Method and apparatus for designing filters for snapshot multispectral imaging systems

Abstract

The application relates to the technical field of spectral imaging, and particularly provides a design method and device for a filter of a snapshot multispectral imaging system, which comprises the following steps: drawing a radiation exitance curve of a to-be-detected target in a preset wavelength range by considering the system response rate; performing integral calculation on the radiation exitance of the radiation exitance curve to obtain radiation power; determining the number of spectral channels; determining the number of filters of the snapshot multispectral imaging system according to the number of spectral channels; dividing the radiation power according to the number of spectral channels, and determining the divided radiation power corresponding to each filter, wherein the divided radiation powers have different wavelength intervals; and designing the bandwidth of the corresponding filter according to the wavelength interval of the divided radiation power. Therefore, the real-time performance of the system can be ensured, the signal-to-noise ratio is improved, the obvious difference in the image can be reduced, the overall balance of the image is improved, and the imaging effect is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of spectral imaging technology, in particular to a design method of a filter of a snapshot multispectral imaging system and a design device of the filter of the snapshot multispectral imaging system. BACKGROUND

[0002] Snapshot multispectral imaging technology is an advanced imaging technology for obtaining spectral information of ground targets. It mainly captures spectral information of different wavebands at the same time to provide more comprehensive and accurate ground object classification and analysis. Figure 1 As shown in the imaging principle of the infrared multispectral video imager, light from a distant scene to be measured is converged into the infrared multispectral video imager through a telescope, and the imaging range is limited and part of the stray light is suppressed through a field diaphragm. The light is collimated into a parallel light beam by a collimating mirror to reach the surface of a filter array, the filter array splits the light for each sub-aperture and extracts signals of a specific wavelength range for different apertures, the aperture diaphragm further suppresses stray light, and then the light is converged and spatially multiplexed by a lens array. Finally, the light reaches the detector focal plane, and signals of multiple different spectral bands of the same scene are obtained, including two-dimensional spatial information and one-dimensional spectral information.

[0003] In order to solve the problem of how to design an optical filter to achieve the best detection effect, there are currently two main ways: the first way is to use a broadband filter for sub-aperture imaging; the second way is to use a filter wheel difference to realize multispectral imaging. Image difference is one of the biggest features of spectral filtering infrared imaging mode, which uses two high-pass filters with different cutoff wavelengths to image respectively, and the difference between the two cutoff wavelengths is calculated to obtain the difference image between the two cutoff wavelengths.

[0004] The disadvantage of the first way is that an equal-bandwidth filter is used, and there may be a significant response difference in the system's optical lens and the detector's response rate in the 7-14um range. After 11um, the response decreases, resulting in poor signal-to-noise ratio of the image and large response difference of the image. On the other hand, it will limit the adjustment of the integration time of the detector and bring difficulties to the non-uniform correction of different channel images.

[0005] The disadvantage of the second way is that multiple spectral channels cannot be imaged at the same time, and the real-time performance will be reduced. At the same time, the filter design mentioned above uses a single-end same cutoff and a gradient decreasing method on the other end, which will also cause different radiant intensities received by each spectral channel, resulting in obvious response difference in the image.

[0006] Therefore, for the design of a filter suitable for a snapshot multispectral imaging system, the related technology has the problems of non-uniformity between channels, high signal-to-noise ratio, and obvious response difference in the image. SUMMARY

[0007] To solve one of the above technical problems, the present application provides the following technical solutions.

[0008] The first aspect of the present application provides a design method of a filter of a snapshot multispectral imaging system, comprising the following steps: drawing a radiation emittance curve of a target to be measured in a preset wavelength range considering a system response rate; performing integral calculation on the radiation emittance of the radiation emittance curve to obtain a radiation power; determining a number of spectral channels; determining a number of filters of the snapshot multispectral imaging system according to the number of spectral channels; dividing the radiation power according to the number of spectral channels, and determining a divided radiation power corresponding to each filter, wherein each divided radiation power has a different wavelength interval; and designing a bandwidth of the corresponding filter according to the wavelength interval of the divided radiation power.

[0009] In addition, the design method of the filter of the snapshot multispectral imaging system according to the above embodiments of the present application can further have the following additional technical features.

[0010] According to one embodiment of the present application, the snapshot multispectral imaging system comprises an optical system and a detector, and the drawing of the radiation emittance curve of the target to be measured in the preset wavelength range considering the system response rate comprises: detecting the optical transmittance of the optical system and the spectral response rate of the detector in the preset wavelength range; calculating the blackbody radiation emittance of the target to be measured in the preset wavelength range; and drawing the radiation emittance curve of the target to be measured in the preset wavelength range considering the system response rate according to the optical transmittance of the optical system, the spectral response rate of the detector and the blackbody radiation emittance of the target to be measured.

[0011] According to one embodiment of the present application, the drawing of the radiation emittance curve of the target to be measured in the preset wavelength range considering the system response rate according to the optical transmittance of the optical system, the spectral response rate of the detector and the blackbody radiation emittance of the target to be measured comprises: calculating the system response rate of the snapshot multispectral imaging system in the preset wavelength range according to the optical transmittance of the optical system and the spectral response rate of the detector; and drawing the radiation emittance curve of the target to be measured in the preset wavelength range considering the system response rate according to the blackbody radiation emittance and the system response rate.

[0012] According to one embodiment of the present application, the division of the radiation power is achieved by dividing the area enclosed by the radiation emittance curve and the X-axis by a line perpendicular to the X-axis.

[0013] According to one embodiment of the present application, determining the divided radiation power corresponding to each filter comprises: determining at least one continuous wavelength interval of the divided radiation power corresponding to each filter, wherein each of the divided radiation powers can be obtained by subtracting the wideband of different filters.

[0014] According to one embodiment of the present application, designing the bandwidth of the corresponding filter according to the wavelength interval of the divided radiation power comprises: determining the overall wavelength interval of the divided radiation power corresponding to each filter, calculating the difference between the maximum value and the minimum value of the overall wavelength interval, and determining the bandwidth of the filter according to the difference.

[0015] According to one embodiment of the present application, the preset wavelength range is 7-14 um.

[0016] The second aspect embodiment of the present application provides a design device for filters of a snapshot multi-spectral imaging system, comprising: a drawing module configured to draw a radiation emittance curve of a target to be measured in a preset wavelength range considering the system response rate; a calculation module configured to integrate the radiation emittance of the radiation emittance curve to obtain a radiation power; a first determination module configured to determine the number of spectral channels; a second determination module configured to determine the number of filters of the snapshot multi-spectral imaging system according to the number of spectral channels; a third determination module configured to divide the radiation power according to the number of spectral channels, and determine the divided radiation power corresponding to each filter, wherein each of the divided radiation powers has a different wavelength interval; and a design module configured to design the bandwidth of the corresponding filter according to the wavelength interval of the divided radiation power.

[0017] The technical scheme of the embodiment of the present application calculates the radiation emittance curve of the target to be measured considering the system response rate, divides the radiation power on the basis of the curve, and the divided radiation power has a corresponding relationship with the filter, and the bandwidth of the corresponding filter is designed according to the divided radiation power. Therefore, the real-time performance of the system can be ensured, the signal-to-noise ratio is improved, the obvious difference in the image is reduced, the overall balance of the image is improved, and the imaging effect is improved. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 FIG. 1 is a structural schematic diagram of a snapshot multi-spectral imaging system in the related art;

[0019] Figure 2 FIG. 4 is a flowchart of a design method for filters of a snapshot multi-spectral imaging system according to an embodiment of the present application.

[0020] Figure 3 FIG. 5 is a blackbody radiation emittance curve diagram of a target to be measured according to one specific example of the present application.

[0021] Figure 4 A graph of system response rate of an optical system for one specific example of the present application.

[0022] Figure 5 A graph of radiant exitance of a target under test considering system response rate for one specific example of the present application.

[0023] Figure 6 A table showing the wavelength intervals of the radiant power corresponding to the nine filters in Mode One for one specific example of the present application.

[0024] Figure 7 A table showing the wavelength intervals of the radiant power corresponding to the nine filters in Mode Two for one specific example of the present application.

[0025] Figure 8 A block diagram of the design device for the filters of the snapshot multispectral imaging system according to an embodiment of the present application. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0027] Figure 1 A structural diagram of a snapshot multispectral imaging system according to the related art.

[0028] As shown in Figure 1 , the snapshot multispectral imaging system includes an optical system 1 and a detector 2. The optical system 1 includes a telescope objective 11, a field stop 12, a relay collimator 13, a filter array 14, and a microlens array 15.

[0029] In order to design the filters in the filter array 14, achieve equalization between the spectral channels and high signal-to-noise ratio, and improve the optical imaging effect, the present application provides a design method for the filters of a snapshot multispectral imaging system.

[0030] Figure 2 A flowchart of the design method for the filters of a snapshot multispectral imaging system according to an embodiment of the present application.

[0031] As shown in Figure 2 , the design method for the filters of a snapshot multispectral imaging system includes the following steps S1 to S6.

[0032] S1, draw the radiation exitance curve of the target to be tested in a preset wavelength range considering the system response rate.

[0033] The system response rate refers to the optical response rate of the snapshot multispectral imaging system.

[0034] The preset wavelength range can be 7-14 um.

[0035] Specifically, first, the system response rate is calculated, and the radiation exitance of the target to be tested in the 7-14 um range is calculated based thereon, and the radiation exitance curve of the target to be tested is drawn in the coordinate system with wavelength as the X-axis and radiation exitance as the Y-axis.

[0036] S2, the radiation exitance of the radiation exitance curve is integrated to obtain the radiation power.

[0037] S3, determine the number of spectral channels.

[0038] Specifically, the number of spectral channels is determined according to the requirements of the scene to be tested, such as 4 channels, 6 channels, etc.

[0039] S4, determine the number of filters of the snapshot multispectral imaging system according to the number of spectral channels.

[0040] Specifically, the filter corresponds to the spectral channel one by one, so the number of filters is the same as the number of spectral channels.

[0041] S5, divide the radiation power according to the number of spectral channels, and determine the corresponding divided radiation power of each filter, wherein each part of the divided radiation power has a different wavelength interval.

[0042] Further, the area enclosed by the radiation exitance curve and the X-axis is divided by a line perpendicular to the X-axis to achieve the division of the radiation power.

[0043] Specifically, the area enclosed by the radiation exitance curve and the X-axis forms a radiation exitance region. For the radiation exitance curve, the radiation power of the radiation exitance region is divided by a line perpendicular to the X-axis to divide the radiation power into the number of spectral channels. Therefore, each part of the divided radiation power has a corresponding wavelength interval, and each wavelength interval is different.

[0044] Then, in order to ensure sufficient energy and energy balance between different spectral channels, at least one part of the divided radiation power corresponding to each filter is determined according to the imaging requirements, which may correspond to one, two, three, etc. Divided radiation power, specific according to actual requirements.

[0045] S6, design the bandwidth of the corresponding filter according to the wavelength interval of the divided radiation power.

[0046] Specifically, each portion of the divided radiation power corresponds to a wavelength interval, and at least one portion of the divided radiation power corresponds to a filter, so that for each filter, the bandwidth of the filter can be calculated according to the wavelength interval of the corresponding portion of the divided radiation power.

[0047] For example, when a filter corresponds to one portion of the divided radiation power, the difference between the wavelength intervals of the one portion of the divided radiation power is the bandwidth of the filter; when a filter corresponds to three consecutive portions of the divided radiation power, the difference between the overall wavelength intervals of the three portions of the divided radiation power is the bandwidth of the filter.

[0048] The design method of the filter of the snapshot multispectral imaging system in the embodiment of the application can calculate the radiation exitance curve of the target under test in consideration of the system response rate, divide the radiation power on the basis of the curve, and design the bandwidth of the corresponding filter according to the divided radiation power.

[0049] In this way, the real-time performance of the system can be ensured, the signal-to-noise ratio can be improved, the obvious difference between images can be reduced, the overall balance of the images can be improved, and the imaging effect can be improved.

[0050] In one embodiment, step S1 can include detecting the optical transmittance of the optical system and the spectral response rate of the detector in a preset wavelength range; calculating the blackbody radiation exitance of the target under test in the preset wavelength range; and drawing the radiation exitance curve of the target under test in the preset wavelength range in consideration of the system response rate according to the optical transmittance of the optical system, the spectral response rate of the detector, and the blackbody radiation exitance of the target under test.

[0051] Further, drawing the radiation exitance curve of the target under test in the preset wavelength range in consideration of the system response rate according to the optical transmittance of the optical system, the spectral response rate of the detector, and the blackbody radiation exitance of the target under test can include calculating the system response rate of the snapshot multispectral imaging system in the preset wavelength range according to the optical transmittance of the optical system and the spectral response rate of the detector; and drawing the radiation exitance curve of the target under test in the preset wavelength range in consideration of the system response rate according to the blackbody radiation exitance and the system response rate.

[0052] Specifically, first, the optical transmittance of the optical system 1, specifically including the optical transmittance of the telescope objective 11, the field stop 12, the relay collimator 13, the filter array 14 and the microlens array 15, in the preset wavelength range 7-14 um is detected, and the spectral response rate of the detector 2 in 7-14 um is detected. The blackbody radiation emittance of the target to be measured in 7-14 um is calculated, and the blackbody radiation emittance curve of the target to be measured is drawn (the X axis is the wavelength 7-14 um, and the Y axis is the blackbody radiation emittance). Then, according to the optical transmittance of the optical system 1 and the spectral response rate of the detector 2 in 7-14 um, the system response rate of the snapshot multi-spectral imaging system in the preset wavelength range 7-14 um is calculated, and the system response rate curve is drawn according to the system response rate (the X axis is the wavelength 7-14 um, and the Y axis is the system response rate). Finally, the product of the blackbody radiation emittance curve and the system response rate curve is obtained, and the radiation emittance curve is drawn, that is, the radiation emittance curve of the target to be measured in the preset wavelength range 7-14 um (the X axis is the wavelength 7-14 um, and the Y axis is the radiation emittance).

[0053] The radiation emittance of the radiation emittance curve is integrated to obtain the radiation power, and the radiation power is equally divided into the number of spectral channels (that is, the number of filters).

[0054] In one embodiment, the equal division of the radiation power is achieved by equally dividing the area surrounded by the radiation emittance curve and the X axis by a line perpendicular to the X axis.

[0055] Specifically, the area surrounded by the radiation emittance curve and the X axis is the radiation emittance region, which is equally divided into the number of spectral channels by a line perpendicular to the X axis to obtain the radiation power after equal division, and each part of the radiation power after equal division corresponds to a wavelength interval. At this time, the radiation power in each interval range is the same, and the corresponding range of the presented image is also basically the same, wherein the number of spectral channels, the number of parts of the radiation power after equal division and the number of filters are the same. Then, the radiation power after equal division corresponding to each filter is determined.

[0056] In one embodiment, the determination of the radiation power after equal division corresponding to each filter in step S5 can include: determining at least one part of the radiation power after equal division corresponding to each filter, which is continuous in the wavelength interval, wherein each part of the radiation power after equal division can be obtained by subtracting the wideband of different filters.

[0057] Specifically, in order to obtain sufficient energy while ensuring the energy balance among different spectral channels, each filter corresponds to one or more portions of the divided radiation power, wherein the overall wavelength of the multiple portions of the divided radiation power is continuous, and when designing the bandwidth of the filter, the correspondence between the filter and the divided radiation power only needs to satisfy the following condition: each portion of the divided radiation power can be obtained by subtracting the bandwidths of different filters, that is, the radiation power of each spectral channel can be obtained by subtracting the bandwidths of different filters.

[0058] For example, assuming that the number of spectral channels, the number of filters and the number of portions of the divided radiation power are all n, 1≤i≤n. When i≤n-2, the ith portion of the radiation power to the i+2th portion of the radiation power corresponds to one filter; when i=n-1, the ith portion of the radiation power and the i+1th portion of the radiation power correspond to one filter; and when i=n, the ith portion of the radiation power corresponds to one filter.

[0059] Then, step S5 is performed, that is, the bandwidth of the corresponding filter is designed according to the wavelength interval of the divided radiation power.

[0060] In one embodiment, step S5 can include determining the overall wavelength interval of the divided radiation power corresponding to each filter, calculating the difference between the maximum value and the minimum value of the overall wavelength interval, and determining the bandwidth of the filter according to the difference.

[0061] Specifically, for each filter, when it corresponds to one portion of the divided radiation power, the difference between the maximum value and the minimum value of the wavelength interval of the radiation power is calculated, which is the bandwidth of the filter; and when it corresponds to multiple continuous portions of the divided radiation power, the difference between the maximum value and the minimum value of the corresponding overall wavelength interval is calculated, which is the bandwidth of the filter.

[0062] Thus, by dividing the radiation power, the radiation power in the wavelength interval with weak system response rate is increased by increasing the bandwidth of the filter, thereby ensuring the balance among different spectral channels.

[0063] The design method of the filter of the snapshot multi-spectral imaging system according to the embodiment of the present application is described below by means of a specific example in combination with the drawings.

[0064] In one specific example, the number of spectral channels is 9 channels, and the number of filters is 9.

[0065] First, the blackbody radiance curve of the to-be-detected target in the range of 7-14 um is detected and plotted as shown in FIG. 1, and the system response rate curve of the optical system in the range of 7-14 um is detected and plotted as shown in FIG. 2. Figure 3 Figure 4 First, the blackbody radiance curve of the to-be-detected target in the range of 7-14 um is detected and plotted as shown in FIG. 1, and the system response rate curve of the optical system in the range of 7-14 um is detected and plotted as shown in FIG. 2.

[0066] ​Then, a product of multiplying the blackbody radiation emittance curve and the system response rate curve is calculated, and a curve is drawn according to the product Figure 5 The radiation emittance curve of the target to be measured in the range of 7-14 um is shown in FIG. 2, and the curve is divided into 9 equal parts by vertical dotted lines Figure 5 The area surrounded by the curve and the X-axis is divided into 9 equal parts by the vertical dotted lines, and the radiation power after the 9 equal divisions is obtained, as shown in FIG. 3 Figure 6 and Figure 7 The wavelength intervals of the radiation powers after the 9 equal divisions are 7.0000-7.6200, 7.6200-8.1500, 8.1500-8.6400, 8.6400-9.1300, 9.1300-9.6300, 9.6300-10.1900, 10.1900-10.8600, 10.8600-11.8500, and 11.8500-14.0000 um, respectively.

[0067] Further, the corresponding relationship between the radiation powers after the 9 equal divisions and the filter bands is designed. In the design, it should be ensured that the radiance power of each spectral channel can be obtained by making difference between different filters. For example, two modes can be designed at this time.

[0068] Referring to Figure 6 , mode one:

[0069] The radiation powers of 7.0000-7.6200, 7.6200-8.1500, and 8.1500-8.6400 um correspond to the first filter, and the bandwidth of the filter is 8.6400 um-7.0000 um=1640 nm.

[0070] The radiation powers of 7.6200-8.1500, 8.1500-8.6400, and 8.6400-9.1300 um correspond to the second filter, and the bandwidth of the filter is 9.1300 um-7.6200 um=1510 nm.

[0071] The radiation powers of 8.1500-8.6400, 8.6400-9.1300, and 9.1300-9.6300 um correspond to the third filter, and the bandwidth of the filter is 9.6300 um-8.1500 um=1480 nm.

[0072] The radiation powers of 8.6400-9.1300, 9.1300-9.6300, and 9.6300-10.1900 um correspond to the fourth filter, and the bandwidth of the filter is 10.1900 um-8.6400 um=1550 nm.

[0073] 9.1300-9.6300, 9.6300-10.1900 and 10.1900-10.8600 of the radiation power correspond to the fifth filter, the bandwidth of which is 10.8600um-9.1300um=1730nm;

[0074] 9.6300-10.1900, 10.1900-10.8600 and 10.8600-11.8500 of the radiation power correspond to the sixth filter, the bandwidth of which is 11.8500um-9.6300um=2220nm;

[0075] 10.1900-10.8600, 10.8600-11.8500 and 11.8500-14.0000 of the radiation power correspond to the seventh filter, the bandwidth of which is 14.0000um-10.1900um=3810nm;

[0076] 10.8600-11.8500 and 11.8500-14.0000 of the radiation power correspond to the eighth filter, the bandwidth of which is 14.0000um-10.8600um=3140nm;

[0077] 11.8500-14.0000 of the radiation power correspond to the ninth filter, the bandwidth of which is 14.0000um-11.8500um=2150nm.

[0078] Referring to Figure 7 , Mode Two:

[0079] 7.0000-7.6200, 7.6200-8.1500 and 8.1500-8.6400 of the radiation power correspond to the first filter, the bandwidth of which is 8.6400um-7.0000um=1640nm;

[0080] 7.6200-8.1500, 8.1500-8.6400 and 8.6400-9.1300 of the radiation power correspond to the second filter, the bandwidth of which is 9.1300um-7.6200um=1510nm;

[0081] 8.1500-8.6400, 8.6400-9.1300 and 9.1300-9.6300 of the radiation power correspond to the third filter, the bandwidth of which is 9.6300um-8.1500um=1480nm;

[0082] 8.6400~9.1300, 9.1300~9.6300 and 9.6300~10.1900 of the radiant power correspond to the fourth filter, the bandwidth of the filter is 10.1900um-8.6400um=1550nm;

[0083] 9.1300~9.6300, 9.6300~10.1900 and 10.1900~10.8600 of the radiant power correspond to the fifth filter, the bandwidth of the filter is 10.8600um-9.1300um=1730nm;

[0084] 9.6300~10.1900, 10.1900~10.8600 and 10.8600~11.8500 of the radiant power correspond to the sixth filter, the bandwidth of the filter is 11.8500um-9.6300um=2220nm;

[0085] 10.1900~10.8600, 10.8600~11.8500 and 11.8500~14.0000 of the radiant power correspond to the seventh filter, the bandwidth of the filter is 14.0000um-10.1900um=3810nm;

[0086] 10.8600~11.8500 and 11.8500~14.0000 of the radiant power correspond to the eighth filter, the bandwidth of the filter is 14.0000um-10.8600um=3140nm;

[0087] 10.1900~10.8600 and 10.8600~11.8500 of the radiant power correspond to the ninth filter, the bandwidth of the filter is 11.8500um-10.1900um=1660nm.

[0088] The above design ensures that the radiant power of each spectral channel can be obtained by mutually subtracting different filters, for example, the seventh spectral channel is (10.19um-14um) minus the eighth and ninth channels to obtain the radiant power of (10.19-10.86) and (11.85-14um) respectively. Further solving the radiant intensity corresponding to all independent spectral channels.

[0089] In general, the embodiment of the present application improves the design scheme of the current snapshot multi-spectral system filter, combines the advantages of the equal-bandwidth split-aperture and the rotating-wheel single-side difference filter design method, and realizes the design scheme of the split-aperture equal-radiance difference. Combined with the optical system and the system response, the equalization and high signal-to-noise ratio between the spectral channels can be realized.

[0090] High time resolution is realized by means of split-aperture, and high signal-to-noise ratio is realized by means of wideband filter to improve radiance. In addition, the radiance region is divided in equal radiance by combining the optical system transmittance in 7-14um and the response rate of the detector, so that the radiance received by each spectral channel is the same. The image has the advantages of multispectral, high signal-to-noise ratio and overall response, which greatly reduces the difficulty of image non-uniformity correction and ensures the balance between different spectral channels. In this case, the gain of the detector can be increased to avoid overexposure caused by excessive response of a local channel.

[0091] In summary, the design method of the snapshot multispectral imaging system filter of the embodiment of the application can provide theoretical support for the design of the filter of the multispectral imaging system. The bandwidth of the filter is adjusted through simulation calculation to make the response of each spectral channel basically the same, which ensures the real-time performance of the multispectral imaging system and has a good signal-to-noise ratio, and reduces the error between different channels. At the same time, the overall balance of the image is improved, so that the signal-to-noise ratio can be improved by increasing the gain of the detector.

[0092] Corresponding to the design method of the snapshot multispectral imaging system filter of the above embodiment, the application further provides a design device of a snapshot multispectral imaging system filter.

[0093] Figure 8 The structure block diagram of the design device of the snapshot multispectral imaging system filter of the embodiment of the application.

[0094] As shown in Figure 8 The design device of the snapshot multispectral imaging system filter includes a drawing module 10, a calculation module 20, a first determination module 30, a second determination module 40, a third determination module 50 and a design module 60.

[0095] The drawing module 10 is used to draw the radiation exitance curve of the target to be measured in the preset wavelength range considering the system response rate; the calculation module 20 is used to integrate the radiation exitance of the radiation exitance curve to obtain the radiation power; the first determination module 30 is used to determine the number of spectral channels; the second determination module 40 is used to determine the number of filters of the snapshot multispectral imaging system according to the number of spectral channels; the third determination module 50 is used to divide the radiation power according to the number of spectral channels, and determine the corresponding divided radiation power of each filter, wherein each divided radiation power has a different wavelength interval; and the design module 60 is used to design the bandwidth of the corresponding filter according to the wavelength interval of the divided radiation power.

[0096] It should be noted that the specific embodiments of the snapshot multispectral imaging system filter design device can refer to the specific embodiments of the snapshot multispectral imaging system filter design method described above, and to avoid redundancy, details will not be described here.

[0097] The snapshot multispectral imaging system filter design device of the embodiments of the present application can not only ensure the real-time performance of the system, but also improve the signal-to-noise ratio, reduce the obvious difference between images, improve the overall balance of the images, and thus improve the imaging effect.

[0098] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Although the embodiments of the present application have been shown and described above, it is understood that the above embodiments are exemplary and cannot be construed as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above embodiments within the scope of the present application.

Claims

1. A method for designing a filter for a snapshot multispectral imaging system, characterized in that, Includes the following steps: Plot the radiative exitance curve of the target under test within a preset wavelength range, taking into account the system response rate; The radiant power is obtained by integrating the radiant exitance of the radiant exitance curve. Determine the number of spectral channels; The number of filters for the snapshot multispectral imaging system is determined based on the number of spectral channels. The radiation power is divided equally according to the number of spectral channels, and the radiation power after equalization for each filter is determined, wherein each portion of the radiation power after equalization has a different wavelength range. The bandwidth of the corresponding filter is designed based on the wavelength range of the radiated power after equalization.

2. The method for designing a filter for a snapshot multispectral imaging system according to claim 1, characterized in that, The snapshot multispectral imaging system includes an optical system and a detector, and plots the radiant exitance curve of the target under test within a preset wavelength range, taking into account the system responsivity, including: The optical transmittance of the optical system and the spectral responsivity of the detector are detected within a preset wavelength range. Calculate the blackbody radiative exitance of the target under test within the preset wavelength range; Based on the optical transmittance of the optical system, the spectral responsivity of the detector, and the blackbody radiative exitance of the target under test, a radiative exitance curve of the target under test within a preset wavelength range is plotted, taking into account the system responsivity.

3. The method for designing a filter for a snapshot multispectral imaging system according to claim 2, characterized in that, Based on the optical transmittance of the optical system, the spectral responsivity of the detector, and the blackbody radiative exitance of the target under test, a radiative exitance curve of the target under test within a preset wavelength range, considering the system responsivity, is plotted, including: Calculate the system responsivity of the snapshot multispectral imaging system within the preset wavelength range based on the optical transmittance of the optical system and the spectral responsivity of the detector; Based on the blackbody radiative exitance and the system responsivity, a radiative exitance curve of the target under test within a preset wavelength range is plotted, taking into account the system responsivity.

4. The method for designing a filter for a snapshot multispectral imaging system according to claim 1, characterized in that, The radiant power is evenly distributed by dividing the area enclosed by the radiant exitance curve and the X-axis by a line perpendicular to the X-axis.

5. The method for designing a filter for a snapshot multispectral imaging system according to claim 1, characterized in that, Determining the radiant power after equalization for each of the filters includes: Determine at least one equalized portion of the radiant power of a wavelength range corresponding to each of the filters, wherein each equalized portion of the radiant power can be obtained by subtracting the bandwidths of different filters.

6. The method for designing a filter for a snapshot multispectral imaging system according to claim 5, characterized in that, The bandwidth of the corresponding filter is designed based on the wavelength range of the equally divided radiant power, including: Determine the overall wavelength range of the radiated power after equalization for each filter, and calculate the difference between the maximum and minimum values ​​of the overall wavelength range. Determine the bandwidth of the filter based on this difference.

7. The method for designing a filter for a snapshot multispectral imaging system according to claim 1, characterized in that, The preset wavelength range is 7µm-14µm.

8. A design device for a filter in a snapshot-type multispectral imaging system, characterized in that, include: The plotting module is used to plot the radiative exitance curve of the target under test within a preset wavelength range, taking into account the system response rate. The calculation module is used to integrate the radiant exitance of the radiant exitance curve to obtain the radiant power; The first determining module is used to determine the number of spectral channels; The second determining module is used to determine the number of filters in the snapshot multispectral imaging system based on the number of spectral channels; The third determining module is used to divide the radiation power equally according to the number of spectral channels and determine the equalized radiation power corresponding to each filter, wherein each equalized radiation power has a different wavelength range. The design module is used to design the bandwidth of the corresponding filter based on the wavelength range of the evenly distributed radiation power.

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