Method and device for designing optical filter of snapshot type multispectral imaging system

Abstract

The invention relates to the technical field of spectral imaging, and particularly provides a design method and device for an optical filter of a snapshot type multispectral imaging system, and the method comprises the steps: drawing a radiation exitance curve of a to-be-measured target in a preset wavelength range when the system response rate is considered; carrying out integral calculation on the radiation exitance of the radiation exitance curve to obtain radiation power; determining the number of spectrum channels; determining the number of optical filters of the snapshot type multispectral imaging system according to the number of the spectral channels; the radiation power is equally divided according to the number of the spectrum channels, the equally divided radiation power corresponding to each optical filter is determined, and each equally divided radiation power has different wavelength intervals; and designing the bandwidth of the corresponding optical filter according to the wavelength interval of the equally divided radiation power. Therefore, the real-time performance of the system can be ensured, the signal-to-noise ratio is improved, meanwhile, the obvious difference existing in the images can be reduced, the overall balance of the images is improved, and the imaging effect is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of spectral imaging, and particularly to a design method for a filter of a snapshot multi-spectral imaging system and a design device for a filter of a snapshot multi-spectral imaging system. Background Art

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

[0003] To solve the problem of how to design an optical filter to achieve the best detection effect, there are mainly two current techniques: The first method is to use broadband filters for split-aperture imaging; the second method is to use a filter wheel for differential multi-spectral imaging. Image differentiation is one of the most significant features of the spectral filtering infrared imaging mode. It uses two high-pass filters with different cut-off wavelengths for imaging respectively, and calculates the radiation difference image between the two cut-off wavelength differences from the differences between them.

[0004] The disadvantage of the first method is that it uses filters with equal bandwidth. Due to the optical lens of the system and the response rate of the detector, there may be obvious corresponding differences in the range of 7-14um. The response decreases after 11um, resulting in poor image signal-to-noise ratio and large response differences in 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 images in different channels.

[0005] The disadvantage of the second method, the wheel-type image differentiation, is that it cannot image multiple spectral channels simultaneously, and the real-time performance will be reduced. At the same time, the filter design mentioned above, which uses the same cut-off at one end and a gradient descent at the other end, will also result in different irradiances received by each spectral channel, leading to obvious response differences in the image.

[0006] Therefore, for the design of filters applicable to snapshot multi-spectral imaging systems, the related technologies have problems such as unbalanced channels, high signal-to-noise ratio, and obvious response differences in the image. Summary of the Invention

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

[0008] A design method for a filter of a snapshot multi-spectral imaging system according to an embodiment of the first aspect of the present invention includes the following steps: drawing a radiant emittance curve of a target to be measured within a preset wavelength range considering the system response rate; calculating the radiant power by integrating the radiant emittance of the radiant emittance curve; determining the number of spectral channels; determining the number of filters of the snapshot multi-spectral imaging system according to the number of spectral channels; equally dividing the radiant power according to the number of spectral channels, and determining the equally divided radiant power corresponding to each filter, wherein each equally divided radiant power has a different wavelength interval; designing the bandwidth of the corresponding filter according to the wavelength interval of the equally divided radiant power.

[0009] In addition, the design method for a filter of a snapshot multi-spectral imaging system according to the above embodiment of the present invention may further have the following additional technical features.

[0010] According to an embodiment of the present invention, the snapshot multi-spectral imaging system includes an optical system and a detector. Drawing a radiant emittance curve of a target to be measured within a preset wavelength range considering the system response rate includes: detecting the optical transmittance of the optical system and the spectral response rate of the detector within the preset wavelength range; calculating the blackbody radiant emittance of the target to be measured within the preset wavelength range; and drawing a radiant emittance curve of the target to be measured within 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 radiant emittance of the target to be measured.

[0011] According to an embodiment of the present invention, drawing a radiant emittance curve of a target to be measured within a 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 radiant emittance of the target to be measured includes: calculating the system response rate of the snapshot multi-spectral imaging system within the preset wavelength range according to the optical transmittance of the optical system and the spectral response rate of the detector; and drawing a radiant emittance curve of the target to be measured within the preset wavelength range considering the system response rate according to the blackbody radiant emittance and the system response rate.

[0012] According to an embodiment of the present invention, the equally dividing of the radiant power is achieved by equally dividing the area enclosed by the radiant emittance curve and the X-axis with a line perpendicular to the X-axis.

[0013] According to an embodiment of the present invention, determining the evenly divided radiation power corresponding to each of the filters includes: determining at least one portion of the evenly divided radiation power with continuous wavelength intervals corresponding to each of the filters, wherein each portion of the evenly divided radiation power can be obtained by taking the difference through the broadband of different filters.

[0014] According to an embodiment of the present invention, designing the bandwidth of the corresponding filter according to the wavelength interval of the evenly divided radiation power includes: determining the overall wavelength interval of the evenly 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 an embodiment of the present invention, the preset wavelength range is 7um - 14um.

[0016] An embodiment of the second aspect of the present invention provides a design device for a filter of a snapshot multi-spectral imaging system, including: a drawing module for drawing the radiant emittance curve of a target to be measured within a preset wavelength range considering the system response rate; a calculation module for integrally calculating the radiant emittance of the radiant emittance curve to obtain the radiation power; a first determination module for determining the number of spectral channels; a second determination module for determining the number of filters of the snapshot multi-spectral imaging system according to the number of spectral channels; a third determination module for evenly dividing the radiation power according to the number of spectral channels and determining the evenly divided radiation power corresponding to each filter, wherein each portion of the evenly divided radiation power has a different wavelength interval; and a design module for designing the bandwidth of the corresponding filter according to the wavelength interval of the evenly divided radiation power.

[0017] The technical solution of the embodiment of the present invention calculates the radiant emittance curve of the target to be measured considering the system response rate, evenly divides the radiation power based on this curve, and there is a corresponding relationship between the evenly divided radiation power and the filter, and designs the bandwidth of its corresponding filter according to the evenly divided radiation power. Thus, it can not only ensure the real-time performance of the system but also improve the signal-to-noise ratio, and at the same time reduce the obvious differences in the image, improve the overall balance of the image, and thus improve the imaging effect. Description of the Drawings

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

[0019] Figure 2 It is a flowchart of the design method of the filter of the snapshot multi-spectral imaging system according to the embodiment of the present invention.

[0020] Figure 3 It is a blackbody radiant emittance curve diagram of the target to be measured in a specific example of the present invention.

[0021] Figure 4 The curve graph of the system response rate of the optical system for a specific example of the present invention.

[0022] Figure 5 The radiant emittance curve graph of the target to be measured when considering the system response rate for a specific example of the present invention.

[0023] Figure 6 The schematic diagram of the table of the wavelength intervals of the radiant power corresponding to 9 filters respectively in Method 1 for a specific example of the present invention.

[0024] Figure 7 The schematic diagram of the table of the wavelength intervals of the radiant power corresponding to 9 filters respectively in Method 2 for a specific example of the present invention.

[0025] Figure 8 The structural block diagram of the filter design device of the snapshot multi - spectral imaging system according to the embodiment of the present invention. Detailed implementation manners

[0026] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0027] Figure 1 The structural schematic diagram of the snapshot multi - spectral imaging system in the related art.

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

[0029] In order to design each filter in the filter array 14, achieve the equalization between each spectral channel and a high signal - to - noise ratio, and improve the optical imaging effect, the embodiment of the present invention proposes a design method for the filter of the snapshot multi - spectral imaging system.

[0030] Figure 2 The flowchart of the design method for the filter of the snapshot multi - spectral imaging system according to the embodiment of the present invention.

[0031] As Figure 2 shown, the design method for the filter of the snapshot multi - spectral imaging system includes the following steps S1 to S6.

[0032] S1. Plot the radiant emittance curve of the target to be measured within a preset wavelength range considering the system response rate.

[0033] Among them, the system response rate refers to the optical response rate of the snapshot multi-spectral imaging system.

[0034] Among them, the preset wavelength range can be 7um - 14um.

[0035] Specifically, first calculate the system response rate, and based on it, calculate the radiant emittance of the target to be measured within the range of 7 - 14um, and plot the radiant emittance curve of the target to be measured in a coordinate system with the wavelength as the X-axis and the radiant emittance as the Y-axis.

[0036] S2. Perform integral calculation on the radiant emittance of the radiant emittance curve to obtain the radiant power.

[0037] S3. Determine the number of spectral channels.

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

[0039] S4. Determine the number of filters of the snapshot multi-spectral imaging system according to the number of spectral channels.

[0040] Specifically, the filters correspond one-to-one with the spectral channels, so the number of filters is the same as the number of spectral channels.

[0041] S5. Divide the radiant power evenly according to the number of spectral channels, and determine the evenly divided radiant power corresponding to each filter, where each portion of the evenly divided radiant power has a different wavelength interval.

[0042] Furthermore, the even division of the radiant power is achieved by evenly dividing the area enclosed by the radiant emittance curve and the X-axis with a line perpendicular to the X-axis.

[0043] Specifically, the area enclosed by the radiant emittance curve and the X-axis constitutes the radiant emittance region. For the radiant emittance curve, the radiant power of the radiant emittance region is evenly divided with a line perpendicular to the X-axis, so as to evenly divide the radiant power into the number of spectral channel portions. Therefore, each portion of the evenly divided radiant power has a corresponding wavelength interval, and the wavelength intervals are different from each other.

[0044] Then, in order to ensure sufficient energy acquisition and energy balance between different spectral channels, determine at least one portion of the evenly divided radiant power corresponding to each filter according to the imaging requirements, which may correspond to one portion, two portions, three portions, etc. of the evenly divided radiant power, and is specifically determined according to the actual requirements.

[0045] S6. Design the bandwidth of the corresponding filter according to the wavelength interval of the evenly divided radiant power.

[0046] Specifically, each divided radiation power corresponds to a wavelength range, and at least one divided radiation power corresponds to a filter. Therefore, for each filter, its bandwidth can be calculated according to the wavelength range of the divided radiation power corresponding to it.

[0047] For example, when a certain filter corresponds to a divided radiation power, the difference in the wavelength range of this radiation power is the bandwidth of this filter; when a certain filter corresponds to three consecutive divided radiation powers, the difference in the overall wavelength range of the three radiation powers is the bandwidth of this filter.

[0048] The design method of the filter of the snapshot multi-spectral imaging system according to the embodiment of the present invention calculates the radiant emittance curve of the target to be measured considering the system response rate, divides the radiation power on the basis of this curve, and there is a corresponding relationship between the divided radiation power and the filter, and designs the bandwidth of the corresponding filter according to the divided radiation power.

[0049] Thereby, both the real-time performance of the system can be ensured and the signal-to-noise ratio can be improved. At the same time, the obvious differences in the image can be reduced, the overall balance of the image can be improved, and thus the imaging effect can be improved.

[0050] In one embodiment, step S1 may include: detecting the optical transmittance of the optical system and the spectral response rate of the detector within a preset wavelength range; calculating the blackbody radiant emittance of the target to be measured within the preset wavelength range; and drawing the radiant emittance curve of the target to be measured within 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 radiant emittance of the target to be measured.

[0051] Further, drawing the radiant emittance curve of the target to be measured within 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 radiant emittance of the target to be measured may include: calculating the system response rate of the snapshot multi-spectral imaging system within the preset wavelength range according to the optical transmittance of the optical system and the spectral response rate of the detector; and drawing the radiant emittance curve of the target to be measured within the preset wavelength range considering the system response rate according to the blackbody radiant emittance and the system response rate.

[0052] Specifically, first, detect the optical transmittance of the optical system 1 within the preset wavelength range of 7 - 14 μm, specifically including the optical transmittance of the telescopic objective 11, the field stop 12, the relay collimator 13, the filter array 14, and the microlens array 15, and detect the spectral responsivity of the detector 2 within 7 - 14 μm. Calculate the blackbody radiant emittance of the target to be measured within 7 - 14 μm, and plot the blackbody radiant emittance curve of the target to be measured (the X-axis is the wavelength 7 - 14 μm, and the Y-axis is the blackbody radiant emittance). Then, according to the optical transmittance of the optical system 1 and the spectral responsivity of the detector 2 within 7 - 14 μm, calculate the system responsivity of the snapshot multispectral imaging system within the preset wavelength range of 7 - 14 μm, and plot the system responsivity curve based on it (the X-axis is the wavelength 7 - 14 μm, and the Y-axis is the system responsivity). Finally, based on the product of the blackbody radiance curve and the system responsivity curve, plot the radiant emittance curve, which is the radiant emittance curve of the target to be measured within the preset wavelength range of 7 - 14 μm (the X-axis is the wavelength 7 - 14 μm, and the Y-axis is the radiant emittance).

[0053] Integrate the radiant emittance of the radiant emittance curve to obtain the radiant power, and then evenly divide the radiant power into the number of spectral channels (i.e., the number of filters).

[0054] In one embodiment, the even division of the radiant power is achieved by evenly dividing the area enclosed by the radiant emittance curve and the X-axis with a line perpendicular to the X-axis.

[0055] Specifically, the area enclosed by the radiant emittance curve and the X-axis is the radiant emittance region. The radiant emittance region is evenly divided into the number of spectral channels by a line perpendicular to the X-axis to obtain multiple evenly divided radiant powers. Each evenly divided radiant power corresponds to a wavelength interval. At this time, the radiant power within each interval range is the same, and the corresponding range of the presented image is also basically the same. Among them, the number of spectral channels, the number of evenly divided radiant power portions, and the number of filters are all the same. Then, determine the evenly divided radiant power corresponding to each filter.

[0056] In one embodiment, determining the evenly divided radiant power corresponding to each filter in step S5 may include: determining at least one portion of the evenly divided radiant power with continuous wavelength intervals corresponding to each filter, where each evenly divided radiant power can be obtained by taking the difference through the broadband of different filters.

[0057] Specifically, in order to obtain sufficient energy while ensuring energy balance between different spectral channels, each filter corresponds to one or more equally divided radiation powers. Among them, the overall wavelengths of multiple equally divided radiation powers are continuous. When designing the bandwidth of the filter, the correspondence between the filter and the equally divided radiation power only needs to meet the following conditions: Each equally divided radiation power can be obtained by taking the difference between the broadband of different filters, that is, the radiation power of each spectral channel can be obtained by taking the difference between the bandwidths of different filters.

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

[0059] After that, step S5 is executed, that is, the bandwidth of the corresponding filter is designed according to the wavelength range of the equally divided radiation power.

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

[0061] Specifically, for each filter, when it corresponds to one equally divided radiation power, calculate the difference between the maximum value and the minimum value of the wavelength range of the radiation power, which is the bandwidth of the filter; when it corresponds to multiple consecutive equally divided radiation powers, calculate the difference between the maximum value and the minimum value of the corresponding overall wavelength range, which is the bandwidth of the filter.

[0062] Thus, by equally dividing the radiation power, it is achieved that the radiation power is increased by increasing the bandwidth of the filter in the wavelength range where the system responsivity is weak, ensuring the balance between different spectral channels.

[0063] The following uses a specific example in conjunction with the drawings to illustrate the design method of the filter of the snapshot multi-spectral imaging system according to the embodiment of the present invention.

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

[0065] First, detect and plot Figure 3 the blackbody radiance curve of the target to be measured shown in the figure in the range of 7 - 14 μm, and Figure 4 the system responsivity curve of the optical system shown in the figure in the range of 7 - 14 μm.

[0066] Then, calculate the product of the blackbody radiant emittance curve and the system responsivity curve, and draw the Figure 5 radiant emittance curve of the target to be measured in the range of 7-14um as shown, and through Figure 5 the vertical dotted line shown, divide the area enclosed by this curve and the X-axis into 9 equal parts to obtain the radiant power after 9 equal divisions, as Figure 6 and Figure 7 shown. The wavelength ranges of the radiant power after each equal division 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, 11.8500~14.0000, with the unit of um.

[0067] Further design the corresponding relationship between the radiant power of each part of each filter and the bandwidth of the filter. When designing, it should be ensured that the radiance power of each spectral channel can be obtained by taking the difference between different filters. For example, two methods can be designed at this time:

[0068] Referring to Figure 6 , Method 1:

[0069] The radiant power of 7.0000~7.6200, 7.6200~8.1500 and 8.1500~8.6400 corresponds to the first filter, and the bandwidth of this filter is 8.6400um - 7.0000um = 1640nm;

[0070] The radiant power of 7.6200~8.1500, 8.1500~8.6400 and 8.6400~9.1300 corresponds to the second filter, and the bandwidth of this filter is 9.1300um - 7.6200um = 1510nm;

[0071] The radiant power of 8.1500~8.6400, 8.6400~9.1300 and 9.1300~9.6300 corresponds to the third filter, and the bandwidth of this filter is 9.6300um - 8.1500um = 1480nm;

[0072] The radiant power of 8.6400~9.1300, 9.1300~9.6300 and 9.6300~10.1900 corresponds to the fourth filter, and the bandwidth of this filter is 10.1900um - 8.6400um = 1550nm;

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

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

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

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

[0077] The radiation power of 11.8500 - 14.0000 corresponds to the ninth filter, and the bandwidth of this filter is 14.0000um - 11.8500um = 2150nm.

[0078] Refer to Figure 7 Method 2:

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

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

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

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

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

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

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

[0086] The radiation power of 10.8600~11.8500 and 11.8500~14.0000 corresponds to the eighth filter, and the bandwidth of this filter is 14.0000um - 10.8600um = 3140nm;

[0087] The radiation power of 10.1900~10.8600 and 10.8600~11.8500 corresponds to the ninth filter, and the bandwidth of this filter is 11.8500um - 10.1900um = 1660nm.

[0088] The above design ensures that the radiance power of each spectral channel can be obtained by taking the difference between different filters. For example, the seventh spectral channel is (10.19um - 14um), and subtracting the eighth and ninth channels can obtain the radiation power of (10.19 - 10.86) and (11.85 - 14um) respectively. Further, the radiance corresponding to all independent spectral channels is solved.

[0089] Generally speaking, the embodiment of the present invention improves the design scheme of the filter of the current snapshot multi - spectral system, combines the advantages of the equal - bandwidth sub - aperture and the rotating - wheel single - side differential filter design methods, and realizes the design scheme of sub - aperture equal - radiance difference. Combining with the optical system and system response, the equalization between spectral channels and high signal - to - noise ratio can be achieved.

[0090] High time resolution is achieved through the sub-aperture method, and a broadband filter is used to improve the radiance to achieve a high signal-to-noise ratio. In combination with the transmittance of the optical system in the 7-14um range and the responsivity of the detector, the radiance region is divided into equal radiance levels, ensuring that the radiance received by each spectral channel is the same. The image has the advantages of multi-spectral, high signal-to-noise ratio, and overall identical response. This significantly 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 overly strong response in a local channel.

[0091] In summary, the design method of the filter for the snapshot multi-spectral imaging system according to the embodiments of the present invention can provide theoretical support for the filter design of this type of multi-spectral imaging system. By adjusting the filter bandwidth through simulation calculations to make the responses of each spectral channel basically the same, it not only ensures the real-time performance of the multi-spectral imaging system but also has a good signal-to-noise ratio, and reduces errors for subsequent differences between different channels. At the same time, it improves the overall balance of the image, facilitating the improvement of the signal-to-noise ratio by increasing the gain of the detector.

[0092] Corresponding to the design method of the filter for the snapshot multi-spectral imaging system in the above embodiments, the present invention also proposes a design device for the filter of the snapshot multi-spectral imaging system.

[0093] Figure 8 It is a structural block diagram of the design device for the filter of the snapshot multi-spectral imaging system according to the embodiments of the present invention.

[0094] As Figure 8 shown, the design device for the filter of the snapshot multi-spectral imaging system 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 radiant emittance curve of the target to be measured within a preset wavelength range considering the system responsivity; the calculation module 20 is used to perform integral calculation on the radiant emittance of the radiant emittance curve to obtain the radiant 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 multi-spectral imaging system according to the number of spectral channels; the third determination module 50 is used to equally divide the radiant power according to the number of spectral channels and determine the equally divided radiant power corresponding to each filter, where each portion of the equally divided radiant power has a different wavelength interval; the design module 60 is used to design the bandwidth of the corresponding filter according to the wavelength interval of the equally divided radiant power.

[0096] It should be noted that for the specific implementation of the filter design device of the snapshot multi-spectral imaging system, reference can be made to the specific implementation of the filter design method of the snapshot multi-spectral imaging system above. To avoid redundancy, it will not be elaborated in detail here.

[0097] The filter design device of the snapshot multi-spectral imaging system according to the embodiment of the present invention can not only ensure the real-time performance of the system but also improve the signal-to-noise ratio. At the same time, it can reduce the obvious differences in the image and improve the overall balance of the image, thereby improving the imaging effect.

[0098] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for designing a filter for a snapshot multispectral imaging system, characterized in that: The following steps are involved: Draw the radiant emittance curve of the target to be measured within the preset wavelength range when considering the system response rate; Integrating the radiation emittance of the radiation emittance curve to obtain radiation power; Determine the number of spectral channels; Determining the number of filters of the snapshot multi-spectral imaging system according to the number of spectral channels; The radiation power is evenly divided according to the number of spectral channels, and the evenly divided radiation power corresponding to each filter is determined, wherein each evenly divided radiation power has a different wavelength range; The bandwidth of the corresponding filter is designed according to the wavelength range of the equally divided radiation power.

2. The method for designing a filter for a snapshot multispectral imaging system according to claim 1, characterized in that: The snapshot multi-spectral imaging system includes an optical system and a detector, and draws a radiation emittance curve of a target to be measured within a preset wavelength range when considering the system response rate, including: detecting the optical transmittance of the optical system and the spectral response rate of the detector within a preset wavelength range; Calculate the blackbody radiation emittance of the target to be measured within the preset wavelength range; According to the optical transmittance of the optical system, the spectral response rate of the detector and the black body radiation emittance of the target to be measured, a radiation emittance curve of the target to be measured within a preset wavelength range is plotted when the system response rate is taken into account.

3. The method for designing a filter for a snapshot multispectral imaging system according to claim 2, characterized in that: According to the optical transmittance of the optical system, the spectral response rate of the detector and the black body radiation emittance of the target to be measured, a radiation emittance curve of the target to be measured within a preset wavelength range is drawn when the system response rate is considered, including: Calculating the system response rate of the snapshot multi-spectral imaging system within the preset wavelength range according to the optical transmittance of the optical system and the spectral response rate of the detector; According to the black body radiation emittance and the system response rate, a radiation emittance curve of the target to be measured within a preset wavelength range is plotted when the system response rate is taken into account.

4. The method for designing a filter for a snapshot multispectral imaging system according to claim 1, characterized in that: The radiation power is evenly divided by evenly dividing the area enclosed by the radiation emittance curve and the X-axis through 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 averaged radiation power corresponding to each filter includes: Determine at least one portion of continuous averaged radiation power of the wavelength interval corresponding to each filter, wherein each portion of the averaged radiation power can be obtained by subtracting the broadbands of different filters.

6. The method for designing a filter for a snapshot multispectral imaging system according to claim 5, characterized in that: Designing the bandwidth of the corresponding filter according to the wavelength range of the equally divided radiation power includes: The overall wavelength range of the averaged radiation power corresponding to each filter is determined, and the difference between the maximum value and the minimum value of the overall wavelength range is calculated, and the bandwidth of the filter is determined according to the 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 7um-14um.

8. A design device for a snapshot multispectral imaging system filter, characterized in that: include: A drawing module, used for drawing a radiation emittance curve of a target to be measured within a preset wavelength range when considering the system response rate; A calculation module, used for integrating the radiation emittance of the radiation emittance curve to obtain radiation power; A first determination module, used to determine the number of spectral channels; A second determination module is used to determine the number of filters of the snapshot multi-spectral imaging system according to the number of spectral channels; A third determination module is used to divide the radiation power equally according to the number of spectral channels, and determine the equally divided radiation power corresponding to each filter, wherein each equally divided radiation power has a different wavelength range; The design module is used to design the bandwidth of the corresponding filter according to the wavelength range of the equally divided radiation power.

Images