Method for synthesizing white light wide spectrum BRDF based on three primary colors

Abstract

A method for synthesizing white light wide spectrum BRDF based on three primary colors comprises the steps that firstly, a measuring system is built, and the spectral intensity of a sample to be measured and the spectral intensity of a standard reflecting plate under different wavelength conditions are measured respectively; calculating the spectrum BRDF data of the sample according to the spectrum ratio relation of the two; on this basis, BRDF data corresponding to three primary colors of red, green and blue are extracted from spectral BRDF data of the sample, the wavelength range of red light is 630-760 nm, the wavelength range of green light is 500-570 nm, and the wavelength range of blue light is 430-450 nm; weighting the BRDF data of each wave band according to the solar spectrum energy distribution to obtain a wide-spectrum BRDF corresponding to three primary colors; and finally, synthesizing the wide-spectrum BRDF according to the three-primary-color energy proportion in D65 standard white light to obtain white light BRDF data representing the reflection characteristics of the material under the white light irradiation condition. According to the method, a three-primary-color energy mapping and white light wide-spectrum synthesis strategy based on spectrum BRDF data is proposed for the first time, quantitative characterization of the real reflection characteristics of the material under the natural light condition is achieved, and a new data processing approach is provided for wide-spectrum scattering modeling and optical surface reflection characteristic research.

Description

Technical Field

[0001] This invention relates to the field of white light spectral BRDF technology, and in particular to a method for synthesizing white light broadband BRDF based on three primary colors. Background Technology

[0002] In the fields of optical detection and target surface characterization, the broadband bidirectional reflectance distribution function (BRDF) is a key parameter describing the scattering characteristics of an object's surface to incident light. Traditional BRDF measurements are mostly based on monochromatic light sources, and the results can reflect the material's reflection behavior at specific wavelengths. However, practical detection systems (such as those using natural light illumination, remote sensing imaging, and active / passive optical detection) often operate over a wide spectral range, especially when using visible white light as the illumination source. In these cases, the spectral response of the target surface's reflectance characteristics will be closely related to the spectral composition of the light source. Therefore, accurately obtaining the BRDF under broadband white light conditions is a crucial issue for achieving high-precision optical detection and surface imaging.

[0003] White light is not a single wavelength of light, but a composite light formed by the superposition of light energies from different wavelengths, and the contribution weights of different wavelengths in detection vary significantly. For example, in D65 standard white light that conforms to the visual response of the human eye, the energy weight ratio of the three primary color channels is... R : G : B =0.2126:0.7152:0.0722, which means that under broadband illumination conditions, the green band contributes the most significantly to brightness, followed by red, while the contribution of blue is relatively small. Therefore, a single wavelength BRDF cannot represent the true reflective properties of materials under actual visible light conditions and must be weighted and integrated based on the spectral characteristics of the light source.

[0004] However, current research on white light BRDFs mainly relies on direct measurements across the entire spectrum, and a quantitative framework for synthesizing broadband white light BRDFs using the characteristics of red, green, and blue primary color BRDFs has not yet been established. Patent application CN121067275A discloses a method for fabricating a white light source and a computer-readable storage medium. Its core idea is to fit a mixed color spectrum based on the spectral parameters corresponding to the three primary colors and preset initial weighting coefficients, and then optimize the weights of the three primary colors according to the target white light spectrum to obtain an optimized mixed color spectrum, thereby enhancing the saturation and contrast of the light source. This prior art focuses on the spectral synthesis and luminous performance optimization of white light sources, but does not address the measurement and modeling of broadband BRDFs based on material reflectivity. Summary of the Invention

[0005] To overcome the problems of the existing technology, the present invention aims to propose a method for synthesizing a broadband white light BRDF based on three primary colors. By acquiring the BRDF characteristics of the target in the red, green, and blue visible light primary color bands respectively, and using the white light spectral energy distribution to weightedly synthesize the three primary color BRDFs, a broadband white light BRDF can be obtained without direct measurement of the entire spectrum. Compared with the existing schemes that rely on overall white light reflectance measurement, this invention incorporates the independent reflectance behavior of materials in different spectral bands into the white light BRDF construction process for the first time. This strategy not only avoids the instrument complexity and light source consistency errors caused by direct broadband measurement, but also accurately quantifies the contribution of each band of reflectance characteristics to the white light scattering results, thereby significantly improving the accuracy and material adaptability of white light BRDF modeling.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A method for synthesizing broadband white light using three primary colors (BRDF), the method comprising: Step 1: Set up the measurement system and measure the spectral intensity values ​​of the sample and the standard reflector. Step 2: Calculate the spectral BRDF data of the sample based on the ratio of the spectral intensity of the sample and the standard reflector. Step 3: Divide the obtained spectral BRDF data into wavelength partitions and extract the BRDF data corresponding to the three primary colors: red light wavelength is 630-760nm, green light wavelength is 500-570nm, and blue light wavelength is 430-450nm. Step 4: Weight the extracted spectral BRDF data according to the solar spectrum energy distribution to obtain broadband BRDF data within the wavelength range corresponding to the three primary colors. Step 5: Calculate the broadband BRDF data based on the three primary color weights of D65 standard white light to obtain white light BRDF data based on the synthesis of the three primary colors.

[0007] Step 1 specifically involves: A measurement system was constructed, comprising an illumination module, an angle control module, a sample mounting module, a data acquisition module, and a control and data processing module. The illumination module provides a white light source, which, after collimation, illuminates the surface of the sample under test. The angle control module includes an incident arm and a scattering arm. The incident arm adjusts the angle of incidence of the incident light relative to the sample's normal, while the scattering arm rotates around the sample to change the angle of reception of the scattered light, thus achieving precise control of the bistatic scattering geometry. The sample mounting module, located at the center of the measurement system, fixes the sample or standard reflector and ensures that the center of the sample surface coincides with the rotation centers of the incident and scattered light axes. The data acquisition module, located at the end of the scattering arm, receives the intensity information of scattered light at corresponding wavelengths under different scattering angles. The control and data processing module is electrically connected to the illumination module, angle control module, and data acquisition module to synchronously control the changes in the light source wavelength, incident angle, and scattering angle, and to record and process the acquired scattered light signals. The spectral intensity value of the standard reflector under the same incident and reflection conditions is also measured. Spectral intensity values ​​of the sample ; in, Zenith angle, It is the azimuth angle. i and s These represent incident and scattered radiation, respectively. λ is the wavelength.

[0008] Step 2 specifically involves: The bidirectional reflectance of the sample is: ; in, The BRDF of the sample is represented as the spectrum. The BRDF is represented as the spectrum of a standard reflector. Therefore, the BRDF of the sample is: ; According to the BRDF definition, the incident intensity per unit area should not change with the incident angle. However, the incident angle changes continuously during the experiment, leading to a change in the irradiated area and thus increasing the incident illuminance. To ensure that the incident intensity does not change with the angle, it is necessary to divide the established spectral BRDF formula by... The BRDF spectrum of the sample becomes: ; Furthermore, the BRDF of a standard reflector is: ; in, The hemispherical reflectivity of the standard reflector is considered a constant in subsequent measurements because its surface reflectivity is fixed after manufacturing. Simplifying the above formula, the final expression for the BRDF spectrum of the sample is: .

[0009] Step 4 specifically involves: The formula for weighting the energy distribution of the solar spectrum is: , in Given the energy distribution of the AM 1.5 standard solar spectrum, the broadband BRDF of red light is obtained using the weighting formula. The broadband BRDF of green light is The broadband BRDF of blue light is .

[0010] Step 5 specifically involves: Using the spectral power distribution of a standard D65 white light source as the channel synthesis weights, the broadband BRDFs of the red, green, and blue channels are weighted and synthesized to obtain the expression for the white light BRDF: , in, R : G : B = 0.2126 : 0.7152 : 0.0722.

[0011] A system based on the synthesis of a broadband white light BRDF using three primary colors, for implementing the method described in steps 1 to 5, includes: A measurement system module is constructed to configure the light source, detector and optical path structure, and to acquire the spectral reflectance intensity data of the sample under test and the standard reflector at each specified wavelength. The spectral BRDF solving module calculates the spectral BRDF data of the sample based on the spectral ratio between the sample and the standard reflector. The three primary color extraction module extracts the corresponding red, green and blue BRDF data from the spectral BRDF data. The wavelength range of red light is 630–760 nm, the wavelength range of green light is 500–570 nm, and the wavelength range of blue light is 430–450 nm. The three-primary-color broadband BRDF solving module performs weighted processing on the BRDF data of each band according to the solar spectral energy distribution to obtain the broadband BRDF corresponding to the three primary colors; The white light broadband BRDF solving module synthesizes broadband BRDFs based on the energy ratios of the three primary colors in D65 standard white light, obtaining white light BRDF data that characterizes the reflectance properties of materials under white light illumination.

[0012] A device based on a three-primary-color synthesized white light broadband BRDF includes: A memory and a processor, wherein the memory is used to store computer programs; When the processor executes the computer program, it implements the method for synthesizing a broadband white light BRDF based on three primary colors as described in steps 1 to 5.

[0013] A computer-readable storage medium storing a computer program that, when executed by a processor, is capable of synthesizing a white-light broadband BRDF based on the method described in steps 1 to 5.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. Using the spectral ratio between the sample and the standard reflector to replace absolute reflectance calibration avoids the problems of high difficulty and significant error accumulation associated with absolute calibration. This ratio method can directly obtain the relative reflectance characteristics of the material at different wavelengths, simplifying the calculation process, increasing accuracy, and accurately describing the spectral scattering characteristics of the material.

[0015] 2. As a typical representative of natural illumination, the solar spectrum exhibits a non-uniform energy distribution. By weighting the solar spectrum, the contribution of each band of the BRDF can be made to match the actual incident energy ratio under natural illumination, thereby obtaining broadband reflectance characteristics that more closely resemble real-world illumination conditions. This step significantly improves the environmental adaptability and physical accuracy of white light BRDFs.

[0016] 3. D65 standard white light is an internationally recognized standard light source. Its RGB energy ratio (0.2126 : 0.7152 : 0.0722) reflects the consistency between the human eye's colorimetric response and standard daylight environment. By synthesizing white light BRDFs using this standard, a broadband white light BRDF with visual consistency and comparability under standard lighting conditions can be generated, making the results applicable to various fields such as standard optical measurement, target recognition, and material characterization.

[0017] In summary, the broadband BRDF construction method for synthesizing white light based on three primary colors proposed in this invention achieves an effective approximation of the broadband reflectance characteristics of white light by performing partitioning extraction, energy weighting, and three-primary-color reconstruction on the measured spectral BRDF. In this method, spectral BRDF data of red, green, and blue wavelengths represent the response of white light in different spectral ranges, and are weighted according to the energy distribution of the solar spectrum or standard light source. This ensures that the synthesized white light BRDF can reflect the physical reflectance characteristics of material surfaces under real broadband illumination while avoiding the complexity and equipment dependence of direct broadband measurement. This RGB synthesized white light model cleverly utilizes the advantages of stable and highly repeatable narrowband measurements, integrating multi-segment narrowband reflectance information into a unified broadband reflectance description. This not only improves the fidelity of the material's spectral characteristics but also provides a high-precision and highly operable technical path for broadband optical detection, imaging simulation, and material characterization. The comparison with the actual weighted white light BRDF shows that the deviation of the synthesis results is less than 5%, indicating that the proposed RGB synthesis white light method has high accuracy and strong applicability, and can provide a reliable data foundation for subsequent rough surface scattering analysis, target characteristic identification and verification of broadband coherent detection model. Attached Figure Description

[0018] Figure 1 This is a flowchart of a method for modeling a broadband white light BRDF based on the synthesis of three primary colors, provided in one embodiment of the present invention; Figure 2 Figure 1 shows a physical measurement device provided in one embodiment of the present invention; Figure 3 This is a comparison image of the RGB composite white light broadband BRDF of the physical sample 1 provided in one embodiment of the present invention in the 430-760nm band at 10 degrees of incidence and the white light broadband BRDF after direct measurement of solar weight. Figure 4 This is a comparison image of the RGB composite white light broadband BRDF of the physical sample 1 provided in one embodiment of the present invention in the 430-760nm band at 30 degrees of incidence and the white light broadband BRDF after direct measurement of solar weight; Figure 5 This is a comparison image of the RGB composite white light broadband BRDF of the physical sample 1 provided in one embodiment of the present invention in the 430-760nm band at 45 degrees of incident light and the white light broadband BRDF after direct measurement of solar weight. Figure 6 Figure 2 shows a physical measurement device provided in one embodiment of the present invention; Figure 7This is a comparison image of the RGB composite white light broadband BRDF of two physical samples in the 430-760nm band at 10 degrees of incidence and the white light broadband BRDF after direct measurement of solar weight, provided in one embodiment of the present invention. Figure 8 This is a comparison image of the RGB composite white light broadband BRDF of two physical samples in the 430-760nm band at 30 degrees of incidence and the white light broadband BRDF after direct measurement of solar weight, provided in one embodiment of the present invention. Figure 9 This is a comparison image of the RGB composite white light broadband BRDF of two physical samples in the 430-760nm band at 45° incident angle and the white light broadband BRDF after direct measurement of solar weight, provided in one embodiment of the present invention. Figure 10 This is a schematic diagram of the structure of an electronic device provided in another embodiment of the present invention. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the various embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details are presented in the embodiments of the present invention to facilitate a better understanding of the invention. However, the technical solutions claimed in the present invention can be implemented even without these technical details and various variations and modifications based on the following embodiments. The division of the following embodiments is for ease of description and should not constitute any limitation on the specific implementation of the present invention. The various embodiments can be combined with and referenced by each other without contradiction.

[0020] One embodiment of the present invention proposes a broadband BRDF modeling method for white light synthesized from three primary colors, which is applied to electronic devices. The electronic device can be a terminal or a server; this embodiment and the following embodiments will use a server as an example for illustration. The implementation details of the broadband BRDF modeling method for white light synthesized from three primary colors proposed in this embodiment are described below. The following content is only for ease of understanding and is not essential for implementing this solution.

[0021] The specific process of the broadband BRDF modeling method for white light synthesized from three primary colors proposed in this embodiment can be described as follows: Figure 1 As shown, it includes: Step 101: Set up a measurement system to measure the spectral intensity values ​​of the sample and the standard reflector.

[0022] The illumination module uses an HDL-Ⅱ-DH light source, the angle control module and sample mounting module use Zolix's TBR100 series, and the data acquisition module uses an AvaSpec-ULS2048x64-EVO spectrometer.

[0023] In practical implementation, under the same incident and reflection conditions, the spectral intensity value of the standard reflector... Spectral intensity values ​​of the sample ; in Zenith angle, It is the azimuth angle. i and s These represent incident and scattered radiation, respectively. λ is the wavelength.

[0024] Step 102: Obtain the BRDF data of the sample spectrum using the calculation formula for the sample and the standard reflector.

[0025] In one example, the bidirectional reflectance of the sample is: ; in, The BRDF of the sample is represented as the spectrum. The BRDF is represented as the spectrum of a standard reflector.

[0026] The BRDF of the sample is as follows: ; According to the BRDF definition, the incident intensity per unit area should not change with the incident angle. However, the incident angle changes continuously during the experiment, leading to a change in the irradiated area and thus increasing the incident illuminance. To ensure that the incident intensity does not change with the angle, it is necessary to divide the established spectral BRDF formula by... The BRDF spectrum of the sample becomes: ; Because the BRDF of a standard reflector is: ; in The hemispherical reflectivity of the standard reflector is considered a constant in subsequent measurements because its surface reflectivity is fixed after manufacturing.

[0027] Integrating the preceding steps, the final expression for the BRDF spectrum of the sample is: .

[0028] Beneficial effects: Using the spectral ratio of the sample and the standard reflector to replace absolute reflectance calibration avoids the problems of high difficulty and significant error accumulation associated with absolute calibration. This ratio method can directly obtain the relative reflectance characteristics of materials at different wavelengths, simplifying the calculation process, increasing accuracy, and accurately describing the spectral scattering characteristics of materials.

[0029] Step 103: Divide the measured spectral BRDF data into wavelength partitions and extract the BRDF data corresponding to the three primary colors.

[0030] The wavelength range corresponding to the red light channel is 630–760 nm, the wavelength range corresponding to the green light channel is 500–570 nm, and the wavelength range corresponding to the blue light channel is 430–450 nm.

[0031] Step 104: Weight the extracted spectral BRDF data according to the solar spectral energy distribution to obtain broadband BRDF data within the wavelength range corresponding to the three primary colors. This includes: The weighting formula is: , in, The energy distribution of the AM 1.5 standard solar spectrum is given. The broadband BRDF of red light is obtained using the weighting formula. The broadband BRDF of green light is The broadband BRDF of blue light is .

[0032] Beneficial effects: As a typical representative of natural illumination, the solar spectrum exhibits a non-uniform energy distribution. By using solar spectrum weighting, the contribution of each band of the BRDF can be made to match the actual incident energy ratio under natural illumination, thereby obtaining broadband reflectance characteristics that more closely resemble real-world illumination conditions. This step significantly improves the environmental adaptability and physical accuracy of white light BRDFs.

[0033] Step 105: Calculate the BRDF based on the weights of the three primary colors of D65 standard white light to obtain white light BRDF data based on the synthesis of the three primary colors. This includes: Using the spectral power distribution of a standard D65 white light source as the channel synthesis weights, the broadband BRDFs of the red, green, and blue channels are weighted and synthesized to obtain the expression for the white light BRDF: , in, R : G : B = 0.2126 : 0.7152 : 0.0722.

[0034] Beneficial effects: D65 standard white light is an internationally recognized standard light source. Its RGB energy ratio (0.2126 : 0.7152 : 0.0722) reflects the consistency between the human eye's colorimetric response and standard daylight environment. By synthesizing white light BRDFs using this standard, broadband white light BRDFs with visual consistency and comparability under standard lighting conditions can be generated, making the results applicable to various fields such as standard optical measurement, target recognition, and material characterization.

[0035] For the synthetic white light BRDF model proposed in this invention, in the embodiments, silver coating (such as...) was selected respectively. Figure 2 (as shown) and coated gold (as shown) Figure 6 Two samples made of different materials were subjected to spectral BRDF measurement experiments under various incident angles. Based on the measured spectral BRDF data, and by weighting the reflection contribution of different wavelengths according to the solar spectral energy distribution, the experimental white light broadband BRDF of the samples under natural illumination was obtained. Subsequently, this experimental white light BRDF was compared with a white light BRDF synthesized based on the reflection characteristics of the three primary colors of red, green, and blue. The comparison results for the silver-coated sample are shown below. Figure 3 , Figure 4 and Figure 5 As shown, the comparison results of the gold-coated samples are as follows: Figure 7 , Figure 8 and Figure 9 As shown in the results, the error between the white light BRDF synthesized from the three primary colors and the experimental white light BRDF is less than 5%, indicating a high degree of agreement. This demonstrates that the proposed three-primary-color synthesized white light broadband BRDF method can accurately reconstruct the reflection characteristics of materials under white light illumination, exhibiting good reliability and applicability. It can provide an effective data foundation for broadband scattering modeling, optical surface characteristic analysis, and the construction of coherent detection systems.

[0036] Another embodiment of the present invention relates to a broadband BRDF modeling system for white light synthesized from three primary colors, comprising: Construct a measurement system module, configure the light source, detector and optical path, and acquire the spectral reflectance intensity data of the sample under test and the standard reflector at each specified wavelength; The spectral BRDF solving module calculates the spectral BRDF data of the sample based on the spectral ratio between the sample and the standard reflector. The three primary color extraction module extracts the corresponding red, green and blue BRDF data from the spectral BRDF data, where the red light wavelength range is 630–760 nm, the green light wavelength range is 500–570 nm, and the blue light wavelength range is 430–450 nm. The three-primary-color broadband BRDF solving module performs weighted processing on the BRDF data of each band according to the solar spectral energy distribution to obtain the broadband BRDF corresponding to the three primary colors; The white light broadband BRDF solving module synthesizes broadband BRDF based on the energy ratio of the three primary colors in D65 standard white light, and obtains white light BRDF data that characterizes the reflectance properties of materials under white light illumination. Another embodiment of the present invention relates to an electronic device, such as Figure 10 As shown, it includes: at least one processor 201; and a memory 202 communicatively connected to the at least one processor 201; wherein the memory 202 stores instructions executable by the at least one processor 201, the instructions being executed by the at least one processor 201 to enable the at least one processor 201 to execute a three-primary-color synthesized white light broadband BRDF modeling method in the above embodiments.

[0037] The memory and processor are connected via a bus, which can include any number of interconnecting buses and bridges, connecting various circuits of one or more processors and memories. The bus can also connect various other circuits, such as peripheral devices, voltage regulators, and power management circuits, which are well known in the art and will not be described further herein. The bus interface provides an interface between the bus and the transceiver. The transceiver can be a single element or multiple elements, such as multiple receivers and transmitters, providing a unit for communicating with various other devices over a transmission medium. Data processed by the processor is transmitted over the wireless medium via an antenna, which further receives data and transmits it to the processor.

[0038] The processor manages the bus and general processing, and also provides various functions, including timing, peripheral interfaces, voltage regulation, power management, and other control functions. Memory is used to store data used by the processor during operation.

[0039] Another embodiment of the present invention relates to a computer-readable storage medium storing a computer program. When executed by a processor, the computer program implements the method embodiments described above.

[0040] That is, those skilled in the art will understand that all or part of the steps in the methods of the above embodiments can be implemented by a program instructing related hardware. This program is stored in a storage medium and includes several instructions to cause a device (which may be a microcontroller, chip, etc.) or processor to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, ROM (Read-Only Memory), RAM (Random Access Memory), magnetic disks, or optical disks.

[0041] Those skilled in the art will understand that the above embodiments are specific embodiments for implementing the present invention, and in practical applications, various changes in form and detail may be made without departing from the spirit and scope of the present invention.

Claims

1. A method for synthesizing broadband white light BRDF based on three primary colors, characterized in that, The method includes: Step 1: Set up the measurement system and measure the spectral intensity values ​​of the sample and the standard reflector. Step 2: Calculate the spectral BRDF data of the sample based on the ratio of the spectral intensity of the sample and the standard reflector. Step 3: Divide the obtained spectral BRDF data of the sample into wavelength partitions and extract the BRDF data of the corresponding three primary colors: red light wavelength is 630-760nm, green light wavelength is 500-570nm, and blue light wavelength is 430-450nm. Step 4: Weight the extracted spectral BRDF data according to the solar spectrum energy distribution to obtain broadband BRDF data within the wavelength range corresponding to the three primary colors. Step 5: Calculate the broadband BRDF data based on the three primary color weights of D65 standard white light to obtain white light BRDF data based on the synthesis of the three primary colors.

2. The method for synthesizing broadband white light BRDF based on three primary colors according to claim 1, characterized in that, Step 1 specifically involves: A measurement system was constructed, comprising an illumination module, an angle control module, a sample mounting module, a data acquisition module, and a control and data processing module. The illumination module provides a white light source, which, after collimation, illuminates the surface of the sample under test. The angle control module includes an incident arm and a scattering arm. The incident arm adjusts the angle of incidence of the incident light relative to the sample's normal, while the scattering arm rotates around the sample to change the angle of reception of the scattered light, thus achieving precise control of the bistatic scattering geometry. The sample mounting module, located at the center of the measurement system, fixes the sample or standard reflector and ensures that the center of the sample surface coincides with the rotation centers of the incident and scattered light axes. The data acquisition module, located at the end of the scattering arm, receives the intensity information of scattered light at corresponding wavelengths under different scattering angles. The control and data processing module is electrically connected to the illumination module, angle control module, and data acquisition module to synchronously control the changes in the light source wavelength, incident angle, and scattering angle, and to record and process the acquired scattered light signals. The spectral intensity value of the standard reflector under the same incident and reflection conditions is also measured. Spectral intensity values ​​of the sample ; in, Zenith angle, It is the azimuth angle. i and s These represent incident and scattered radiation, respectively. λ is the wavelength.

3. The method for synthesizing broadband white light based on three primary colors BRDF according to claim 1, characterized in that, Step 2 specifically involves: The bidirectional reflectance of the sample is: ； in, The BRDF of the sample is represented as the spectrum. The BRDF is represented as the spectrum of a standard reflector. Therefore, the BRDF of the sample is: ； According to the BRDF definition, the incident intensity per unit area should not change with the incident angle. However, the incident angle changes continuously during the experiment, leading to a change in the irradiated area and thus increasing the incident illuminance. To ensure that the incident intensity does not change with the angle, it is necessary to divide the established spectral BRDF formula by... The BRDF spectrum of the sample becomes: ； Furthermore, the BRDF of a standard reflector is: ； in, The hemispherical reflectivity of the standard reflector is considered a constant in subsequent measurements because its surface reflectivity is fixed after manufacturing. Simplifying the above formula, the final expression for the BRDF spectrum of the sample is: 。 4. The method for synthesizing a broadband white light BRDF based on three primary colors according to claim 1, characterized in that: Step 4 specifically involves: The formula for weighting the energy distribution of the solar spectrum is: ， in, Given the energy distribution of the AM 1.5 standard solar spectrum, the broadband BRDF of red light is obtained using the weighting formula. The broadband BRDF of green light is The broadband BRDF of blue light is .

5. The method for synthesizing a broadband white light BRDF based on three primary colors according to claim 1, characterized in that: Step 5 specifically involves: Using the spectral power distribution of a standard D65 white light source as the channel synthesis weights, the broadband BRDFs of the red, green, and blue channels are weighted and synthesized to obtain the expression for the white light BRDF: ， in, R : G : B = 0.2126 : 0.7152 : 0.0722.

6. A system based on the synthesis of a broadband white light BRDF using three primary colors, characterized in that: To implement the method according to any one of claims 1 to 5, comprising: The measurement system includes an illumination module, an angle control module, a sample mounting module, a data acquisition module, and a control and data processing module; it is used to configure the light source, detector, and optical path structure to acquire the spectral intensity values ​​of the sample under test and the standard reflector, respectively. The spectral BRDF solving module calculates the spectral BRDF data of the sample based on the spectral ratio between the sample and the standard reflector. The three primary color extraction module extracts the corresponding red, green and blue BRDF data from the spectral BRDF data. The wavelength range of red light is 630–760 nm, the wavelength range of green light is 500–570 nm, and the wavelength range of blue light is 430–450 nm. The three-primary-color broadband BRDF solving module performs weighted processing on the BRDF data of each band according to the solar spectral energy distribution to obtain the broadband BRDF corresponding to the three primary colors; The white light broadband BRDF solving module synthesizes broadband BRDFs based on the energy ratios of the three primary colors in D65 standard white light, obtaining white light BRDF data that characterizes the reflectance properties of materials under white light illumination.

7. A device based on a three-primary-color synthesized white light broadband BRDF, characterized in that: include: A memory and a processor, wherein the memory is used to store computer programs; When the processor executes the computer program, it implements the method of synthesizing a broadband white light BRDF based on three primary colors as described in any one of claims 1 to 5.

8. A computer-readable storage medium storing a computer program that, when executed by a processor, is capable of synthesizing a white-light broadband BRDF based on the method of any one of claims 1 to 5.

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