Snapshot type spectral imaging system based on peak shifting shearing

Abstract

The invention belongs to the technical field of spectral imaging, and particularly relates to a snapshot type spectral imaging system based on peak shifting shearing. The system comprises a band-pass diaphragm, a pixel-level filtering array and a detector which are sequentially arranged in the direction of an optical axis, the band-pass diaphragm is used for transmitting light of a specified wave band, the pixel-level filtering array is used for cutting off the light of the specified wave band, and the detector is used for imaging the light transmitting the pixel-level filtering array. The broadband spectrum channel is processed in a peak shifting shearing mode, data collection of the narrow spectrum channel is achieved, the spectrum resolution can be improved, and the manufacturing process difficulty is reduced.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of spectral imaging, and particularly relates to a snapshot spectral imaging system based on staggered peak cutting. BACKGROUND

[0002] The snapshot spectral imaging technology forms three-dimensional data information by superimposing two-dimensional image information and spectral information, has simple structure, improves the data acquisition capability, and is widely applied in the fields of aerospace, environmental monitoring, industrial detection, biological medicine and the like. The pixel-level filter array is a core device for realizing miniaturized spectral sensing in the snapshot spectral imaging system, and the spectral information is acquired by integrating the filter unit on the photosensitive pixel, so that the device volume and cost are greatly reduced. However, the performance of the pixel-level filter array depends on the manufacturing precision of the narrow-band filter unit, and the existing process faces a significant bottleneck. The nanometer-level precision control needs to be realized through thin film deposition, photolithography and the like, and the pixel size is only several microns to tens of microns, so that slight process fluctuation will lead to bandwidth expansion, and the high spectral imaging demand cannot be met. Therefore, a new snapshot spectral imaging system is urgently needed to make up for the insufficient filter performance caused by hardware defects and reduce the manufacturing precision dependence. SUMMARY

[0003] Therefore, the application creates to provide a snapshot spectral imaging system based on staggered peak cutting, so as to solve the problem of high manufacturing process difficulty for ensuring the spectral resolution in the prior art. The application adopts the staggered peak cutting mode to process the wide spectral channel, realizes the data acquisition of the narrow spectral channel, can improve the spectral resolution, and reduce the manufacturing process difficulty.

[0004] To achieve the above-mentioned purpose, the technical scheme of the application creates is as follows: A snapshot spectral imaging system based on staggered peak cutting comprises a band-pass window sheet, a pixel-level filter array and a detector which are sequentially arranged along the optical axis direction, wherein the band-pass window sheet is used for transmitting light of a specified waveband, the pixel-level filter array is used for filtering out light of the specified waveband, and the detector is used for imaging the light transmitted through the pixel-level filter array. The pixel-level filter array comprises m*n spectral channel units, each of which comprises a×b-1 trap wave spectral channels and one panchromatic channel or a×b band-pass spectral channels.

[0005] Further, when each spectral channel unit comprises a×b-1 trap wave spectral channels and one panchromatic channel, the panchromatic channel is located at the lower right corner of the spectral channel unit.

[0006] Further, in the spectral channel unit, the trap wave spectral channels are numbered from left to right and from top to bottom, wherein the spectral spectral energy of the first trap wave spectral channel is smaller than that of the second trap wave spectral channel. : ; wherein, is the energy value received by the detector when the incident light is incident on the detector through the full-color channel, is the energy value received by the detector when the incident light is incident on the detector through the first notch spectral channel.

[0007] Further, in the spectral channel unit, the spectral band energy of the cth notch spectral channel other than the first notch spectral channel and the full-color channel is , 2≤c≤a×b-1: ; wherein, is the energy value received by the detector when the incident light is incident on the detector through the cth notch spectral channel, is the spectral band energy of the c-1th notch spectral channel.

[0008] Further, in each spectral channel unit, the center wavelength of the ith notch spectral channel is the start wavelength of the i+1th notch spectral channel.

[0009] Further, when each spectral channel unit includes a×b bandpass spectral channels, in the spectral channel unit, the bandpass spectral channels are numbered from left to right and from top to bottom, and the spectral band energy of the kth bandpass spectral channel is : ; wherein, is the energy value received by the detector when the incident light is incident on the detector through the kth bandpass spectral channel.

[0010] Further, in each spectral channel unit, the center wavelength of the ith bandpass spectral channel is the start wavelength of the i+1th bandpass spectral channel.

[0011] Further, when each spectral channel unit includes a×b-1 notch spectral channels and one full-color channel, the start wavelength of the bandpass window piece is the center wavelength of the first notch spectral channel, and the cutoff wavelength of the bandpass window piece is the center wavelength of the a×b-1th notch spectral channel. When each spectral channel unit includes a×b bandpass spectral channels, the start wavelength of the bandpass window piece is the center wavelength of the first bandpass spectral channel, and the cutoff wavelength of the bandpass window piece is the center wavelength of the a×bth bandpass spectral channel.

[0012] Compared with the prior art, the present application can achieve the following beneficial effects: The snapshot spectral imaging system based on staggered cutting in the application is designed with staggered peak positions in each channel spectrum in the light filtering array, and the narrow channel spectrum information is solved by the way of wide channel spectrum staggered subtraction, which improves the spectral resolution by one time and reduces the difficulty of manufacturing process. BRIEF DESCRIPTION OF DRAWINGS

[0013] The accompanying drawings, which form a part of this application, are included to provide a further understanding of the application and are incorporated in and constitute a part of this application. The embodiments of the application illustrated in the drawings are presented by way of example or for purposes of illustration and not limitation. Figure 1 Structure schematic view of the snapshot spectral imaging system based on staggered cutting according to the embodiment of the application; Figure 2 Structure schematic view of the spectral channel unit according to the embodiment of the application; Figure 3 Spectral response schematic view of each spectral channel when each spectral channel unit includes a x b-1 notch spectral channels and one panchromatic channel according to the embodiment of the application; Figure 4 Spectral response schematic view of each spectral channel when each spectral channel unit includes a x b bandpass spectral channels according to the embodiment of the application.

[0014] Reference signs: 1, bandpass window sheet; 2, pixel-level light filtering array; 3, detector. DETAILED DESCRIPTION

[0015] In order to make the purpose, technical scheme and advantages of the application clearer, the application is further described in detail below with reference to the drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the application, and do not constitute limitation to the application.

[0016] It should be noted that the embodiments in the application and the features in the embodiments can be combined with each other without conflict.

[0017] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application. In addition, the terms "first", "second" and the like are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined with "first", "second" and the like can be explicitly or implicitly included one or more. In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0018] In the description of the present application, it should be noted that unless otherwise specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be connected inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0019] The present application will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

[0020] As shown in Figures 1 to 2 The present application provides a snapshot spectral imaging system based on staggered cutting, which comprises a band-pass window sheet 1, a pixel-level filter array 2 and a detector 3 arranged in sequence along the optical axis direction, wherein the band-pass window sheet 1 is used to transmit light of a specified waveband, the pixel-level filter array 2 is used to filter out light of the specified waveband, and the detector 3 is used to image the light transmitted through the pixel-level filter array 2. The pixel-level filter array 2 comprises m x n spectral channel units, each spectral channel unit comprising a x b-1 notch spectral channels and one panchromatic channel, or each spectral channel unit comprising a x b band-pass spectral channels.

[0021] In some embodiments, when each spectral channel unit comprises a x b-1 notch spectral channels and one panchromatic channel, the panchromatic channel is located at the lower right corner of the spectral channel unit.

[0022] In some embodiments, within the spectral channel unit, the notch spectral channels are numbered from left to right and from top to bottom, wherein the spectral spectral energy of the first notch spectral channel is less than 10% of the spectral spectral energy of the second notch spectral channel. : ; in, The energy value received by detector 3 is the energy of the incident light as it enters the detector through the panchromatic channel. The energy value received by detector 3 is the incident light that enters detector 3 through the first notch spectral channel.

[0023] In some embodiments, within the spectral channel unit, the spectral band energy of the c-th notch spectral channel, excluding the first notch spectral channel and the panchromatic channel, is: 2≤c≤a×b-1: ; in, The energy value received by detector 3 is the incident light that enters detector 3 through the c-th notch spectral channel. is the spectral energy of the (c-1)th notch spectral channel.

[0024] In some embodiments, within each spectral channel unit, the center wavelength of the i-th notch spectral channel is the starting wavelength of the (i+1)-th notch spectral channel.

[0025] In some embodiments, when each spectral channel unit includes a×b bandpass spectral channels, the bandpass spectral channels are numbered from left to right and from top to bottom within the spectral channel unit, and the spectral band energy of the k-th bandpass spectral channel is... : ; in, Let be the energy value received by detector 3 when incident light enters detector 3 through the k-th bandpass spectral channel.

[0026] In some embodiments, within each spectral channel unit, the center wavelength of the i-th bandpass spectral channel is the starting wavelength of the (i+1)-th bandpass spectral channel.

[0027] In some embodiments, when each spectral channel unit includes a×b-1 notch spectral channels and a panchromatic channel, the starting wavelength of the bandpass window 1 is the center wavelength of the first notch spectral channel, and the cutoff wavelength of the bandpass window 1 is the center wavelength of the a×b-1th notch spectral channel. When each spectral channel unit includes a×b bandpass spectral channels, the starting wavelength of the bandpass window 1 is the center wavelength of the first bandpass spectral channel, and the cutoff wavelength of the bandpass window 1 is the center wavelength of the a×b bandpass spectral channel.

[0028] This invention selects the incident light spectrum by combining a bandpass window 1 and a pixel-level filter array 2, and acquires spectral data through subsequent computational processing. The snapshot-type spectral imaging system based on peak shearing designed in this invention achieves high spectral resolution and high energy utilization while maintaining a simple structure and low manufacturing difficulty.

[0029] The following section provides a detailed introduction to the snapshot-based spectral imaging system based on peak shearing.

[0030] Example 1 When each spectral channel unit includes 3×3-1 notch spectral channels and one panchromatic channel, the panchromatic channel can transmit light of all wavelengths. Within the spectral channel unit, each notch spectral channel is numbered from left to right and from top to bottom. The bandpass window 1 is then labeled with G. BP This indicates that the bandpass window 1 is located on the outermost side of detector 3 and is used for spectral selection of the incident light, such as... Figure 3 As shown, bandpass window 1—G BP The starting wavelength is the center wavelength of band 1 in the notch filter array, and the cutoff wavelength is the cutoff wavelength of band 8 in the pixel-level notch filter array. Each notch spectral channel is designed as a band-stop filter system using a notch film system design, forming a pixel-level notch filter array. The pixel-level notch filter array is located on the surface of detector 3 and modulates the light passing through the bandpass window 1. The pixel-level notch filter array has m×n spectral channel units, and each a×b pixel constitutes a group of spectral channel units, with a=b being the optimal combination. In this embodiment, the spectral channel unit consists of 3×3 pixels. Within each group of spectral channel units, bands 1 to 8 are notch spectral channels designed with a notch film system. The center wavelengths of each notch spectral channel are staggered, and the center wavelength of the i-th notch spectral channel is the notch starting wavelength of the (i+1)-th notch spectral channel. Band 9 is uncoated and is a panchromatic channel used to calculate the data of each spectral channel.

[0031] like Figure 3 As shown, G i Y represents the energy value received by detector 3, where 1 ≤ i ≤ 9. j The energy of the multispectral band selected for the j-th spectral channel, 1≤j≤8.

[0032] Within each spectral channel unit, the spectral energy of the first spectral channel is: ; The spectral energy of the second spectral channel is: ; The spectral energy of the third spectral channel is: ; The spectral energy of the 8th spectral channel is: ; Since channel 9 is a panchromatic channel, the pixel-level notch filter array can calculate the energy of 8 spectral bands. Simultaneously, by utilizing the staggered peak positions of each channel, narrowband spectral data acquisition is achieved through a cropping method, resulting in a cropped spectral channel bandwidth that is half the bandwidth of the original spectral channel.

[0033] Example 2 When each spectral channel unit includes a×b bandpass spectral channels, within the spectral channel unit, each bandpass spectral channel is numbered from left to right and from top to bottom, and the bandpass window 1 is labeled with G. BP This indicates that the bandpass window 1 is located on the outermost side of detector 3 and is used for spectral selection of the incident light, such as... Figure 4 As shown, bandpass window 1—G BP The starting wavelength is the center wavelength of band1 in the bandpass filter array, and the cutoff wavelength is the center wavelength of band9 in the pixel-level bandpass filter array.

[0034] like Figure 4 As shown, G i Y represents the energy value received by detector 3, where 1 ≤ i ≤ 9. j The energy of the multispectral band selected for the j-th spectral channel, 1≤j≤9.

[0035] Within each spectral channel unit, the spectral energy of the first spectral channel is: ; The spectral energy of the second spectral channel is: ; The spectral energy of the third spectral channel is: ; The spectral energy of the 9th spectral channel is: ; By interleaving the peak positions of each channel, narrowband spectral data acquisition is achieved through shearing. The bandwidth of the acquired spectral channel after shearing is half that of the original spectral channel.

[0036] It should be understood that the various forms of processes shown above can be used to reorder, add, or delete steps. For example, the steps described in this invention disclosure can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution disclosed in this invention can be achieved, and this is not limited herein.

[0037] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A snapshot-type spectral imaging system based on peak shearing, characterized in that: It includes a bandpass window, a pixel-level filter array, and a detector arranged sequentially along the optical axis. The bandpass window is used to transmit light of a specified wavelength, the pixel-level filter array is used to filter out light of a specified wavelength, and the detector is used to image the light transmitted through the pixel-level filter array. The pixel-level filter array includes m×n spectral channel units, each of which includes a×b-1 notch spectral channels and one panchromatic channel, or each of which includes a×b bandpass spectral channels.

2. The snapshot spectral imaging system based on peak shearing according to claim 1, characterized in that: When each spectral channel unit includes a×b-1 notch spectral channels and one panchromatic channel, the panchromatic channel is located in the lower right corner of the spectral channel unit.

3. The snapshot spectral imaging system based on peak shearing according to claim 2, characterized in that: Within the spectral channel unit, each notch spectral channel is numbered from left to right and from top to bottom. The spectral energy of the first notch spectral channel is... : ； in, The energy value received by the detector is the energy of the incident light as it enters the detector through the panchromatic channel. The energy value received by the detector is the energy of the incident light as it enters the detector through the first notch spectral channel.

4. The snapshot spectral imaging system based on peak shearing according to claim 3, characterized in that: Within the spectral channel unit, the spectral band energy of the c-th notch spectral channel, excluding the first notch spectral channel and the panchromatic channel, is: 2≤c≤a×b-1: ； in, Let c be the energy value received by the detector after the incident light enters the detector through the c-th notch spectral channel. is the spectral energy of the (c-1)th notch spectral channel.

5. The snapshot spectral imaging system based on peak shearing according to claim 4, characterized in that: Within each spectral channel unit, the center wavelength of the i-th notch spectral channel is the starting wavelength of the (i+1)-th notch spectral channel.

6. The snapshot spectral imaging system based on peak shearing according to claim 1, characterized in that: When each spectral channel unit includes a×b bandpass spectral channels, the bandpass spectral channels are numbered from left to right and from top to bottom within the spectral channel unit. The spectral energy of the k-th bandpass spectral channel is... : ； in, Let be the energy value received by the detector when the incident light is incident on the detector through the k-th bandpass spectral channel.

7. The snapshot spectral imaging system based on peak shearing according to claim 6, characterized in that: Within each spectral channel unit, the center wavelength of the i-th bandpass spectral channel is the starting wavelength of the (i+1)-th bandpass spectral channel.

8. The snapshot spectral imaging system based on peak shearing according to claim 2 or 6, characterized in that: When each spectral channel unit includes a×b-1 notch spectral channels and one panchromatic channel, the starting wavelength of the bandpass window is the center wavelength of the first notch spectral channel, and the cutoff wavelength of the bandpass window is the center wavelength of the a×b-1th notch spectral channel. When each spectral channel unit includes a×b bandpass spectral channels, the starting wavelength of the bandpass window is the center wavelength of the first bandpass spectral channel, and the cutoff wavelength of the bandpass window is the center wavelength of the a×b bandpass spectral channel.

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