Abstract: An imaging system is an imaging system using a compressed sensing technology, and includes a filter array including types of filters different from one another in transmission spectrum, an image sensor that generates image data based on light that passes through the filter array, a processing circuit that generates hyperspectral image data including images corresponding to four or more bands included in a target wavelength region on the basis of the image data and a reconstruction table decided on the basis of a spatial distribution of the transmission spectra of the types of filters, and a light source that emits reference light used for calibration for correcting the reconstruction table and having a wavelength of at least one of the four or more bands, and the processing circuit corrects the reconstruction table on the basis of reference image data which the image sensor generates by detecting the reference light.

Abstract: An information processing method performed using a computer, includes: acquiring a compressed image, in which information regarding wavelength bands is compressed, and identifying, based on at least one of (1) pixel values of pixels included in the compressed image, or (2) a size of a structure of a target represented by the compressed image, at least one first pixel that is included in the compressed image and that is estimated to cause a reconstruction error in images corresponding to the respective wavelength bands, the images being reconstructed from the compressed image.

Abstract: A filter array according to one aspect of the present disclosure is provided with filters arranged two-dimensionally. The filters include multiple types of first filters having mutually different transmission spectra, of which each transmission spectrum includes first peaks, and multiple types of second filters having mutually different transmission spectra, of which each transmission spectrum includes one or more second peaks. The number of the first peaks in the transmission spectrum of each of the multiple types of first filters is greater than the number of the one or more second peaks in the transmission spectrum of each of the multiple types of second filters, and the multiple types of first filters and the multiple types of second filters are disposed in a mixed arrangement.

Abstract: A filter array includes optical filters arranged in two dimensions. The optical filters include a first filter and a second filter. The first filter includes a first multimode filter having, within a target wavelength range, first peak wavelengths at each of which the optical transmittance is at a local maximum, and a first band-limiting filter having, as a limiting band, a first sub-wavelength range that is a part of the target wavelength range. The second filter includes a second multimode filter having, within the target wavelength range, second peak wavelengths at each of which the optical transmittance is at a local maximum, at least one of the second peak wavelengths being different from the first peak wavelengths, and a second band-limiting filter restricting transmission of light in a second sub-wavelength range that is a part of the target wavelength range and that is different from the first sub-wavelength range.

Abstract: A signal processing method is performed by a computer. The signal processing method includes: obtaining first compressed image data including hyperspectral information and indicating a two-dimensional image in which the hyperspectral information is compressed, the hyperspectral information being luminance information on each of at least four wavelength bands included in a target wavelength range; extracting partial image data from the first compressed image data; and generating first two-dimensional image data corresponding to a first wavelength band and second two-dimensional image data corresponding to a second wavelength band from the partial image data.

Abstract: A filter array according to one aspect of the present disclosure is provided with filters arranged two-dimensionally. The filters include multiple types of first filters having mutually different transmission spectra, of which each transmission spectrum includes first peaks, and multiple types of second filters having mutually different transmission spectra, of which each transmission spectrum includes one or more second peaks. The number of the first peaks in the transmission spectrum of each of the multiple types of first filters is greater than the number of the one or more second peaks in the transmission spectrum of each of the multiple types of second filters, and the multiple types of first filters and the multiple types of second filters are disposed in a mixed arrangement.

Abstract: A filter array includes optical filters that are disposed in a two-dimensional plane. At least one optical filter of the optical filters includes an interference layer having a first surface and a second surface opposite the first surface, and a reflective layer provided on the first surface. A transmission spectrum of the at least one optical filter has maximum values. The reflective layer is not provided on the second surface.

Abstract: An imaging system includes a light source, an imaging apparatus that captures an image of a subject illuminated by light from the light source to generate image data, which includes image information regarding each of four or more bands or information regarding a compressed image in which the image information regarding the four or more bands is compressed as a single image, and a processing apparatus. The processing apparatus determines whether or not pixel values of pixels in the image data satisfy a predetermined condition, and causes, in a case where the predetermined condition is not satisfied, a lighting condition caused by the light source to be changed under a condition where a spectral shape of light from the light source does not change at the subject's location.

Abstract: A light detection device includes a filter array including filters including first and second filters and an image sensor that includes pixels and detects light transmitted through the filter array. A first transmission spectrum of the first filter having local maxima differs from a second transmission spectrum of the second filter having local maxima. The filters are arranged in a matrix pattern along first and second directions crossing each other. The pixels are arranged in a matrix pattern along third and fourth directions crossing each other. At least one of Rp1 or Rp2 differs from 1. The Rp1 is a quotient obtained by dividing a pitch of the filters in the first direction by a pitch of the pixels in the third direction. The Rp2 is a quotient obtained by dividing a pitch of the filters in the second direction by a pitch of the pixels in the fourth direction.

Abstract: A signal processing method executed by a computer includes acquiring designation information for designating N wavelength bands corresponding to N spectral images generated on a basis of a compressed image in which spectral information is compressed, N being an integer greater than or equal to 4; estimating a reconstruction error of each of the N spectral images on the basis of the designation information; and outputting a signal indicative of the reconstruction error.

Abstract: A device used in a system for generating spectral images corresponding to four or more wavelength bands includes optical filters different in spectral transmittance and an image sensor that detects light through the optical filters, in which when the wavelength bands are given numbers in an ascending or descending order of a central wavelength, the image sensor outputs i-th mask data by detecting only light corresponding to an i-th wavelength band and outputs j-th mask data by detecting only light corresponding to a j-th wavelength band among the wavelength bands, a correlation coefficient between the i-th and j-th mask data is greater than or equal to 0.8 in a combination where |i?j| is 1, and is equal to or less than 0.8 in at least one combination where |i?j| is greater than or equal to 2 and less than or equal to N?1.

Abstract: An imaging system includes an imaging apparatus that repeatedly acquires a compressed image in which information regarding light of four or more wavelength bands from a target is compressed, and a processing apparatus. The processing apparatus extracts a partial region including a region of the target from the compressed image so as to compensate for a relative motion between the target and the imaging apparatus, and generates spectral images corresponding to wavelength bands, based on data of the partial region of the compressed image.

Abstract: A filter array, which is to be used in a photodetection system that generates image data of each of N wavelength bands (where N is an integer greater than or equal to 4), includes optical filters whose light transmittances in each of the N wavelength bands differ from each other. (?1/?1)?0.1, . . . , and (?N/?N)?0.1, where ?i is a mean value of transmittances, corresponding one-to-one to the optical filters, with respect to light of an i-th wavelength band (where i is an integer greater than or equal to 1 and less than or equal to N) among the N wavelength bands, and where ?i is a standard deviation of the transmittances, corresponding one-to-one to the optical filters, with respect to the light of the i-th wavelength band.

Abstract: There is provided an imaging system including: a filter array that includes filters having different transmission spectra; an image sensor that images light passing through the filter array and generates image data; and a processing circuit, in which the processing circuit acquires luminance pattern data generated on the basis of subject data that includes spectral information of at least one substance, the luminance pattern data being generated by predicting a luminance pattern detected when the substance is imaged by the image sensor, acquires first image data obtained by imaging a target scene by the image sensor, and generates output data regarding whether the substance is present in the target scene by comparing the luminance pattern data with the first image data.

Abstract: A signal processing method executed by a computer includes acquiring compressed image data including two-dimensional image information of a subject obtained by compressing hyperspectral information in a target wavelength region, acquiring reference spectrum data including information on one or more spectra associated with the subject, and generating, from the compressed image data, pieces of two-dimensional image data corresponding to designated wavelength bands decided on the basis of the reference spectrum data.

Abstract: An imaging apparatus includes: at least one light source that emits excitation light for irradiating an object including at least one light emitter; a coding filter array including filters whose transmission spectra differ from each other; an image sensor that captures an image of object light, which is generated by irradiating the object with the excitation light, through the coding filter array and generates compressed image data; and a processing circuit that generates hyperspectral image data based on the compressed image data. The object light includes emission light, which is produced by the at least one light emitter by absorbing the excitation light, and reflection light of the excitation light reflected by the object. The filters include two filters whose transmission spectra differ from each other. A spectrum of the excitation light overlaps a transmission region in the transmission spectrum of each of the two filters.

Abstract: An image processing apparatus includes a storage device storing coding information indicating light transmission characteristics of an encoding mask including optical filters that are arranged in two dimensions and whose light transmission characteristics are different from one another and a signal processing circuit that generates reconstructed images on a basis of a compressed image generated through imaging that employs the encoding mask and the coding information, that estimates an error in the reconstructed images, and that outputs a signal indicating the error.

Abstract: A method for evaluating a user's skin condition, the method being performed by a computer, includes acquiring image data concerning part of the user's body and including information for four or more bands, determining an evaluation region in the part of the user's body in an image representing the part of the user's body in accordance with an input from the user, and generating, based on the image data, and outputting evaluation data representing an evaluation result of skin condition in the evaluation region.

Abstract: An imaging system is an imaging system using a compressed sensing technology, and includes a filter array including types of filters different from one another in transmission spectrum, an image sensor that generates image data based on light that passes through the filter array, a processing circuit that generates hyperspectral image data including images corresponding to four or more bands included in a target wavelength region on the basis of the image data and a reconstruction table decided on the basis of a spatial distribution of the transmission spectra of the types of filters, and a light source that emits reference light used for calibration for correcting the reconstruction table and having a wavelength of at least one of the four or more bands, and the processing circuit corrects the reconstruction table on the basis of reference image data which the image sensor generates by detecting the reference light.

Abstract: A method executed by a computer includes obtaining matrix data representing an encoding matrix used to encode a spectral data cube including image information in wavelength bands and to generate a compressed image and/or a decoding matrix used to generate the spectral data cube by decoding from the encoded compressed image, editing the matrix data in a way of causing the image information in at least one of the wavelength bands in the spectral data cube to be altered in the spectral data cube after being generated by decoding, and outputting the matrix data after the editing.