Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
  • G01J3/00—Spectrometry; Spectrophotometry; Monochromators; Measuring colours
  • G01J3/02—Details
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
  • G01J3/00—Spectrometry; Spectrophotometry; Monochromators; Measuring colours
  • G01J3/46—Measurement of colour; Colour measuring devices, e.g. colorimeters
  • G01J3/50—Measurement of colour; Colour measuring devices, e.g. colorimeters using electric radiation detectors
  • G01J3/51—Measurement of colour; Colour measuring devices, e.g. colorimeters using electric radiation detectors using colour filters
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
  • G03B11/00—Filters or other obturators specially adapted for photographic purposes
  • G03B11/04—Hoods or caps for eliminating unwanted light from lenses, viewfinders or focusing aids
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
  • G03B15/00—Special procedures for taking photographs; Apparatus therefor

Definitions

• the technology disclosed herein relates to optical components, processing devices, processing methods, and programs.
• JP 2016-183957 A discloses a spectrometer that measures the spectral characteristics of an object.
• the spectrometer includes a combination of a front optical member, a birefringent optical member, a camera, and a processor.
• the front optical member includes a diffuser that receives light from the object.
• the birefringent optical member receives the light from the diffuser and generates interference fringes.
• the camera receives the interference fringes.
• the processor generates the spectral characteristics of the object.
• JP Patent Publication 08-285688 A discloses a spectral image analysis device including a band-pass interference filter, an imaging means, a first optical means, a second optical means, a subtraction means, and a display means.
• the band-pass interference filter can change the light transmission band.
• the imaging means has a plurality of light-receiving cells.
• the first optical means forms an image of an object on the interference filter.
• the second optical means forms an image on the interference filter on each light-receiving cell of the imaging means.
• the subtraction means calculates the difference between the first output of each light-receiving cell when the interference filter is set to a first transmission band and the second output of each light-receiving cell when the interference filter is set to a second transmission band different from the first transmission band, for each corresponding light-receiving cell.
• the display means visually displays the output of the subtraction means.
• JP 2008-165806 A discloses an image processing system that includes an external illumination unit, an image capture unit, and an image processing unit.
• the external illumination unit is equipped with multiple illumination light sources having different spectral distribution characteristics.
• the image capture unit includes an imaging optical system for capturing an image of a subject, an image sensor unit for acquiring a subject signal from the subject, an image capture operation unit for performing image capture operations, a connection contact unit for interlocking with the external illumination unit, and a spectrum detection unit for detecting the spectrum of light from the external illumination unit.
• the image capture unit obtains multiple subject spectral images by interlocking the multiple illumination light sources with the exposure timing of the image sensor unit and selectively turning on the multiple illumination light sources.
• the image processing unit includes an image memory unit for storing the subject spectral images captured by the image capture unit, and performs a desired image calculation from the subject spectral images stored in the image memory unit and the spectral data acquired by the spectrum detection unit.
• the external illumination unit is detachably attached to the image capture unit.
• an imaging device that includes a light source spectroscopy sensor that performs wavelength spectroscopy on light from a light source that illuminates a measurement target and detects light for each wavelength, and a multispectral camera that performs wavelength spectroscopy imaging of the measurement target.
• the light source spectroscopy sensor is configured to be capable of spectroscopy at more wavelengths than the multispectral camera.
• One embodiment of the technology disclosed herein provides an optical member, a processing device, a processing method, and a program that can contribute to the efficient measurement of the spectrum of a light source, compared to, for example, sequentially measuring the spectrum for each of multiple angles relative to the light source.
• the first aspect of the technology disclosed herein is an optical member that includes a first portion having an attachment portion that is attached to a lens device having an optical system, and a plurality of second portions provided on the first portion, each of the second portions having a first opening and a second opening, and the plurality of second portions including a third portion in which the first opening is angled relative to the second opening.
• a second aspect of the technology disclosed herein is an optical member that includes a first member having an attachment portion that is attached to a lens device having an optical system, and a plurality of openings provided in the first member, each of which has a first opening and a second opening, and the plurality of openings includes an opening in which the first opening is angled with respect to the second opening.
• a third aspect of the technology disclosed herein is an optical element according to the first aspect, in which the plurality of second portions include a fourth portion in which the first opening opens in the optical axis direction of the lens device.
• a fourth aspect of the technology disclosed herein is an optical element according to the third aspect, in which the second portions include third portions, and the third portions are arranged around the fourth portion.
• a fifth aspect of the technology disclosed herein is an optical element according to the third or fourth aspect, in which the fourth portion is disposed in the center of the first portion.
• a sixth aspect of the technology disclosed herein is an optical element according to any one of the third to fifth aspects, in which the second portions include third portions, and the third portions have fifth portions arranged in a ring shape around the fourth portion, and sixth portions arranged in a ring shape around the fourth portion outside the fifth portions.
• a seventh aspect of the technology disclosed herein is an optical element according to the sixth aspect, in which the angle of the sixth portion is greater than the angle of the fifth portion.
• the eighth aspect of the technology disclosed herein is an optical element according to the first aspect and any one of the third to seventh aspects, in which each second portion is formed into a cylindrical shape.
• a ninth aspect of the technology disclosed herein is an optical element according to the first aspect and any one of the third to eighth aspects, in which the first opening is open on a side other than the lens device side, and the second opening is open on the lens device side.
• a tenth aspect of the technology disclosed herein is an optical element according to any one of the first aspect and the third to ninth aspects, in which the third portion is an optical element that is inclined with respect to the optical axis direction of the lens device.
• An eleventh aspect of the technology disclosed herein is an optical element according to any one of the third to seventh aspects and the eighth to tenth aspects subordinate to the third aspect, in which the fourth portion is an optical element extending in the optical axis direction of the lens device.
• a twelfth aspect of the technology disclosed herein is an optical element according to the first aspect and any one of the third to eleventh aspects, in which the angle is an angle corresponding to at least one of the zenith angle and the azimuth angle.
• a thirteenth aspect of the technology disclosed herein is an optical element according to the first aspect and any one of the third to twelfth aspects, in which the multiple second portions are arranged in correspondence with at least one of the zenith angle and the azimuth angle.
• the fourteenth aspect of the technology disclosed herein is an optical element according to the first aspect and any one of the third to thirteenth aspects, in which a diffusion plate that diffuses light is disposed in the second opening.
• a fifteenth aspect of the technology disclosed herein is an optical element according to the first aspect and any one of the third to fourteenth aspects, in which the second portions include adjacent seventh portions, and a portion of the range of the light incidence angle limited by one of the seventh portions overlaps with a portion of the range of the light incidence angle limited by the other of the seventh portions.
• a sixteenth aspect of the technology disclosed herein is an optical element according to any one of the first aspect and the third to fifteenth aspects, in which the first shape, which is the shape of the first opening, is a rectangular shape or an arc shape.
• a seventeenth aspect of the technology disclosed herein is an optical element according to any one of the first aspect and the third to sixteenth aspects, in which the first shape, which is the shape of the first opening, is similar to the second shape, which is the shape of the second opening.
• the 18th aspect of the technology disclosed herein is an optical element according to the first aspect and any one of the third to seventeenth aspects, in which the range of the incident angle of light limited by the multiple second portions is set to the first incident angle range.
• a 19th aspect of the technology disclosed herein is an optical element according to any one of the first aspect and the third to eighteenth aspects, in which the lens device is an optical element that is a lens device of a spectroscopic imaging device.
• the twentieth aspect of the technology disclosed herein is an optical element according to the first aspect and any one of the third to nineteenth aspects, comprising a first optical element having a first portion and a plurality of second portions, and a second optical element that fixes the first optical element at a position away from the object side of the lens device.
• a 21st aspect of the technology disclosed herein is a processing device that includes a processor, which acquires a subject image obtained by capturing an image of the subject with a first imaging device, acquires a light source image obtained by capturing an image of the light source with a second imaging device having an optical member according to any one of the first to twentieth aspects, and derives the spectral reflectance of the subject when the subject is irradiated with light from the light source at a first angle and captured from a second angle.
• a twenty-second aspect of the technology disclosed herein is a processing device according to the twenty-first aspect, in which the spectral reflectance is derived based on an image of the subject, an image of the light source, and a bidirectional reflectance distribution function of the subject.
• a 23rd aspect of the technology disclosed herein is a processing device according to the 21st or 22nd aspect, in which the light source image includes information regarding the wavelength and intensity of light for at least one of the zenith angle and the azimuth angle.
• a 24th aspect of the technology disclosed herein is a processing device according to the 22nd aspect and the 23rd aspect dependent on the 22nd aspect, in which the processor derives a first reflection coefficient, which is the reflection coefficient of the subject, based on an image of the subject, and derives a bidirectional reflectance distribution function coefficient included in the bidirectional reflectance distribution function based on the first reflection coefficient depending on the type of the subject, and deriving the spectral reflectance of the subject includes deriving a second reflection coefficient, which is the reflection coefficient of the subject at a second angle when light is irradiated onto the subject from a first angle, based on a light source spectral function based on the spectrum of the light source determined based on the light source image, and the bidirectional reflectance distribution function coefficient.
• a 25th aspect of the technology disclosed herein is a processing method that includes obtaining a subject image obtained by imaging a subject with a first imaging device, obtaining a light source image obtained by imaging a light source with a second imaging device having an optical member according to any one of the first to twentieth aspects, and deriving the spectral reflectance of the subject when the subject is imaged from a second angle by irradiating the subject with light from the light source.
• a 26th aspect of the technology disclosed herein is a program for causing a computer to execute a process including obtaining a subject image obtained by imaging a subject with a first imaging device, obtaining a light source image obtained by imaging a light source with a second imaging device having an optical member according to any one of the first to twentieth aspects, and deriving the spectral reflectance of the subject when the subject is imaged from a second angle by irradiating the subject with light from the light source at a first angle.
• FIG. 1 is a block diagram illustrating an example of an imaging system.
• FIG. 2 is a perspective view showing an example of a photographic camera.
• FIG. 2 is a perspective view showing an example of a light source camera.
• FIG. 2 is a perspective view showing an example of an attachment.
• FIG. 2 is a plan view showing an example of an attachment.
• 6 is a cross-sectional view taken along line F6-F6 in FIG. 5.
• FIG. 4 is a cross-sectional view showing an example of a first incident angle range and a second incident angle range.
• FIG. 2 is a vertical cross-sectional view showing an example of an attachment and a spacer.
• FIG. 2 is a block diagram showing an example of a hardware configuration of a multispectral camera.
• FIG. 2 is an exploded perspective view showing an example of a pupil division filter.
• FIG. 2 is an exploded perspective view showing an example of a portion of a photoelectric conversion element.
• FIG. 2 is a block diagram showing an example of a functional configuration of a multispectral camera.
• 11 is a block diagram showing an example of the operation of an output value acquisition unit and an interference removal processing unit.
• FIG. 2 is a block diagram showing an example of a functional configuration of the processing device.
• 4 is a block diagram showing an example of the operation of an image acquisition unit;
• FIG. 11 is a block diagram showing an example of the operation of a light source spectral distribution deriving unit.
• FIG. 13 is a block diagram showing an example of the operation of a spectral reflectance deriving unit.
• FIG. 13 is a block diagram showing an example of a detailed operation of a spectral reflectance deriving unit.
• FIG. 13 is a flowchart showing an example of the flow of a spectral image generation process.
• 10 is a flowchart showing an example of the flow of a spectral reflectance derivation process.
• 13 is a flowchart showing an example of the flow of a reflection coefficient derivation process.
• FIG. 13 is a plan view showing an example of a modified example of the cylindrical portion.
• LED is an abbreviation for "light emitting diode”.
• CMOS is an abbreviation for "Complementary Metal Oxide Semiconductor”.
• CCD is an abbreviation for "Charge Coupled Device”.
• I/F is an abbreviation for "Interface”.
• RAM is an abbreviation for "Random Access Memory”.
• CPU is an abbreviation for "Central Processing Unit”.
• GPU is an abbreviation for "Graphics Processing Unit”.
• EEPROM is an abbreviation for "Electrically Erasable and Programmable Read Only Memory”.
• HDD is an abbreviation for "Hard Disk Drive”.
• BRDF is an abbreviation for "Bidirectional Reflectance Distribution Function”.
• RGB is an abbreviation for "Red Green Blue”.
• TPU is an abbreviation for "Tensor processing unit”.
• SSD is an abbreviation for "Solid State Drive”.
• USB is an abbreviation for "Universal Serial Bus”.
• ASIC is an abbreviation for "Application Specific Integrated Circuit”.
• FPGA is an abbreviation for "Field-Programmable Gate Array”.
• PLD is an abbreviation for "Programmable Logic Device”.
• SoC is an abbreviation for "System-on-a-Chip”.
• IC is an abbreviation for "Integrated Circuit”.
• straight line refers to a straight line in the sense of including, in addition to being a perfect straight line, an error that is generally acceptable in the technical field to which the technology of this disclosure belongs and an error that does not go against the spirit of the technology of this disclosure.
• plane refers to a plane in the sense of including, in addition to being a perfect plane, an error that is generally acceptable in the technical field to which the technology of this disclosure belongs and an error that does not go against the spirit of the technology of this disclosure.
• an imaging system S includes a subject camera 1, a light source camera 2, a light source 3, and a processing device 4.
• the imaging system S is a system that derives the spectral reflectance of a subject 5 in the processing device 4 when light is irradiated from a first angle by the light source 3 onto the subject 5 and the subject 5 is imaged from a second angle by the subject camera 1.
• the first angle is defined by a zenith angle ⁇ 1 and an azimuth angle ⁇ 1
• the second angle is defined by a zenith angle ⁇ 2 and an azimuth angle ⁇ 2.
• the Ax-axis direction, the Ay-axis direction, and the Az-axis direction are mutually orthogonal directions.
• the Ax-axis direction, the Ay-axis direction, and the Az-axis direction may be any direction, including horizontal and vertical directions.
• the line L 0 is a normal line to the surface of the subject 5, the line L 1 is a line connecting the light source 3 and the subject 5, and the line L 2 is a line connecting the captured camera 1 and the subject 5.
• the line L 0 extends in the Az-axis direction.
• the lines L 0 , L 1 , and L 2 intersect at a point P on the surface of the subject 5.
• the coordinates of the point P in the XY coordinate system are expressed by the coordinates (x, y).
• the point P on the surface of the subject 5 is referred to as the "subject position (x, y)".
• the zenith angle ⁇ 1 is the angle between the lines L0 and L1 when viewed from the Ay-axis direction, and the azimuth angle ⁇ 1 is the angle around the line L1 .
• the zenith angle ⁇ 2 is the angle between the lines L0 and L2 when viewed from the Ay-axis direction, and the azimuth angle ⁇ 2 is the angle around the line L2 .
• the zenith angle ⁇ 1, the azimuth angle ⁇ 1, the zenith angle ⁇ 2, and the azimuth angle ⁇ 2 are all angles at the subject position (x, y).
• the captured camera 1 and the light source 3 are disposed at positions spaced apart in the Az-axis direction from the subject 5 when viewed from the Ay-axis direction.
• the captured camera 1 and the light source 3 are disposed at positions spaced apart from each other in the Ax-axis direction when viewed from the Ay-axis direction.
• the light source camera 2 is disposed, for example, on a line L1 .
• the light source camera 2 may be disposed at a position away from the line L1 and in the vicinity of the subject 5.
• the vicinity of the subject 5 is, for example, a position where a light source spectral distribution (see FIG. 16 ) to be described later acquired by the light source camera 2 falls within an error range when the light source camera 2 is disposed at the subject position (x, y) and when the light source camera 2 is disposed in the vicinity of the subject 5.
• the light source 3 may be any type of light source. Examples of the light source 3 include an LED light source, a laser light source, or an incandescent light bulb. The light source 3 may be the sun, or a reflective member that reflects light emitted from another light source. The light emitted from the light source 3 is unpolarized.
• the subject camera 1 is an example of a "first imaging device” according to the technology of the present disclosure.
• the light source camera 2 is an example of a “second imaging device” according to the technology of the present disclosure.
• the light source 3 is an example of a "light source” according to the technology of the present disclosure.
• the processing device 4 is an example of a "processing device” according to the technology of the present disclosure.
• the subject camera 1 includes a lens device 12 and an imaging device body 14.
• the lens device 12 has a pupil division filter 16 that splits incident light into multiple wavelength bands.
• the subject camera 1 is a multispectral camera that captures light split into multiple wavelength ranges by the pupil division filter 16 to generate and output spectral images 72A-72C.
• spectral images 72A to 72C generated based on light dispersed into three wavelength bands will be described as multiple spectral images.
• the three wavelength bands are merely an example, and four or more wavelength bands may be used.
• the subject camera 1 may be a multispectral camera capable of capturing an image of a subject with a higher wavelength resolution than a multispectral camera capable of capturing light dispersed into three wavelength bands.
• the spectral images 72A-72C may include images obtained by capturing light in the visible light band, and may also include images that visualize light in wavelength bands that cannot be perceived by the human eye (e.g., near-infrared band and/or ultraviolet band, etc.).
• the light source camera 2 comprises a lens device 12, an image capture device body 14, and an optical member 130.
• the lens device 12 and the image capture device body 14 have the same configuration as the lens device 12 and the image capture device body 14 of the subject camera 1 (see FIG. 2).
• the optical member 130 comprises an attachment 132 and a spacer 134.
• the spacer 134 is attached to the object side end of the lens device 12, and the attachment 132 is attached to the object side end of the spacer 134.
• Optical member 130 is an example of an "optical member” according to the technology of the present disclosure.
• Attachment 132 is an example of a "first optical member” according to the technology of the present disclosure.
• Spacer 134 is an example of a "second optical member” according to the technology of the present disclosure.
• Light source camera 2 is an example of a “spectroscopic imaging device” according to the technology of the present disclosure.
• Lens device 12 is an example of a “lens device” according to the technology of the present disclosure.
• the attachment 132 has a base portion 136 and a plurality of cylindrical portions 138.
• the base portion 136 is formed in a flat plate shape. When viewed in a plan view from the axial direction of the base portion 136, the base portion 136 is formed in a circular shape.
• the plurality of cylindrical portions 138 are provided on the base portion 136.
• the plurality of cylindrical portions 138 extend from the base portion 136 toward the object side.
• the plurality of cylindrical portions 138 are formed integrally with the base portion 136. Note that the plurality of cylindrical portions 138 may be separate from the base portion 136.
• Each cylindrical portion 138 is formed in a cylindrical shape.
• the base portion 136 is an example of a "first portion” and a “first member” according to the technology disclosed herein.
• the plurality of cylindrical portions 138 are an example of a “multiple second portions” and a “multiple openings” according to the technology disclosed herein.
• the multiple cylindrical portions 138 are arranged in accordance with the zenith angle ⁇ 1 and the azimuth angle ⁇ 1 (see FIG. 1). Specifically, the multiple cylindrical portions 138 include a cylindrical portion 138A arranged in the center of the base portion 136, multiple cylindrical portions 138B arranged in a ring shape around the cylindrical portion 138A on the outside of the cylindrical portion 138A, and multiple cylindrical portions 138C arranged in a ring shape around the cylindrical portion 138A on the outside of the multiple cylindrical portions 138B.
• Cylindrical portion 138A, cylindrical portion 138B, and cylindrical portion 138C are arranged side by side in the direction of zenith angle ⁇ 1 (i.e., the radial direction of base portion 136). Furthermore, the multiple cylindrical portions 138B are arranged in a ring shape in the direction of azimuth angle ⁇ 1 (i.e., the circumferential direction of base portion 136). Similarly, the multiple cylindrical portions 138C are also arranged in a ring shape in the direction of azimuth angle ⁇ 1.
• the number of cylindrical portions 138A is one
• the number of cylindrical portions 138B arranged around cylindrical portion 138A is six
• the number of cylindrical portions 138C arranged around cylindrical portions 138B is eight. Note that the number and arrangement of the cylindrical portions 138 may be other than those described above.
• FIG. 6 is a cross-sectional view taken along line F6-F6 in FIG. 5.
• the base portion 136 has a first surface 142 and a second surface 144.
• the first surface 142 is the surface on the object side of the base portion 136
• the second surface 144 is the surface on the image side of the base portion 136.
• the first surface 142 and the second surface 144 are flat surfaces.
• the first surface 142 and the second surface 144 are each surfaces that are perpendicular to the central axis AC of the base portion 136.
• the central axis AC is an axis that passes through the center of the base portion 136 and extends in the axial direction of the base portion 136.
• the axial direction of the base portion 136 is a direction that coincides with the optical axis direction of the lens device 12 (see FIG. 3).
• the cylindrical portion 138A extends in the axial direction of the base portion 136. Specifically, the cylindrical portion 138A is formed along the central axis AC of the base portion 136. The angle between the central axis A1 of the cylindrical portion 138A and the central axis AC is set to 0°.
• Cylindrical portion 138B and cylindrical portion 138C are inclined with respect to the axial direction of base portion 136. Specifically, cylindrical portion 138B and cylindrical portion 138C are inclined radially outward from base portion 136 with respect to central axis AC of base portion 136. Angle ⁇ 1 between central axis A2 of cylindrical portion 138B and central axis AC is set to an angle greater than 0°. Similarly, angle ⁇ 2 between central axis A3 of cylindrical portion 138C and central axis AC is also set to an angle greater than 0°. Furthermore, angle ⁇ 2 is set to an angle greater than angle ⁇ 1.
• Cylindrical portion 138A is an example of a "fourth portion” according to the technology of the present disclosure.
• Multiple cylindrical portions 138B and multiple cylindrical portions 138C are an example of a "third portion” according to the technology of the present disclosure.
• Multiple cylindrical portions 138B are an example of a "fifth portion” according to the technology of the present disclosure.
• Multiple cylindrical portions 138C are an example of a "sixth portion” according to the technology of the present disclosure.
• Each cylindrical portion 138 has a first opening 146 and a second opening 148.
• the first opening 146 is formed at the end of the cylindrical portion 138 on the object side, and the second opening 148 is formed at the end of the cylindrical portion 138 on the image side.
• the first opening 146 opens on the object side, and the second opening 148 opens on the image side.
• the first opening 146 and the second opening 148 communicate with each other through a hole 140 formed inside the cylindrical portion 138.
• the first opening 146 of the cylindrical portion 138A is perpendicular to the central axis A1 of the cylindrical portion 138A
• the first opening 146 of the cylindrical portion 138B is perpendicular to the central axis A2 of the cylindrical portion 138B
• the first opening 146 of the cylindrical portion 138C is perpendicular to the central axis A3 of the cylindrical portion 138C.
• the first opening 146 of the cylindrical portion 138A opens in the axial direction of the base portion 136 and is parallel to the first surface 142.
• the first opening 146 of the cylindrical portion 138B is inclined with respect to the first surface 142 and has an angle with respect to the first surface 142.
• the first opening 146 of the cylindrical portion 138C is inclined with respect to the first surface 142 and has an angle with respect to the first surface 142.
• the second opening 148 of each cylindrical portion 138 opens in a direction opposite to the first surface 142 and is parallel to the first surface 142.
• the first opening 146 of the cylindrical portion 138B has an angle relative to the second opening 148 of the cylindrical portion 138B according to the zenith angle ⁇ 1 and the azimuth angle ⁇ 1. Specifically, the angle between the first opening 146 and the second opening 148 of the cylindrical portion 138B is set to an angle ⁇ 1 in response to the cylindrical portion 138B being inclined in the direction of the zenith angle ⁇ 1 and the azimuth angle ⁇ 1 relative to the central axis AC of the base portion 136.
• the first opening 146 of the cylindrical portion 138C has an angle relative to the second opening 148 of the cylindrical portion 138C according to the zenith angle ⁇ 1 and the azimuth angle ⁇ 1.
• the angle between the first opening 146 and the second opening 148 of the cylindrical portion 138C is set to an angle ⁇ 2 in response to the cylindrical portion 138C being inclined in the directions of the zenith angle ⁇ 1 and the azimuth angle ⁇ 1 relative to the central axis AC of the base portion 136.
• the angle ⁇ 2 is set to an angle greater than the angle ⁇ 1.
• the angles ⁇ 1 and ⁇ 2 are examples of "angles" related to the technology disclosed herein.
• the shape of the first opening 146 is a rectangle.
• the shape of the second opening 148 is also a rectangle.
• the rectangles of the first opening 146 and the second opening 148 are squares.
• the shape of the first opening 146 is similar to the shape of the second opening 148.
• the opening area of the first opening 146 is larger than the opening area of the second opening 148.
• the shape of the first opening 146 is an example of a "first shape” according to the technology disclosed herein.
• the shape of the second opening 148 is an example of a "second shape" according to the technology disclosed herein.
• a diffuser plate 150 that diffuses light is disposed in each second opening 148.
• the diffuser plate 150 has a size and shape that covers the second opening 148.
• the diffuser plate 150 is disposed perpendicular to the central axis AC of the base portion 136, and covers the second opening 148.
• the diffuser plate 150 diffuses the light irradiated from the light source 3 (see FIG. 1), thereby functioning as a secondary light source when the light source 3 is the primary light source.
• each cylindrical portion 138 has a range R of the angle of incidence of light limited by the cylindrical portion 138 (hereinafter referred to as the "incident angle range R").
• the incident angle range R is defined as the range between the first line La and the second line Lb.
• the first line La is a line extending toward the object side from a line connecting a first side 146A of the multiple sides of the first opening 146 and a first side 148A of the multiple sides of the second opening 148 that is opposite to the first side 146A.
• the second line Lb is a line extending toward the object side from a line connecting a second side 146B of the multiple sides of the first opening 146 and a second side 148B of the multiple sides of the second opening 148 that is opposite to the second side 146B.
• the multiple cylindrical portions 138 include adjacent cylindrical portions 138.
• adjacent cylindrical portions 138 refer to all of the multiple cylindrical portions 138 that are adjacent in the circumferential direction and/or radial direction of the base portion 136.
• the incidence angle range R of each cylindrical portion 138 is set to a range in which a portion of the incidence angle range R1 of one of the adjacent cylindrical portions 138 overlaps with a portion of the incidence angle range R2 of the other of the adjacent cylindrical portions 138.
• the incidence angle range R1 and the incidence angle range R2 have an overlapping range R3.
• the incident angle range R of light limited by each cylindrical portion 138 is set to the same incident angle range.
• the angle between the first line La and the second line Lb that define the incident angle range R is constant.
• the same incident angle range is an example of the "first incident angle range” according to the technology of the present disclosure.
• Adjacent cylindrical portions 138 are an example of the "seventh portion” according to the technology of the present disclosure.
• the attachment 132 has an attachment portion 152.
• the attachment portion 152 extends from the second surface 144 to the image side.
• the spacer 134 is formed in a cylindrical shape.
• the attachment portion 152 is attached to the object side end of the spacer 134.
• the spacer 134 has an attachment portion 154 attached to the object side end of the lens device 12.
• the spacer 134 fixes the attachment 132 at a position away from the object side of the lens device 12.
• the first opening 146 opens on a side different from the lens device 12 side (i.e., the object side)
• the second opening 148 opens on the lens device 12 side (i.e., the image side).
• the attachment portion 152 is an example of an "attachment portion" according to the technology disclosed herein.
• FIG. 9 shows an example of the configuration of a multispectral camera 10 that is used as the subject camera 1 and the light source camera 2.
• the multispectral camera 10 includes a lens device 12 and an imaging device body 14.
• the lens device 12 has the pupil division filter 16 described above.
• the pupil division filter 16 has a frame 18, spectral filters 20A-20C, and polarizing filters 22A-22C.
• the frame 18 has openings 24A-24C.
• the openings 24A-24C are formed in a line around the optical axis OA.
• each opening 24A-24C will be referred to as "opening 24.”
• the spectral filters 20A-20C are provided in the openings 24A-24C, respectively, and are arranged in a line around the optical axis OA. As a result, the center of gravity of each of the spectral filters 20A-20C is located at a position different from the optical axis OA.
• Each of the spectral filters 20A to 20C is a bandpass filter that transmits light in a specific wavelength band.
• the spectral filters 20A to 20C have different wavelength bands. Specifically, the spectral filter 20A has a first wavelength band ⁇ 1 , the spectral filter 20B has a second wavelength band ⁇ 2 , and the spectral filter 20C has a third wavelength band ⁇ 3 .
• each of the spectral filters 20A to 20C will be referred to as the "spectral filter 20.” Furthermore, when there is no need to distinguish between the first wavelength band ⁇ 1 , the second wavelength band ⁇ 2 , and the third wavelength band ⁇ 3 , each of the first wavelength band ⁇ 1 , the second wavelength band ⁇ 2 , and the third wavelength band ⁇ 3 will be referred to as the "wavelength band ⁇ .”
• Polarizing filters 22A to 22C are provided corresponding to spectral filters 20A to 20C, respectively. Specifically, polarizing filter 22A is provided in opening 24A and is superimposed on spectral filter 20A. Polarizing filter 22B is provided in opening 24B and is superimposed on spectral filter 20B. Polarizing filter 22C is provided in opening 24C and is superimposed on spectral filter 20C.
• Each of the polarizing filters 22A to 22C is an optical filter that transmits light that vibrates in a specific direction.
• the polarizing filters 22A to 22C have a polarization axis with a different polarization angle.
• the polarizing filter 22A has a first polarization angle ⁇ 1
• the polarizing filter 22B has a second polarization angle ⁇ 2
• the polarizing filter 22C has a third polarization angle ⁇ 3 .
• the polarization axis may be referred to as a transmission axis.
• the first polarization angle ⁇ 1 is set to 0°
• the second polarization angle ⁇ 2 is set to 45°
• the third polarization angle ⁇ 3 is set to 90°.
• each of the polarizing filters 22A to 22C will be referred to as the "polarizing filter 22.” Furthermore, when there is no need to distinguish between the first polarization angle ⁇ 1 , the second polarization angle ⁇ 2 , and the third polarization angle ⁇ 3 , each of the first polarization angle ⁇ 1 , the second polarization angle ⁇ 2 , and the third polarization angle ⁇ 3 will be referred to as the "polarization angle ⁇ .”
• the number of the openings 24 is three, corresponding to the number of the wavelength bands ⁇ , but the number of the openings 24 may be greater than the number of the wavelength bands ⁇ (i.e., the number of the spectral filters 20). Furthermore, the openings 24 that are not used may be blocked by a shielding member (not shown). Furthermore, in the example shown in FIG. 10, the spectral filters 20 have different wavelength bands ⁇ , but the spectral filters 20 may include spectral filters 20 having the same wavelength band ⁇ .
• the lens device 12 includes an optical system 26, and the imaging device body 14 includes an image sensor 28.
• the optical system 26 includes a pupil division filter 16, a first lens 30, and a second lens 32.
• the first lens 30 allows light from the object side to be incident on the pupil division filter 16.
• the second lens 32 forms an image of the light that has passed through the pupil division filter 16 on the light receiving surface 34A of the photoelectric conversion element 34 provided in the image sensor 28.
• the pupil division filter 16 is disposed at the pupil position of the optical system 26.
• the pupil position refers to the diaphragm surface that limits the brightness of the optical system 26.
• the pupil position here includes nearby positions, and nearby positions refer to the range from the entrance pupil to the exit pupil.
• the configuration of the pupil division filter 16 is as described using Figure 10.
• Figure 9 shows multiple spectral filters 20 and multiple polarizing filters 22 arranged in a straight line along a direction perpendicular to the optical axis OA.
• the image sensor 28 includes a photoelectric conversion element 34 and a signal processing circuit 36.
• the image sensor 28 is a CMOS image sensor.
• a CMOS image sensor is exemplified as the image sensor 28, but the technology of the present disclosure is not limited to this, and the technology of the present disclosure is valid even if the image sensor 28 is another type of image sensor, such as a CCD image sensor.
• FIG. 9 shows a schematic configuration of the photoelectric conversion element 34.
• FIG. 11 specifically shows a portion of the configuration of the photoelectric conversion element 34.
• the photoelectric conversion element 34 has a pixel layer 38, a polarizing filter layer 40, and a spectral filter layer 42. Note that the configuration of the photoelectric conversion element 34 shown in FIG. 11 is only an example, and the technology disclosed herein can be applied even if the photoelectric conversion element 34 does not have the spectral filter layer 42.
• the pixel layer 38 has a plurality of pixels 44.
• the plurality of pixels 44 are arranged in a matrix and form the light receiving surface 34A of the photoelectric conversion element 34.
• Each pixel 44 is a physical pixel having a photodiode (not shown), which photoelectrically converts the received light and outputs an electrical signal according to the amount of received light.
• the pixels 44 provided in the photoelectric conversion element 34 will be referred to as “physical pixels 44" to distinguish them from the pixels that form the spectral image. Also, the pixels that form the spectral image 72 will be referred to as “image pixels.”
• the photoelectric conversion element 34 outputs the electrical signals output from the multiple physical pixels 44 to the signal processing circuit 36 as imaging data.
• the signal processing circuit 36 digitizes the analog imaging data input from the photoelectric conversion element 34.
• the imaging data is image data that represents the captured image 70.
• the multiple physical pixels 44 form multiple pixel blocks 46.
• Each pixel block 46 is formed by a total of four physical pixels 44, two vertically and two horizontally.
• the four physical pixels 44 forming each pixel block 46 are shown arranged in a straight line along a direction perpendicular to the optical axis OA, but the four physical pixels 44 are arranged adjacent to each other in the vertical and horizontal directions of the photoelectric conversion element 34 (see FIG. 11).
• the polarizing filter layer 40 has a plurality of types of polarizers 48A to 48D.
• Each of the polarizers 48A to 48D is an optical filter that transmits light vibrating in a specific direction.
• the polarizers 48A to 48D have polarization axes with different polarization angles. Specifically, the polarizer 48A has a first polarization angle ⁇ 1 , the polarizer 48B has a second polarization angle ⁇ 2 , the polarizer 48C has a third polarization angle ⁇ 3 , and the polarizer 48D has a fourth polarization angle ⁇ 4.
• the first polarization angle ⁇ 1 is set to 0°
• the second polarization angle ⁇ 2 is set to 45°
• the third polarization angle ⁇ 3 is set to 90°
• the fourth polarization angle ⁇ 4 is set to 135°.
• each of the polarizers 48A to 48D will be referred to as "polarizer 48.” Furthermore, when there is no need to distinguish between the first polarization angle ⁇ 1 , the second polarization angle ⁇ 2 , the third polarization angle ⁇ 3 , and the fourth polarization angle ⁇ 4 , each of the first polarization angle ⁇ 1 , the second polarization angle ⁇ 2 , the third polarization angle ⁇ 3 , and the fourth polarization angle ⁇ 4 will be referred to as "polarization angle ⁇ .”
• the spectral filter layer 42 has a B filter 50A, a G filter 50B, and an R filter 50C.
• the B filter 50A is a blue-range filter that transmits the most light in the blue wavelength band of light in a plurality of wavelength bands.
• the G filter 50B is a green-range filter that transmits the most light in the green wavelength band of light in a plurality of wavelength bands.
• the R filter 50C is a red-range filter that transmits the most light in the red wavelength band of light in a plurality of wavelength bands.
• the B filter 50A, the G filter 50B, and the R filter 50C are assigned to each pixel block 46.
• the B filter 50A, the G filter 50B, and the R filter 50C are shown arranged in a line along a direction perpendicular to the optical axis OA, but as an example, as shown in FIG. 11, the B filter 50A, the G filter 50B, and the R filter 50C are arranged in a matrix in a default pattern arrangement.
• the B filter 50A, the G filter 50B, and the R filter 50C are arranged in a matrix in a Bayer array, which is an example of a default pattern arrangement.
• the default pattern arrangement may be an RGB stripe array, an R/G checkerboard array, an X-Trans (registered trademark) array, a honeycomb array, or the like, in addition to the Bayer array.
• filter 50 when there is no need to distinguish between the B filter 50A, the G filter 50B, and the R filter 50C, they will each be referred to as "filter 50.”
• the imaging device body 14 includes, in addition to the image sensor 28, a control driver 52, an input/output I/F 54, a computer 56, and a communication device 58.
• the input/output I/F 54 is connected to the signal processing circuit 36, the control driver 52, the computer 56, and the communication device 58.
• the computer 56 has a processor 60, storage 62, and RAM 64.
• the processor 60 controls the entire multispectral camera 10.
• the processor 60 is, for example, a processing device including a CPU and a GPU, and the GPU operates under the control of the CPU and is responsible for executing image-related processing.
• a processing device including a CPU and a GPU is given as an example of the processor 60, but this is merely one example, and the processor 60 may be one or more CPUs that integrate a GPU function, or one or more CPUs that do not integrate a GPU function.
• the processor 60, storage 62, and RAM 64 are connected via a bus 66, which is connected to the input/output I/F 54.
• the storage 62 is a non-transitory storage medium, and stores various parameters and programs.
• the storage 62 is a flash memory (e.g., an EEPROM).
• EEPROM e.g., EEPROM
• the RAM 64 temporarily stores various information and is used as a work memory. Examples of the RAM 64 include a DRAM and/or an SRAM.
• the processor 60 reads the necessary programs from the storage 62 and executes the read programs on the RAM 64.
• the processor 60 controls the control driver 52 and the signal processing circuit 36 according to the programs executed on the RAM 64.
• the control driver 52 controls the photoelectric conversion element 34 under the control of the processor 60.
• the communication device 58 is connected to the processor 60 via the input/output I/F 54 and the bus 66.
• the communication device 58 is also connected to the processing device 4 so that it can communicate with it via a wired or wireless connection.
• the communication device 58 is responsible for sending and receiving information between the processing device 4. For example, the communication device 58 transmits data to the processing device 4 in response to a request from the processor 60.
• the communication device 58 also receives data transmitted from the processing device 4, and outputs the received data to the processor 60 via the bus 66.
• a spectral image generation program 80 is stored in the storage 62.
• the processor 60 reads the spectral image generation program 80 from the storage 62 and executes the read spectral image generation program 80 on the RAM 64.
• the processor 60 executes a spectral image generation process for generating a plurality of spectral images 72 in accordance with the spectral image generation program 80 executed on the RAM 64.
• the spectral image generation process is realized by the processor 60 operating as an output value acquisition unit 82 and an interference removal processing unit 84 in accordance with the spectral image generation program 80.
• the output value acquisition unit 82 acquires the output value Y of each physical pixel 44 based on the imaging data.
• the output value Y of each physical pixel 44 corresponds to the luminance value of each pixel included in the captured image 70 represented by the imaging data.
• the output value Y of each physical pixel 44 is a value including interference (i.e., crosstalk). That is, since light of each wavelength band ⁇ of the first wavelength band ⁇ 1 , the second wavelength band ⁇ 2 , and the third wavelength band ⁇ 3 is incident on each physical pixel 44, the output value Y is a mixture of a value corresponding to the amount of light of the first wavelength band ⁇ 1 , a value corresponding to the amount of light of the second wavelength band ⁇ 2 , and a value corresponding to the amount of light of the third wavelength band ⁇ 3 .
• the processor 60 In order to obtain the spectral image 72, the processor 60 must perform a process of separating and extracting values corresponding to each wavelength band ⁇ from the output value Y for each physical pixel 44, that is, a process of removing interference, on the output value Y. Therefore, in this embodiment, in order to obtain the spectral image 72, the interference removal processing unit 84 performs interference removal processing on the output value Y of each physical pixel 44 acquired by the output value acquisition unit 82.
• the output value Y of each physical pixel 44 includes, for red, green, and blue, each luminance value for each polarization angle ⁇ as a component of the output value Y.
• the output value Y of each physical pixel 44 is expressed by equation (1).
• Y ⁇ 1_R is the luminance value of the red component of the output value Y whose polarization angle is the first polarization angle ⁇ 1
• Y ⁇ 2_R is the luminance value of the red component of the output value Y whose polarization angle is the second polarization angle ⁇ 2
• Y ⁇ 3_R is the luminance value of the red component of the output value Y whose polarization angle is the third polarization angle ⁇ 3
• Y ⁇ 4_R is the luminance value of the red component of the output value Y whose polarization angle is the fourth polarization angle ⁇ 4 .
• Y ⁇ 1_G is the luminance value of the green component of the output value Y whose polarization angle is the first polarization angle ⁇ 1
• Y ⁇ 2_G is the luminance value of the green component of the output value Y whose polarization angle is the second polarization angle ⁇ 2
• Y ⁇ 3_G is the luminance value of the green component of the output value Y whose polarization angle is the third polarization angle ⁇ 3
• Y ⁇ 4_G is the luminance value of the green component of the output value Y whose polarization angle is the fourth polarization angle ⁇ 4 .
• Y ⁇ 1_B is the luminance value of the blue component of the output value Y whose polarization angle is the first polarization angle ⁇ 1
• Y ⁇ 2_B is the luminance value of the blue component of the output value Y whose polarization angle is the second polarization angle ⁇ 2
• Y ⁇ 3_B is the luminance value of the blue component of the output value Y whose polarization angle is the third polarization angle ⁇ 3
• Y ⁇ 4_B is the luminance value of the blue component of the output value Y whose polarization angle is the fourth polarization angle ⁇ 4 .
• the pixel value X of each image pixel forming the spectral image 72 includes, as components of the pixel value X, a luminance value X ⁇ 1 of polarized light in a first wavelength band ⁇ 1 having a first polarization angle ⁇ 1 (hereinafter referred to as the “first wavelength band polarized light”), a luminance value X ⁇ 2 of polarized light in a second wavelength band ⁇ 2 having a second polarization angle ⁇ 2 (hereinafter referred to as the “second wavelength band polarized light”), and a luminance value X ⁇ 3 of polarized light in a third wavelength band ⁇ 3 having a third polarization angle ⁇ 3 (hereinafter referred to as the “third wavelength band polarized light”).
• the pixel value X of each image pixel is expressed by equation (2).
• Interference matrix A is the interference matrix.
• Interference matrix A (not shown) is a matrix that indicates the characteristics of interference.
• Interference matrix A is determined in advance based on multiple known values such as the spectrum of the incident light, the spectral transmittance of the first lens 30, the spectral transmittance of the second lens 32, the spectral transmittances of the multiple spectral filters 20, and the spectral sensitivity of the image sensor 28.
• the interference cancellation matrix A + is a matrix defined based on the spectrum of the incident light, the spectral transmittance of the first lens 30, the spectral transmittance of the second lens 32, the spectral transmittances of the multiple spectral filters 20, and the spectral sensitivity of the image sensor 28.
• the interference cancellation matrix A + is stored in advance in the storage 62.
• the interference cancellation processing unit 84 acquires the interference cancellation matrix A + stored in the storage 62 and the output value Y of each physical pixel 44 acquired by the output value acquisition unit 82, and outputs the pixel value X of each image pixel according to equation (4) based on the acquired interference cancellation matrix A + and the output value Y of each physical pixel 44.
• the pixel value X of each image pixel includes, as its components, a luminance value X ⁇ 1 of the first wavelength band polarized light, a luminance value X ⁇ 2 of the second wavelength band polarized light, and a luminance value X ⁇ 3 of the third wavelength band polarized light.
• the spectral image 72A of the captured image 70 corresponds to the luminance value X ⁇ 1 of the light in the first wavelength band ⁇ 1 (i.e., an image based on the luminance value X ⁇ 1 ).
• the spectral image 72B of the captured image 70 corresponds to the luminance value X ⁇ 2 of the light in the second wavelength band ⁇ 2 (i.e., an image based on the luminance value X ⁇ 2 ).
• the spectral image 72C of the captured image 70 corresponds to the luminance value X ⁇ 3 of the light in the third wavelength band ⁇ 3 (i.e., an image based on the luminance value X ⁇ 3 ).
• the interference removal process is performed by the interference removal processor 84, whereby the captured image 70 is separated into a spectral image 72A corresponding to the luminance value X ⁇ 1 of the first wavelength band polarized light, a spectral image 72B corresponding to the luminance value X ⁇ 2 of the second wavelength band polarized light, and a spectral image 72C corresponding to the luminance value X ⁇ 3 of the third wavelength band polarized light. That is, the captured image 70 is separated into spectral images 72 for each wavelength band ⁇ of the multiple spectral filters 20.
• the processing device 4 includes a computer 92.
• the computer 92 includes a processor 94, a storage 96, and a RAM 98.
• the processor 94, the storage 96, and the RAM 98 are realized by hardware similar to the processor 60, the storage 62, and the RAM 64 described above (see FIG. 9).
• the processor is an example of a "processor" according to the technology disclosed herein.
• Storage 96 stores a spectral reflectance derivation program 100.
• Spectral reflectance derivation program 100 is an example of a "program" according to the technology of the present disclosure.
• Processor 94 reads out spectral reflectance derivation program 100 from storage 96 and executes the read out spectral reflectance derivation program 100 on RAM 98.
• Processor 94 executes a spectral reflectance derivation process in accordance with the spectral reflectance derivation program 100 executed on RAM 98.
• the spectral reflectance derivation process is realized by processor 94 operating as image acquisition unit 102, light source spectral distribution derivation unit 104, and spectral reflectance derivation unit 106 in accordance with the spectral reflectance derivation program 100.
• the spectral reflectance derivation process is data processing of the imaging data transmitted from subject camera 1 and light source camera 2 and received by processing device 4.
• the image acquisition unit 102 acquires a subject image 120 obtained by capturing an image of a subject 5 using a subject camera 1.
• the subject image 120 includes a plurality of spectral images 72 obtained by capturing an image of the subject 5.
• the image acquisition unit 102 also acquires a light source image 122 obtained by capturing an image of a light source 3 using a light source camera 2.
• the light source image 122 includes a plurality of spectral images 72 obtained by capturing an image of the light source 3.
• each spectral image 72 included in the light source image 122 includes a plurality of images 124.
• Each image 124 corresponds to light that passes through each cylindrical portion 138 provided in the attachment 132 and is imaged on the light receiving surface 34A (see FIG. 9).
• the position of the image 124 in the spectral image 72 corresponds to the position of the cylindrical portion 138, i.e., the zenith angle ⁇ 1 and the azimuth angle ⁇ 1 (see FIG. 1).
• the brightness value of the image 124 corresponds to the intensity of the light that has passed through the cylindrical portion 138.
• each spectral image 72 included in the light source image 122 includes multiple images 124, and thus includes the spectral distribution of the light source 3 for each zenith angle ⁇ 1 and azimuth angle ⁇ 1 (hereinafter referred to as the "light source spectral distribution") as information regarding the wavelength and intensity of light for each zenith angle ⁇ 1 and azimuth angle ⁇ 1.
• the light source spectral distribution refers to the light intensity distribution for each zenith angle ⁇ 1 and azimuth angle ⁇ 1 in each wavelength band ⁇ .
• the light source spectral distribution derivation unit 104 derives the light source spectral distribution corresponding to each wavelength band ⁇ based on the multiple images 124 included in the spectral image 72.
• the bidirectional reflectance distribution function (hereinafter referred to as "subject BRDF”) of the subject 5 is stored in the storage 96.
• the subject BRDF is a function that represents the angular distribution characteristics of the intensity of light reflected by the subject 5 when incident light is incident on the subject 5 from a specific angle.
• the subject BRDF is stored in the storage 96 for each wavelength band ⁇ .
• the spectral reflectance derivation unit 106 derives the spectral reflectance of the subject 5 when light is irradiated from the light source 3 at a first angle onto the subject 5 and the subject 5 is imaged from a second angle (see FIG. 1) (hereinafter referred to as the "specific spectral reflectance") for each wavelength band ⁇ based on the spectral image 72 included in the subject image 120, the light source spectral distribution, and the subject BRDF.
• the spectral reflectance derivation unit 106 executes a reflection coefficient derivation process to derive a specific spectral reflectance.
• the spectral reflectance derivation unit 106 has a first reflection coefficient derivation unit 108, a subject type identification unit 110, a BRDF coefficient derivation unit 112, and a second reflection coefficient derivation unit 114.
• the reflection coefficient derivation process is realized by the first reflection coefficient derivation unit 108, the subject type identification unit 110, the BRDF coefficient derivation unit 112, and the second reflection coefficient derivation unit 114.
• the reflection coefficient derivation process is executed for each wavelength band ⁇ .
• the first reflection coefficient derivation unit 108 derives a first reflection coefficient, which is the reflection coefficient of the subject 5 in the wavelength band ⁇ , based on the spectral image 72 included in the subject image 120 acquired by the image acquisition unit 102.
• the first reflection coefficient is expressed by a function h(x, y; ⁇ ).
• x corresponds to the x coordinate of the subject position (x, y) and represents the horizontal position of the spectral image 72.
• y corresponds to the y coordinate of the subject position (x, y) and represents the vertical position of the spectral image 72.
• the first reflection coefficient may be referred to as the "first reflection coefficient h(x, y; ⁇ )."
• the subject type identification unit 110 identifies the type of subject 5 based on, for example, information indicating the type of subject 5 given to the processing device 4 by the user and/or the result of image processing performed on the spectral image 72 included in the subject image 120.
• the type of subject 5 may be the specific name of the plant, or the specific type of subject 5, such as whether the subject 5 is a plant or soil.
• Storage 96 stores BRDF coefficient information that indicates the relationship between the first reflection coefficient h(x, y; ⁇ ), the type of subject 5, and the BRDF coefficient.
• the BRDF coefficient is a coefficient included in the subject BRDF, and is expressed by the function ci(x, y; ⁇ ).
• the BRDF coefficient may be referred to as the "BRDF coefficient ci(x, y; ⁇ )."
• the BRDF coefficient derivation unit 112 derives the BRDF coefficient ci(x, y; ⁇ ) based on the BRDF coefficient information and the first reflection coefficient h(x, y; ⁇ ) according to the type of subject 5.
• the second reflection coefficient derivation unit 114 derives a second reflection coefficient, which is the reflection coefficient of the subject 5 at a second angle when light is irradiated from the light source 3 at a first angle, based on the light source spectral distribution derived by the light source spectral distribution derivation unit 104 and the BRDF coefficients ci(x, y; ⁇ ) derived by the BRDF coefficient derivation unit 112.
• the light source spectral distribution is expressed by the function f( ⁇ 1, ⁇ 1; ⁇ ).
• the light source spectral distribution may be referred to as "light source spectral distribution f( ⁇ 1, ⁇ 1; ⁇ )."
• the spectrum of light irradiated from the light source 3 to the subject 5 from the first angle is expressed by the function f'( ⁇ '1, ⁇ '1; ⁇ ).
• the spectrum of light irradiated from the light source 3 to the subject 5 from the first angle may be referred to as the "specific spectrum f'( ⁇ '1, ⁇ '1; ⁇ )."
• the second reflection coefficient is expressed by the function h'[f'](x, y; ⁇ '2, ⁇ '2; ⁇ ).
• the second reflection coefficient may be referred to as "second reflection coefficient h'[f'](x, y; ⁇ '2, ⁇ '2; ⁇ ).
• the subject BRDF is expressed by the function g( ⁇ 1, ⁇ 1; ⁇ 2, ⁇ 2; ⁇ ).
• the subject BRDF may be referred to as "subject BRDFg( ⁇ 1, ⁇ 1; ⁇ 2, ⁇ 2; ⁇ )."
• Equation (5) The relationship between the first reflection coefficient h(x, y; ⁇ ), the light source spectral distribution f( ⁇ 1, ⁇ 1; ⁇ ), and the subject BRDF g( ⁇ 1, ⁇ 1; ⁇ 2, ⁇ 2; ⁇ ) is expressed by equation (5).
• the first reflection coefficient h(x, y; ⁇ ) is expressed by equations (7) and (8).
• the BRDF coefficients ci(x,y; ⁇ ) are estimated from the first reflection coefficients h(x,y; ⁇ ) calculated using equations (7) and (8). Details will be described later for each case.
• the BRDF coefficients ci(x,y; ⁇ ) are estimated, the subject BRDFg( ⁇ 1, ⁇ 1; ⁇ 2, ⁇ 2; ⁇ ) is estimated.
• the second reflection coefficients h'[f'](x,y; ⁇ '2, ⁇ '2; ⁇ ) are obtained as calculated by the formulas (9) and (10). Then, the specific spectral reflectance is derived based on the second reflection coefficients.
• Case 1 is a case where the reflection characteristics of the subject 5 are composed of subject BRDFg0 ( ⁇ 1, ⁇ 1; ⁇ 2, ⁇ 2; ⁇ ) which is a subject BRDF that does not depend on the state of the subject 5, and subject BRDFg1 ( ⁇ 1, ⁇ 1; ⁇ 2, ⁇ 2; ⁇ ) which is a subject BRDF whose degree of reflection changes depending on the state of the subject 5.
• An example of case 1 is a case where the BRDF characteristics of an object are expressed by superposition of reflection on the surface of the object and reflection inside the object, and the state inside the object does not change.
• reflection inside the object is treated as subject BRDFg0 ( ⁇ 1, ⁇ 1; ⁇ 2, ⁇ 2; ⁇ ), and reflection on the surface of the object is treated as subject BRDFg1 ( ⁇ 1, ⁇ 1; ⁇ 2, ⁇ 2; ⁇ ).
• the unknown BRDF coefficient ci(x, y; ⁇ ) is one c1, so c1 is estimated from the first reflection coefficient h(x, y; ⁇ ) derived at one second angle using equation (11).
• Case 2 is a case where the reflection characteristics of the subject 5 are composed of subject BRDFg 0 ( ⁇ 1, ⁇ 1; ⁇ 2, ⁇ 2) which is a constant subject BRDF that does not depend on the wavelength band ⁇ , and subject BRDFg 1 ( ⁇ 1, ⁇ 1; ⁇ 2, ⁇ 2; ⁇ ) which is a subject BRDF whose reflectance is 0 in a specific wavelength band ⁇ .
• An example of the subject 5 is a plant. Since plants are green, there are wavelengths in the blue or red wavelength band where the spectral reflectance is approximately 0.
• the subject BRDF corresponds to subject BRDFg 1 ( ⁇ 1, ⁇ 1; ⁇ 2, ⁇ 2).
• the shine on the surface of the plant has a constant reflectance independent of the wavelength.
• the subject BRDF corresponds to subject BRDFg 0 ( ⁇ 1, ⁇ 1; ⁇ 2, ⁇ 2; ⁇ ).
• c0 which is independent of the wavelength band ⁇ , is estimated in the wavelength band ⁇ where H1 is 0 (hereinafter referred to as the "wavelength band ⁇ ref ") using equation (12), and then c1 in other wavelength bands ⁇ is estimated using equation (13).
• Case 3 is a case where the angle of the subject camera 1 is changed and the subject 5 is imaged multiple times.
• the first reflection coefficient h(x, y; ⁇ ) is derived at multiple second angles, and the unknown BRDF coefficient ci(x, y; ⁇ ) is estimated using simultaneous equations.
• the first reflection coefficient hj(x, y; ⁇ ) is expressed by Equation (14).
• the estimated solution c * of the unknown BRDF coefficient ci(x, y; ⁇ ) is expressed by equation (15).
• H + represents a generalized inverse matrix of Moore-Penrose.
• Figure 19 shows an example of the flow of the spectral image generation process according to this embodiment.
• step ST10 the output value acquisition unit 82 acquires the output value Y of each physical pixel 44 based on the imaging data output from the image sensor 28 (see FIG. 13). After the process of step ST10 is executed, the spectral image generation process proceeds to step ST12.
• step ST12 the interference elimination processing unit 84 acquires the interference elimination matrix A + stored in the storage 62 and the output value Y of each physical pixel 44 acquired in step ST10, and outputs the pixel value X of each image pixel based on the acquired interference elimination matrix A + and the output value Y of each physical pixel 44 (see FIG. 13).
• the captured image 70 is separated into a spectral image 72A corresponding to the luminance value X ⁇ 1 of the first wavelength band polarized light, a spectral image 72B corresponding to the luminance value X ⁇ 2 of the second wavelength band polarized light, and a spectral image 72C corresponding to the luminance value X ⁇ 3 of the third wavelength band polarized light.
• the spectral image generation process ends.
• Figure 20 shows an example of the flow of the spectral reflectance derivation process according to this embodiment.
• step ST20 the image acquisition unit 102 acquires a subject image 120 obtained by capturing an image of the subject 5 with the subject camera 1, and a light source image 122 obtained by capturing an image of the light source 3 with the light source camera 2 (see FIG. 15).
• step ST22 the spectral reflectance derivation process proceeds to step ST22.
• step ST22 the light source spectral distribution derivation unit 104 derives a light source spectral distribution corresponding to each wavelength band ⁇ based on each spectral image 72 included in the light source image 122 acquired in step ST20 (see FIG. 16).
• step ST24 the spectral reflectance derivation processing proceeds to step ST24.
• step ST24 the spectral reflectance derivation unit 106 derives a specific spectral reflectance for each wavelength band ⁇ based on the spectral image 72 included in the subject image 120 acquired in step ST20, the light source spectral distribution derived in step ST22, and the subject BRDF stored in the storage 96 (see FIG. 17).
• the specific spectral reflectance is derived based on the second reflection coefficient (see FIG. 18) derived by the reflection coefficient derivation process.
• Figure 21 shows an example of the flow of the reflection coefficient derivation process according to this embodiment.
• step ST30 the first reflection coefficient derivation unit 108 derives the first reflection coefficient, which is the reflection coefficient of the subject 5 in the wavelength band ⁇ , based on the spectral image 72 included in the subject image 120 acquired in step ST20 (see FIG. 18).
• step ST32 the reflection coefficient derivation process proceeds to step ST32.
• step ST32 the subject type identification unit 110 identifies the type of subject 5 (see FIG. 18). After the process of step ST32 is executed, the reflection coefficient derivation process proceeds to step ST34.
• step ST34 the BRDF coefficient derivation unit 112 derives a BRDF coefficient based on the BRDF coefficient information stored in the storage 96 and the first reflection coefficient derived in step ST30, depending on the type of subject 5 identified in step ST32 (see FIG. 18).
• step ST34 the reflection coefficient derivation process proceeds to step ST36.
• step ST36 the second reflection coefficient derivation unit 114 derives a second reflection coefficient, which is the reflection coefficient of the subject 5 at the second angle when light is irradiated from the light source 3 to the subject 5 from the first angle, based on the light source spectral distribution derived in step ST22 and the BRDF coefficient derived in step ST34 (see FIG. 18). As a result, a specific spectral reflectance is derived based on the second reflection coefficient.
• the reflection coefficient derivation processing ends. Note that the processing method described above as the function of the processing device 4 is one example of a "processing method" according to the technology disclosed herein.
• the attachment 132 (see Figures 6 to 8) according to this embodiment includes a base portion 136 and multiple cylindrical portions 138.
• Each cylindrical portion 138 has a first opening 146 and a second opening 148.
• the multiple cylindrical portions 138 include multiple cylindrical portions 138B and multiple cylindrical portions 138C in which the first opening 146 is angled relative to the second opening 148. Therefore, the spectrum for each angle of the zenith angle ⁇ 1 and the azimuth angle ⁇ 1 can be measured at the same time based on the light that has passed through the multiple cylindrical portions 138B and the multiple cylindrical portions 138C. This contributes to more efficient measurement of the spectrum of the light source 3 than, for example, measuring the spectrum for each of the multiple angles in sequence.
• the multiple cylindrical portions 138 include a cylindrical portion 138A in which the first opening 146 opens in the optical axis direction of the lens device 12. Therefore, the spectrum in the optical axis direction of the lens device 12 can be measured based on the light that passes through the cylindrical portion 138A.
• the cylindrical portion 138A also extends in the optical axis direction of the lens device 12. Therefore, the spectrum in the optical axis direction of the lens device 12 can be measured based on the light that passes through the cylindrical portion 138A.
• the cylindrical portion 138A is also disposed in the center of the base portion 136. Therefore, the spectrum in the optical axis direction of the lens device 12 can be measured on the optical axis OA of the lens device based on the light that has passed through the cylindrical portion 138A.
• the multiple cylindrical portions 138 also include multiple cylindrical portions 138B and multiple cylindrical portions 138C, which are arranged around the cylindrical portion 138A. Therefore, it is possible to measure the spectrum for each zenith angle ⁇ 1 and azimuth angle ⁇ 1 based on the light that has passed through the multiple cylindrical portions 138B and the multiple cylindrical portions 138C.
• the multiple cylindrical portions 138B are arranged in a ring shape around the cylindrical portion 138A, and the multiple cylindrical portions 138C are arranged in a ring shape around the cylindrical portion 138A outside the multiple cylindrical portions 138B. Therefore, with the position of the cylindrical portion 138A as a reference, it is possible to measure the spectrum for each zenith angle ⁇ 1 and azimuth angle ⁇ 1 based on the light that has passed through the multiple cylindrical portions 138B and the multiple cylindrical portions 138C.
• the multiple cylindrical sections 138B are arranged to correspond to the zenith angle ⁇ 1 and the azimuth angle ⁇ 1. Therefore, it is possible to measure the spectrum for each zenith angle ⁇ 1 and azimuth angle ⁇ 1 based on the light that has passed through the multiple cylindrical sections 138B.
• the multiple cylindrical sections 138C are arranged to correspond to the zenith angle ⁇ 1 and the azimuth angle ⁇ 1. Therefore, it is possible to measure the spectrum for each zenith angle ⁇ 1 and azimuth angle ⁇ 1 based on the light that has passed through the multiple cylindrical sections 138C.
• cylindrical portion 138B and cylindrical portion 138C are inclined with respect to the optical axis direction of lens device 12. Therefore, it is possible to measure the spectrum in a direction inclined with respect to the optical axis direction of lens device 12 based on the light that has passed through cylindrical portion 138B and cylindrical portion 138C.
• the first opening 146 of the cylindrical portion 138B has an angle ⁇ 1 relative to the second opening 148 of the cylindrical portion 138B that corresponds to the zenith angle ⁇ 1 and the azimuth angle ⁇ 1. Therefore, it is possible to measure the spectrum in the direction of the zenith angle ⁇ 1 and the azimuth angle ⁇ 1 that correspond to the angle ⁇ 1.
• the first opening 146 of the cylindrical portion 138C has an angle ⁇ 2 relative to the second opening 148 of the cylindrical portion 138C that corresponds to the zenith angle ⁇ 1 and the azimuth angle ⁇ 1. Therefore, it is possible to measure the spectrum in the direction of the zenith angle ⁇ 1 and the azimuth angle ⁇ 1 that correspond to the angle ⁇ 2.
• the angle ⁇ 2 of the cylindrical portion 138C is greater than the angle ⁇ 1 of the cylindrical portion 138B. Therefore, based on the light that has passed through the cylindrical portion 138C, it is possible to measure the spectrum in the direction of the zenith angle ⁇ 1, which is greater than the zenith angle ⁇ 1 corresponding to the cylindrical portion 138B.
• the base portion 136 is formed in a flat plate shape, and each cylindrical portion 138 is formed in a cylindrical shape extending from the base portion 136. Therefore, the amount of material used for the attachment 132 can be reduced, for example, compared to when the base portion 136 is formed in a dome shape.
• the first opening 146 opens to a side other than the lens device 12 side
• the second opening 148 opens to the lens device 12 side. Therefore, by making the light that enters the cylindrical portion 138 from a side other than the lens device 12 side exit to the lens device 12 side, the light that passes through the cylindrical portion 138 can be restricted.
• a diffusion plate 150 that diffuses light is disposed in the second opening 148. Therefore, when the light source 3 is used as a primary light source, the light diffused by the diffusion plate 150 can be used as a secondary light source. This makes it possible to prevent the intensity of the light that passes through the cylindrical portion 138 and is imaged on the light receiving surface 34A from being locally saturated.
• the multiple cylindrical portions 138 also include adjacent cylindrical portions 138, and a portion of the incidence angle range R1 of one of the adjacent cylindrical portions 138 overlaps with a portion of the incidence angle range R2 of the other of the adjacent cylindrical portions 138. Therefore, compared to a case where the incidence angle range R1 and the incidence angle range R2 do not overlap, it is possible to measure the spectrum for each angle of the zenith angle ⁇ 1 and the azimuth angle ⁇ 1 without omission.
• the first shape which is the shape of the first opening 146, is a rectangle. Therefore, the image 124 corresponding to the light that passes through each cylindrical portion 138 and is imaged on the light receiving surface 34A can also be made to be a rectangle. This makes it possible to improve the accuracy when deriving the light source spectral distribution based on multiple images 124, for example, compared to when the images 124 have a shape other than a rectangle.
• the first shape which is the shape of the first opening 146
• the second shape which is the shape of the second opening 148. Therefore, the image 124 corresponding to the light that passes through the first opening 146 and the second opening 148 and is focused on the light receiving surface 34A can be made to have a shape that corresponds to the first shape and the second shape.
• the incidence angle ranges R of light limited by the multiple cylindrical portions 138 are set to the same incidence angle range. Therefore, for example, the accuracy of deriving the light source spectral distribution based on the multiple images 124 can be improved compared to a case where the incidence angle ranges R are set to different incidence angle ranges.
• the subject camera 1 is a multispectral camera. Therefore, multiple spectral images 72 can be obtained by capturing an image of the subject 5 once.
• the light source camera 2 is also a multispectral camera. Therefore, multiple spectral images 72 can be obtained by capturing an image of the light source 3 once.
• the optical member 130 also includes an attachment 132 and a spacer 134, and the attachment 132 is attached to the object side end of the lens device 12 via the spacer 134. Therefore, the attachment 132 can be fixed at a position away from the object side of the lens device 12 by the spacer 134. This makes it easier to focus on the attachment 132 compared to, for example, a case where the attachment 132 is directly attached to the object side end of the lens device 12.
• the processor 94 of the processing device 4 also acquires a subject image 120 obtained by capturing an image of the subject 5 with the subject camera 1, and acquires a light source image 122 obtained by capturing an image of the light source 3 with the light source camera 2.
• the processor 94 then derives a specific spectral reflectance, which is the spectral reflectance of the subject 5 when the subject 5 is irradiated with light from the light source 3 at a first angle and the subject 5 is captured at a second angle. Therefore, the specific spectral reflectance can be obtained without directly measuring the specific spectral reflectance.
• the specific spectral reflectance is derived based on the subject image 120, the light source image 122, and the subject BRDF. Therefore, the specific spectral reflectance can be derived with higher accuracy than when the specific spectral reflectance is derived without using the subject image 120, the light source image 122, and the subject BRDF.
• the light source image 122 also includes information regarding the wavelength and intensity of light for each zenith angle ⁇ 1 and azimuth angle ⁇ 1. This makes it possible to derive the light source spectral distribution corresponding to each wavelength band ⁇ based on the light source image 122.
• the shape of the first opening 146 is a rectangle, but as an example, as shown in FIG. 22, for example, in the cylindrical portions 138B and 138C, the shape of the first opening 146 may be an arc shape centered on the center of the base portion 136 (see FIG. 5, etc.). Similarly, in the cylindrical portions 138B and 138C, the shape of the second opening 148 may also be an arc shape. Furthermore, the shapes of the first opening 146 and the second opening 148 of the cylindrical portion 138A may be circular.
• the multiple cylindrical parts 138 include a cylindrical part 138A arranged in the center of the base part 136, multiple cylindrical parts 138B arranged in a ring shape around the cylindrical part 138A, and multiple cylindrical parts 138C arranged in a ring shape around the cylindrical part 138A outside the multiple cylindrical parts 138B, corresponding to the zenith angle ⁇ 1 and the azimuth angle ⁇ 1.
• the multiple cylindrical parts 138 may be arranged in a straight line in the radial direction of the base part 136, corresponding to the zenith angle ⁇ 1.
• the multiple cylindrical parts 138 may be arranged in a ring shape around the center of the base part 136, corresponding to the azimuth angle ⁇ 1.
• the first opening 146 may have an angle with respect to the second opening 148 corresponding to either the zenith angle ⁇ 1 or the azimuth angle ⁇ 1.
• a multispectral camera 10 is used for the object camera 1 and the light source camera 2, but a hyperspectral camera may also be used, or an RGB camera with a spectral filter may also be used.
• the processor 60 is exemplified for the multispectral camera 10, but at least one other CPU, at least one GPU, and/or at least one TPU may be used in place of the processor 60 or together with the processor 60.
• the processor 94 is exemplified as the processing device 4, but instead of the processor 94 or together with the processor 94, at least one other CPU, at least one GPU, and/or at least one TPU may be used.
• the multispectral camera 10 has been described with an example in which the spectral image generation program 80 is stored in the storage 62, but the technology of the present disclosure is not limited to this.
• the spectral image generation program 80 may be stored in a portable non-transitory computer-readable storage medium (hereinafter simply referred to as a "non-transitory storage medium") such as an SSD or USB memory.
• the spectral image generation program 80 stored in the non-transitory storage medium may be installed in the computer 56 of the multispectral camera 10.
• the spectral image generation program 80 may be stored in a storage device such as another computer or server device connected to the multispectral camera 10 via a network, and the spectral image generation program 80 may be downloaded in response to a request from the multispectral camera 10 and installed in the computer 56 of the multispectral camera 10.
• spectral image generation program 80 it is not necessary to store the entire spectral image generation program 80 in a storage device such as another computer or server device connected to the multispectral camera 10, or in the storage 62; only a portion of the spectral image generation program 80 may be stored.
• the processing device 4 has been described using an example in which the spectral reflectance derivation program 100 is stored in the storage 96, but the technology of the present disclosure is not limited to this.
• the spectral reflectance derivation program 100 may be stored in a non-transitory storage medium.
• the spectral reflectance derivation program 100 stored in a non-transitory storage medium may be installed in the computer 92 of the processing device 4.
• the spectral reflectance derivation program 100 may be stored in a storage device such as another computer or server device connected to the processing device 4 via a network, and the spectral reflectance derivation program 100 may be downloaded in response to a request from the processing device 4 and installed in the computer 92 of the processing device 4.
• spectral reflectance derivation program 100 it is not necessary to store the entire spectral reflectance derivation program 100 in a storage device such as another computer or server device connected to the processing device 4, or in the storage 96; only a portion of the spectral reflectance derivation program 100 may be stored therein.
• the multispectral camera 10 has a built-in computer 56, the technology of the present disclosure is not limited to this, and for example, the computer 56 may be provided outside the multispectral camera 10.
• processing device 4 has a built-in computer 92
• the technology disclosed herein is not limited to this, and for example, the computer 92 may be provided outside the processing device 4.
• a computer 56 including a processor 60, storage 62, and RAM 64 is exemplified for the multispectral camera 10, but the technology of the present disclosure is not limited to this, and a device including an ASIC, FPGA, and/or PLD may be applied instead of the computer 56. Also, a combination of a hardware configuration and a software configuration may be used instead of the computer 56.
• a computer 92 including a processor 94, storage 96, and RAM 98 is exemplified as the processing device 4, but the technology of the present disclosure is not limited to this, and a device including an ASIC, FPGA, and/or PLD may be applied instead of the computer 92. Also, a combination of a hardware configuration and a software configuration may be used instead of the computer 92.
• processors listed below can be used as hardware resources for executing the various processes described in the above embodiment.
• An example of a processor is a CPU, which is a general-purpose processor that functions as a hardware resource for executing various processes by executing software, i.e., a program.
• Another example of a processor is a dedicated electronic circuit, which is a processor with a circuit configuration designed specifically for executing a specific process, such as an FPGA, PLD, or ASIC. All of the processors have built-in or connected memory, and all of the processors use the memory to execute various processes.
• the hardware resources that execute the various processes may be composed of one of these various processors, or may be composed of a combination of two or more processors of the same or different types (for example, a combination of multiple FPGAs, or a combination of a CPU and an FPGA). Also, the hardware resources that execute the various processes may be a single processor.
• a configuration using a single processor first, there is a configuration in which one processor is configured by combining one or more CPUs with software, and this processor functions as a hardware resource that executes various processes. Secondly, there is a configuration in which a processor is used that realizes the functions of the entire system, including multiple hardware resources that execute various processes, on a single IC chip, as typified by SoCs. In this way, various processes are realized using one or more of the above-mentioned various processors as hardware resources.
• these various processors can be electronic circuits that combine circuit elements such as semiconductor elements.
• the above gaze detection process is merely one example. It goes without saying that unnecessary steps can be deleted, new steps can be added, and the processing order can be changed without departing from the spirit of the invention.
• a and/or B is synonymous with “at least one of A and B.”
• a and/or B means that it may be just A, or just B, or a combination of A and B.
• the same concept as “A and/or B” is also applied when three or more things are expressed by linking them with “and/or.”

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• 2023
  • 2023-09-28 JP JP2024552905A patent/JPWO2024090134A1/ja active Pending
  • 2023-09-28 WO PCT/JP2023/035531 patent/WO2024090134A1/ja not_active Ceased

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