41 results about "Bidirectional reflectance distribution function" patented technology

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 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.

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 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 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 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.

The present application relates to the technical field of performance simulation, in particular to a LED display screen performance simulation method based on digital twinning, comprising the following steps: constructing a three-dimensional geometry of the LED display screen and defining the LED lamp bead array topology structure, assigning a bidirectional reflectance distribution function to the display screen surface, and assigning a thermal expansion coefficient and an elastic modulus to the internal solder joints. Based on the defined three-dimensional geometry structure, the lamp bead array topology relationship and the material physical parameters are set, the accurate mapping between the digital model and the real device is realized, and a more actual performance response basis is provided; by introducing the real environment light distribution and the thermal cycle temperature range, the time-varying environmental load conditions are obtained, the restoration degree of the actual service conditions of the display screen is improved, and the authenticity of the performance prediction results is effectively improved; further, the stress and strain tensor data at the solder joints are extracted to form solder joint damage records, and quantitative evaluation of material damage is realized.

Synchronized camera images and radar images are captured from a scene. A shared spatial representation of the scene is generated by encoding spatial features into a spatial hash table shared by a geometry encoder. The shared spatial representation is decoded using a geometry decoder to produce camera occupancy values and radar occupancy values. A normal multi-layer perceptron (MLP) is used to predict surface normals at spatial locations of the scene based on the shared spatial representation, and one or more bidirectional reflectance distribution function (BRDF) bases are used to model radar reflectance. Camera density and radar density values are generated by applying a density decoding function to the spatial representation using the BRDF bases and the predicted surface normals. Predicted camera images are rendered from the camera density and reflectance values. Predicted radar images are rendered from the radar density and reflectance values via a radar-specific volume rendering process.

The invention discloses a rapid training and rendering method and device for 3DGS relighting, and belongs to the technical field of image rendering, and the method specifically comprises the steps: completing one-time complete scene reconstruction of a whole scene based on an original 3DGS algorithm, pre-calculating hierarchical integral results corresponding to different roughness levels of a spherical harmonic basis function, and obtaining a final final result; pre-calculating an integral map of a bidirectional reflection distribution function, and performing ray tracing on a 3DGS scene to calculate color information and visibility information; during training, updating hierarchical environment incident light information for environment information in each iteration; during rendering, illumination items in a rendering equation are reconstructed by utilizing a pre-calculated integral result, an integral map, hierarchical environment incident light information, color information and visibility information, and attributes of Gaussian primitives are optimized through back propagation. According to the method and the device, the rendering efficiency can be better improved under the condition of keeping the high quality of the 3DGS.

The present application relates to the technical field of laser transmission characteristic test, and more particularly to a kind of middle wave infrared laser long-distance transmission attenuation characteristic field test method and device.The method is indirect measurement method, by building diffuse reflection board at specified position of transmission path, laser arriving on diffuse reflection board is quantitatively measured using detector, combined with bidirectional reflection distribution function of diffuse reflection board, the power to target after long-distance atmospheric transmission of laser is obtained, by comparing with the laser output power of emission end, the long-distance transmission power attenuation characteristic of laser can be obtained, solve the current laser atmospheric transmission attenuation characteristic measurement, laser radar has no middle wave infrared measurement method, and the problem that direct measurement cannot be measured by detector directly receiving after long-distance transmission spot size is too large, cannot be measured by detector directly receiving the power of specified position of transmission path.The measuring device structure is simple, and the long-distance transmission power attenuation characteristic of middle wave infrared laser can be indirectly measured.

The application discloses a low, slow and small aircraft infrared radiation characteristic calculation method and a storage medium. The calculation method adopts a modular design idea to realize low, slow and small aircraft infrared radiation brightness, projection area and infrared radiation intensity calculation functions. A simplified target geometric model is adopted to realize radiation component and target projection area calculation, a target environment radiation model is adopted to realize target self-radiation brightness and environment radiation brightness calculation, and a bidirectional reflection distribution function model is adopted to realize target reflection environment radiation component calculation. The low, slow and small aircraft infrared radiation characteristic calculation method is reasonable in modeling, reliable in calculation data, meets actual engineering design requirements, and can provide a theoretical basis and data support for index demonstration, project scheme design, imaging system simulation and the like of infrared thermal imaging equipment such as an infrared search and tracking system and an infrared reconnaissance system for low, slow and small aircrafts.

The invention discloses a hyperspectral polarization image waveband optimization method based on a pBRDF model, and the method comprises the following steps: measuring the roughness coefficients of the surfaces of a target and a background object, detecting the optical constant negative refractive indexes of the surfaces of the target and the background object under different wavelengths, and calculating the optical constant negative refractive indexes of the surfaces of the target and the background object according to the polarization bidirectional reflection distribution function of the target surface. Polarization degrees of a background and a target are calculated by using a Stokes vector to obtain a contrast ratio of the polarization degrees between the background and the target, and then a quantitative change relation between a wavelength and the contrast ratio of the polarization degrees of the background and the target is deduced by combining parameters of image acquisition equipment and a shooting environment influence; and a basis can be provided for optimal design and performance evaluation of the hyperspectral polarization image wave band.

The utility model relates to the technical field of BRDF rapid measuring systems, in particular to a novel BRDF rapid measuring system which comprises a base, an annular groove is formed in the base, a semicircular supporting frame is installed in the annular groove, and the axis of the semicircular supporting frame and the circle center of the base are arranged in an overlapped mode. According to the measuring system for rapidly measuring the BRDF distribution data on the surface of the material, the measuring system can be fixed through screws, the measuring angle can be manually changed, and the cost and complexity of the measuring system are greatly reduced while the measuring range and the measuring precision are guaranteed; the system can realize bidirectional reflectance distribution function measurement of a hemispherical space at one time, the measurement time is shorter, and in addition, the device is simple in measurement method, good in repeatability and applicable to measurement of various materials.

The invention provides a multi-aircraft combined real-time bidirectional reflectance distribution function modeling system and method, and the method comprises the steps: planning the flight height and spatial distribution of a multi-aircraft formation relative to a target, controlling the formation to synchronously collect the multi-angle spectral radiance of the target, the sun downlink irradiance, and the solar zenith angle and solar azimuth data, and calculating and outputting the BRDF model of the target in real time by using the data. According to the method, on-board real-time measurement is carried out on the sun downlink irradiance, so that the BRDF modeling precision is effectively improved. Meanwhile, multi-angle data can be synchronously acquired by adopting multiple unmanned aerial vehicles and air-ground collaborative observation and a single flight task, a traditional ground point distribution mode is replaced, the data acquisition efficiency is greatly improved, and the manpower and time cost is greatly reduced.