Open environment crop chlorophyll fluorescence parameter imaging detection method and device

Abstract

The invention provides an open environment crop chlorophyll fluorescence parameter imaging detection method and device, and the method comprises the steps: carrying out the crop canopy segmentation of a crop canopy hyperspectral image based on a crop canopy mask image, and obtaining a crop canopy image; performing hierarchical segmentation based on the crop canopy image according to a clustering algorithm to obtain an upper-layer leaf image and a lower-layer leaf image; determining upper-layer chlorophyll fluorescence intensity of the upper-layer leaf image and lower-layer chlorophyll fluorescence intensity of the lower-layer leaf image; respectively compensating the upper chlorophyll fluorescence intensity and the lower chlorophyll fluorescence intensity based on the balanced brightness and crop absorption photosynthetically active radiation to obtain an upper chlorophyll fluorescence signal correction value and a lower chlorophyll fluorescence signal correction value; and constructing a visual chlorophyll fluorescence parameter spatial distribution image based on the upper-layer chlorophyll fluorescence signal correction value and the lower-layer chlorophyll fluorescence signal correction value. The method can realize rapid and accurate imaging detection of the chlorophyll fluorescence parameters of the crop canopies in the open environment.

Description

Technical Field

[0001] The present invention relates to the technical field of crop chlorophyll detection, and in particular to a method and device for imaging and detecting chlorophyll fluorescence parameters of crops in an open environment. Background Art

[0002] After absorbing light energy, chlorophyll molecules distribute it in three ways: photosynthesis, thermal dissipation, and fluorescence. Less than 2% of this energy is emitted as fluorescence. These three sources of energy compete with each other, increasing and decreasing in turn.

[0003] Photosynthesis is an essential component of crop growth, nutrient accumulation, and yield, and can directly reflect a crop's nutritional and stress status. Chlorophyll fluorescence parameters, such as the primary light energy conversion efficiency (Fv / Fm) of the photosystem II (PS II complex), the actual light energy conversion efficiency (Fv' / Fm') of PS II, the photochemical quenching coefficient (qP), and the non-photochemical quenching coefficient (qN), are known as crop photosynthesis probes. They can reflect nearly all changes in photosynthesis and provide a direct, non-destructive, and accurate method for diagnosing functional changes and stress states in crops. Currently, existing technologies for measuring chlorophyll fluorescence parameters require long periods of dark adaptation and require measurements in a closed space equipped with an excitation light source, which cannot meet the needs of high-throughput field testing.

[0004] Crop canopies are not uniform in structure. Differences in leaf arrangement and inclination can lead to significant variations in chlorophyll fluorescence emission intensity across different regions. When performing two-dimensional chlorophyll fluorescence measurements within a canopy, the photosynthetic efficiency and fluorescence emission rate vary with leaf depth, as light conditions decay layer by layer within the canopy. This results in spatial heterogeneity in fluorescence signal intensity and spectral characteristics across different regions, impacting the accuracy and comparability of overall measurement results.

[0005] It can be seen that the plant canopy chlorophyll fluorescence parameter detection method in the related art has the technical problem of low accuracy. Summary of the Invention

[0006] The present invention provides a method and device for detecting chlorophyll fluorescence parameters of crops in an open environment, which are used to solve the defect of low accuracy of the existing method for detecting chlorophyll fluorescence parameters of plant canopies, and realize rapid and accurate detection of chlorophyll fluorescence imaging of crop canopies.

[0007] The present invention provides a method for imaging and detecting chlorophyll fluorescence parameters of crops in an open environment, comprising the following steps: acquiring a captured hyperspectral image of a crop canopy when it is detected that the sunlight intensity is greater than a preset threshold; removing crop environmental interference from the hyperspectral image of the crop canopy to obtain a crop canopy mask image; performing crop canopy segmentation on the hyperspectral image of the crop canopy based on the crop canopy mask image to obtain a crop canopy image; performing layered segmentation based on the crop canopy image according to a clustering algorithm to obtain an upper leaf image and a lower leaf image; determining the upper layer chlorophyll fluorescence intensity of the upper leaf image and the lower layer chlorophyll fluorescence intensity of the lower leaf image; compensating the upper layer chlorophyll fluorescence intensity and the lower layer chlorophyll fluorescence intensity based on balanced brightness and crop absorption of photosynthetically active radiation to obtain upper layer chlorophyll fluorescence signal correction values and lower layer chlorophyll fluorescence signal correction values; and constructing a visualized chlorophyll fluorescence parameter spatial distribution image based on the upper layer chlorophyll fluorescence signal correction values and the lower layer chlorophyll fluorescence signal correction values.

[0008] According to a method for imaging and detecting chlorophyll fluorescence parameters of crops in an open environment provided by the present invention, the upper chlorophyll fluorescence intensity and the lower chlorophyll fluorescence intensity are compensated based on the balanced brightness and the photosynthetically active radiation absorbed by the crops, respectively, to obtain a corrected value of the upper chlorophyll fluorescence signal and a corrected value of the lower chlorophyll fluorescence signal, including: determining the upper balanced brightness of the upper leaf image and the lower balanced brightness of the lower leaf image; determining the photosynthetically active radiation absorbed by the upper crop of the upper leaf image and the photosynthetically active radiation absorbed by the lower crop of the lower leaf image; compensating the upper chlorophyll fluorescence intensity based on the upper balanced brightness and the photosynthetically active radiation absorbed by the upper crop to obtain a corrected value of the upper chlorophyll fluorescence signal; compensating the lower chlorophyll fluorescence intensity based on the lower balanced brightness and the photosynthetically active radiation absorbed by the lower crop to obtain a corrected value of the lower chlorophyll fluorescence signal.

[0009] According to a method for detecting chlorophyll fluorescence parameters of crops in an open environment provided by the present invention, determining the upper-layer balanced brightness of the upper leaf image and the lower-layer balanced brightness of the lower leaf image includes: determining the upper-layer balanced brightness of the upper leaf image and the lower-layer balanced brightness of the lower leaf image based on the reflectivity of the crop canopy in the 550-nanometer band image, the reflectivity of the crop canopy in the 687-nanometer band image, and the reflectivity of the crop canopy in the 760-nanometer band image, respectively: in, Indicates the upper layer balanced brightness, Indicates the balanced brightness of the lower layer, Represents the coordinates of the pixel points in the mask area of the upper leaf image, Represents the coordinates of the pixel points in the mask area of the lower leaf image, Indicates the number of effective pixels in the crop canopy area, represents the weighting coefficient of the 550 nm band, represents the reflectance of the crop canopy in the 550 nm band image, represents the weighting coefficient of the 687 nm band, represents the reflectance of the crop canopy in the 687 nm band image, represents the weighting coefficient of the 760 nm band, Represents the reflectance of crop canopy in 760 nm band image.

[0010] According to a method for detecting chlorophyll fluorescence parameters of crops in an open environment by imaging, the method comprises determining the absorption of photosynthetically active radiation by upper crops in the upper leaf image and the absorption of photosynthetically active radiation by lower crops in the lower leaf image, comprising: determining a normalized difference red edge vegetation index of the crop canopy based on the crop canopy reflectivity in a near-infrared band and the crop canopy reflectivity in a red edge band; determining the absorption of photosynthetically active radiation by upper crops based on the photosynthetically active radiation value of the upper leaf image and the normalized difference red edge vegetation index of the crop canopy; and determining the absorption of photosynthetically active radiation by lower crops based on the photosynthetically active radiation value of the lower leaf image and the normalized difference red edge vegetation index of the crop canopy.

[0011] According to a method for imaging and detecting chlorophyll fluorescence parameters of crops in an open environment provided by the present invention, the determining of the upper chlorophyll fluorescence intensity of the upper leaf image and the lower chlorophyll fluorescence intensity of the lower leaf image comprises: based on the Fraunhofer dark line extraction method, extracting the upper chlorophyll fluorescence intensity of the upper leaf image and the lower chlorophyll fluorescence intensity of the lower leaf image in the 687 nm band and the 760 nm band in the reflectance spectrum of the earth's oxygen absorption band, respectively; wherein the upper chlorophyll fluorescence intensity comprises: the chlorophyll fluorescence intensity of the upper 687 nm band and the chlorophyll fluorescence intensity of the upper 760 nm band; the lower chlorophyll fluorescence intensity comprises: the chlorophyll fluorescence intensity of the lower 687 nm band and the chlorophyll fluorescence intensity of the lower 760 nm band.

[0012] According to a method for detecting chlorophyll fluorescence parameters of crops in an open environment, the present invention provides a method for imaging and detecting chlorophyll fluorescence parameters of crops in an open environment. The method comprises: compensating the chlorophyll fluorescence intensity of the upper layer and the chlorophyll fluorescence intensity of the lower layer based on the balanced brightness and the photosynthetically active radiation absorbed by the crop, and obtaining a corrected value of the chlorophyll fluorescence signal of the upper layer and the corrected value of the chlorophyll fluorescence signal of the lower layer. The method comprises: represents the corrected value of the upper chlorophyll fluorescence signal, represents the preset first coefficient, represents the chlorophyll fluorescence intensity in the upper 687 nm band, represents the preset second coefficient, represents the chlorophyll fluorescence intensity in the upper 760 nm band, Indicates the upper layer balanced brightness, It indicates that the upper crops absorb photosynthetically active radiation; represents the corrected value of the lower chlorophyll fluorescence signal, represents the preset third coefficient, represents the chlorophyll fluorescence intensity at 687 nm in the lower layer. represents the preset fourth coefficient, represents the chlorophyll fluorescence intensity in the lower 760 nm band, Indicates the balanced brightness of the lower layer, It indicates that the lower crops absorb photosynthetically active radiation.

[0013] The present invention also provides an open environment crop chlorophyll fluorescence parameter imaging detection device, comprising the following modules: an acquisition module, for acquiring a collected crop canopy hyperspectral image when detecting that the sunlight intensity is greater than a preset threshold; a removal module, for removing crop environmental interference from the crop canopy hyperspectral image to obtain a crop canopy mask image; a segmentation module, for performing crop canopy segmentation on the crop canopy hyperspectral image based on the crop canopy mask image to obtain a crop canopy image; a stratification module, for performing stratified segmentation based on the crop canopy image according to a clustering algorithm to obtain an upper leaf a determination module for determining the upper chlorophyll fluorescence intensity of the upper leaf image and the lower chlorophyll fluorescence intensity of the lower leaf image; a compensation module for compensating the upper chlorophyll fluorescence intensity and the lower chlorophyll fluorescence intensity based on balanced brightness and crop absorption of photosynthetically active radiation, respectively, to obtain a corrected value of the upper chlorophyll fluorescence signal and a corrected value of the lower chlorophyll fluorescence signal; a construction module for constructing a visualized chlorophyll fluorescence parameter spatial distribution image based on the corrected value of the upper chlorophyll fluorescence signal and the corrected value of the lower chlorophyll fluorescence signal.

[0014] The present invention also provides an electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, the method for imaging and detecting chlorophyll fluorescence parameters of crops in an open environment as described above is implemented.

[0015] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the method for imaging and detecting chlorophyll fluorescence parameters of crops in an open environment as described in any one of the above is implemented.

[0016] The present invention also provides a computer program product, comprising a computer program, which, when executed by a processor, implements any of the above-described methods for imaging and detecting chlorophyll fluorescence parameters of crops in an open environment.

[0017] The present invention provides an imaging and detection method and device for chlorophyll fluorescence parameters of crops in an open environment. First, a hyperspectral image is acquired under sufficient daylight conditions, and pure crop canopy information is extracted by eliminating environmental interference and segmenting the canopy. Next, a clustering algorithm is used to divide the canopy into upper and lower leaf regions, and the chlorophyll fluorescence intensities of these regions are calculated separately. Then, based on the balanced brightness and photosynthetically active radiation absorption characteristics, the fluorescence intensities of the upper and lower layers are compensated and corrected to eliminate the influence of uneven light distribution. Finally, by constructing a spatial distribution image of the fluorescence parameters, the differences in photosynthetic activity in the vertical direction of the crop canopy are intuitively presented, providing a quantitative basis for monitoring the physiological status of the crop. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced one by one below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 The figure is a flow chart of the open environment crop chlorophyll fluorescence parameter imaging detection method provided by the present invention.

[0020] Figure 2 This is a schematic diagram of crop canopy stratification provided by the present invention.

[0021] Figure 3 This is the spatial distribution diagram of crop chlorophyll fluorescence parameters provided by the present invention.

[0022] Figure 4 The diagram is a schematic structural diagram of the device for detecting chlorophyll fluorescence parameters of crops in an open environment provided by the present invention.

[0023] Figure 5 It is a simplified connection diagram of the device provided by the present invention.

[0024] Figure 6 This is a hardware structure diagram of the data acquisition module provided by the present invention.

[0025] Figure 7The diagram is a schematic diagram of the program structure of the open environment crop chlorophyll fluorescence parameter imaging detection device provided by the present invention.

[0026] Figure 8 It is a schematic diagram of the physical structure of the electronic device provided by the present invention. DETAILED DESCRIPTION

[0027] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0028] On the one hand, the structure of plant canopies is not uniform. Differences in leaf arrangement, inclination distribution, interlayer overlap, leaf density, and thickness can lead to significant variations in chlorophyll fluorescence emission intensity across different regions. When performing two-dimensional chlorophyll fluorescence detection within the canopy, as light conditions decay layer by layer within the canopy, photosynthetic efficiency and fluorescence emission rate vary with leaf depth. This results in spatial heterogeneity in fluorescence signal intensity and spectral characteristics across different regions, affecting the accuracy and comparability of the overall detection results.

[0029] On the other hand, the red light and red edge bands of chlorophyll fluorescence in the 650-800nm range overlap with the crop reflectance spectrum. The strong absorption characteristics of chlorophyll to red light cause the fluorescence signal to be reabsorbed and re-emitted multiple times inside the leaves, causing the fluorescence signal to attenuate nonlinearly when penetrating the canopy, reducing the true detection intensity of the fluorescence spectrum, thereby increasing detection errors and increasing the uncertainty of extracting chlorophyll fluorescence parameters.

[0030] Therefore, the present invention proposes a method and device for detecting chlorophyll fluorescence parameters of crops in an open environment, which can synchronously obtain the spectral information and spatial information of the crop canopy in an open environment, solve the impact of canopy heterogeneity on chlorophyll fluorescence parameter detection, and compensate for the fluorescence spectrum intensity in the red light band, thereby improving the accuracy of chlorophyll fluorescence parameter detection.

[0031] Optionally, the open environment crop chlorophyll fluorescence parameter imaging detection method of the embodiment of the present application can be executed by a server, or by a terminal device, or jointly by a server and a terminal device, taking the open environment crop chlorophyll fluorescence parameter imaging detection method of the embodiment of the present application executed by a server as an example.

[0032] Figure 1 FIG. 1 is a flow chart of the open environment crop chlorophyll fluorescence parameter imaging detection method provided by the present invention, as shown in FIG. Figure 1As shown, the method includes the following: Step 101: When it is detected that the sunlight intensity is greater than a preset threshold, a collected hyperspectral image of the crop canopy is acquired.

[0033] In an embodiment of the present invention, the ambient light intensity is obtained to test whether the sunlight intensity can meet the chlorophyll fluorescence signal acquisition requirements. When the sunlight intensity is greater than a preset threshold, a hyperspectral image of the crop canopy at 550-800nm is collected.

[0034] In some embodiments, a near-infrared reflectance spectrum image is selected, a whiteboard reflectance threshold is set to 95%, and a whiteboard mask image is obtained based on the following formula: , further extract the 550-800nm white board irradiance value .

[0035] in, represents the whiteboard mask image, Reflectance spectrum image representing the near-infrared band.

[0036] Step 102 : removing crop environment interference from the crop canopy hyperspectral image to obtain a crop canopy mask image.

[0037] In an embodiment of the present invention, since the crop environment background affects the extraction of canopy chlorophyll fluorescence signals, the soil adjusted vegetation index is calculated and optimized, and the crop environment background is separated by the Otsu segmentation method to generate a crop canopy (two-dimensional) mask image.

[0038] The calculation formula for the optimized soil adjusted vegetation index is as follows: Where, Indicates optimized soil adjustment vegetation index, 、 They represent the reflectivity of the red light band image and the reflectivity of the near-infrared band image respectively.

[0039] Step 103 : performing crop canopy segmentation on the crop canopy hyperspectral image based on the crop canopy mask image to obtain a crop canopy image.

[0040] In an embodiment of the present invention, a crop canopy mask image (canopy area is 1, background is 0) is first aligned with the crop canopy hyperspectral image to ensure consistent spatial resolution. The mask is then applied band by band, and the pixel values of the background area outside the mask are set to zero or marked as invalid values (NaN) through matrix multiplication, retaining the spectral data of the canopy area, thereby obtaining a crop canopy image.

[0041] Step 104 : performing hierarchical segmentation based on the crop canopy image according to a clustering algorithm to obtain an upper leaf image and a lower leaf image.

[0042] refer to Figure 2 , Figure 2 This is a schematic diagram of crop canopy stratification provided by the present invention.

[0043] Different leaf positions in the canopy receive different sunlight intensities. In order to reduce the impact of crop canopy heterogeneity on chlorophyll fluorescence distribution differences, the photosynthetically active radiation value of the crop canopy image is calculated. .

[0044] in, Expressed as the average irradiance over the crop canopy in the near-infrared band.

[0045] The K-means clustering algorithm was used to perform hierarchical segmentation on crop canopy images. Using the photosynthetically active radiation value of the crop canopy image as the clustering criterion, the canopy was divided into upper and lower leaves. The specific steps involved setting the number of clusters K = 2, initializing the cluster centers using K-means, calculating the Euclidean distance between each pixel and the cluster center, assigning the pixel to the closest cluster, and updating the mean until convergence. The final segmentation yielded images of upper leaves in the upper layer and lower leaves in the lower layer.

[0046] Step 105 : determining the fluorescence intensity of the upper chlorophyll layer of the upper leaf image and the fluorescence intensity of the lower chlorophyll layer of the lower leaf image.

[0047] Since fluorescence accounts for the largest proportion of the total radiation energy in the Earth’s oxygen absorption band (687nm in the O2-B band and 760nm in the O2-A band), the Fraunhofer dark line extraction method is used to extract the chlorophyll fluorescence intensity (signal) of the upper layer of the crop canopy and the chlorophyll fluorescence intensity (signal) of the lower layer of the crop canopy from the reflectance spectrum.

[0048] Step 106 , based on the balanced brightness and the photosynthetically active radiation absorbed by the crop, respectively compensate the upper chlorophyll fluorescence intensity and the lower chlorophyll fluorescence intensity to obtain the upper chlorophyll fluorescence signal correction value and the lower chlorophyll fluorescence signal correction value.

[0049] In an embodiment of the present invention, based on the balanced brightness of the canopy layers and the absorption of photosynthetically active radiation by crops, the upper chlorophyll fluorescence intensity and the lower chlorophyll fluorescence intensity in the red light band are compensated to obtain the upper chlorophyll fluorescence signal correction value and the lower chlorophyll fluorescence signal correction value.

[0050] Step 107 : constructing a visualized chlorophyll fluorescence parameter spatial distribution image based on the upper layer chlorophyll fluorescence signal correction value and the lower layer chlorophyll fluorescence signal correction value.

[0051] In the embodiment of the present invention, the calculation formula of the chlorophyll fluorescence parameter of each pixel in the two-dimensional space of the crop is expressed as: in, Represents the chlorophyll fluorescence parameters of each pixel of the crop; 、 、 are the coefficients of each parameter; and Indicates the corrected value of the chlorophyll fluorescence signal in the upper layer and the lower layer; Represents the constant correction value of chlorophyll fluorescence parameters.

[0052] refer to Figure 3 , Figure 3 This is the spatial distribution diagram of crop chlorophyll fluorescence parameters provided by the present invention.

[0053] In the embodiment of the present invention, the calculated chlorophyll fluorescence parameter intensity value of each pixel is assigned a different color to obtain a visualized chlorophyll fluorescence parameter spatial distribution image.

[0054] Through the above steps of the embodiment of the present invention, first, a hyperspectral image is acquired under sufficient daylight conditions, and pure crop canopy information is extracted by eliminating environmental interference and canopy segmentation; then, a clustering algorithm is used to divide the canopy into upper and lower leaf regions, and their chlorophyll fluorescence intensities are calculated separately; then, based on the balanced brightness and photosynthetically active radiation absorption characteristics, the fluorescence intensities of the upper and lower layers are compensated and corrected to eliminate the influence of uneven light distribution; finally, by constructing a fluorescence parameter spatial distribution image, the differences in photosynthetic activity in the vertical direction of the crop canopy are intuitively presented, providing a quantitative basis for monitoring the physiological status of the crop.

[0055] According to the present invention, a method for detecting chlorophyll fluorescence parameters of crops in an open environment is provided. Based on the balanced brightness and the photosynthetically active radiation absorbed by the crop, the upper chlorophyll fluorescence intensity and the lower chlorophyll fluorescence intensity are compensated respectively to obtain the upper chlorophyll fluorescence signal correction value and the lower chlorophyll fluorescence signal correction value, including: Determining the upper balanced brightness of the upper leaf image and the lower balanced brightness of the lower leaf image; Determine the photosynthetically active radiation absorbed by the upper crops of the upper leaf image and the photosynthetically active radiation absorbed by the lower crops of the lower leaf image; Based on the upper layer balanced brightness and the photosynthetically active radiation absorbed by the upper layer crops, the chlorophyll fluorescence intensity of the upper layer is compensated to obtain the upper layer chlorophyll fluorescence signal correction value; Based on the balanced brightness of the lower layer and the absorption of photosynthetically active radiation by the crops in the lower layer, the chlorophyll fluorescence intensity of the lower layer is compensated to obtain the corrected value of the chlorophyll fluorescence signal of the lower layer.

[0056] In the embodiment of the present invention, the reflectance of the crop canopy in the three bands of 550nm, 687nm and 760nm images is extracted to calculate the upper balanced brightness of the canopy. Balance brightness values with the lower layers of the canopy .

[0057] According to the present invention, a method for detecting chlorophyll fluorescence parameters of crops in an open environment is provided, which determines the upper-layer balanced brightness of an upper leaf image and the lower-layer balanced brightness of a lower leaf image, including: Based on the reflectivity of the crop canopy in the 550 nm band image, the reflectivity of the crop canopy in the 687 nm band image, and the reflectivity of the crop canopy in the 760 nm band image, the upper layer balanced brightness of the upper leaf image and the lower layer balanced brightness of the lower leaf image are determined respectively: in, Indicates the upper layer balanced brightness, Indicates the balanced brightness of the lower layer, Represents the coordinates of the pixel points in the mask area of the upper leaf image, Represents the coordinates of the pixel points in the mask area of the lower leaf image, Indicates the number of effective pixels in the crop canopy area, represents the weighting coefficient of the 550 nm band, represents the reflectance of the crop canopy in the 550 nm band image, represents the weighting coefficient of the 687 nm band, represents the reflectance of the crop canopy in the 687 nm band image, represents the weighting coefficient of the 760 nm band, Represents the reflectance of crop canopy in 760 nm band image.

[0058] This method, implemented in this embodiment of the present invention, uses reflectance data from three characteristic bands, 550nm, 687nm, and 760nm, to calculate the average brightness values of leaves in the upper and lower layers of the canopy, effectively quantifying the vertical optical property differences within the crop canopy. The weighted combination of the 550nm band, which reflects leaf structure, the 687nm band, which is sensitive to chlorophyll absorption, and the 760nm band, which characterizes canopy biomass, overcomes the limitations of individual bands and accurately captures the optical heterogeneity between leaves in the upper (well-lit) and lower (significantly shaded) layers.

[0059] According to the present invention, a method for detecting chlorophyll fluorescence parameters of crops in an open environment is provided, which determines the absorption of photosynthetically active radiation by upper crops in upper leaf images and the absorption of photosynthetically active radiation by lower crops in lower leaf images, including: Based on the crop canopy reflectance in the near-infrared band and the crop canopy reflectance in the red edge band, the crop canopy normalized difference red edge vegetation index is determined; The photosynthetically active radiation absorbed by the upper crops is determined based on the photosynthetically active radiation value of the upper leaf image and the normalized difference red edge vegetation index of the crop canopy; The photosynthetically active radiation absorbed by the lower layer crops is determined based on the photosynthetically active radiation value of the lower leaf image and the normalized difference red edge vegetation index of the crop canopy.

[0060] The specific calculation formula for crop absorption of photosynthetically active radiation is as follows: in, represents the crop canopy normalized difference red edge vegetation index, represents the crop canopy reflectance in the near-infrared band, represents the crop canopy reflectance in the red edge band, Indicates that crops absorb photosynthetically active radiation. It represents the photosynthetically active radiation value of the crop canopy. express The weighting coefficient of Indicates the constant correction value.

[0061] Through the embodiments of the present invention, the normalized difference red edge index (NDRE) is calculated by using the reflectance of the near-infrared (NIR) and red-edge bands to effectively characterize the chlorophyll content and photosynthetic activity of the canopy; combined with the photosynthetically active radiation (PAR) data of the upper and lower layers of the canopy, the actual absorption efficiency (APAR) of light energy by leaves in the upper layer (sufficiently illuminated) and the lower layer (significantly shaded) are quantified respectively.

[0062] According to the present invention, a method for detecting chlorophyll fluorescence parameters of crops in an open environment is provided, which determines the fluorescence intensity of the upper chlorophyll layer of an upper leaf image and the fluorescence intensity of the lower chlorophyll layer of a lower leaf image, comprising: Based on the Fraunhofer dark line extraction method, the fluorescence intensity of the upper chlorophyll layer of the upper leaf image and the fluorescence intensity of the lower chlorophyll layer of the lower leaf image were extracted in the 687nm band and 760nm band of the Earth's oxygen absorption band reflectance spectrum, respectively. The upper chlorophyll fluorescence intensity includes: the chlorophyll fluorescence intensity of the upper 687 nm band and the chlorophyll fluorescence intensity of the upper 760 nm band; the lower chlorophyll fluorescence intensity includes: the chlorophyll fluorescence intensity of the lower 687 nm band and the chlorophyll fluorescence intensity of the lower 760 nm band.

[0063] Since fluorescence accounts for the largest proportion of the total radiation energy in the Earth's oxygen absorption band (687nm in the O2-B band and 760nm in the O2-A band), the Fraunhofer dark line extraction method is used to extract the fluorescence intensity of the upper and lower chlorophyll layers of the crop canopy from the reflectance spectrum.

[0064] in, , and is the wavelength within the absorption line, left band, and right band; and Indicates the weight of the left and right bands of the absorption line; 、 、 It is expressed as the solar irradiance spectrum intensity to the left, inside, and right of the absorption line; 、 、 represents the spectral intensity of crop canopy reflected radiance to the left, inside, and right of the absorption line; Represents the chlorophyll fluorescence intensity within the absorption line. Therefore, the chlorophyll fluorescence intensity of the upper layer and the lower layer of the crop canopy in the earth's oxygen absorption band (687nm in the O2-B band and 760nm in the O2-A band) are extracted and are 、 and 、 .

[0065] The present invention, based on the Fraunhofer dark line principle, extracts chlorophyll fluorescence intensity signals from upper and lower canopy leaves in two oxygen absorption bands. By calculating the ratio of solar irradiance within and outside the absorption line to the canopy radiance, the 687nm / 760nm fluorescence intensity of the upper and lower layers can be accurately separated, enabling non-destructive testing of canopy photosynthetic activity in the vertical direction.

[0066] According to the present invention, a method for detecting chlorophyll fluorescence parameters of crops in an open environment is provided. Based on the balanced brightness and the photosynthetically active radiation absorbed by the crop, the upper chlorophyll fluorescence intensity and the lower chlorophyll fluorescence intensity are compensated respectively to obtain the upper chlorophyll fluorescence signal correction value and the lower chlorophyll fluorescence signal correction value, including: represents the corrected value of the upper chlorophyll fluorescence signal, represents the preset first coefficient, represents the chlorophyll fluorescence intensity in the upper 687 nm band, represents the preset second coefficient, represents the chlorophyll fluorescence intensity in the upper 760 nm band, Indicates the upper layer balanced brightness, It indicates that the upper crops absorb photosynthetically active radiation; represents the corrected value of the lower chlorophyll fluorescence signal, represents the preset third coefficient, represents the chlorophyll fluorescence intensity at 687 nm in the lower layer. represents the preset fourth coefficient, represents the chlorophyll fluorescence intensity in the lower 760 nm band, Indicates the balanced brightness of the lower layer, It indicates that the lower crops absorb photosynthetically active radiation.

[0067] In the embodiment of the present invention, the fluorescence intensity of the upper chlorophyll extracted based on the Fraunhofer dark line method is 、 and the fluorescence intensity of the lower chlorophyll layer 、 , upper balanced brightness Balance brightness with the lower layer , and the upper crops absorb photosynthetically active radiation and the lower crops absorb photosynthetically active radiation Combined, the upper layer chlorophyll fluorescence signal correction value and the lower layer chlorophyll fluorescence signal correction value are calculated. The details can be seen in the above formula, and the present invention will not be repeated here.

[0068] refer to Figure 4 , Figure 4This is a structural schematic diagram of the open environment crop chlorophyll fluorescence parameter imaging detection device provided by the present invention, which includes: a main control processing module (including a display, a main control chip, and a built-in SD memory card), a data acquisition module (including a narrow-band hyperspectral imaging acquisition module and a heat dissipation module), a power supply module (including a power supply and a power display module), a fluorescence signal processing and visualization module (including open environment chlorophyll fluorescence signal extraction, open environment chlorophyll fluorescence signal correction, and open environment chlorophyll fluorescence signal detection model), and a daylight intensity measurement module (including a light intensity sensor).

[0069] Among them, the power supply module supplies power to the main control processing module, daylight intensity measurement module and data acquisition module; the daylight intensity measurement module is composed of a light intensity sensor, which is used to measure the daylight intensity value in an open environment; the data acquisition module is mainly composed of a narrow-band hyperspectral imaging acquisition module, which is mainly used to measure the imaging reflectance spectrum and irradiance information of the crop canopy. The spectral range acquired by the narrow-band hyperspectral is 500-920nm, the spectral sampling frequency is 1nm, the spectral accuracy is 2.5nm, the spectral band is continuously adjustable, and the image resolution is 1280*1024; the fluorescence signal processing and visualization module mainly realizes the extraction and correction of chlorophyll fluorescence signals in open environments and the establishment of chlorophyll fluorescence parameter detection models, and finally realizes the visualization of the spatial distribution of crop chlorophyll fluorescence parameters.

[0070] refer to Figure 5 , Figure 5 This is a simplified connection diagram of the device provided by the present invention, which includes 1 a power supply, 2 a processor, 3 a data acquisition module, 4 a light intensity sensor and 5 a display.

[0071] refer to Figure 6 , Figure 6 This is the hardware structure diagram of the data acquisition module provided by the present invention, wherein 1 is the narrow-band hyperspectral imaging acquisition module, 2 is the heat dissipation module, 3 is the M7 screw hole structure, 4 is the Type-C interface, and 5 is the M3.5 screw hole.

[0072] refer to Figure 7 , Figure 7 This is a schematic diagram of the program structure of the open environment crop chlorophyll fluorescence parameter imaging detection device provided by the present invention, which includes: starting, system initialization, measuring daylight intensity, judging whether it is greater than a threshold, collecting crop canopy hyperspectral images, removing canopy environmental interference, extracting canopy layers, calculating and correcting the chlorophyll fluorescence signal intensity values of each layer, detecting the chlorophyll fluorescence parameter value of each pixel in the canopy, storing the results, displaying the chlorophyll fluorescence parameter spatial distribution map, and ending.

[0073] like Figure 7As shown, the system is divided into modules for daylight intensity measurement, data acquisition, data storage, data processing, and result output. Before data acquisition, the daylight intensity is measured. Only when the daylight intensity reaches a specific threshold can crop spectral images be collected. The crop canopy mask image is extracted by optimizing the soil-adjusted vegetation index and the Otsu segmentation method. The mask image is used to segment the crop soil background, retaining the crop canopy. The whiteboard irradiance (E), canopy irradiance (L), and canopy reflectance (R) are extracted. The chlorophyll fluorescence intensity value of each pixel is calculated and corrected. All collected data and data processing results are stored locally in real time, and the data is displayed and historical results are viewed on the display. The specific steps include the following.

[0074] Step 1: Turn on the power switch to supply power to each module and initialize the system.

[0075] Step 2: Obtain the ambient light intensity to test whether the sunlight intensity can meet the chlorophyll fluorescence signal acquisition requirements.

[0076] Step 3: Collect spectral image data of crop canopy at 550-800nm.

[0077] Step 4: Select the reflectance spectrum image of the near-infrared band, set the whiteboard reflectance threshold, perform whiteboard segmentation, generate a whiteboard mask image, and extract the 550-800nm whiteboard irradiance value .

[0078] Step 5, calculate , extract the crop canopy mask image, and realize the crop canopy segmentation of each band image based on the canopy mask image.

[0079] Step 6: Calculate the canopy photosynthetically active radiation and use the K-means clustering algorithm to segment the canopy into upper leaves and lower leaves based on the differences in photosynthetically active radiation.

[0080] Step 7: Calculate the balanced brightness of the upper and lower layers respectively and The chlorophyll fluorescence intensities of the upper and lower layers of crops in the Earth's oxygen absorption band (687nm in the O2-B band and 760nm in the O2-A band) were extracted and obtained. 、 and 、 .

[0081] Step 8: Extract photosynthetically active radiation absorbed by crops and Based on the balanced brightness of the canopy layers and the absorption of photosynthetically active radiation by crops, the chlorophyll fluorescence intensity of the upper and lower layers in the red light band is compensated to obtain the corrected values of the chlorophyll fluorescence signals of the upper and lower layers. and .

[0082] Step 9: Combine the corrected chlorophyll fluorescence signals from the upper and lower layers to construct a crop chlorophyll fluorescence parameter detection model. By embedding the constructed model into the system software, the chlorophyll fluorescence parameters of each pixel in the crop's two-dimensional space can be obtained.

[0083] The present invention provides a method and apparatus for measuring chlorophyll fluorescence parameters in an open environment. This modular and lightweight design facilitates rapid field acquisition. Using sunlight as the excitation light source eliminates the complex process of manually providing the excitation light source in a closed environment. The method processes the collected spectral data in real time, extracting the weak chlorophyll fluorescence signal from the reflectance spectrum, enabling more real-time and rapid measurement of chlorophyll fluorescence parameters.

[0084] The present invention solves the problems of chlorophyll fluorescence distribution differences and chlorophyll reabsorption caused by canopy heterogeneity, realizes hierarchical clustering through the differences in canopy photosynthetically active radiation, combines the canopy's balanced brightness and absorbed photosynthetically active radiation, extracts and corrects the chlorophyll fluorescence intensity in the red light band of the upper and lower layers of the crop canopy, and can more accurately reflect the photosynthetic efficiency of the crop canopy and improve the detection accuracy of chlorophyll fluorescence parameters.

[0085] This method can image the distribution of chlorophyll fluorescence parameters of crops in open environments at the crop canopy scale. Compared to single-point fluorescence spectrum measurement, it balances spatial and spectral resolution, extending point measurement to surface measurement and enabling two-dimensional spatial distribution detection of chlorophyll fluorescence parameters.

[0086] The following describes the chlorophyll fluorescence parameter imaging detection device for open environment crops provided by the present invention. The chlorophyll fluorescence parameter imaging detection device for open environment crops described below and the chlorophyll fluorescence parameter imaging detection method for open environment crops described above can be referenced to each other.

[0087] An acquisition module is used to acquire the collected crop canopy hyperspectral image when it is detected that the sunlight intensity is greater than a preset threshold; a removal module, configured to remove crop environmental interference from the crop canopy hyperspectral image to obtain a crop canopy mask image; a segmentation module, configured to perform crop canopy segmentation on the crop canopy hyperspectral image based on the crop canopy mask image to obtain a crop canopy image; a stratification module, configured to perform stratified segmentation based on the crop canopy image according to a clustering algorithm to obtain an upper leaf image and a lower leaf image; a determination module, configured to determine the chlorophyll fluorescence intensity of the upper layer of the upper leaf image and the chlorophyll fluorescence intensity of the lower layer of the lower leaf image; a compensation module for compensating the chlorophyll fluorescence intensity of the upper layer and the chlorophyll fluorescence intensity of the lower layer based on the balanced brightness and the photosynthetically active radiation absorbed by the crop, respectively, to obtain a corrected value of the chlorophyll fluorescence signal of the upper layer and the chlorophyll fluorescence signal of the lower layer; A construction module is used to construct a visual chlorophyll fluorescence parameter spatial distribution image based on the upper layer chlorophyll fluorescence signal correction value and the lower layer chlorophyll fluorescence signal correction value.

[0088] Specifically, the above-mentioned open environment crop chlorophyll fluorescence parameter imaging detection device provided by the present invention can implement all the method steps implemented in the above-mentioned open environment crop chlorophyll fluorescence parameter imaging detection method embodiment, and can achieve the same technical effect. The parts and beneficial effects of this embodiment that are the same as the method embodiment will not be described in detail here.

[0089] Figure 8 This is a schematic diagram of the physical structure of the electronic device provided by the present invention, such as Figure 8 As shown, the electronic device may include: a processor 810 , a communication interface 820 , a memory 830 and a communication bus 840 , wherein the processor 810 , the communication interface 820 and the memory 830 communicate with each other via the communication bus 840 . The processor 810 can call the logic instructions in the memory 830 to execute the open environment crop chlorophyll fluorescence parameter imaging detection method, which includes: when it is detected that the sunlight intensity is greater than a preset threshold, obtaining a collected crop canopy hyperspectral image; removing crop environmental interference from the crop canopy hyperspectral image to obtain a crop canopy mask image; performing crop canopy segmentation on the crop canopy hyperspectral image based on the crop canopy mask image to obtain a crop canopy image; performing layered segmentation based on the crop canopy image according to a clustering algorithm to obtain an upper leaf image and a lower leaf image; determining the upper chlorophyll fluorescence intensity of the upper leaf image and the lower chlorophyll fluorescence intensity of the lower leaf image; based on the balanced brightness and the crop absorption of photosynthetically active radiation, compensating the upper chlorophyll fluorescence intensity and the lower chlorophyll fluorescence intensity respectively to obtain an upper chlorophyll fluorescence signal correction value and a lower chlorophyll fluorescence signal correction value; and constructing a visual chlorophyll fluorescence parameter spatial distribution image based on the upper chlorophyll fluorescence signal correction value and the lower chlorophyll fluorescence signal correction value.

[0090] Furthermore, the logic instructions in the aforementioned memory 830 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the portion that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product, stored in a storage medium, includes instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods described in various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, mobile hard drives, read-only memories (ROMs), random access memories (RAMs), magnetic disks, or optical disks.

[0091] On the other hand, the present invention also provides a computer program product, which includes a computer program. The computer program can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the open environment crop chlorophyll fluorescence parameter imaging detection method provided by the above methods, the method comprising: when it is detected that the sunlight intensity is greater than a preset threshold, obtaining a collected crop canopy hyperspectral image; performing crop environmental interference removal on the crop canopy hyperspectral image to obtain a crop canopy mask image; performing crop environmental interference removal on the crop canopy hyperspectral image based on the crop canopy mask image. Canopy segmentation is performed to obtain a crop canopy image; hierarchical segmentation is performed based on the crop canopy image according to a clustering algorithm to obtain an upper leaf image and a lower leaf image; the upper chlorophyll fluorescence intensity of the upper leaf image and the lower chlorophyll fluorescence intensity of the lower leaf image are determined; based on the balanced brightness and the absorption of photosynthetically active radiation by the crop, the upper chlorophyll fluorescence intensity and the lower chlorophyll fluorescence intensity are compensated respectively to obtain a corrected value of the upper chlorophyll fluorescence signal and a corrected value of the lower chlorophyll fluorescence signal; based on the corrected value of the upper chlorophyll fluorescence signal and the corrected value of the lower chlorophyll fluorescence signal, a visual chlorophyll fluorescence parameter spatial distribution image is constructed.

[0092] On the other hand, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which is implemented when the computer program is executed by a processor to execute the open environment crop chlorophyll fluorescence parameter imaging detection method provided by the above methods, the method comprising: when it is detected that the sunlight intensity is greater than a preset threshold, acquiring a collected crop canopy hyperspectral image; performing crop environmental interference removal on the crop canopy hyperspectral image to obtain a crop canopy mask image; performing crop canopy segmentation on the crop canopy hyperspectral image based on the crop canopy mask image to obtain a crop canopy image; and performing crop canopy segmentation on the crop canopy hyperspectral image based on the crop canopy mask image to obtain a crop canopy image. According to the clustering algorithm, the crop canopy image is hierarchically segmented to obtain the upper leaf image and the lower leaf image; the upper chlorophyll fluorescence intensity of the upper leaf image and the lower chlorophyll fluorescence intensity of the lower leaf image are determined; based on the balanced brightness and the absorption of photosynthetically active radiation by the crop, the upper chlorophyll fluorescence intensity and the lower chlorophyll fluorescence intensity are compensated respectively to obtain the upper chlorophyll fluorescence signal correction value and the lower chlorophyll fluorescence signal correction value; based on the upper chlorophyll fluorescence signal correction value and the lower chlorophyll fluorescence signal correction value, a visual chlorophyll fluorescence parameter spatial distribution image is constructed.

[0093] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, i.e., they may be located in one location or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of the present embodiment. Persons of ordinary skill in the art will be able to understand and implement the present invention without inventive effort.

[0094] Through the above description of the embodiments, those skilled in the art will clearly understand that each embodiment can be implemented using software plus a necessary general-purpose hardware platform, or of course, hardware. Based on this understanding, the essence of the above technical solution, or the portion that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a magnetic disk, or an optical disk, and includes a number of instructions for causing a computer device (such as a personal computer, server, or network device) to execute the methods described in each embodiment or certain portions of the embodiments.

[0095] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for detecting chlorophyll fluorescence parameters of crops in an open environment by imaging, characterized in that: include: When it is detected that the sunlight intensity is greater than a preset threshold, the collected crop canopy hyperspectral image is obtained; removing crop environment interference from the crop canopy hyperspectral image to obtain a crop canopy mask image; performing crop canopy segmentation on the crop canopy hyperspectral image based on the crop canopy mask image to obtain a crop canopy image; Performing hierarchical segmentation based on the crop canopy image according to a clustering algorithm to obtain an upper leaf image and a lower leaf image; Determining the chlorophyll fluorescence intensity of the upper layer of the upper leaf image and the chlorophyll fluorescence intensity of the lower layer of the lower leaf image; Based on the balanced brightness and the photosynthetically active radiation absorbed by the crop, the upper chlorophyll fluorescence intensity and the lower chlorophyll fluorescence intensity are compensated respectively to obtain a corrected value of the upper chlorophyll fluorescence signal and a corrected value of the lower chlorophyll fluorescence signal; Based on the corrected value of the upper chlorophyll fluorescence signal and the corrected value of the lower chlorophyll fluorescence signal, a visual chlorophyll fluorescence parameter spatial distribution image is constructed.

2. The open environment crop chlorophyll fluorescence parameter imaging detection method according to claim 1, characterized in that: The method of compensating the upper chlorophyll fluorescence intensity and the lower chlorophyll fluorescence intensity based on the balanced brightness and the photosynthetically active radiation absorbed by the crop to obtain the upper chlorophyll fluorescence signal correction value and the lower chlorophyll fluorescence signal correction value includes: Determining an upper-layer balanced brightness of the upper-layer blade image and a lower-layer balanced brightness of the lower-layer blade image; Determining the absorption of photosynthetically active radiation by upper crops in the upper leaf image and the absorption of photosynthetically active radiation by lower crops in the lower leaf image; Based on the upper layer balanced brightness and the photosynthetically active radiation absorbed by the crops in the upper layer, the chlorophyll fluorescence intensity in the upper layer is compensated to obtain a corrected value of the chlorophyll fluorescence signal in the upper layer; Based on the lower layer balanced brightness and the photosynthetically active radiation absorbed by the crops in the lower layer, the chlorophyll fluorescence intensity of the lower layer is compensated to obtain a corrected value of the chlorophyll fluorescence signal of the lower layer.

3. The open environment crop chlorophyll fluorescence parameter imaging detection method according to claim 2, characterized in that: The determining of the upper-layer balanced brightness of the upper-layer blade image and the lower-layer balanced brightness of the lower-layer blade image includes: Based on the reflectivity of the crop canopy in the 550 nm band image, the reflectivity of the crop canopy in the 687 nm band image, and the reflectivity of the crop canopy in the 760 nm band image, the upper layer balanced brightness of the upper leaf image and the lower layer balanced brightness of the lower leaf image are determined respectively: in, Indicates the upper layer balanced brightness, Indicates the balanced brightness of the lower layer, Represents the coordinates of the pixel points in the mask area of the upper leaf image, Represents the coordinates of the pixel points in the mask area of the lower leaf image, Indicates the total number of pixels. represents the weighting coefficient of the 550 nm band, represents the reflectance of the crop canopy in the 550 nm band image, represents the weighting coefficient of the 687 nm band, represents the reflectance of the crop canopy in the 687 nm band image, represents the weighting coefficient of the 760 nm band, Represents the reflectance of crop canopy in 760 nm band image.

4. The open environment crop chlorophyll fluorescence parameter imaging detection method according to claim 2, characterized in that: The determining of the photosynthetically active radiation absorbed by the upper crop in the upper leaf image and the photosynthetically active radiation absorbed by the lower crop in the lower leaf image comprises: Based on the crop canopy reflectance in the near-infrared band and the crop canopy reflectance in the red edge band, the crop canopy normalized difference red edge vegetation index is determined; Determining the photosynthetically active radiation absorbed by the upper layer crops based on the photosynthetically active radiation value of the upper layer leaf image and the crop canopy normalized difference red edge vegetation index; The photosynthetically active radiation absorbed by the lower layer crops is determined based on the photosynthetically active radiation value of the lower layer leaf image and the crop canopy normalized difference red edge vegetation index.

5. The open environment crop chlorophyll fluorescence parameter imaging detection method according to claim 2, characterized in that: The determining of the chlorophyll fluorescence intensity of the upper layer of the upper leaf image and the chlorophyll fluorescence intensity of the lower layer of the lower leaf image comprises: Based on the Fraunhofer dark line extraction method, the chlorophyll fluorescence intensity of the upper layer of the upper leaf image and the chlorophyll fluorescence intensity of the lower layer of the lower leaf image are extracted in the 687 nm band and the 760 nm band of the Earth's oxygen absorption band reflectance spectrum, respectively; The upper chlorophyll fluorescence intensity includes: the chlorophyll fluorescence intensity of the upper 687 nm band and the chlorophyll fluorescence intensity of the upper 760 nm band; the lower chlorophyll fluorescence intensity includes: the chlorophyll fluorescence intensity of the lower 687 nm band and the chlorophyll fluorescence intensity of the lower 760 nm band.

6. The open environment crop chlorophyll fluorescence parameter imaging detection method according to claim 5, characterized in that: The method of compensating the upper chlorophyll fluorescence intensity and the lower chlorophyll fluorescence intensity based on the balanced brightness and the photosynthetically active radiation absorbed by the crop to obtain the upper chlorophyll fluorescence signal correction value and the lower chlorophyll fluorescence signal correction value includes: represents the corrected value of the upper chlorophyll fluorescence signal, represents the preset first coefficient, represents the chlorophyll fluorescence intensity in the upper 687 nm band, represents the preset second coefficient, represents the chlorophyll fluorescence intensity in the upper 760 nm band, Indicates the upper layer balanced brightness, It indicates that the upper crops absorb photosynthetically active radiation; represents the corrected value of the lower chlorophyll fluorescence signal, represents the preset third coefficient, represents the chlorophyll fluorescence intensity at 687 nm in the lower layer. represents the preset fourth coefficient, represents the chlorophyll fluorescence intensity in the lower 760 nm band, Indicates the balanced brightness of the lower layer, It indicates that the lower crops absorb photosynthetically active radiation.

7. An open environment crop chlorophyll fluorescence parameter imaging detection device, characterized in that: include: An acquisition module is used to acquire the collected crop canopy hyperspectral image when it is detected that the sunlight intensity is greater than a preset threshold; a removal module, configured to remove crop environmental interference from the crop canopy hyperspectral image to obtain a crop canopy mask image; a segmentation module, configured to perform crop canopy segmentation on the crop canopy hyperspectral image based on the crop canopy mask image to obtain a crop canopy image; a stratification module, configured to perform stratified segmentation based on the crop canopy image according to a clustering algorithm to obtain an upper leaf image and a lower leaf image; a determination module, configured to determine the chlorophyll fluorescence intensity of the upper layer of the upper leaf image and the chlorophyll fluorescence intensity of the lower layer of the lower leaf image; a compensation module for compensating the chlorophyll fluorescence intensity of the upper layer and the chlorophyll fluorescence intensity of the lower layer based on the balanced brightness and the photosynthetically active radiation absorbed by the crop, respectively, to obtain a corrected value of the chlorophyll fluorescence signal of the upper layer and the chlorophyll fluorescence signal of the lower layer; A construction module is used to construct a visual chlorophyll fluorescence parameter spatial distribution image based on the upper layer chlorophyll fluorescence signal correction value and the lower layer chlorophyll fluorescence signal correction value.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that: When the processor executes the computer program, the open environment crop chlorophyll fluorescence parameter imaging detection method according to any one of claims 1 to 6 is implemented.

9. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the open environment crop chlorophyll fluorescence parameter imaging detection method according to any one of claims 1 to 6 is implemented.

10. A computer program product comprising a computer program, characterized in that When the computer program is executed by a processor, the open environment crop chlorophyll fluorescence parameter imaging detection method according to any one of claims 1 to 6 is implemented.

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