62 results about "Photometric stereo" patented technology

The invention discloses an image recognition system for industrial part defect detection, and particularly relates to the field of part defect detection, which comprises a multi-axis controllable light source array module, a high-speed polarization camera module, an edge computing node module, a double-branch semantic segmentation network module and a physical constraint post-processing module, according to the invention, through combination of time-sharing stroboscopic illumination and polarization image sequence acquisition, multi-dimensional perception of surface topography and material differences is realized; generating an elevation map and a normal map by using photometric stereo solution, constructing a differential rendering layer reverse matching CAD model, and extracting flash sensitive features; a double-branch U-Net network is adopted to fuse geometric and polarization characteristics, the characterization capability is enhanced through a trans-attention mechanism, and a pixel-level mask is output; and finally, mapping a two-dimensional result to a three-dimensional coordinate system by means of calibration parameters, carrying out geometric verification in combination with a tolerance zone and a height threshold value, and automatically generating a structured defect report containing position, size, grade and visual information.

An appearance determination device includes at least one processor. The at least one processor carries out a determination step of determining whether an object of determination is conforming or nonconforming, in accordance with a color image and a shape image, the color image being generated by photometric stereo and representing a color optical image of the object of determination, the shape image being generated by the photometric stereo and representing a shape of the object of determination.

The invention discloses a small-size visual tactile sensor based on a UV mark, and relates to the field of sensors. The visual tactile sensor solves the problem that the existing visual tactile sensor cannot realize high-precision force and texture perception on the same sensor at the same time, independently or in a time-sharing manner. A UV fluorescence labeling layer which is transparent under visible light and develops under ultraviolet light is arranged on the contact surface of the elastomer; the composite light source module comprises a UV light source unit and an RGB light source unit which can be independently controlled; the UV light source or the RGB light source is turned on through time-sharing switching, so that the image acquisition module can acquire mark point displacement images used for calculating contact force distribution or photometric stereo images used for reconstructing contact surface textures in a time-sharing manner. According to the invention, the problem that a traditional sensor cannot realize lossless switching of force and texture sensing functions on a single device is fundamentally solved by using the invisibility characteristic of the UV mark and a dual-light-source time-sharing working mode. The method is used for robot touch sensing.

A multispectral luminosity three-dimensional imaging system based on a nanocrystalline color conversion light source comprises a nanocrystalline light source module, an illumination control module, an image acquisition module and a three-dimensional reconstruction calculation module. The nanocrystalline light source module realizes multi-band accurate illumination; the illumination control module realizes independent lighting of a light source channel by channel based on a shift register and a single chip microcomputer, and outputs a synchronous trigger signal to a camera, so that each image corresponds to the unique light source direction; the image acquisition module acquires a multi-wavelength and multi-direction reflection image sequence, and uses a mask to limit an effective area; and the three-dimensional reconstruction calculation module estimates the light source direction, performs photometric stereo solution on each spectral channel, reconstructs a complete three-dimensional surface topography through cross-channel normal fusion and Poisson depth recovery, and generates a multispectral albedo graph and a pseudo-color normal graph. According to the invention, the stability and precision of normal estimation and depth recovery under a complex material surface are improved, and miniaturized, high-fidelity and multiband photometric three-dimensional imaging is realized.

This application proposes a method, controller, system, medium, and product for constructing a large-scale 3D reconstruction model. The method includes: acquiring training images; rendering the training images based on mesh rasterization to obtain a photometric stereo image; inputting the photometric stereo image into a preset explicit network to obtain a three-dimensional representation of the photometric stereo image; rendering the three-dimensional representation to obtain various rendered images, and predicting the albedo of the three-dimensional representation to obtain an albedo map; calculating the loss based on various rendered images, the albedo map, and the photometric stereo image using a preset loss function to obtain a loss value; and optimizing the explicit network based on the loss value to obtain a constructed large-scale 3D reconstruction model. Therefore, this application calculates the loss using various rendered images, the albedo map, and the photometric stereo image, and then optimizes the explicit network based on the loss value to obtain a constructed large-scale 3D reconstruction model, thereby improving the accuracy and quality of the 3D reconstruction model construction.

The invention discloses an intelligent material scanning device and method based on multi-angle polarized illumination, and the device comprises a box body, and a camera assembly, a polarization filter, an illumination assembly and a rotating table which are sequentially distributed in the box body from top to bottom, and the polarization filter is rotatably connected to the front end of an objective lens of the camera assembly. The lighting assembly is provided with a plurality of light sources distributed on the hemispherical surface in a longitude and latitude mode. The camera assembly obtains image data on the rotating table through the polarization filter. The objective of the invention is to design an intelligent material scanning device which is low in cost, high in precision and ecologically open, and based on the combination of a physical polarization means and a photometric stereo method, the generated material is real and uniform under different environment illumination.

The application provides an inflatable flexible visual-tactile device and method for measuring surface topography of an object. The device comprises an inflatable flexible visual-tactile sensor, a clamp and a support, the inflatable flexible visual-tactile sensor comprises a tactile perception unit and a visual imaging unit; when the surface of the object contacts the sensor, the flexible film and the external reflective layer in the tactile perception unit are deformed, and are attached to the surface of the object under the action of the internal air pressure of the inflatable flexible visual-tactile sensor; the deformed flexible film is reconstructed in three dimensions by using photometric stereo technology, so that the reconstruction of the whole surface topography of the object and the real-time measurement of the size are realized. The device adopts a sealed inflatable structure design, omits the skeleton support to expand the effective measurement range of the flexible film, and simultaneously makes the flexible film closely attached to the surface of the measured object under the action of the air pressure, so that the accurate surface concave-convex feature information of the object is collected, and the reconstruction accuracy and the measurement accuracy of the complex surface topography of the object are significantly improved.

The application discloses a kind of identification system and method based on photometric stereo, comprising: image acquisition module and data processing device, the image acquisition module is according to predetermined illumination mode and object rotation angle and is photographed image, forms a group of image data including multiple different illumination and angle conditions, and image data is uploaded to data processing device inside, the image acquisition device includes: top shell, controller, bottom shell, workpiece moving mechanism and image acquisition mechanism.The identification system and method based on photometric stereo, introduce more advanced fusion strategy, combine the physical illumination model of photometric stereo with the self-attention mechanism of physical perception, strengthen the physical interpretability of features, and then solve the problem that traditional fusion algorithm ignores the physical law of illumination, and realize the multi-angle image acquisition of different height levels of workpiece, obtain the image information of each side and front and back of workpiece, provide rich data for subsequent comprehensive analysis and three-dimensional reconstruction.

The present application belongs to the technical field of image processing, and particularly relates to a non-Lambertian surface photometric stereo model and method based on three-dimensional convolution. The present application discloses a non-Lambertian surface photometric stereo model based on three-dimensional convolution, which comprises an information fusion layer, an inter-frame feature extraction layer, a spatial feature extraction layer, a maximum pooling layer and a regression layer. The information fusion layer is used for fusing each image and corresponding light source information, so as to ensure one-to-one correspondence between the image and the light source in subsequent processing. The inter-frame feature extraction layer is used for extracting inter-frame information, obtaining information between input image frames, and estimating the normal map. The spatial feature extraction layer extracts structural information inside a single image for normal map recovery. The maximum pooling layer is used for dimension reduction, removal of redundant information, compression of features, simplification of network complexity, reduction of calculation amount and reduction of memory consumption.

Embodiments of the invention provide an image processing method and apparatus, and an electronic device. The method comprises the steps of obtaining images acquired by an image acquisition device when a lens is located at different optical axis positions in different illumination modes; generating a super depth-of-field depth map based on the obtained image; generating a photometric stereo normal vector diagram based on the obtained image, and generating a photometric stereo depth map based on the photometric stereo normal vector diagram; and correcting depth information in the same depth-of-field region in the super depth-of-field depth map according to a photometric stereo normal vector in the photometric stereo normal vector map, and correcting depth information in a low texture region in the super depth-of-field depth map according to a photometric stereo depth value in the photometric stereo depth map. The detail depth information in the same depth-of-field region can be corrected by the photometric stereo normal vector, and the missing depth information in the low-texture region can be restored by the photometric stereo depth value, so that the super depth-of-field depth map which can well reflect the depth details of the collection view field can be obtained.

The invention relates to a visual tactile sensor and a sensing method thereof. The visual tactile perception method is applied to a visual tactile sensor provided with a soft elastic body, and comprises the following steps: configuring a light source, and enabling the light source to irradiate a reflecting medium which is arranged on one side of a contact object of the soft elastic body and has a non-directional reflection characteristic or a partial non-directional reflection characteristic through the soft elastic body; wherein the reflecting medium comprises a first reflecting medium acting on internal environment reflection of the soft elastomer and a second reflecting medium for marking; the albedo of the first reflecting medium is different from that of the second reflecting medium; collecting a visual change image of a local position and a normal line generated by the reflection medium because the reflection medium contacts the object with the soft elastomer; and performing photometric stereo calculation on the visual change image to perceive the mechanical characteristic data of the soft elastomer in the current state. According to the method, the first reflection medium and the second reflection medium with different reflectivity are arranged, so that a normal resolving blind area caused by the fact that a mark destroys a photometric stereo reflection model is eliminated.

The present application relates to the field of industrial vision detection and automatic manufacturing of clothes, and particularly to a shirt automatic sewing detection system based on industrial vision; comprising: a motion phase monitoring module, a time sequence synchronization control module, a multi-partition directional lighting module, an image acquisition module, a normal vector calculation module and an abnormality discrimination module; monitoring the phase signal of the mechanical mechanism, extracting the target object's stationary time window, and generating a time-sharing trigger signal in the window to activate the independent lighting sectors of different spatial orientations in turn, synchronously executing continuous exposure to obtain multi-orientation illumination images of the same cloth area; based on the photometric stereo algorithm, calculating the surface normal vector data, extracting the three-dimensional topological features, and outputting the abnormality discrimination results of forms such as broken lines, missing seams, wrinkles, floating lines or bulges; the present application realizes high signal-to-noise ratio three-dimensional form detection of the same color and same quality shirt sewing area under high-speed sewing conditions.

The application discloses a kind of real-time surface defect detection device and method of automobile parts friction stir welding, including friction welding component limiting platform, for fixing the measured friction welding component, the measured surface of measured friction welding component has side-by-side first welding edge and second welding edge;Polarized imaging component and polarized light source are relatively displaced in the length direction of first welding edge and second welding edge;Polarized imaging component includes first polarized imaging component and second polarized imaging component;Polarized light source includes first polarized light source and second polarized light source, which simultaneously irradiate first welding edge and second welding edge, the polarization direction of first polarized light source and first polarized imaging component is perpendicular to the light source polarization direction of second polarized light source and second polarized imaging component.The application effectively solves the shortcoming that simple photometric stereo method cannot realize edge moving while photographing, and also solves the defect that simple binocular camera cannot realize defect information strengthening.

This invention discloses a method and system for constructing the true value of the microscopic morphology of the inner wall of a pipeline based on spatial domain triggering and dynamic shutter control, belonging to the field of pipeline inspection technology. It employs a dynamic time-division stroboscopic acquisition strategy based on spatial sampling consistency to ensure that the four image sequences required for photometric stereo vision overlap in physical space. It introduces dynamic shutter control based on instantaneous velocity to reduce the non-uniformity of imaging quality caused by the variable speed movement of multiple sensor modules. A robust photometric stereo algorithm is used to decouple and separate the pure pipe wall texture and micro-geometry, and reconstruct a high-precision 3D depth map. Finally, standardized true value data integrating position, texture, and geometry is constructed. This invention solves the problem in existing photometric stereo vision methods where multiple frames acquired under different lighting conditions are difficult to keep spatially consistent when the carrier is in continuous motion or experiencing mechanical micro-vibration, leading to significant errors in normal vector calculation and 3D reconstruction results.

The application relates to the field of building engineering detection and computer vision technology and discloses a building engineering quality defect visual identification and diagnosis method, which comprises the following steps: collecting a multi-illumination direction image sequence, separating an initial surface normal graph and an albedo graph by using photometric stereo calculation, inferring a normalized stiffness field graph through a deep neural network, constructing a discrete physical grid to apply a virtual load, solving a mechanical equilibrium equation to calculate a displacement field and performing a differentiable reverse rendering, reversely optimizing network parameters by using the difference between a rendered image and an observed image, and judging defects and outputting diagnosis data based on the optimized stiffness field graph. By introducing a self-supervised closed loop of physical mechanics constraints, the application effectively eliminates the interference of surface stains on detection, realizes quantitative inference from visual features to material constitutive properties, and improves the robustness and physical interpretability of defect identification.

This invention relates to a photometric stereoscopic 2.5D mold monitoring imaging method, comprising a pre-calibration step and a real-time monitoring step. The real-time monitoring step includes: S1: sequentially triggering multiple light sources from different directions to illuminate individually via pulse control signals, and simultaneously triggering a camera to acquire multiple corresponding mold surface images; S2: performing pixel-level synthesis of the multiple mold surface images to generate a stable image with uniform illumination; S3: calculating the pixel-level surface normal vector distribution based on the photometric stereoscopic method; S4: performing integral reconstruction of the normal vector distribution to generate a 2.5D height map; S5: detecting mold surface anomalies based on the stable image and / or the 2.5D height map. This invention, through multi-directional light source collaborative illumination and image synthesis strategy, accurately solves the problem of uneven illumination in unilateral bright and dark areas, obtaining a bright and clear detection image of the entire surface, while also possessing high stability and real-time performance, meeting the needs of industrial mold monitoring.

A real-time photometric stereo vision method and device based on an event camera, belonging to the field of computer vision, includes: lighting pattern design; simultaneously acquiring lighting signals and synchronization signals generated by lighting changes in the test object using an event camera; using the synchronization signals to calibrate the lighting direction when other events occur, achieving synchronous acquisition; constructing null vectors directly related to the surface normals of the test object from each pair of consecutively occurring events; and fusing the null vectors to solve for the surface normals. This invention reconstructs the surface normals of the test object from the basic model triggered by the event camera, reducing the cost of multiple cameras and synchronization; it utilizes the high event resolution of the event camera to acquire data under continuously changing light sources, increasing data sampling density and improving the quality of normal estimation; and it leverages the high dynamic range of the event camera to improve data acquisition speed and quality through native high dynamic range and compressed event representation.

The present application belongs to the technical field of food microorganism detection, and discloses a food microorganism colony intelligent identification and counting system based on deep learning; image data of different illumination angles of a culture dish is acquired, a meniscus transition zone is accurately identified, and the culture surface is divided into a central flat area and an edge meniscus area. A three-dimensional meniscus surface model is constructed based on photometric stereo method, a refraction offset is calculated to realize distortion correction, and brightness normalization is realized through Fresnel reflection analysis. An adaptive segmentation strategy is adopted for different areas, a position-aware attention mechanism based on radial distance coding is introduced, and the recognition effect is optimized by dynamically adjusting the lighting parameters to accurately process the cross-area colonies. The present application realizes high-precision colony identification and counting in the whole area of the culture dish, and improves the integrity and reliability of microorganism detection.

This invention discloses a detection method and system for detecting tire defects, comprising the following steps: acquiring original image sequences of the tire under four different illumination angles; calculating the normal vector data N and albedo data ρ of the target surface based on the original image sequence using a photometric stereo algorithm and a preset light source direction matrix L; constructing a feature image containing three independent physical dimensions based on the normal vector data N and albedo data ρ: a first feature map representing macroscopic geometric deformation, a second feature map representing the spectral properties of the material, and a third feature map representing microscopic texture deviation; merging the first, second, and third feature maps into multi-channel image data, and using it as input data for training or inference of a deep learning model to output whether the tire has defects and the type of defects; this invention constructs high signal-to-noise ratio input data to determine whether the tire has defects.

The invention relates to a visual tactile sensor and a detection method thereof. The visual tactile sense detection method is applied to a visual tactile sense sensor capable of carrying out photometric stereo and volume phase scattering comprehensive calculation according to the distribution condition of scattering media in the visual tactile sense sensor, and comprises the following steps: configuring a light source to illuminate a soft elastomer in the visual tactile sense sensor; collecting a visual change image of the scattering medium in the soft elastomer caused by contact deformation of the soft elastomer; and performing photometric stereo and volume phase scattering comprehensive calculation on the visual change image to obtain mechanical characteristics and / or deformation characteristics of contact deformation of the soft elastomer. According to the application, the scattering medium in gradient distribution is constructed in the soft elastomer, and a vulnerable surface reflecting film is replaced by a volume phase scattering mechanism, so that the durability and environmental adaptability of the sensor are remarkably improved. And the gradient distribution of the scattering medium forms sensitivity layering, so that high-sensitivity and wide-range detection is realized.

The invention discloses a method and a system for extracting ceramic attached fingerprint information by using a photometric stereo method, which are applied to the technical field of fingerprint extraction, and comprise the following steps: collecting ceramic inner wall fingerprint image information under light sources in different directions, and reconstructing a normal vector of a ceramic inner wall surface based on the photometric stereo method; wherein the number of the light sources in different directions is at least three; on the basis of a gradient domain fusion technology, fusing gradient information of images under light sources in different directions to estimate a surface normal, distributing corresponding weights for the gradient information by using a physics-based rendering model according to light source directions, and adjusting the weights and model parameters by using an optimization algorithm to minimize reconstruction errors; and traversing the reconstructed normal image by using a 3 * 3 template, detecting a neighborhood structure of each pixel point, identifying end points and bifurcation points, and removing false feature points by using an algorithm based on distance and edge position. According to the method, the fingerprint image extraction clearness and accuracy are effectively improved.

The invention provides a precise calibration tire laser engraving method and device. The precise calibration tire laser engraving method comprises the following steps that a motion executing mechanism with a laser engraving unit is moved to the position above a tire, and coarse positioning is conducted; a to-be-engraved area of the tire is precisely positioned in a photometric three-dimensional mode and a laser ranging mode and serves as standard coordinates for calibration; before the subsequent tire is engraved, the movement executing mechanism is moved to the position above the tire, and then the actual coordinates of the to-be-engraved area of the current tire are obtained in a photometric three-dimensional mode and a laser ranging mode; and adjusting the position of the motion execution mechanism according to the comparison result of the actual coordinate and the standard coordinate until the actual coordinate confirmed by the photometric stereo mode and the laser ranging mode is the same as the standard coordinate. According to the technical scheme, by fusing the multi-mode sensing information, high-precision visual servo calibration is achieved, the quality and efficiency of tire laser engraving are improved, and the defects of a traditional method in the aspects of precision, adaptability, stability and the like are overcome.

The application relates to the field of three-dimensional optical detection and intelligent measurement, and specifically discloses a heterogeneous Transform wafer three-dimensional detection system and method fusing physical priori, which comprises a data acquisition module configured to acquire multi-modal data of a wafer surface to be measured, wherein the multi-modal data at least comprises structured light data and photometric stereo data; a data processing module connected to the data acquisition module and configured to: construct a heterogeneous Transform model fusing physical priori; fuse and register the multi-modal data by taking the physical priori as a constraint to generate a high-precision three-dimensional model of the wafer surface. By effectively embedding physical priori knowledge into the Transform model, the fusion precision of the heterogeneous data is significantly improved; compared with traditional methods, the three-dimensional reconstruction precision can still be kept high under complex reflection and shielding conditions.

This invention belongs to the field of machine vision inspection technology for bearing cover defects, specifically relating to a method and system for detecting bearing cover defects. Addressing the technical problems of misjudgment due to black spots on the bearing cover surface and uneven lighting caused by curved surfaces, this invention employs a dual-station architecture: the first station uses multiple light sources at different angles to individually illuminate the bearing cover, combined with a photometric stereo algorithm to synthesize images, effectively highlighting deep defects at the bottom and suppressing interference from surface black spots, while simultaneously completing the inspection of incoming material orientation and dimensions; the second station, for groups of bearing covers, first uses combined light sources to acquire images for code dot quantity and coding integrity inspection, then switches the light source mode to eliminate curved surface interference and perform placement orientation inspection. This invention links visual inspection with a robotic arm, achieving full automation from material loading and multi-dimensional inspection to the rejection of defective products, significantly improving inspection accuracy and efficiency, and effectively reducing the misjudgment rate and production losses.

This invention relates to the field of image processing and character recognition technology, specifically disclosing an AI-powered intelligent recognition and full-process traceability system for furnace batch numbers of steel plates used in shipbuilding. By collecting reflectance data from multiple narrow bands on the steel plate surface, a multispectral image cube is generated. Linear spectral demixing is performed based on an endmember spectral library to reconstruct a matrix spectral image free from oil and oxide layer interference. Candidate image blocks containing furnace batch number characters are extracted through photometric stereo analysis and gradient enhancement. An encoding-decoding structure based on an attention mechanism outputs a furnace batch number text sequence. This text sequence is then associated with production batch information to generate a unique traceability identifier, which is stored in a database. This invention achieves highly robust recognition of furnace batch numbers and full-process closed-loop traceability under harsh environments, significantly improving character recognition accuracy and quality traceability efficiency.

The application discloses a kind of training-free snapshot photometric stereo vision methods based on spectral compression imaging, comprising: (1) setting multiple different wavelength monochromatic light sources to simultaneously irradiate object from different directions, form high-dimensional spectral-angle data cube;(2) the spectral-angle data cube is modulated in space by coded aperture, along the spectrum dimension is sheared translation by using optical dispersion element, finally integrates on single-channel image sensor, generates single two-dimensional gray compressed measurement image;(3) inverse problem model is constructed, and multiple illumination image sequence is decoupled and recovered from single two-dimensional gray compressed measurement image using iterative optimization algorithm based on physical drive;(4) the surface normal map of the measured object is predicted by inputting multiple illumination image sequence into pre-trained photometric stereo vision network module.The application can realize low-cost, high data efficiency and high physical fidelity three-dimensional reconstruction by single snapshot.

The invention discloses a three-dimensional imaging method based on photometric stereo of a line scanning camera, which comprises the following steps: 1, establishing a photometric stereo imaging system consisting of the line scanning camera, a multi-angle line light source and a synchronous control module, and obtaining an image sequence of a measured object under a multi-illumination condition; 2, processing the image sequence by using a highlight detection algorithm to obtain brightness information of the surface of the detected object, and then adaptively selecting an applicable reflection model from the image sequence; and 3, processing the image sequence by adopting a highlight suppression and normal robust estimation algorithm to obtain a surface normal graph of the measured object, and then obtaining a three-dimensional morphology graph of the measured object by utilizing fast Fourier transform, a Laplace operator and a self-adaptive histogram equalization method. According to the invention, high-precision three-dimensional detection and reconstruction of surface tiny defects can be realized to obtain a high-precision three-dimensional shape, and the method is suitable for various industrial winding tapes and flat plate materials, and has high resolution, high stability and good material adaptability.

In an example, a light system is provided that allows for increased reliability in directly detecting defects in components by capturing multiple different images of the component under different lighting conditions and using a photometric stereo technique to reconstruct a three-dimensional (3D) model of the component, which can be used to perform additional operations to increase the reliability of defect detection, such as measuring the height of variations in a surface of the component.

The invention belongs to the technical field of robot digital image acquisition and processing, and discloses a high-speed large-bandwidth image acquisition and three-dimensional reconstruction system and method for a handheld visual tactile dexterous hand, the high-speed large-bandwidth image acquisition and three-dimensional reconstruction system is composed of an FPGA board card and a GPU board card, the FPGA board card is integrated with a high-speed large-bandwidth image processing system, and the GPU board card is integrated with a 3D Gaussian three-dimensional reconstruction system; the high-speed large-bandwidth image processing system comprises an image acquisition unit, an image preprocessing unit, a photometric three-dimensional reconstruction unit and a feature extraction and fusion unit; the 3D Gaussian three-dimensional reconstruction system comprises a depth regression unit, a Gaussian parameter estimation unit and a 3D Gaussian reconstruction unit; according to the invention, high-speed large-bandwidth acquisition of fusion information of the palm eye and the visual tactile sensor, 3D Gaussian three-dimensional reconstruction and high-speed calculation of photometric stereo visual tactile sense can be realized, and the precision, speed and robustness of environment perception of the robot dexterous hand are improved.

The application provides a multi-light-source array self-calibratable photometric stereo three-dimensional measurement method, device, equipment and medium, comprising: a multi-light-source array module is uniformly arranged at the outer peripheral position of a support in a circular ring structure, a control module is connected with the multi-light-source array module and an imaging acquisition module, and a calibration processing module is connected with the control module and the imaging acquisition module; the control module is used for controlling the lighting sequence and light intensity of the multi-light-source array module, and realizing synchronous triggering with the imaging acquisition module; under a preset calibration mode, the multi-light-source array module rotates to irradiate a hemispherical calibration block with known diffuse reflection characteristics and shape parameters, the built-in sensor data is fused, the three-dimensional space coordinates, the incident direction and the actual light intensity of each light source are solved by using a geometric reflection model, the correction parameters are used for subsequent photometric stereo measurement, a three-dimensional topographic model is generated, and the measurement accuracy and system robustness are improved.