JPWO2018207613A1 - Imaging system and imaging method - Google Patents

Abstract

The present invention realizes a wide angle, multi-wavelength, and high resolution video recording while miniaturizing the apparatus with a simple configuration via a single element. An imaging system 100 for imaging an imaging target including a plurality of optical information, wherein the imaging target is divided for each optical information and then encoded, and a volume hologram optical element 104 and each code encoded by the volume hologram optical element are provided. An image sensor 106 that multiplexes the multiplexed image to obtain a multiplexed image, an image processing unit 108 that performs image restoration processing on the multiplexed image obtained by the image sensor by compression sensing, and separates and reconstructs imaging data of an imaging target. , Is provided.

Description

  The present invention relates to an imaging system and an imaging method for imaging an imaging target including a plurality of optical information with high resolution. This application claims priority based on Japanese Patent Application No. 2017-093613 filed on May 10, 2017 in Japan, and is hereby incorporated by reference into this application. Is done.

  In recent years, in applications such as panoramic photography, digital archiving, environmental preservation, satellite photography, pathological diagnosis, security, crime prevention, and the like, video recording has been moving toward a large amount of information. In particular, there is an increasing demand for higher resolution of captured video recording in order to cope with a new use of video recording, such as biometric authentication, recognition of minute objects, and texture measurement.

  As a conventional technique for realizing wide-angle and high-resolution or multi-wavelength and high-resolution video recording to be imaged, Patent Document 1 discloses an imaging apparatus capable of acquiring high-resolution image information by a sensor array method. Patent Document 2 discloses an imaging device capable of acquiring a high-resolution image by a mechanical scanning method. As a conventional technique for realizing multi-wavelength and high-resolution, Japanese Patent Application Laid-Open No. H11-163873 collectively encodes multi-wavelength imaging with a single element by a system design that fuses an encoding optical element and image restoration processing (compression sensing). There is disclosed an imaging technique to be developed.

U.S. Pat. No. 8,259,212 U.S. Pat. No. 6,101,265 U.S. Pat. No. 7,336,353

  However, in the sensor array system, although high resolution of video recording is realized, the problem is that the optical system becomes large in size and high in cost. On the other hand, in the mechanical scanning method, although the size of the apparatus can be reduced after increasing the resolution of the video recording, the optical system is complicated and the shooting time is long because many times of shooting are required. Is an issue.

  As described above, in order to cope with high resolution of video recording and to simplify the optical system and downsize the apparatus, it is possible to increase the angle of video recording, increase the number of wavelengths, and increase the size of the video with a simple configuration through a single element. It is preferable to realize the resolution. In other words, there is a demand for realizing high-resolution video recording with a large amount of information by a small-sized device through a single optical element that independently encodes image information of a plurality of visual fields and wavelengths.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and is intended to realize a wide angle, multi-wavelength, and high resolution video recording while reducing the size of the device with a simple configuration via a single element. It is an object to provide a new and improved imaging system and method that are possible.

  One embodiment of the present invention is an imaging system for imaging an imaging target including a plurality of pieces of optical information, wherein the imaging target is divided for each optical information and then encoded, and the volume hologram optical element and the volume hologram optical element An image sensor that multiplexes each coded image encoded in to obtain a multiplexed image, and performs image restoration processing on the multiplexed image obtained by the image sensor by compression sensing to obtain imaging data of the imaging target. And an image processing unit for separating and reconstructing.

  According to one embodiment of the present invention, by providing the volume hologram optical element in front of the image sensor, each piece of optical information included in the imaging target can be divided for each optical information and independently encoded. For this reason, the multiplexed image of each optical information is acquired by the image sensor, and the multiplexed image is separated and reconstructed by the image processing unit. High resolution can be realized.

  At this time, in one aspect of the present invention, the volume hologram optical element divides the plurality of pieces of optical information included in the imaging target for each angle with the volume hologram element or for each wavelength width of the optical information. It may be encoded.

  With this configuration, the volume hologram optical element can divide each optical information included in the imaging target for each angle or for each wavelength width and independently encode the optical information. After the generation, the multiplexed image is separated and reconstructed by the image processing unit, so that wide angle, multi-wavelength, and high resolution video recording can be efficiently realized with a simple configuration.

  In one embodiment of the present invention, the volume hologram optical element may be formed by stacking a plurality of hologram elements having different interference fringe patterns.

  By doing so, the number of times of multiple exposure of the hologram can be reduced in the process of configuring the volume hologram optical element, so that the diffraction efficiency of the volume hologram optical element and the risk of crosstalk can be reduced.

  In one aspect of the present invention, the plurality of hologram elements included in the volume hologram optical element may be configured to be capable of adjusting a tilt angle or an arrangement.

  In this way, even after exposing the volume hologram optical element and providing interference fringes, the tilt angle or arrangement of each hologram element can be adjusted to flexibly design and control the PSF (Point Spread Function). become.

  In one aspect of the present invention, the image processing unit may restore the image of the multiplexed image using the sparsity of an image to be restored.

  With this configuration, it is mathematically possible to restore the multiplexed image generated from the encoded image that is divided for each optical information to be imaged and independently encoded by the volume hologram optical element and the image sensor. Therefore, it is possible to realize a wide angle, multi-wavelength, and high resolution video recording.

  In one embodiment of the present invention, a lens may be provided between the volume hologram optical element and the image sensor.

  With this configuration, it is possible to realize imaging with a high information amount using a simple optical system including only the volume hologram optical element, the image sensor, and the lens.

  In one embodiment of the present invention, a lensless method may be adopted in which no lens is provided between the volume hologram optical element and the image sensor.

  With this configuration, it is possible to realize imaging with a high information amount using a simple optical system including only the volume hologram optical element and the image sensor.

  Further, another aspect of the present invention is an imaging method for imaging an imaging target including a plurality of optical information, a dividing step of dividing the plurality of optical information of the imaging target for each small visual field and wavelength width, An encoding step of encoding each of the plurality of optical information divided in the step by a volume hologram optical element to obtain an encoded image; and an image sensor for each of the encoded images obtained for each of the plurality of optical information. A multiplexing step of multiplexing to obtain a multiplexed image, and a restoration processing step of restoring the multiplexed image by compressed sensing using the sparsity of an image to be restored. .

  According to another aspect of the present invention, by providing the volume hologram optical element in front of the image sensor, each piece of optical information included in the imaging target can be divided for each piece of optical information and independently encoded. For this reason, the multiplexed image of each optical information is acquired by the image sensor, and the multiplexed image is separated and reconstructed by the image processing unit. High resolution can be realized.

  As described above, according to the present invention, wide angle, multi-wavelength, and high resolution of image recording can be efficiently realized by a simple optical system configuration in which a volume hologram optical element is provided on the front side of an image sensor. .

FIG. 1 is a block diagram illustrating a schematic configuration of an imaging system according to an embodiment of the present invention. 2A and 2B are block diagrams each showing a schematic configuration of an imaging unit provided in the imaging system according to the embodiment of the present invention. FIG. 3 is an operation explanatory diagram of the imaging system according to the embodiment of the present invention. FIG. 4 is a flowchart showing an outline of an imaging method to which the imaging system according to one embodiment of the present invention is applied. FIG. 5A to FIG. 5D are explanatory diagrams illustrating imaging results of the imaging system according to the embodiment of the present invention. 6A and 6B are explanatory diagrams illustrating a schematic configuration of one mode of a volume hologram optical element included in an imaging system according to an embodiment of the present invention. FIG. 7 is an explanatory diagram showing an imaging result by the imaging system according to the embodiment of the present invention including the volume hologram optical element shown in FIGS. 6A and 6B.

  Hereinafter, preferred embodiments of the present invention will be described in detail. Note that the present embodiment described below does not unduly limit the contents of the present invention described in the claims, and all the configurations described in the present embodiment are indispensable means for solving the present invention. Is not always the case.

  First, a schematic configuration of an imaging system according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a schematic configuration of an imaging system according to an embodiment of the present invention. FIGS. 2A and 2B show a schematic configuration of an imaging unit provided in the imaging system according to an embodiment of the present invention. It is a block diagram.

  The imaging system 100 according to one embodiment of the present invention is applied when imaging an imaging target including a plurality of pieces of optical information. In other words, the imaging system 100 according to the present embodiment increases the resolution of the imaging target and performs imaging when the imaging target has a wide field of view, a multi-wavelength, and a high information amount such that any one of them is applicable. Applied when

  As illustrated in FIG. 1, an imaging system 100 according to the present embodiment includes an imaging unit 102 that converts a pixel signal obtained by imaging an imaging target serving as a subject into image data, and an image data that is converted by the imaging unit 102. And an image processing unit 108 for performing predetermined image processing.

  In the present embodiment, the imaging unit 102 has a function of imaging an imaging target using emitted light, and includes a volume holographic optical element (hereinafter, also referred to as vHOE) 104 and an image sensor 106. Composed of The volume hologram optical element 104 has a function of dividing an imaging target for each optical information, and then encoding and modulating it. The image sensor 106 has a function of multiplexing each of the encoded images encoded by the volume hologram optical element 104 to obtain a multiplexed image.

  In the present embodiment, as shown in FIG. 2A, the imaging unit 102 is provided with a lens 105 between a volume hologram optical element 104 having a modulation function and an image sensor 106, and can be used as an imaging unit 102a of a filter addition type. Good. Also. When the volume hologram optical element 104 has both a modulation function and a lens function, as shown in FIG. 2B, the imaging section 102 is a lensless imaging section 102b composed of only the volume hologram optical element 104 and the image sensor 106. It may be. Further, the lens function may be reconstructed into an image with a lens array to further shorten the focal length and make the optical system thinner. The operation and function of the imaging unit 102 according to the present embodiment will be described later in detail.

  The image processing unit 108 has a function of performing image processing on the image data acquired by the imaging unit 102. In the present embodiment, the image processing unit 108 performs image processing such that the multiplexed image acquired by the image sensor 106 is subjected to image restoration processing by compressed sensing to separate and reconstruct imaging data of an imaging target.

  More specifically, the image processing unit 108 uses the property of having many elements having a value of 0 when the reconstruction target is represented as an image vector, that is, using a sparse property to reduce a small data to a large-scale data. With mathematical techniques applicable to linear systems. At this time, the macro imaging can be expressed by a linear system, and the natural image can be sparsely expressed almost without exception by performing some basis transformation using a basis transformation matrix or the like. Is also useful for coded imaging (large-scale image reconstruction). Therefore, as an application thereof, it is possible to realize separation and reconstruction of a multiplex image of independently modulated imaging information.

  As described above, in the present embodiment, the imaging unit 102 is provided with the volume hologram optical element 104 in front of the image sensor 106, whereby each optical information included in the imaging target is divided for each optical information and independently Can be encoded. For this reason, the multiplexed image of each optical information is acquired by the image sensor 106, and then the multiplexed image is separated and reconstructed by the image processing unit 108. Multiple wavelengths and high resolution can be realized.

  Next, details of the operation of the imaging system according to the embodiment of the present invention will be described with reference to the drawings. FIG. 3 is an operation explanatory diagram of the imaging system according to the embodiment of the present invention.

  An imaging system 100 according to an embodiment of the present invention uses a volume hologram optical element (vHOE) 104 as an optical element constituting an imaging unit 102, so that a small imaging system that captures image information of a plurality of wavelengths and fields of view. Is realized. That is, the imaging system 100 of the present embodiment is characterized by using the volume hologram optical element 104 to enable simultaneous realization of a compact device and a high imaging information amount in a camera.

  The volume hologram optical element 104 has a wavefront reproducibility for reproducing a wavefront of light recorded at the time of hologram exposure when light is incident, and an angle selectivity for enabling recording / reproduction of a wavefront independent of each incident angle of light. It has wavelength selectivity that enables recording and reproduction of an independent wavefront for each wavelength of light.

  In particular, since the volume hologram optical element 104 physically utilizes Bragg diffraction, there is essentially no limitation on the incident angle of light. Therefore, as the angle selectivity of the volume hologram optical element 104, for example, it is possible to transmit light entering the camera at an incident angle of 90 degrees to the sensor.

  In addition, the wavelength selectivity of the volume hologram optical element 104 does not essentially limit the size of the wavelength, so that wavefront recording / reproduction can be performed independently not only with visible light but also with sound waves, infrared rays, X-rays, and the like. . For this reason, the volume hologram optical element 104 has a prism function so as to guide all light incident from various fields to the image sensor 106, and has a different impulse response (PSF: Point Spread Function) for each field and wavelength. ) Can be implemented, so that field- and wavelength-independent optical coding and its multiple image shooting can be realized by one element.

  As described above, the volume hologram optical element 104 has wavefront reproducibility, angle selectivity, and wavelength selectivity. Therefore, by utilizing these properties of the volume hologram optical element 104, a visual code and a wavelength-independent optical code are utilized. A high-performance optical element having a prism function that can be combined and multiplexed can be realized. In particular, when the imaging unit 102 has a lens system, the volume hologram optical element 104 includes a prism (light propagation direction modulation) function, a viewing wavelength independent coding function, and a sensor surface of the coded image. When the imaging unit 102 is of a lensless type, the volume hologram optical element 104 has an imaging function (convex lens function or condensing phase modulation) in addition to these functions. Function).

  For this reason, in the present embodiment, first, the volume hologram optical element 104 provided on the front stage side of the imaging unit 102 converts a plurality of pieces of optical information to be imaged through the volume hologram optical element 104 into a small visual field and wavelength width. Divide each. Specifically, as shown in FIG. 3, when the flower D1 and the apple D2 are included as the optical information to be imaged, the light angle A1 serving as a visual field for imaging the flower D1, the flower D1 and the apple D2, Are divided into light angles A2 and A3, which are the fields of view of the blank portion between, and light angles A4, which are the fields of view for imaging the apple D2. In the present embodiment, a plurality of optical information to be imaged is divided for each small visual field by the volume hologram optical element 104, but may be divided for each wavelength width.

  Then, the volume hologram optical element 104 independently modulates and encodes each of the optical information divided for each of the light angles A1 to A4. Each of the multiplexed encoded images encoded by the volume hologram optical element 104 is acquired as an image of the multiplexed image D3 by the image sensor 106 as shown in FIG.

  The multiplexed image D3 obtained by the image sensor 106 is subjected to image restoration processing and separated and reconstructed as imaging data of an imaging target by an image processing unit 108 provided on the subsequent stage of the imaging unit 102. In the present embodiment, the multiplexed image D3 is separated and reconstructed by an image restoration process using compressed sensing that actively utilizes the sparsity of the image.

  In the present embodiment, when the image processing unit 108 performs the compression sensing of the multiplexed image D3, the upper limit of the information amount of the reconstructed image (the product of the angle of view, the sampling resolution, and the number of wavelengths) is limited to the compression of the reconstructed image. It depends on the rate, that is, how sparsely the object can be represented on some basis space. For example, if the purpose is to reconstruct a Lena image used as a standard image for experiments in the field of image engineering with an image quality index (Peak Signal-to-Noise Ratio) of 30 dB or more, the compression ratio that can be set is approximately 10. Therefore, the upper limit of the improvement in the sampling resolution is ten times that of a wide-angle camera having the same angle of view. Further, if the deterioration of the image quality of the reconstructed image is further allowed, further improvement in resolution can be expected. At this time, how much image quality is acceptable is appropriately defined by the video system to which the application is applied.

  As described above, in the present embodiment, by utilizing the wavefront reproducibility, angle selectivity, and wavelength selectivity of the volume hologram optical element (vHOE) 104, it cannot be realized by a general refraction / reflection type optical element. High-performance optical elements. In particular, in recent years, since the commercial photopolymer used for the volume hologram optical element 104 has been improved in sensitivity and stability, the volume hologram optical element 104 can be generated with high accuracy. The feasibility of imaging a large amount of information (all or any of a wide field of view, multiple wavelengths, and a high number of pixels) using an optical element is increasing.

  In recent years, with the development of signal processing technology, the "compression sensing" technology, which is the image reconstruction process required for multiple image separation, has matured, and it is possible to implement image processing technology at practical processing speed and accuracy. Thus, multiplex imaging of a plurality of images and separation thereof can be accurately realized. For this reason, in the present embodiment, the volume hologram optical element (vHOE) 104 having a high degree of design freedom and the image processing unit 106 capable of executing the high-precision signal processing are integrated and designed to achieve the high resolution of the existing imaging method. A new optical-computer integrated type imaging system 100 that overcomes the physical limitations of image formation.

  Next, an imaging method to which the imaging system according to one embodiment of the present invention is applied will be described with reference to the drawings. FIG. 4 is a flowchart showing an outline of an imaging method to which the imaging system according to the embodiment of the present invention is applied, and FIGS. 5A to 5D show imaging results by the imaging system according to the embodiment of the present invention. FIG.

  An imaging method to which an imaging system according to an embodiment of the present invention is applied is an imaging method for imaging an imaging target including a plurality of optical information, and a wide angle of video recording is efficiently achieved with a simple optical system configuration. It is characterized by being able to realize multiple wavelengths and high resolution. In the present embodiment, as shown in FIG. 4, the imaging method includes a dividing step S11, an encoding step S12, a multiplexing step S13, and a restoration processing step S14, and these steps S11 to S14 are performed. By performing the processing in the flow shown in FIG. 4, widening of the angle of video recording, multi-wavelength, and high resolution can be efficiently realized.

  In the dividing step S11, a plurality of pieces of optical information of the imaging target are divided for each small visual field and wavelength width. In the present embodiment, since the volume hologram optical element is provided on the front side of the imaging unit, a plurality of pieces of optical information to be imaged through the volume hologram optical element are divided into small visual fields and wavelength widths. .

  In the encoding step S12, a plurality of pieces of optical information divided in the division step S11 are encoded by the volume hologram optical element to obtain an encoded image. In the present embodiment, each of the optical information divided for each field of view and each wavelength width is independently modulated and encoded by the volume hologram optical element.

  In the multiplexing step S13, each of the encoded images obtained for each of the plurality of optical information is multiplexed by an image sensor to obtain a multiplexed image. In the present embodiment, each of the encoded images encoded by the volume hologram optical element, which is multiplexed, is obtained as an image of the multiplexed image by the image sensor.

  In the restoration processing step S14, the multiplexed image is restored by compression sensing using the sparsity of the image to be restored, and separated and reconstructed. In the present embodiment, the multiplexed image obtained by the image sensor is separated and reconstructed by the image processing unit by the image restoration process by the compressed sensing that actively uses the sparsity of the image.

  As described above, in the present embodiment, by providing the volume hologram optical element on the front stage side of the image sensor, the optical information is divided into individual pieces of optical information included in the imaging target by utilizing the properties of the volume hologram optical element, and independently. Can be encoded. For this reason, a multiplexed image of each optical information is generated by an image sensor, and the multiplexed image is separated and reconstructed by an image processing unit. Resolution can be realized. In other words, a small and simple optical system composed only of the vHOE and the image sensor, or, in some cases, only the vHOE and the image sensor and some auxiliary optical elements such as lenses, provides a wide field of view, a multi-wavelength, and a high pixel count. , Or an image with a high information amount that satisfies any of them.

  By applying the imaging system and the imaging method of the present embodiment, a captured image shown in FIG. 5A can be obtained. On the other hand, FIG. 5B shows an example in which the coding based on the image division of the image recorded in FIG. 5A is displayed in an easily understandable manner with the division width emphasized. In addition, by applying the imaging system and the imaging method of the present embodiment and separating and reconstructing the image by an image restoration process using compressed sensing that actively utilizes the sparsity of the image, the image of one view shown in FIG. An image of another field of view shown in FIG. 5D is obtained. From this, it can be seen that the imaging system of the present embodiment and the imaging complement method can efficiently realize wide-angle video recording, multiple wavelengths, and high resolution with a simple configuration.

  As described above, the volume hologram optical element 104 can reproduce the wavefront of light recorded at the time of hologram exposure when light is incident, and can record and reproduce a wavefront independent of each incident angle of light. Angle selectivity, and a wavelength selectivity enabling recording and reproduction of an independent wavefront for each wavelength of light. In particular, in order for the volume hologram optical element 104 to have angle selectivity and wavelength selectivity, different interference fringe patterns corresponding to the respective angles and wavelengths need to be provided on the volume hologram optical element 104. For this reason, conventionally, in order to provide different interference fringe patterns on the volume hologram optical element, multiple exposures have been performed as many times as necessary to provide different interference fringe patterns.

  However, when multiple exposures are performed to provide a plurality of different interference fringe patterns on one volume hologram optical element, problems such as a decrease in diffraction efficiency of the volume hologram optical element and occurrence of crosstalk occur. In particular, in order for the volume hologram optical element to have a high degree of angle selectivity and wavelength selectivity, it is necessary to provide a larger number of interference fringe patterns, and the above-described problems associated with multiple exposures become significant.

  For this reason, in the volume hologram optical element 104 provided in the imaging system 100 according to one embodiment of the present invention, for example, a plurality of hologram elements 104a, 104b, which have different optical characteristics such as diffraction efficiency and refraction angle as shown in FIG. After providing different interference fringe patterns on each of 104c and 104d, it is also possible to adopt a configuration in which the hologram elements 104a, 104b, 104c and 104d are stacked as shown in FIG. 6B. That is, in the present embodiment, the volume hologram optical element 104 may be configured by laminating a plurality of hologram elements 104a, 104b, 104c, and 104d having different interference fringe patterns.

  As described above, by stacking a plurality of hologram elements 104a, 104b, 104c, and 104d having different patterns of interference fringes, the volume hologram optical element 104 allows incident light having various angles as shown in FIG. 6B. Since the optical information has an angle selectivity and a wavelength selectivity, each optical information included in the object to be imaged is divided and encoded for each optical information, and enters the image sensor of the camera 103. For this reason, since each optical information included in the imaging target is divided for each optical information and independently encoded, a multiplexed image of each optical information is acquired by the image sensor, and then the subsequent image processing unit 108 By separating and reconstructing the multiplexed image (see FIG. 1), it is possible to efficiently realize wide-angle video recording, multiple wavelengths, and high resolution of video recording.

  Further, in the present embodiment, the volume hologram optical element 104 is not formed by multiple exposure, but is formed by exposing a desired interference fringe pattern to each of the different hologram elements 104a, 104b, 104c, and 104d. The hologram elements 104a, 104b, 104c, and 104d are configured to be stacked. For this reason, the number of multiple exposures of the hologram can be reduced, so that the diffraction efficiency of the volume hologram optical element 104 can be reduced and the risk of occurrence of crosstalk can be reduced.

  In the hologram element, by exposing a photopolymer constituting the hologram element to light, a monomer constituting the photopolymer moves to form a desired interference fringe. However, when trying to form different interference fringe patterns on the photopolymer constituting one hologram element, there is a problem that crosstalk occurs between the interference fringes.

  For this reason, in the present embodiment, the patterns of different interference fringes are formed by exposing the respective hologram elements 104a, 104b, 104c, and 104d, respectively, and the movement of the monomers constituting the interference fringes is stopped. Therefore, the hologram elements 104a, 104b, 104c, and 104d are stacked to form the volume hologram optical element 104. By doing so, the interference fringes formed on each of the hologram elements 104a, 104b, 104c, and 104d are in a stable state, so that the optical performance of the volume hologram optical element 104 is improved.

  Further, in the present embodiment, the volume hologram optical element 104 has a configuration in which a plurality of hologram elements 104a, 104b, 104c, and 104d having different interference fringe patterns are stacked, so that these hologram elements 104a, 104b, and 104c are stacked. , 104d can be configured such that the tilt angle or arrangement can be adjusted. Therefore, even after the exposure of the volume hologram optical element 104 to form interference fringes, the PSF can be designed and controlled flexibly by adjusting the inclination angles or arrangement of the hologram elements 104a, 104b, 104c, and 104d. become.

  With such a configuration of the volume hologram optical element 104 included in the imaging system 100 according to an embodiment of the present invention, as shown in FIG. 7, printing that displays “A” as a laser-certified diffusion object is performed. When the paper D6 and the printing paper D7 displaying “B” are imaged by the camera 103 having a lens and an image sensor, a multiple image D8 of “A” and “B” displayed on these printing papers D6 and D7 is obtained. You. Also, by applying the imaging system and the imaging method of the present embodiment to separate and reconstruct by image restoration processing using compressed sensing that actively utilizes the sparsity of the image, an image D9 of one visual field by the reconstructed visual field is obtained. And an image D10 of another field of view.

  For this reason, even when the volume hologram optical element 104 has a configuration in which a plurality of hologram elements 104a, 104b, 104c, and 104d having different interference fringe patterns are stacked, the wide-angle image recording, the multiple wavelengths, and the high resolution can be efficiently performed. It can be seen that the realization is feasible. In the present embodiment, the volume hologram optical element 104 is formed by stacking four different hologram elements 104a, 104b, 104c, and 104d. Is not limited to four, and may be configured from other numbers.

  As described above, by applying the imaging system and the imaging method according to an embodiment of the present invention, single-shot wide-angle, multi-wavelength, high-resolution imaging as realized by a camera array and a sensor array can be performed by volume hologram optics. This can be realized by a small and simple optical system which only includes an element and an image sensor (in some cases, an auxiliary optical element such as a lens).

  That is, by using a volume hologram optical element as an optical element that independently encodes image information of a plurality of fields of view and wavelengths as an imaging means of an imaging system, a compact device such as a miniaturized camera can be used. It is possible to easily realize a wide-angle recording, a multi-wavelength recording, and a high resolution and a high imaging information amount.

  Therefore, an ultra-high pixel multispectral camera can be realized with a size, cost, and imaging time that can be easily used by the user. That is, the imaging system and the imaging method according to an embodiment of the present invention can be applied as a new basic technology for image input in the information age in which information acquisition of an image and an image analysis object is progressing, so that an extremely large industrial scale can be realized. Have a value.

  Although the embodiment of the present invention has been described in detail as described above, those skilled in the art can easily understand that many modifications that do not substantially depart from the novel matter and effects of the present invention are possible. I can do it. Therefore, such modified examples are all included in the scope of the present invention.

  For example, in the description or drawings, a term described at least once together with a broader or synonymous different term can be replaced with the different term in any part of the description or drawing. Further, the configuration and operation of the imaging system are not limited to those described in the embodiment of the present invention, and various modifications can be made.

Reference Signs List 100 imaging system, 102 imaging unit, 103 camera, 104 volume hologram optical element, 104a, 104b, 104c, 104d hologram element, 106 image sensor, 108 image processing unit

Claims (8)

An imaging system for imaging an imaging target including a plurality of optical information,
A volume hologram optical element that encodes the image object after dividing it for each optical information,
An image sensor that multiplexes each encoded image encoded by the volume hologram optical element to obtain a multiplexed image,
An image processing system comprising: an image processing unit configured to perform image restoration processing on the multiplexed image acquired by the image sensor by compressed sensing to separate and reconstruct imaging data of the imaging target.   The volume hologram optical element encodes the plurality of pieces of optical information included in the imaging target after dividing the plurality of pieces of optical information for each angle with the volume hologram element or for each wavelength width of the optical information. 2. The imaging system according to 1.   The imaging system according to claim 1, wherein the volume hologram optical element is configured by stacking a plurality of hologram elements having different interference fringe patterns.   4. The imaging system according to claim 3, wherein the plurality of hologram elements constituting the volume hologram optical element are configured to be capable of adjusting a tilt angle or an arrangement, respectively. 5.   5. The imaging system according to claim 1, wherein the image processing unit performs a restoration process on the multiplexed image using the sparsity of an image to be restored. 6.   The imaging system according to any one of claims 1 to 5, wherein a lens is provided between the volume hologram optical element and the image sensor.   The imaging system according to any one of claims 1 to 5, wherein a lensless system is used in which no lens is provided between the volume hologram optical element and the image sensor. An imaging method for imaging an imaging target including a plurality of optical information,
A dividing step of dividing the plurality of optical information of the imaging target for each small visual field and wavelength width;
An encoding step of encoding with the volume hologram optical element for each of the plurality of optical information divided in the step to obtain an encoded image,
A multiplexing step of multiplexing each of the encoded images obtained for each of the plurality of optical information with an image sensor to obtain a multiplexed image,
A restoring process of restoring the multiplexed image by compressed sensing using the sparsity of the image to be restored.

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