Data correction method and device of micro-nano structure spectrum camera

Abstract

The invention discloses a data correction method and device for a micro-nano structure spectrum camera, and relates to the technical field of spectrum imaging. The method comprises the following steps: symmetrically and equally dividing a half field angle of a spectrum camera into a plurality of angle sub-regions along a main optical axis direction, wherein the angle sub-regions respectively correspond to different incident angle ranges; preprocessing the original spectral data; dividing line pixels of the same wavelength band in the imaging sensor according to angle sub-regions, and establishing a mapping relation with an incident angle; a micro-nano structure optical filter matched with the incident angle range of each row of pixels is configured for each row of pixels; and selecting the pixel data of which the incidence angle accords with the response range of the optical filter, splicing the pixel data according to a row sequence, generating a correction spectrum and outputting a full-wave band correction result. Full-band spectral data correction with high consistency, high precision and spatial continuity is realized by constructing pixel partitioning based on incident angle mapping, matching micro-nano structure optical filter configuration and an angle dominant data splicing strategy.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of spectral imaging, in particular to a data correction method and device for a micro-nano structure spectral camera. BACKGROUND

[0002] A spectral camera is a camera that can capture different spectral information at the same time. It can provide more abundant and accurate image data than traditional single-band cameras, so it is widely used in remote sensing, medical imaging, agricultural monitoring and other fields. Spectral cameras usually use multiple filters to achieve selective filtering of different wavebands. Micro-nano structure filters (such as photonic crystals, super surfaces, etc.) are widely used in spectral cameras because they are smaller in size and can provide higher spectral resolution. However, the performance of micro-nano structure filters is sensitive to the angle of incident light. In theory, the incident light in the optical path design of the spectral camera should be parallel light. However, in actual application, due to the existence of the camera's field of view angle, the angle of the incident light will change, especially in the case of a large field of view angle, the incident angle of the light deviates greatly from the parallel light assumption. This change in angle will cause the transmittance and spectral selectivity of the micro-nano structure filter to deviate, thereby affecting the imaging effect.

[0003] Although some micro-nano structure filters currently consider angle dependence by optimizing different incident angle ranges to correct the effects of angle, because the incident angles of light received by each pixel on the CCD or CMOS sensor are different, even if the filter is optimized for a specific incident angle, it cannot provide ideal transmittance in all pixels. Especially in a large field of view angle, a single angle correction cannot meet the needs of different pixels for light of different incident angles. The existing angle correction method is difficult to fully adapt to the angle changes of all pixels, especially when the field of view angle is large or the imaging resolution is high. Therefore, a new data correction method for micro-nano structure spectral cameras is needed. SUMMARY

[0004] Based on the above-mentioned shortcomings of the prior art, the purpose of the present application is to provide a data correction method and device for a micro-nano structure spectral camera to solve the above technical problems.

[0005] To achieve the above-mentioned purpose, the present application provides the following technical solution: a data correction method for a micro-nano structure spectral camera, comprising: symmetrically dividing the half field of view angle of the spectral camera along the main optical axis into a preset number of angle sub-regions, each angle sub-region corresponding to a different incident angle range; preprocessing the obtained original spectral data; Divide multiple row pixels corresponding to the same wavelength band in the imaging sensor into angular sub-regions, so that each angular sub-region corresponds to a group of row pixels, and establish a mapping relationship between the row pixels and the incident angle; In the multiple rows of pixels corresponding to each wavelength band, micro-nanostructure filters adapted to different incident angle ranges are respectively configured, so that the angular response range of the filter configured for each row of pixels matches the incident angle range of its corresponding angular sub-region; Selecting pixel data whose incident angle falls within the angular response range of the configured micro-nanostructure filter from among the multiple rows of pixels corresponding to each wavelength band; The selected pixel data are spliced ​​in row order to generate the corrected spectral data of the wavelength band, and the full-band spectral correction results are output.

[0006] The present invention further provides that the angular width of the angular sub-region satisfy , is the angular width, Half field of view, To divide the parameters, the dividing step includes: The number of each angle sub-area is symmetrical with the main optical axis, and the angular width of the angle sub-area is Number them as integer multiples of ; Map the pixel rows corresponding to each band on the imaging sensor according to the numbering order of the angular sub-regions, so that the incident angle received by each pixel segment is the same as the incident angle range of the corresponding angular sub-region; The incident angle range is determined by the angular width of the angular sub-region. and half field of view Decide.

[0007] The present invention is further configured such that the preprocessing includes performing a dark background value subtraction process on each pixel in the acquired original spectral data; The pixel signal intensity is standardized according to the standard white plate reflectance calibration, and the original signal intensity is converted into a relative spectral response value; The normalization coefficient used in the normalization process is determined based on a reference response value under irradiation with a standard light source.

[0008] The present invention is further configured such that the micro-nanostructured optical filter is a microstructured device having a directionally selective response characteristic. The types of micro-nanostructured optical filters include photonic crystal filters, subwavelength structured filters, and metasurface filters, and have the following characteristics: The micro-nanostructure filters arranged in different rows in the same wavelength band have the same structural center wavelength and correspond to different incident angle response windows; The micro-nano structure filter has maximum transmittance within a design incident angle range, and a central wavelength shift less than a preset allowable deviation value.

[0009] The application further provides that, in the process of selecting the pixel data, only pixel data whose incident angle falls within the design angle boundary of the micro-nano structure filter configured by the row of pixels is selected, the minimum incident angle and the maximum incident angle of the design angle boundary being the same as the incident angle range of the angle sub-region mapped by the row of pixels.

[0010] The application further provides that, in the process of selecting the pixel data, only pixel data whose incident angle falls within the design angle boundary of the micro-nano structure filter configured by the row of pixels is selected, the minimum incident angle and the maximum incident angle of the design angle boundary being the same as the incident angle range of the angle sub-region mapped by the row of pixels.

[0011] The application further provides that, the division parameters of the angle sub-region are The angle sub-region is set according to the required angle resolution and the incident angle response characteristics of the filter, and satisfies: wherein, is the maximum allowed incident angle of the micro-nano structure filter.

[0012] The application further provides that, the imaging sensor is a CMOS sensor or a CCD sensor, and the relationship between the pixel size and the focal length satisfies: wherein, is the size of a single pixel of the sensor, is the focal length, is the preset minimum angle sub-region width.

[0013] The application further provides a data correction device of a micro-nano structure spectral camera, the device comprising: a field of view division module: used for dividing the half field of view angle of the spectral camera into a preset number of angle sub-regions along the direction of the principal axis, each angle sub-region corresponding to a different incident angle range; a spectral preprocessing module: used for preprocessing the obtained original spectral data; a pixel mapping module: used for dividing a plurality of row pixels corresponding to the same wavelength segment in the imaging sensor according to the angle sub-regions, so that each angle sub-region corresponds to a group of row pixels, and a mapping relationship between the row pixels and the incident angles is established; a filter configuration module: used for configuring a micro-nano structure filter adapted to different incident angle ranges in the plurality of row pixels corresponding to each wavelength segment, so that the angle response range of the filter configured by each row pixel matches the incident angle range of the corresponding angle sub-region; a pixel screening module: used for selecting pixel data whose incident angle falls within the angle response range of the configured micro-nano structure filter in the plurality of row pixels corresponding to each wavelength segment; The spectral splicing module is used for splicing the selected pixel data in sequence, generating corrected spectral data of the wavelength segment, and outputting the full-wavelength spectral correction result.

[0014] The present application provides a kind of micro-nano structure spectral camera data correction method and device, the method is by the half field angle of spectral camera along the main optical axis direction symmetry equal division is divided into the angle subzone of pre-set quantity, each angle subzone corresponds to a different incident angle range;The original spectral data obtained is preprocessed;The multiple row pixels corresponding to the same wavelength segment in imaging sensor are divided according to angle subzone, so that each angle subzone corresponds to a group of row pixels, the mapping relationship between row pixel and incident angle is established;In the multiple row pixels corresponding to each wavelength segment, respectively configure micro-nano structure filter piece suitable for different incident angle range, so that the angle response range of the filter piece configured for each row pixel matches the incident angle range of its corresponding angle subzone;In the multiple row pixels corresponding to each wavelength segment, select the pixel data whose incident angle falls in the angle response range of the configured micro-nano structure filter piece;The selected pixel data is spliced in sequence, to generate the corrected spectral data of the wavelength segment, and output the full-wavelength spectral correction result, the beneficial effects include: 1, realize the accurate pixel partitioning based on incident angle mapping: by the half field angle along the main optical axis direction equal division is divided into multiple angle subzone, and establishes the one-to-one mapping relationship with row pixel, so that each pixel corresponds to a definite incident angle range, provides geometric basis for filter response characteristic matching; 2, matching filter configuration: configure micro-nano structure filter piece with different incident angle response window on the row pixel corresponding to different angle subzone, so that the structure center wavelength remains unchanged, under the premise of keeping high transmissivity for different angle regions, improve the overall spectral consistency; 3, angle-guided splicing strategy: according to the arrangement order of row pixel in field of view, splicing the effective data in each angle subzone, ensure that the reconstructed spectral data is spatially continuous and physically consistent, which helps to build the real scene spectral graph for full wavelength.

[0015] The above description is only a summary of the technical scheme of the present application, in order to more clearly understand the technical means of the present application, which can be implemented according to the content of the specification, and in order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the following specific embodiments of the present application are described. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creating any creative labor. In the drawings: Figure 1 A flow chart of a data correction method of a micro-nano structure spectral camera according to an exemplary embodiment of the present application is shown in the figure; Figure 2 A structural schematic diagram of a data correction device of a micro-nano structure spectral camera according to an exemplary embodiment of the present application is shown in the figure. DETAILED DESCRIPTION

[0017] The advantages and effects of the present application can be easily understood by those skilled in the art from the description disclosed in the present specification. The present application can also be implemented or applied in other different specific embodiments, and the details in the present specification can be modified or changed in various ways based on different views and applications without departing from the spirit of the present application. It should be understood that the preferred embodiments are only for illustrating the present application, but not for limiting the protection scope of the present application.

[0018] It should be noted that the diagrams provided in the following embodiments only schematically illustrate the basic concept of the present application, and only the components related to the present application are shown in the diagrams, but not drawn according to the number, shape and size of the components in actual implementation. The type, number and proportion of each component in actual implementation can be arbitrarily changed, and the layout type of the components can also be more complex.

[0019] In the following description, a large number of details are discussed to provide a more thorough explanation of the embodiments of the present application, however, it is obvious for those skilled in the art that the embodiments of the present application can be implemented without these specific details, and in other embodiments, the known structures and devices are shown in the form of block diagrams instead of details, to avoid making the embodiments of the present application difficult to understand. EMBODIMENTS

[0020] A data correction method of a micro-nano structure spectral camera, as shown in the figure, comprises: Figure 1 symmetrically dividing the half field angle of the spectral camera along the main optical axis direction into a preset number of angle sub-zones, each angle sub-zone corresponding to a different incident angle range; preprocessing the obtained original spectral data; dividing the plurality of row pixels corresponding to the same wavelength segment in the imaging sensor according to the angle sub-zone, so that each angle sub-zone corresponds to a group of row pixels, and a mapping relationship between the row pixels and the incident angle is established; configuring the micro-nano structure filter adapted to different incident angle ranges in the plurality of row pixels corresponding to each wavelength segment, so that the angle response range of the filter configured for each row pixel matches the incident angle range of the corresponding angle sub-zone; ​In the multiple row image elements corresponding to each wavelength segment, image element data whose incident angle falls within the angle response range of the configured micro-nano structure filter is selected; The selected image element data is spliced in row order to generate the corrected spectral data of the wavelength segment, and the full-wavelength spectral correction result is output.

[0021] The present application further provides that the angle width of the angle sub-zone satisfies , is the angle width of the angle sub-zone, is the half field of view angle, is the division parameter, and the division step comprises: The number of each angle sub-zone is numbered in integer multiples of the angle width of the angle sub-zone with the main optical axis as the center of symmetry; The image element rows corresponding to each wavelength segment on the imaging sensor are mapped in the number order of the angle sub-zone, so that the incident angle received by each image element segment and the incident angle range of the corresponding angle sub-zone are the same; The incident angle range is determined by the angle width of the angle sub-zone and the half field of view angle ; specifically, in the embodiment, the half field of view angle of the spectral camera is symmetrically divided into a preset number of angle sub-zones along the direction of the main optical axis, the division parameter is , and then angle sub-zones are formed, and the angle width of each angle sub-zone satisfies ; each angle sub-zone is arranged in order from the center of the field of view to both sides with the main optical axis as the center of symmetry, such as , for the multiple row image elements corresponding to the same wavelength segment in the imaging sensor, the multiple row image elements are divided into a plurality of groups in the direction perpendicular to the main optical axis, each group of image elements corresponds to an angle sub-zone, and a mapping relationship between the row image elements and the incident angle is established, so that the incident angle range received by each group of image elements corresponds to the angle width of the corresponding angle sub-zone and the angle interval determined by the number, and through the mapping relationship, the row image elements at different field of view positions correspond to different incident light angles, which provides a basis for the angle response matching of the micro-nano structure filter and the angle compensation of the spectral data; the angle division and mapping mode ensures that the incident angle range can be accurately corresponded in the correction process, thereby improving the consistency and correction accuracy of the spectral response.

[0022] The present application further provides that the preprocessing comprises dark background value deduction processing on each image element in the obtained original spectral data; The image element signal intensity is standardized according to the standard whiteboard reflectivity calibration, and the original signal intensity is converted into a relative spectral response value; ​The standardization coefficient used in the standardization processing is determined based on a reference response value under illumination of a standard light source; specifically, in the embodiment, to ensure that the original spectral data collected by the micro-nano structure spectral camera has high spectral consistency and physical effectiveness, the original signal of each pixel is pre-processed, and the pre-processing step includes dark background value deduction processing and standardization processing; the dark background value deduction processing step is as follows: dark field collection is performed under the condition that the camera is completely shielded from light, and the signal output value of each pixel under the condition of no incident light is recorded as the device background noise; for any pixel, the original signal obtained by the pixel during normal collection is denoted as The dark background value measured under the dark field condition is denoted as The calculation logic of the dark background value deduction result of the pixel is as follows: The effective signal intensity after deduction of the dark background value is the pixel data after deduction of the dark background value, is the spatial position of the pixel on the two-dimensional imaging array, is the wavelength dimension; the dark background value deduction processing can eliminate the baseline interference caused by device thermal noise and circuit bias, and improve the accuracy of subsequent standardization; a standard diffuse white board is used as a reference reflecting surface, for example, a polytetrafluoroethylene (PTFE) material, under the condition of a uniform standard light source, the reference response value of the spectral camera at each pixel is collected wavelength by wavelength The standardization coefficient is defined based on the reference response value, and the calculation logic of the standardization coefficient is as follows: is the standardization coefficient, indicating the relative sensitivity correction factor of the pixel at the wavelength , which is used to compensate for the response non-uniformity of the system optical channel and the filter at different wavebands; is the reference reflecting surface calibration value; the pixel data after deduction of the dark background value and the standardization coefficient are normalized waveband by waveband to obtain the relative spectral response value, and the calculation logic of the relative spectral response value is as follows: is the relative spectral response value; through the above processing, the spectral response error caused by factors such as filter angle sensitivity, imaging system optical error, and pixel sensitivity difference can be effectively eliminated, and a unified spectral response reference of different pixels at different wavelengths is ensured.

[0023] The application further provides that the micro-nano structure filter is a micro-structure device with direction-selective response characteristics, and the type of the micro-nano structure filter includes a photonic crystal filter, a sub-wavelength structure filter, and a super surface filter, and has the following characteristics: The micro-nano structure filters of different rows arranged in the same waveband have the same structural center wavelength and correspond to different incident angle response windows, respectively; The micro-nano structure filter has maximum transmittance in its design incident angle range, and the central wavelength shift is less than a preset allowable deviation value; specifically, in the embodiment, the micro-nano structure filter adopts a periodic nano pattern structure or a metasurface configuration to realize selective transmission of light signals of specific wavelengths and specific incident angles, thereby having a direction-selective response characteristic; the filter types include but are not limited to photonic crystal filters, sub-wavelength structure filters and metasurface filters, and each type of filter can realize the required angle-selective transmission characteristic by adjusting its structure parameters, such as period, layer thickness, refractive index gradient or surface microstructure geometry; in actual application, for each specific waveband row of image elements, although the configured filter has a uniform central wavelength design, due to different angle response ranges at different incident angles, the incident light of different angle sub-regions is selectively transmitted; the application configures micro-nano structure filters with the same central wavelength but different incident angle response windows on each row of image elements in the imaging sensor, so that these filters can realize maximum transmittance in their design angle range, ensuring that the light signals in a specific angle range accurately enter the corresponding image elements; further, to ensure the accuracy of spectral correction, the central wavelength shift of the micro-nano structure filter is controlled within its design incident angle change range, and the shift value does not exceed the preset allowable deviation value; for example, for a filter with a central wavelength of 550 nm, the central wavelength shift within an angle change range of 0-60 degrees needs to meet . The central wavelength shift of the filter within an angle change range of 0-60 degrees needs to meet . , wherein is a preset allowable deviation value according to the spectral resolution requirement of the device; the above design ensures that each filter is sensitive only to light in a specified waveband and a specific incident angle range, avoids interference between different angles, and improves the reliability of angle correction and the accuracy of spectral restoration.

[0024] The application is further configured that in the process of selecting the pixel data, only the pixel data with the incident angle falling within the design angle boundary of the micro-nano structure filter configured by the row of pixels is selected, the minimum incident angle and the maximum incident angle of the design angle boundary are the same as the incident angle range of the angle sub-region mapped by the row of pixels; specifically, in the implementation process, the incident angle of each row of pixels in the imaging sensor is accurately calculated to determine whether the incident angle of the light received by the pixel falls within the design angle boundary of the micro-nano structure filter configured by the pixel; the design angle boundary is composed of the minimum incident angle and the maximum incident angle, and is consistent with the incident angle range of the angle sub-region mapped by the row of pixels, only the pixel data meeting the condition is retained, and the pixel data exceeding the response range of the filter is removed, so as to ensure that the selected data has the best filter transmission performance and spectral response accuracy; the design angle boundary refers to the optical performance boundary of the micro-nano structure filter optimized for a specific incident angle range; through the above screening step, the effective compensation of the incident angle difference at different field positions is realized, and the correction accuracy and consistency of the spectral data are improved.

[0025] The application is further configured that the selected pixel data is spliced in sequence according to the row arrangement order from the center of the field of view to the edge, so as to ensure that the center wavelengths of the overlapping areas of adjacent rows are aligned; specifically, in the embodiment, the selected pixel data is first collected in order according to the spatial arrangement of the imaging sensor, and the row arrangement order is from the center of the field of view to the edge; in order to ensure that the spliced spectral data is continuous and consistent, the center wavelength alignment algorithm is used for correction in the overlapping area of the adjacent row pixel data; specifically, the center wavelength difference of the adjacent two rows of filters is calculated, and the spectral response is adjusted by using the interpolation or spectral resampling method, so that the center wavelength remains consistent; in the correction process, the spectral response of the center area of the field of view is taken as a reference to ensure that the response characteristics of the data of other areas are consistent with the center data; the alignment process effectively eliminates the wavelength shift caused by the angle response difference of the filter, ensures that the spliced spectral data is seamlessly connected in the space and wavelength dimensions, and improves the continuity and accuracy of the corrected spectrum; on the basis of the above, in order to further improve the spectral splicing accuracy, the embodiment uses the weighted average method for spectral reconstruction; in the overlapping area, the spectral response intensity and signal quality of the pixel are combined, the overlapping area data is fused by weighted average, the splicing result is optimized, and the spectral distortion caused by the field of view edge effect is reduced; the weighting strategy not only ensures the consistency of the data after splicing in the wavelength, but also avoids the error caused by the response difference of different incident angles; in addition, the adaptive error compensation algorithm is introduced in the embodiment, the spectral response of different areas is analyzed in real time, and dynamic compensation is carried out based on the error model, so as to ensure that the spliced spectral data maintains high accuracy and high consistency in the full wavelength range; the error model comprehensively considers the spectral deviation caused by the field of view edge effect, the angle response difference and the performance change of the micro-nano structure filter; it is assumed that the spectral response of the splicing area is affected by the incident angle change, the filter transmittance and the non-uniformity of the sensor response, based on this assumption, the error model is adjusted in real time by dynamic compensation, and the compensation process includes: analyzing the light incident angle difference of the field of view position of each pixel, comparing the spectral response of the overlapping area, and correcting the response deviation of the field of view edge; according to the incident angle of the pixel and the angle response characteristics of the filter, the transmittance change is calculated and the spectral response is adjusted; combined with the spatial distribution and response characteristics of the imaging sensor, the non-uniformity of the pixel response is evaluated and corrected; through the above dynamic compensation measures, it is ensured that the spliced spectral data meets the design requirements in terms of accuracy and consistency, and the overall performance of the micro-nano structure spectral camera is improved.

[0026] The application is further configured that the division parameter of the angle sub-area According to the required angle resolution and the incident angle response characteristics of the filter, and meet: , wherein, is the maximum allowed incident angle of the micro-nano structure filter; specifically, the division parameter of the angle sub-area It is determined according to the required angular resolution and the incident angle response characteristics of the micro-nanostructure filter; the maximum allowable incident angle of the micro-nanostructure filter is recorded as , that is, the filter can maintain its designed optical performance and transmittance within this incident angle range; in order to ensure that the incident angle range corresponding to each angle sub-area does not exceed the allowable incident angle of the filter, thereby avoiding the filter performance degradation due to the incident angle deviating from the design range, the parameters are divided Should meet the following requirements: ,in, is a rounding function; in the implementation process, first according to the half field angle of the spectral camera and the maximum permissible angle of incidence of the filter Calculate the minimum partition parameter , which divides the field of view into angle sub-areas, ensuring the angular width of each angle sub-area The maximum allowable incident angle of the filter is not exceeded. Through this division, the angle change of the incident light in each angle sub-area can be controlled within the effective response range of the filter, ensuring the optical performance of the micro-nanostructure filter and the correction accuracy of the spectral data, thereby improving the measurement accuracy and consistency of the entire spectral camera device.

[0027] The present invention is further configured such that the imaging sensor is a CMOS sensor or a CCD sensor, and the relationship between the pixel size and the focal length satisfies: ,in, is the size of a single pixel of the sensor, is the focal length, The minimum angle sub-area width is preset; specifically, the imaging sensor may be a CMOS sensor or a CCD sensor, and the pixel size and lens focal length The relationship between them satisfies the following conditions: , this relationship is used to ensure that the viewing angle range of each pixel does not exceed the corresponding angle sub-region, thereby avoiding the aliasing of light information from different angle sub-regions. Specifically, the ratio of pixel size to focal length The spatial sampling angle of the pixel is determined. Meeting the above conditions can ensure that the angular resolution of the imaging sensor is at least not lower than the minimum angular sub-area division requirement, thereby improving the accuracy of angle mapping and the accuracy of spectral correction. Exceed , the pixel viewing angle is too large, resulting in the mixing of incident angle information of multiple angle sub-areas, reducing the correction effect; therefore, in this embodiment, by reasonably selecting the sensor pixel size and focal length parameters, a spatial sampling condition matching the minimum angle sub-area width is achieved, thereby effectively supporting the subsequent micro-nanostructure filter angle response correction method based on angle sub-area division. Example

[0028] Referring to Figure 2 The data correction device of the exemplary micro-nano structure spectral camera includes: A field-of-view division module is configured to divide a half field-of-view angle of the spectral camera into a preset number of angle sub-zones along a main optical axis direction, each angle sub-zone corresponding to a different incident angle range; A spectral preprocessing module is configured to preprocess the obtained raw spectral data; A pixel mapping module is configured to divide a plurality of row pixels corresponding to the same wavelength segment in the imaging sensor according to the angle sub-zones, so that each angle sub-zone corresponds to a group of row pixels, and a mapping relationship between the row pixels and the incident angles is established; A filter configuration module is configured to configure micro-nano structure filters adapted to different incident angle ranges in the plurality of row pixels corresponding to each wavelength segment, so that the angle response range of the filter configured for each row pixel matches the incident angle range of the corresponding angle sub-zone; A pixel screening module is configured to select pixel data of the row pixels corresponding to each wavelength segment, whose incident angles fall within the angle response range of the configured micro-nano structure filter; A spectral splicing module is configured to splice the selected pixel data in row order to generate corrected spectral data of the wavelength segment, and output a full-wavelength spectral correction result.

[0029] It should be noted that the data correction device of the micro-nano structure spectral camera provided in the above embodiments and the data correction method of the micro-nano structure spectral camera provided in the above embodiments belong to the same concept, and the specific manner in which each module and unit performs operations has been described in detail in the method embodiments, which will not be repeated here. The data correction device of the micro-nano structure spectral camera provided in the above embodiments can complete the above-described functions by different functional modules according to the needs in actual application, i.e., the internal structure of the system is divided into different functional modules to complete all or part of the above-described functions, and this is not limited herein.

[0030] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or replacements within the technical range disclosed in the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A data correction method for a micro-nanostructure spectral camera, characterized in that: include: The half field of view angle of the spectral camera is divided symmetrically along the main optical axis into a preset number of angle sub-areas, each angle sub-area corresponding to a different range of incident angles; Preprocessing the acquired raw spectral data; Divide multiple row pixels corresponding to the same wavelength band in the imaging sensor into angular sub-regions, so that each angular sub-region corresponds to a group of row pixels, and establish a mapping relationship between the row pixels and the incident angle; In the multiple rows of pixels corresponding to each wavelength band, micro-nanostructure filters adapted to different incident angle ranges are respectively configured, so that the angular response range of the filter configured for each row of pixels matches the incident angle range of its corresponding angular sub-region; Selecting pixel data whose incident angle falls within the angular response range of the configured micro-nanostructure filter from among the multiple rows of pixels corresponding to each wavelength band; The selected pixel data are spliced ​​in row order to generate the corrected spectral data of the wavelength band, and the full-band spectral correction results are output.

2. The data correction method for a micro-nanostructure spectral camera according to claim 1, characterized in that: The angular width of the angular sub-region satisfy , is the angular width, Half field of view, To divide the parameters, the dividing step includes: The number of each angle sub-area is symmetrical with the main optical axis, and the angular width of the angle sub-area is Number them as integer multiples of ; Map the pixel rows corresponding to each band on the imaging sensor according to the numbering order of the angular sub-regions, so that the incident angle received by each pixel segment is the same as the incident angle range of the corresponding angular sub-region; The incident angle range is determined by the angular width of the angular sub-region. and half field of view Decide.

3. The data correction method for a micro-nanostructure spectral camera according to claim 1, characterized in that: The preprocessing includes performing dark background value subtraction processing on each pixel in the acquired original spectral data; The pixel signal intensity is standardized according to the standard white plate reflectance calibration, and the original signal intensity is converted into a relative spectral response value; The normalization coefficient used in the normalization process is determined based on a reference response value under irradiation with a standard light source.

4. The data correction method for a micro-nanostructure spectral camera according to claim 1, characterized in that: The micro-nanostructured optical filter is a microstructured device with directionally selective response characteristics. The types of micro-nanostructured optical filters include photonic crystal filters, subwavelength structure filters, and metasurface filters, and have the following characteristics: The micro-nanostructure filters arranged in different rows in the same wavelength band have the same structural center wavelength and correspond to different incident angle response windows; The micro-nanostructure filter has a maximum transmittance within its designed incident angle range, and its central wavelength deviation is less than a preset allowable deviation value.

5. The data correction method for a micro-nanostructure spectral camera according to claim 1, characterized in that: In the process of selecting pixel data, only pixel data whose incident angle is within the designed angle boundary of the micro-nanostructure filter configured for the row of pixels is selected, and the minimum incident angle and the maximum incident angle of the designed angle boundary are the same as the incident angle range of the angle sub-region mapped by the row of pixels.

6. The data correction method for a micro-nanostructure spectral camera according to claim 1, characterized in that: The selected pixel data are sequentially spliced ​​in the order of rows from the center to the edge of the field of view to ensure that the center wavelengths of the overlapping areas of adjacent rows are aligned.

7. The data correction method for a micro-nanostructure spectral camera according to claim 1, characterized in that: The angle sub-area division parameters It is set according to the required angular resolution and the incident angle response characteristics of the filter, and meets the following requirements: ,in, is the maximum allowable incident angle of the micro-nanostructure filter.

8. The data correction method for a micro-nanostructure spectral camera according to claim 1, characterized in that: The imaging sensor is a CMOS sensor or a CCD sensor, and the relationship between the pixel size and the focal length satisfies: ,in, is the size of a single pixel of the sensor, is the focal length, The preset minimum angle sub-area width.

9. A data correction device for a micro-nanostructure spectral camera, used to implement the data correction method for a micro-nanostructure spectral camera according to any one of claims 1 to 8, characterized in that: include: Field of view division module: used to divide the half field of view angle of the spectral camera into a preset number of angular sub-areas symmetrically along the main optical axis, each angular sub-area corresponding to a different range of incident angles; Spectral preprocessing module: used to preprocess the acquired raw spectral data; Pixel mapping module: used to divide multiple row pixels corresponding to the same wavelength band in the imaging sensor into angular sub-regions, so that each angular sub-region corresponds to a group of row pixels, and establish a mapping relationship between row pixels and incident angles; Filter configuration module: used to configure micro-nanostructure filters adapted to different incident angle ranges in multiple row pixels corresponding to each wavelength band, so that the angular response range of the filter configured for each row pixel matches the incident angle range of its corresponding angular sub-region; Pixel screening module: used to select pixel data whose incident angle falls within the angular response range of the configured micro-nanostructure filter from multiple rows of pixels corresponding to each wavelength band; Spectral stitching module: used to stitch the selected pixel data in row order, generate the corrected spectral data of the wavelength band, and output the full-band spectral correction results.

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