60 results about "Bidirectional reflectance distribution function" patented technology

The invention relates to the technical field of laser transmission characteristic testing, in particular to a medium-wave infrared laser long-distance transmission attenuation characteristic external field testing method and device. The method is an indirect measurement method, a diffuse reflection plate is set up at a designated position of a transmission path, laser reaching the diffuse reflection plate is quantitatively measured through a detector, in combination with a bidirectional reflection distribution function of the diffuse reflection plate, the target reaching power of the laser transmitted through the long-distance atmosphere is obtained, and the target reaching power is calculated by comparing the target reaching power with the laser output power of a transmitting end. The laser long-distance transmission power attenuation characteristic can be obtained, and the problems that in current laser atmospheric transmission attenuation characteristic measurement, a laser radar does not have a medium-wave infrared measurement method, and the power of a specified position of a transmission path cannot be directly received and measured through a detector due to the fact that the size of a light spot is too large after long-distance transmission in direct measurement are solved. The measuring device is simple in structure and can support indirect measurement to obtain the long-distance transmission power attenuation characteristics of the medium-wave infrared laser.

The invention provides a method for measuring surface defects of automobile stamping parts by laser scanning, and belongs to the technical field of part surface defect detection.The method includes the steps that a high-curvature area and a low-curvature area are marked, a self-adaptive viewpoint planning path is constructed based on curvature distribution, dense sampling is adopted in the high-curvature area, and the low-curvature area is marked; a laser scanning device is driven to collect three-dimensional point cloud data, anisotropic thermal diffusion defect enhancement processing is performed on point cloud, a sliding window is adopted to calculate a multi-scale box counting fractal dimension to generate a fractal dimension field distribution diagram, a suspected defect area with the fractal dimension deviating from a normal reference value is identified, and a composite feature vector is extracted; a support vector machine classifier is input to judge a real defect, a defect depth value is corrected by adopting multispectral illumination to measure a bidirectional reflection distribution function parameter and combining with a phase measurement profilometry aiming at the condition of a large incident angle, a defect distribution diagram marked with defect information is generated, and the problem of low surface defect detection precision of a high-curvature area is solved.

The invention discloses a cross-medium uplink imaging simulation method based on a downlink light field, and relates to the field of electrical digital data processing, and the method comprises the following steps: building an analysis model of underwater target laser reflection characteristics based on a bidirectional reflection distribution theory; establishing an underwater forward scattering imaging model based on a cross-medium imaging simulation angle; performing simulation imaging on local geometric deformation by solving a geometric relationship between the offset of the pixel point and the surface gradient; simulating laser radar scanning imaging to obtain a cross-medium imaging simulation result; an ideal Lambert bidirectional reflection distribution function is utilized to generate a target uplink light field, target multiple scattering degradation imaging under a calm sea surface condition is solved through a point spread function model, and nonlinear mapping of a wave surface gradient field and light field phase deviation is constructed. Total factor dynamic simulation from laser emission, medium transmission to target imaging is completed.

The invention relates to the technical field of performance simulation, in particular to an LED display screen performance simulation method based on digital twinning, and the method comprises the following steps: constructing the three-dimensional geometry of an LED display screen, defining an LED lamp bead array topological structure, assigning a bidirectional reflection distribution function for the surface of the display screen, and assigning a thermal expansion coefficient and an elastic modulus for internal welding spots. According to the method, based on the defined three-dimensional geometric structure, the lamp bead array topological relation and material physical parameters are set, accurate mapping between a digital model and real equipment is achieved, and a performance response basis closer to reality is provided; by introducing real environment illumination distribution and a thermal cycle temperature range, environment load conditions changing along with time are obtained, the reduction degree of actual service conditions of the display screen is improved, and the authenticity of a performance prediction result is effectively improved; and further extracting stress and strain tensor data at the welding spot to form a welding spot damage record so as to realize quantitative evaluation of material damage.

The invention discloses an image fusion method and device based on infrared polarization imaging, and relates to the technical field of image processing. The method comprises the following steps: acquiring infrared polarization image data of a target scene; based on a polarization bidirectional reflection distribution function, decomposing the image into three kinds of feature original element images including total radiation intensity, linear polarization degree and polarization angle; processing according to a preset task mode to obtain a feature primitive image; calculating the regional information abundance measurement of each feature primitive image and the regional complementarity measurement between every two feature primitive images; and generating a fusion weight map through a normalized exponential function, and outputting a fusion image after carrying out weighted fusion on the feature primitive image. Through physical feature decomposition, task targeted processing and quantitative measurement fusion, the problems of low richness and low accuracy of fused image information in a traditional method are solved.

The invention discloses an automatic driving laser radar simulation method for high-fidelity material modeling, and the method comprises the steps: carrying out the high-fidelity modeling of a complete physical process of a single laser channel, and designing a complete technical chain from laser beam modeling, material reflectivity modeling, light path modeling to post-processing. In laser beam modeling, energy space distribution is accurately depicted by introducing an angle attenuation conical beam model; in material reflectivity modeling, a bidirectional reflection distribution function system covering Lambert body, specular reflection, transmission, retroreflection and general materials is established; in light path modeling, traditional single reflection hypothesis is broken through, time-resolved Monte Carlo path tracking and kernel density estimation are adopted, simulation of multi-path reflection and transmission effects is achieved, traditional model bottlenecks are broken through, complex optical phenomena are simulated, the generation mode has expandability and controllability, rare key scenes are efficiently synthesized, and the method is suitable for large-scale popularization and application. And the method has wide field extension potential and high technical universality.

The invention relates to the technical field of embroidery automation, in particular to an efficient optimization processing system and method for intelligently generating embroidery patterns, and the method comprises the following steps: collecting different styles of embroidery patterns, and establishing a style feature library; receiving the embroidery pattern and the style keyword expected to be fused, and generating the embroidery pattern by using a content recommendation algorithm; according to the pattern complexity, the fabric attributes and the color distribution, recommending an optimal stitching method and a line trend, and optimizing a stitching method combination and an embroidery path by using a reinforcement learning technology; performing analogue simulation, evaluating the color accuracy of the embroidery pattern through a bidirectional reflection distribution function and a chromatic aberration formula, calculating the stitch density, calculating the feature similarity of the generated pattern and the target style pattern, and analyzing the style consistency; and adjusting the pattern according to a simulation result to obtain a final embroidery pattern. According to the method, the intelligent style fusion model is built, the optimal fusion proportion is calculated, the unique first draft of the fusion style embroidery pattern is generated, and a designer is assisted to quickly realize style innovation.

This invention discloses an infrared temperature measurement correction method, apparatus, and system for three-dimensional curved surfaces. The infrared temperature measurement correction method includes: dividing the blade surface into at least two emissivity measurement regions according to the surface type of the blade being measured; acquiring the emissivity distribution of each emissivity measurement region on the blade surface at different temperatures; obtaining bidirectional reflection distribution functions for different surface types based on the projected energy of the infrared light source at different incident angles and the reflected energy received by the infrared camera at different detection angles; and obtaining the corrected measurement temperature based on the acquired emissivity distribution of each emissivity measurement region on the blade surface at different temperatures and the bidirectional reflection distribution functions for different surface types. This invention has a wide range of applications and high correction accuracy, and can be used to correct infrared temperature measurements of curved surfaces such as aero-engine turbine blades in complex environments, enabling non-contact, multi-dimensional, and online measurement of curved surfaces.

The invention relates to the technical field of machine vision and precision industrial detection, in particular to a metal stand board frame processing visual detection system, which comprises a data acquisition module, a processing module, a processing module, a processing module and a processing module, and is characterized in that the data acquisition module is used for acquiring visual detection data of a target object and loading a standard three-dimensional design file and bidirectional reflection distribution function parameters of the target object; the light field reference reconstruction module is used for constructing a virtual optical simulation environment of a target object and generating a simulation illumination image with defects; the dual difference extraction module is used for resolving shadow residual information on the surface of the target object and generating a theoretical residual space; the feature consistency judgment module is used for carrying out authenticity judgment on suspected features in the real residual data and outputting a defect judgment result of the target object based on the trajectory similarity; the feedback optimization module is used for adaptively adjusting the detection parameters based on the defect judgment result and outputting a final quality evaluation signal; according to the invention, the technical problem of low signal-to-noise ratio in a high-reflection environment is solved.

The present invention discloses a method for retrieving aerosol optical depth based on multi-band satellite data. The method comprehensively considers the influence of surface anisotropy and the variation of aerosol types, constructs a database of bidirectional reflectance distribution function (BRDF) of the surface, a candidate aerosol model for each region, and a cost function based on the retrieval results of AOD (550nm) for each band, simplifies the iterative calculation of AOD retrieval, realizes the simultaneous determination of AOD and aerosol types, and improves the retrieval accuracy of AOD.

The present invention relates to a gross primary productivity calculation system using deep learning, and a calculation method using same, wherein gross primary productivity can be estimated on the basis of Sentinel-2 reflectance and photosynthetically active radiation (PAR). In particular, by applying a deep learning model that does not require other weather variables and uses only "Nadir BRDF-adjusted reflectance (NBAR)" of Sentinel-2 and the PAR as input data, accuracy similar to or higher than that of existing models can be achieved, even though the gross primary productivity is derived using deep learning with significantly simplified input data.

The invention provides a broadband bidirectional reflectance distribution function (BRDF) measurement method and system of source-to-direction hemispherical reflectance (DHR), belongs to the technical field of bidirectional reflectance distribution function measurement, and is used for reflection spectrum distribution measurement of materials at different wavebands and detection angles. Existing researches on the aspects of BRDF measurement, modeling, application and the like mainly aim at visible light and near-infrared bands, spectrum BRDF measurement is directly achieved through a broadband light source, the method has the advantages of being rapid, simple and convenient, however, when an incident signal is decomposed to a wavelength point, energy is weak, and the measurement signal-to-noise ratio is affected. According to the invention, the BRDF measurement absolute value is traced to the direction hemisphere reflectivity by using the relation between the BRDF and the reflectivity and adopting a BRDF relative measurement method, so that the measurement of incident light and a detection solid angle is avoided. In the aspect of detection, a band-pass spectrum is selected by using an optical filter, and broadband BRDF measurement is carried out. According to the method and the system, complete measurement of the BRDF is realized, and the method and the system have important significance in the fields of infrared remote sensing and radiation temperature measurement.

A technique for estimating lighting from portraits involves generating a lighting estimate from a single image of a face using a machine learning (ML) system using multiple bidirectional reflectance distribution functions (BRDFs) as a loss function. In some embodiments, the ML system is trained using images of the face formed using HDR lighting calculated from LDR imagery. The technique involves training a lighting estimation model in a supervised manner using a dataset of portraits and their corresponding ground truth lighting.

The application discloses a cross-medium uplink imaging simulation method based on a downlink light field, relates to the field of electric digital data processing, and comprises the following steps: based on a bidirectional reflectance distribution theory, an analysis model of laser reflection characteristics of an underwater target is established; based on an imaging simulation angle of the cross-medium, an imaging model of underwater forward scattering is established; through solving the geometric relation between the offset of a pixel point and a surface gradient, local geometric deformation is simulated and imaged; laser radar scanning imaging is simulated, and a cross-medium imaging simulation result is obtained; an ideal Lambert bidirectional reflectance distribution function is used to generate a target uplink light field, a point spread function model is used to solve target multiple scattering degradation imaging under the condition of a calm sea surface, and through constructing a nonlinear mapping of a wave surface gradient field and a light field phase offset, full-element dynamic simulation from laser emission, medium transmission to target imaging is completed.

The invention provides a spacecraft autonomous modeling method for an unascertained near-earth asteroid target, and belongs to the technical field of spaceflight technology and application thereof, and the method comprises the steps: carrying out typical target extraction, BRDF (Bidirectional Reflection Distribution Function) measurement and characteristic measurement, and application scene measurement, and generating a digital target set; carrying out data processing on the spacecraft, wherein the data processing comprises on-board processing and on-board verification; carrying out algorithm ground verification, including algorithm correctness verification, algorithm clipping and acceleration, and algorithm edge deployment; the satellite-ground combined on-orbit application is specifically characterized in that when a spacecraft is close to a target, target modeling is carried out, data is acquired based on a sensor for on-device processing, target modeling is completed, then data is newly acquired by the sensor for on-device verification and model updating, and model reconstruction and ground processing are introduced by limiting the number of verification times. According to the method, the modeling accuracy can be improved, and the efficient autonomous modeling capability of the spacecraft is comprehensively formed.

The utility model relates to the technical field of bidirectional reflectance distribution function measurement, in particular to a novel bidirectional reflectance distribution function measurement system which comprises a detector rotating shaft module, a sample rotating detection table module, a light source rotating shaft module, a base supporting frame module, a lighting source, a spectrograph and a computer. By arranging the concentric support frame, the concentricity of the light source and the rotation center of the detector is ensured, the perpendicularity of the rotation shaft is also ensured, and the measurement precision of the system is improved; the design of the U-shaped tube of the rotating shaft provides dustproof protection for an internal light path, the stability of the light path is also ensured, the slotting design of the U-shaped tube facilitates fixation of the optical lenses, the distance between the lenses has an adjusting range, the sensitivity and the measurement precision of the device are improved, and the required cost is lower; according to the method, the bidirectional reflectance distribution function of the hemispherical space can be measured at a time, the measurement time is shorter, and the measurement method is simple, good in repeatability and suitable for various material surfaces.

The present invention provides a method and system for reconstructing sunlight-induced chlorophyll fluorescence based on satellite observation data, comprising: collecting and processing ground site observation data, temperature data, leaf area index data, MODIS bidirectional reflectance distribution function nadir-corrected reflectance data, enhanced vegetation index data, normalized difference moisture index data, global land cover classification data, OCO-2 and TROPOMI satellite observation SIF data; then using a machine learning method to reconstruct data using OCO-2 SIF and TROPOMI SIF as original data respectively; then, constructing an empirical formula between the two reconstructed SIF data and the site observation SIF, and optimizing to obtain estimated parameters at the site; then, calculating the estimated parameters of the empirical formula for each land cover type; finally, substituting the two reconstructed SIF data into the empirical formula to obtain a reconstructed SIF with site SIF information.

The present disclosure provides a satellite in-orbit radiation calibration method, device and electronic equipment, comprising: obtaining a set of atmospheric parameters associated with a calibration field; using the set of atmospheric parameters and a first image data set of a first satellite sensor in the calibration field area, constructing a bidirectional reflectance distribution function model of the calibration field; according to the center wavelength of each channel in the first satellite sensor, linearly interpolating the coefficients of the bidirectional reflectance distribution function model to obtain a target model with target coefficients, wherein the target model is a spectrally continuous bidirectional reflectance distribution function model; using a second image data set of a second satellite sensor in the calibration field area, the set of atmospheric parameters and the target model, determining the correction relationship between the simulated apparent radiance simulated by the target model and the actual apparent radiance; using a third image data set of a satellite sensor to be calibrated in the calibration field area, the set of atmospheric parameters, the target model and the correction relationship to calculate the radiation calibration coefficient of the satellite sensor to be calibrated.

A neural process prediction method for surface reflection characteristics based on micro-surface model guidance is proposed. Current BRDF representations based on analytical models or deterministic neural networks perform poorly in complex material modeling and sparse sampling scenarios. There is a lack of standardized and accurate probabilistic prediction methods for tasks related to quantifying prediction uncertainty and analyzing and controlling error propagation. This invention forms an initial model by training a network on a completed BRDF dataset and applying physical guidance constraints. Based on the initial model, a probabilistic model of the bidirectional reflection distribution function is formed to create a family of BRDF function probability distribution models. The prediction process for reflection characteristics in unobserved directions is then completed based on the established family of BRDF function probability distribution models.

The present application provides a kind of milk powder drying tower inner wall coking area image recognition method, by drying tower inner wall image, based on the preset three-dimensional model is carried out cylindrical coordinate reverse projection and obtains plane development diagram;Image is decomposed into specular and diffuse reflection component using bidirectional reflectance distribution function model, and the intrinsic image of diffuse reflection is retained;The image is input into encoder-decoder network preliminary segmentation, and the channel attention vector generated by deep feature is used to weight shallow feature in its skip connection, form semantic-guided texture feature map and fuse with decoder feature, output coking area probability map;Further construct conditional random field model and carry out fine segmentation, one-dimensional potential function is determined by pixel probability, binary potential function fuses label smoothness constraint and distance constraint based on intrinsic image, and the segmentation result is optimized by minimizing energy function;Independent connected region in segmentation map is post-processed, and according to the preset geometric feature threshold and the average probability value of region, false coking area is screened out, and the final recognition result is determined.

This invention discloses an angle-resolved measurement device for spectral polarization-dependent reflection (SVBRDF) of a material surface, belonging to the field of SVBRDF measurement technology. It includes: a light source module, a rotating rocker arm, a three-dimensional moving platform, a spatially fixed detector module, a hollow rotating motor, a bottom rotating motor, a sample holder motor, a plane mirror, and a rocker arm support. The three-dimensional moving platform is mounted on the bottom rotating motor, and the sample holder motor is mounted on the three-dimensional moving platform. The sample is fixed on the sample holder motor and rotates around its own center. The plane mirror is embedded in the rotating rocker arm, which is mounted on the hollow rotating motor, forming a spatial reflection characteristic measurement module for different regions of the material surface. The three-dimensional moving platform changes different regions of the sample surface as measurement targets. The bottom rotating motor changes the zenith angle of the incident light, and the sample holder motor changes the azimuth angle of the incident light.

In the optical filter, the BRDF (bidirectional reflectance distribution function) when visible light having a wavelength of 550 nm is incident at an incidence angle of 0 DEG is 0.1 [1 / sr] or more at an angle of-30 DEG to-5 DEG and 5 DEG to 30 DEG, and the BTDF (bidirectional transmittance distribution function) when infrared light having a wavelength of 850 nmm is incident at an incidence angle of 0 DEG is 0.1 [1 / sr] or more. (-1 DEG value) / (-10 DEG value) and (1 DEG value) / (10 DEG value) are 30 or less.

The invention provides an optical high-component load cross calibration method based on site BRDF (Bidirectional Reflection Distribution Function) characteristics. The method comprises the following steps: constructing a bidirectional reflectance distribution function characteristic library based on MODIS (Moderate Resolution Imaging Spectroradiometer) data; determining cross calibration data of the reference satellite load and the to-be-calibrated satellite load based on a preset calibration field; and performing field matching and information extraction on the cross calibration data by the model parameters, and determining a cross absolute radiometric calibration coefficient of the to-be-calibrated satellite load in a preset calibration field. Through a bidirectional reflection distribution function characteristic library, reflection characteristic differences under different observation geometric conditions can be corrected, and it is ensured that the consistency and comparability of data between different satellite loads are enhanced. Through the orbit parameters, the space-time consistency of the cross calibration data can be ensured. The spectral response difference and geometric difference between the reference satellite load and the to-be-calibrated satellite load are corrected through model parameters of the bidirectional reflectance distribution function characteristic library, the spectral characteristics of the reference satellite load and the to-be-calibrated satellite load are comprehensively matched, and the accuracy of the calibration result is ensured.

The application discloses a kind of for laser cladding laser reflection intensity spatial array test system and method, system includes: laser processing platform, XYZ three-axis ball screw, laser head, workpiece to be processed, light intensity sensor, data acquisition card and computer.System through different light intensity sensor corresponding different reflection angle and distance, record the position coordinates of each light intensity sensor in space, the light intensity sensor data obtained by recording is passed through bidirectional reflection distribution function, using measured data bidirectional reflection distribution function fitting reflection intensity spatial distribution, and the energy size of laser reflection of metal material in unit time is obtained, thus the change of laser energy absorption rate of material surface with time is calculated.The application realizes monitoring in the process of laser cladding workpiece material to the dynamic absorption rate of laser energy, and provides guarantee for the process quality control of laser thermal processing.

The invention discloses an adaptive dimming and energy consumption optimization method and device for an architectural lighting system based on digital twinning, electronic equipment and a storage medium, and relates to the technical field of intelligent optimization, and the method comprises the steps: obtaining physical space data through a photon event sensor and an event camera; updating the digital twin dynamic photon flow field model based on compressed sensing, a radiation transfer equation and a bidirectional reflection distribution function; generating and screening an optimal dimming strategy by using a confrontation generation optimization architecture; personalized adaptation is realized through light environment fingerprint matching and transfer learning; based on a ternary closed-loop self-evolution mechanism, the model and architecture parameters are corrected, and the energy consumption and the lighting effect are dynamically optimized. The light environment modeling precision and the dimming adaptability are improved, the building lighting energy consumption is reduced, intelligent and energy-saving upgrading of the lighting system is achieved, and different user preferences and scene requirements are met.

A system and method for obtaining light distribution information for a physical space, the system may include a camera for capturing a video feed of a physical space. The system may include a 3D model of the physical space and a Bidirectional Reflectance Distribution Function (BRDF) look-up table. The system may include an electronic processor configured to: map the video feed to the 3D model to form a real-time 3D model of the physical space, extract light properties associated with materials, apertures, and emissive light sources in the physical space from the real-time 3D model using the BRDF look-up table. The system may include a ray tracing algorithm for identifying a location of a light source, determining an angle of reflection from the light source on a surface within the physical space, determining a viewer position within the physical space, and determining a light characteristic at the viewer position from the light source.

The invention belongs to the field of computer graphics, and provides a flow matching network-based microstructure material rendering method and system, and the method comprises the steps: carrying out the pure sampling path tracking in a microstructure three-dimensional model, obtaining a plurality of important samples and corresponding sampling weights, carrying out the refusal sampling of the plurality of important samples through employing the sampling weights, and carrying out the refusal sampling of the plurality of important samples; obtaining residual important samples after sampling rejection and a sample survival rate; training a flow matching network model to output importance sampling distribution based on the residual importance samples after sampling rejection, and training a multilayer perceptron neural network model to output an energy attenuation item based on the residual importance samples after sampling rejection and a sample survival rate; and taking a product of an output result of the trained flow matching network model and an output result of the trained multi-layer perceptron neural network model as a final bidirectional reflection distribution function of the microstructure material so as to render the microstructure material. According to the method, rendering can be realized only by performing light sampling among the microstructures.

A filter with backscattering characteristics, wherein the filter has a linear transmittance of 60% or more for at least a portion of wavelengths in the wavelength range of 760 nm to 2000 nm. The bidirectional reflectance distribution function (BRDF) is defined as follows: BRDF(0°; 20°, -60°) is defined for the direction where the polar angle of the incident light's incident direction is 0° and the azimuth angle formed with the incident surface is 20° and the polar angle is -60°. Similarly, BRDF(30°; 20°, -60°) is defined for the direction where the polar angle of the incident light's incident direction is 30° and the azimuth angle formed with the incident surface is 20° and the polar angle is -60°. The value of the bidirectional reflectivity distribution function in the direction where the polar angle of the incident direction is 60°, the azimuth angle formed with the incident surface is 20°, and the polar angle is -60° is BRDF(60°; 20°, -60°), and when the incident light is light with at least a portion of the wavelengths within the visible light wavelength range, |BRDF(0°; 20°, -60°)-BRDF(30°; 20°, -60°)| / BRDF(0°; 20°, -60°) is 1.0 or less, and |BRDF(0°; 20°, -60°)-BRDF(60°; 20°, -60°)| / BRDF(0°; 20°, -60°) is 1.0 or less.