macro pixel, by re-arranged according to j, and generates an intermediate image corresponding to the filter region F _X of the filter unit 2. That, (i, j) = ( 1,1) , then the the value of the pixel of the upper left point of the output values intermediate image of the image region M _X in the macro-pixel, for example, the upper left end of the light field image. This process, by performing for every macro-pixel included in the light field image, it is possible to generate an intermediate image is a two-dimensional image formed by light transmitted through the filter region F _X of the filter unit 2.

In addition, the region detection unit 43 performs the same process on the image regions M _Y and M _Z in each macro pixel included in the light field image, so that an intermediate image corresponding to the filter region F _Y of the filter unit 2 can be obtained. it can also generate an intermediate image corresponding to the filter region F _Z.

The color detection unit 44 detects the color of the subject by the method described above based on the output values of the image regions M _X , M _Y , and M _Z detected by the region detection unit 43. The color detection unit 44 of the present embodiment uses the three intermediate images generated by the region detection unit 43 (three intermediate images corresponding to the filter regions F _X , F _Y , and F _Z of the filter unit 2), respectively. Colors at different positions of the subject can be detected individually.

The region detecting unit 43, three image areas _{M X,} M Y, instead of producing each corresponding intermediate image _{M Z,} three image areas _{M X,} M Y, representative output value of the _{M Z} It may be the structure which acquires. In this case, the color detection unit 44 detects the color of the subject based on the representative output values of the three image regions M _X , M _Y , and M _Z.

  Each of the functional configurations of the binarization processing unit 41, the position specifying unit 42, the region detecting unit 43, and the color detecting unit 44 described above may be partially or entirely, for example, ASIC (Application Specific Integrated Circuit) or FPGA (Field- You may implement | achieve using dedicated hardware, such as Programmable Gate Array.

  Here, details of the inspection light used when adjusting the imaging apparatus 10 will be described. As described above, the inspection light is light used for separating the image region corresponding to the target region of the filter unit 2 from the light field image output from the light receiving element array 4 and specifying the position thereof. Has wavelength characteristics corresponding to the target area. For example, the inspection light is light having a wavelength characteristic determined based on the difference between the spectral transmittance of the target region of the filter unit 2 and the spectral transmittance of other filter regions. More specifically, light having a central wavelength at the maximum difference between the spectral transmittance of the target region of the filter unit 2 and the spectral transmittance of another filter region can be used as the inspection light.

If the filter region _{F X} of the filter unit 2 and the target area, first, the filter region _F spectral transmittance _{T X} (lambda) of _X, the other two filter areas _F Y, _{F Z} spectral transmittance _T Y ( A difference D _X (λ) between λ) and T _Z (λ) is obtained by the following equation (1).
D _X (λ) = T _X (λ) −T _Y (λ) −T _Z (λ) (1)
Then, the difference D _X light having a wavelength of maximum S _X of _(lambda), the inspection light when a filter region F _X the target area, i.e., the image areas M _X from the light-field image photodetector array 4 outputs Is used as an inspection light for separating.

When the filter region F _Y of the filter unit 2 is the target region, similarly, the spectral transmittance T _Y (λ) of the filter region F _{Y and} the spectral transmittances T of the other two filter regions F _X and F _Z are the same. A difference D _Y (λ) between _X (λ) and T _Z (λ) is obtained. Then, the light having the maximum value S _Y of the difference D _Y (λ) is used as the inspection region when the filter region F _Y is the target region, that is, from the light field image output from the light receiving element array 4 to the image region M _Y. Is used as an inspection light for separating.

If the filter unit 2 filter region F _Z a region of interest, likewise, the spectral transmittance of the filter region F _Z T _{Z (λ),} the other two filter areas F _X, spectral transmittance F _Y T A difference D _Z (λ) between _X (λ) and T _Y (λ) is obtained. Then, the light of the wavelength S _{Z having} the maximum value S _Z of the difference D _Z (λ) is used as the inspection light when the filter region F _Z is the target region, that is, from the light field image output from the light receiving element array 4 to the image region M _Z. Is used as an inspection light for separating.

FIG. 8 shows the difference D _X (λ), the difference between the spectral transmittances T _X (λ), T _Y (λ), T _Z (λ) of the three filter regions F _X , F _Y , F _Z of the filter unit 2. D _Y (λ), and _{D Z (λ),} the maximum value _{S X, S Y,} is a diagram showing the _{S Z.} The solid line in FIG. 8 indicates the difference D _X (λ), the alternate long and short dash line indicates the difference D _Y (λ), and the broken line indicates the difference D _Z (λ). In each of the differences D _X (λ), D _Y (λ), and D _Z (λ), the wavelengths at the positions indicated by arrows are maximum values S _X , S _Y , and S _Z.

As the inspection light, monochromatic light having wavelengths S _X , S _Y , and S _Z is ideal. However, since it is difficult to obtain monochromatic light having wavelengths S _X , S _Y , and S _Z , light having a broad spectrum with each wavelength as a center wavelength may be used as inspection light.

When the filter region F _X of the filter unit 2 is the target region, in order to obtain inspection light having the wavelength S _X as the central wavelength, for example, a xenon lamp having intensity in a wide wavelength range including a wide visible light range is used as the light source 61. Use. As the bandpass filter 62 that transmits the light emitted from the light source 61, a bandpass filter having a spectral transmittance with the wavelength S _X as the center wavelength is used. FIG. 9 is a diagram showing the spectral transmittance of the band-pass filter 62 used for obtaining inspection light having the wavelength S _X as the center wavelength. As such a bandpass filter 62, for example, an absorption filter using a dye can be used.

FIG. 10 is an enlarged view of macro pixels included in the light field image output from the light receiving element array 4 when the inspection light having the wavelength S _X as the central wavelength is incident on the filter unit 2 when the imaging apparatus 10 is adjusted. FIG. In light field image photodetector array 4 the inspection light having a center wavelength a wavelength S _X when is incident to the filter unit 2 outputs, as shown in FIG. 10, the pixel of the image area M _X within each macro pixel Only looks bright because it has a large pixel value. That is, the image region M _X and another image region M _Y within each _macro-pixel, the contrast between the M _Z is the largest. For this light field image, by performing a binarization process using the appropriate threshold, it is possible to accurately identify the position of the image region M _X from the resulting binarized image.

In the case of the filter unit 2 filter region F _Y a target area, by using a band-pass filter 62 having the spectral transmittance of the central wavelength of the wavelength S _Y, inspection light having a center wavelength a wavelength S _Y Get. Then, by relative light field image output from the light receiving element array 4 when is incident the inspection light to the filter unit 2 performs binarization processing, from the obtained binarized image of the image region M _Y The position can be specified accurately.

Also, when the filter region F _Z of the filter unit 2 and the target area, by using a band-pass filter 62 having the spectral transmittance of the central wavelength of the wavelength S _Z, inspection light having a center wavelength a wavelength S _Z Get. Then, the binarization process is performed on the light field image output from the light receiving element array 4 when the inspection light is incident on the filter unit 2, so that the image area M _Z is obtained from the obtained binarized image. The position can be specified accurately.

The positions of the image regions M _X , M _Y and M _Z specified as described above are stored in the storage unit 50 of the imaging device 10 as position information. When the subject is actually imaged using the imaging device 10 and the color of the subject is detected, each macro is obtained from the light field image obtained by imaging the subject using the position information stored in the storage unit 50. The pixel image areas M _X , M _Y and M _Z can be detected correctly. Based on the output values of the detected image areas M _X , M _Y , and M _Z , the color of the subject can be detected appropriately.

As described above in detail with specific examples, according to the imaging apparatus 10 of the present embodiment, positions in the image corresponding to the filter regions F _X , F _Y , and F _Z of the filter unit 2 are determined. It is possible to accurately identify and appropriately detect the color of the subject.

Second Embodiment
Next, a second embodiment will be described. In the second embodiment, the binarization process for the light field image at the time of adjustment, the position of the image areas M _X , M _Y , and M _Z are specified using the binarized image, and the position information is stored in the storage unit 50. The adjustment device performs the processing to be performed. Hereinafter, the same components as those in the first embodiment will be denoted by the same reference numerals, and redundant description will be omitted as appropriate, and only the feature points of the second embodiment will be described.

  FIG. 11 is a diagram illustrating a specific configuration example of the imaging apparatus according to the second embodiment. An imaging device 70 illustrated in FIG. 11 includes a lens module 20, a camera unit 30, a calculation device 80, and a storage unit 50. The lens module 20, the camera unit 30, and the storage unit 50 are the same as those in the first embodiment. Unlike the calculation device 40 of the first embodiment, the calculation device 80 includes only the area detection unit 43 and the color detection unit 44, and the binarization processing unit 41 and the position specification unit 42 are not provided.

  In the second embodiment, the adjustment device 90 shown in FIG. 11 is used when adjusting the imaging device 70. The adjusting device 90 includes an arithmetic device 100 in addition to the light source 61 and the bandpass filter 62 (inspection light generating means) similar to those in the first embodiment. The arithmetic device 100 of the adjustment device 90 includes a binarization processing unit 101 similar to the binarization processing unit 41 of the first embodiment and a position specifying unit 102 similar to the position specifying unit 42 of the first embodiment. Is provided.

  The adjustment device 90 drives the light source 61 during adjustment of the imaging device 70 and transmits the light emitted from the light source 61 as inspection light by passing through the band-pass filter 62, and this inspection light is passed to the filter unit 2 of the imaging device 70. Make it incident. Then, a light field image output from the light receiving element array 4 when the inspection light enters the filter unit 2 is acquired from the imaging device 70 and input to the arithmetic device 100.

  Similar to the binarization processing unit 41 of the first embodiment, the binarization processing unit 101 of the arithmetic device 100 applies a light field image output from the light receiving element array 4 when inspection light enters the filter unit 2. The binarization process is performed to generate a binarized image.

  Similar to the position specifying unit 42 of the first embodiment, the position specifying unit 102 of the arithmetic device 100 specifies the coordinates of white pixels using the binarized image generated by the binarization processing unit 101, and By specifying the position of the pixel connection portion, the position of the image region in the macro pixel corresponding to the target region of the filter unit 2 is specified. Then, the position specifying unit 102 stores position information indicating the position of the specified image region in the storage unit 50 of the imaging device 70.

  FIG. 12 is a flowchart illustrating a processing procedure of the adjustment device 90 when performing adjustment with respect to the imaging device 70. Note that the processing procedure of steps S101 to S105 shown in the flowchart of FIG. 12 can also be applied when adjusting the imaging apparatus 10 of the first embodiment. When applying the adjustment to the imaging apparatus 10 of the first embodiment, the processes of step S102 and step S103 are performed inside the imaging apparatus 10.

  When adjusting the imaging device 70, the adjusting device 90 first drives the light source 61, and transmits the light emitted from the light source 61 through the bandpass filter 62 as inspection light. The light enters the filter unit 2 (step S101).

  Next, the binarization processing unit 101 of the adjustment device 90 performs binarization processing on the light field image output from the light receiving element array 4 of the imaging device 70 to generate a binarized image (step S102). ).

  Next, the position specifying unit 102 of the adjustment device 90 specifies the position of the image region in the macro pixel corresponding to the target region of the filter unit 2 using the binarized image generated by the binarization processing unit 101. Then, the position information indicating the identified position is stored in the storage unit 50 of the imaging device 70 (step S103).

  Next, the adjustment device 90 determines whether or not processing has been performed using all the filter regions of the filter unit 2 of the imaging device 70 as target regions (step S104). If there is a filter area that is not the target area (step S104: No), the bandpass filter 62 is switched according to the filter area that is newly set as the target area (step S105), and then the process returns to step S101 and the subsequent processing. repeat. On the other hand, when the process has been performed with all filter regions as target regions (step S104: Yes), the adjustment of the imaging device 70 ends.

As described above, in the second embodiment, the binarization process for the light field image output from the light receiving element array 4 when the inspection light is incident on the filter unit 2 of the imaging device 70, and the obtained binary value. The adjustment device 90 performs processing for specifying the positions of the image areas M _X , M _Y , and M _Z using the converted image and storing the position information in the storage unit 50. Therefore, the same effect as that of the first embodiment can be obtained while reducing the processing load on the imaging device 70.

  Although specific embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments as they are, and is embodied in the implementation stage while adding various modifications without departing from the scope of the invention. be able to. For example, the following modifications can be considered.

(Modification 1)
In the first and second embodiments described above, an absorption filter using a dye is used as the bandpass filter 62 for obtaining inspection light. However, the bandpass filter 62 is not limited to the absorption filter, and for example, an interference filter using a dielectric multilayer film may be used. Since the dielectric multilayer film has a high degree of freedom in designing the spectral transmittance, there is an advantage that a bandpass filter 62 having a spectral transmittance closer to the specification can be produced.

(Modification 2)
In the first and second embodiments described above, a xenon lamp is used as the light source 61. However, the light source 61 is not limited to a xenon lamp, and for example, a halogen lamp or a light emitting diode may be used. The halogen lamp has a light intensity on the short wavelength side lower than that of the xenon lamp, but can be used as the light source 61 because it has an intensity over a wide wavelength region like the xenon lamp. The light emitting diode is generally narrower than the xenon lamp and the halogen lamp, but can be used as the light source 61.

(Modification 3)
In the first and second embodiments described above, the light emitted from the light source 61 such as a xenon lamp is transmitted through the band-pass filter 62, thereby obtaining inspection light having a wavelength characteristic corresponding to the target region. It was. However, in place of the combination of the light source 61 such as a xenon lamp and the bandpass filter 62, a laser diode that emits a laser having a wavelength characteristic corresponding to the target region is used, and imaging is performed using the laser emitted from the laser diode as inspection light. You may make it inject into the filter part 2 of the apparatuses 10 and 70. FIG. Since the laser diode can emit a specific wavelength with high purity, an image having a higher contrast than the first and second embodiments described above can be obtained by using the laser diode as a light source for inspection light. There is an advantage that can be obtained.

DESCRIPTION OF SYMBOLS 1 Main lens 2 Filter part 3 Micro lens array 4 Light receiving element array 10 Imaging device 41 Binarization process part 42 Position specification part 43 Area | region detection part 44 Color detection part 50 Memory | storage part 61 Light source 62 Band pass filter 70 Imaging apparatus 90 Adjustment apparatus 101 binarization processing unit 102 position specifying unit

JP 2013-214950 A

Claims (11)

A filter unit having a plurality of filter regions each having a different wavelength selectivity;
A light receiving element array that receives light transmitted through the filter unit and outputs an image;
A storage unit that stores position information indicating a position on the light receiving element array that receives light transmitted through each filter region for each of a plurality of filter regions of the filter unit;
An area for detecting an image area corresponding to light transmitted through each filter area of the filter section from an image output from the light receiving element array when light from a subject enters the filter section based on the position information A detection unit;
A color detection unit that detects the color of the subject based on the detected output value of the image area;
When one of the plurality of filter regions of the filter unit is set as a target region, the position information corresponding to the target region includes inspection light having a wavelength characteristic corresponding to wavelength selectivity of the target region. Information indicating a position on the light receiving element array specified by using the binarized image obtained by performing binarization processing on the image output from the light receiving element array when entering the filter unit. There is an imaging apparatus. A binarization processing unit for performing the binarization processing;
Using the binarized image, the position on the light receiving element array that receives the light transmitted through the target area is specified, and position information indicating the specified position is used as the position information corresponding to the target area. The imaging apparatus according to claim 1, further comprising a position specifying unit stored in the storage unit.   The imaging apparatus according to claim 1, wherein the filter unit includes at least three filter regions having a spectral transmittance based on a color matching function.   The imaging apparatus according to claim 3, wherein the inspection light is light having a wavelength characteristic determined based on a difference between a spectral transmittance of the target region and a spectral transmittance of another filter region. .   The imaging apparatus according to claim 4, wherein the inspection light is light whose center wavelength is a maximum value of a difference between the spectral transmittance of the target region and the spectral transmittance of another filter region. A filter unit having a plurality of filter regions each having a different wavelength selectivity;
A light receiving element array that receives light transmitted through the filter unit and outputs an image;
An adjustment device that adjusts an imaging apparatus, comprising: a storage unit that stores position information indicating a position on the light receiving element array that receives light transmitted through each filter region for each of a plurality of filter regions of the filter unit. There,
When one of the plurality of filter regions of the filter unit is a target region, inspection light generating means that makes inspection light having a wavelength characteristic corresponding to the wavelength selectivity of the target region incident on the filter unit;
A binarization processing unit that acquires an image output from the light receiving element array when the inspection light enters the filter unit and performs binarization processing on the image;
Using the binarized image obtained by the binarization processing, the position on the light receiving element array that receives the light transmitted through the target area is specified, and the position information indicating the specified position is determined as the target area. And a position specifying unit that stores the position information corresponding to the position information in the storage unit. The inspection light generating means includes
A light source;
The adjustment apparatus according to claim 6, further comprising: a band-pass filter that is different from the filter unit and transmits the light emitted from the light source to be the inspection light.   The adjustment device according to claim 7, wherein the band-pass filter is an absorption filter using a dye or an interference filter using a dielectric multilayer film.   The adjusting device according to claim 7, wherein the light source is any one of a xenon lamp, a halogen lamp, and a light emitting diode.   The adjustment apparatus according to claim 6, wherein the inspection light generation unit causes a laser having a wavelength characteristic corresponding to wavelength selectivity of the target region to enter the filter unit as the inspection light. A filter unit having a plurality of filter regions each having a different wavelength selectivity;
A light receiving element array that receives light transmitted through the filter unit and outputs an image;
A storage unit that stores position information indicating a position on the light receiving element array that receives light transmitted through each filter region for each of a plurality of filter regions of the filter unit,
When one of the plurality of filter regions of the filter unit is a target region, a step of injecting inspection light having a wavelength characteristic corresponding to the wavelength selectivity of the target region into the filter unit;
Performing a binarization process on an image output from the light receiving element array when the inspection light is incident on the filter unit;
Using the binarized image obtained by the binarization processing, the position on the light receiving element array that receives the light transmitted through the target area is specified, and the position information indicating the specified position is determined as the target area. And storing in the storage unit as the position information corresponding to the position information.

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