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78 results about "Vanishing line" patented technology

Method for creating distance map based on monocular camera machine vision

ActiveCN101789123ASolve the problem of difficult to create, expensive distance measurement equipmentImage enhancementImage analysisBoundary detectionVisual perception
The invention discloses a method for creasing a distance map based on monocular camera machine vision, which comprises the following steps: carrying out red component extraction on an image collected by a car camera for obtaining a baseline image; utilizing an edge detection operator for carrying out boundary detection on the baseline image, and further carrying out Hough transform on discontinuity points in the boundary for detecting a boundary line; carrying out the Hough transform on the boundary detection result for finding out straight lines in the image, then carrying out statistical weighting on end points of a plurality of straight lines approaching a vanishing point, taking the average value of detected column coordinates of a group of the straight lines as the column coordinate of the vanishing point of an optical axis of the camera, and taking the average value of row coordinates as the row coordinate position of a vanishing line; and respectively filling distance information from a projection line of the optical axis to the boundaries on the two sides, carrying out approximate treatment on scenes being far away from the vanishing line, eliminating the impacts of long-distance errors on defogging treatment and obtaining the distance-depth map of the scenes. The utilization of the method can solve the problems of difficult creation of the distance map and expensive distance measuring equipment during model defogging.
Owner:INST OF SEMICONDUCTORS - CHINESE ACAD OF SCI

A vision-based vehicle detection, tracking and early warning method

The invention provides a vision-based vehicle detection, tracking and early warning method. The method comprises the steps of collecting the image and calibrating the road vanishing line; defining andgraying the vehicle detection area, and then performing gray stretching on the vehicle detection area image according to the illumination intensity classification of the collected image; constructingthe training sample images and labeling the images as positive sample images and negative sample images manually; extracting the haar feature and LBP feature of the positive sample images and negative sample images to train an Adaboost cascade classifier; dividing the vehicle detection area into different domains, and detecting the vehicle by the Adaboost cascade classifier after training, and judging the vehicle twice according to the illumination intensity. When the vehicle is detected, the KCF target tracking method is used to track the vehicle. The vehicle is tracked, and the distance between the vehicle and the vehicle is calculated by the distance estimation method based on the position, and the collision time is calculated according to the vehicle speed and the distance between thevehicle and the vehicle to give the early warning. The method reduces the computational complexity and improves the vehicle detection accuracy.
Owner:WUHAN UNIV

Height measurement method based on video multi-target tracking

The invention discloses a height measurement method based on video multi-target tracking. The method includes the following steps that background modeling is conducted on video sequences collected by a camera, and foreground images are extracted through background subtraction; each frame image is mapped into an undirected network diagram G=<V, E>; an energy function is built; the built energy function is minimized, and label values of pixels of the current frame image are acquired, wherein the pixels belong to different targets and backgrounds,; different colors are given to the pixels which belong to the different targets, and a tracking frame of the multiple targets is determined; a vanishing point Vy where the camera is perpendicular to the horizontal plane and a vanishing line l of the horizontal plane are calculated; head feature points and foot feature points of the target to be detected in each frame image are extracted; the height of the targets to be detected in each frame image is calculated; the height measurement results of the multi-frame video sequences are merged, and the actual height of the targets to be detected is determined. According to the method, the camera does not need to be completely marked, only the vanishing point and the vanishing line of the horizontal plane need to be calculated, and therefore calculation complexity is reduced.
Owner:DALIAN NATIONALITIES UNIVERSITY

Pose measuring method based on coaxial circle characteristics of target

The invention relates to a pose measuring method based on coaxial circle characteristics of a target and belongs to the technical field of computer vision measurement. The pose measuring method is characterized in that the target is provided with coaxial circle characteristics, curve extraction and ellipse fitting technologies are combined to obtain two coaxial circular projection equations in an image, and circular point projection coordinates and vanishing line equation of a target plane are obtained by means of relation of absolute conic, vanishing line and circular points in projection geometry of the circle characteristics; by means of the polar line-pole theorem, circular center projection coordinates of two coaxial circles are obtained by the vanishing line equation of the plane, and pose and position information of the target is solved by taking the actual distance of the coaxial circles as prior condition and combining the projection of the circular points and the projection coordinates of the circular centers. The pose measuring method based on the coaxial circle characteristics of the target has the advantages that measuring of target pose is completed by means of a single target image of coaxial circle characteristics, so that the pose measuring method is simple to operate and applicable to measurement in real time. Meanwhile, without manual intervention, high-precision measurement is realized.
Owner:DALIAN UNIV OF TECH

Global calibration method of distributed multi-camera system

ActiveCN105809706AOvercoming the effects of image noiseImage enhancementImage analysisMulti cameraError function
The invention discloses a global calibration method of a distributed multi-camera system. The global calibration method includes the steps of using two-dimensional calibration targets formed by two groups of mutually orthogonal parallel straight lines to obtain relative position and attitude initial values through vanishing line equations and known target geometric dimensions based on vanishing point and vanishing line estimation cameras and relative positions and attitudes of the targets, and seeking minimum values of re-projection error functions so as to obtain optimum values of the cameras and the calibration targets; using auxiliary cameras to shoot adjacent target images to obtain a coordinate transformation matrix between the adjacent targets, seeking relative position and attitude initial values of the calibration targets relative to a reference target by an increment method and obtaining optimum values of transformation matrixes of the calibration targets relative to the reference target by seeking minimum values of re-projection error functions based on closed image sequences; through corresponding coordinate transformation, seeking optimum values of the transformation matrixes of the cameras relative to a reference camera to conduct global calibration of the distributed multi-camera system.
Owner:BEIHANG UNIV

Method for calibrating parabolic catadioptric camera by using properties of single sphere and circle tangent line

The invention discloses a method for calibrating a parabolic catadioptric camera by using properties of a single sphere and a circle tangent line. The method is characterized by taking a sphere in a space as a target. The method comprises the specific steps of: firstly, shooting three pictures containing the sphere from different positions by means of the parabolic catadioptric camera; secondly, acquiring antipodal image points according to relationship between image points and antipodal image points thereof in a parabolic catadioptric unit visual sphere model, so as to estimate an antipodal sphere image of a sphere image; thirdly, selecting a point from the sphere images, wherein a tangent line of each image point about the corresponding sphere image and a tangent line of the corresponding antipodal image point about the corresponding antipodal sphere image intersect at an image vanishing point through definition of the antipodal image points, an intersection point of the image vanishing point about polar lines of the sphere image and the antipodal sphere image is an image vanishing point, a straight line where the two image vanishing points are located is an image vanishing line,an intersection point of the image vanishing line and the sphere image is an image of circular points, and the three pictures provide the images of three groups of circular points; and finally, solving inner parameters of the camera by utilizing the constraint of the images of the circular points for an absolute conic curve image.
Owner:YUNNAN UNIV

Highway and urban road lane line identification method

The invention discloses a highway and urban road lane line identification method. The highway and urban road lane line identification method comprises the following steps of: obtaining a lane image through a camera, obtaining internal and external parameters of the camera by utilizing a camera parameter self-calibration method, and obtaining a lane plane vanishing line; performing gray-scale treatment of the lane image, and dividing an interested area; performing median filtering of the image obtained in the previous step; for the median filtered image, extracting textural features of a lane line by using Gabor transformation; describing edge features of the lane line by using multi-angle Haar features, and performing classified identification by utilizing an Adaboost classifier; for a structured road, designing a hyperbola combination model; and estimating parameters of the hyperbola combination model by utilizing an improved Ransac algorithm. By means of the highway and urban road lane line identification method disclosed by the invention, the lane line detection problem in complex environments, such as shadow, abrasion of the lane line and severe weather, can be solved; and furthermore, the highway and urban road lane line identification method has better real-time performance.
Owner:NANJING UNIV OF SCI & TECH

Camera self-calibration method based on absolute quadratic curve image

ActiveCN109064516ACalibration is simple, convenient and practicalGet rid of the bondageImage analysisEssential matrixImaging processing
The invention discloses a camera self-calibration method based on an absolute conic image, belonging to the technical field of image processing and camera calibration. The method comprises the following steps: extracting feature points and feature lines, calculating images of vanishing points, vanishing lines and imaginary circles; according to the image of the vanishing point and the imaginary circle, the image of the absolute quadratic curve is calculated and the intrinsic parameter matrix of the camera is obtained. The rotation matrix is calculated by using the orthogonal property of the rotation matrix, and the translation vector is calculated by using the position of the camera center in the world coordinate system. The Euler angle of the camera is calculated by comparing the erasingline calculated by perspective projection model with the erasing line obtained by fitting the erasing points. Normalization algorithm is used to solve the basic matrix, determine the constraint relationship between different images, and complete camera self-calibration. The invention has the advantages of designing a new target, which is simple, convenient and practical to calibrate, has wide practicability, improves the accuracy of data processing, and reduces the influence of coordinate transformation on data.
Owner:BEIHANG UNIV

Visual detection method for poses and apertures of coplanar equal-size multi-pore workpieces

The invention discloses a visual detection method for the poses and apertures of coplanar equal-size multi-pore workpieces. A binocular camera is used for carrying out shooting on a coplanar equal-size multi-pore workpiece and collecting left and right images, carrying out ellipse detection on a circular hole to obtain contour parameters of an ellipse, and calculating a vanishing line of a plane where the surface of the workpiece is located on the image; and acquiring a real projection image point according to the vanishing line; reconstructing space coordinates of the circle center of the circular hole by binocular vision according to the real projection image points, performing least square fitting on the space coordinates of the circle center to obtain a plane where the workpiece surface is located and a posture, and finally acquiring the aperture of the circular hole in the workpiece surface by using an elliptic equation and the plane where the workpiece surface is located. According to the method, the spatial pose and the surface circular hole diameter of the coplanar equal-size multi-pore workpiece are calculated with high precision, and problems that manual measurement is tedious, and complex detection equipment is high in manufacturing cost and difficult to maintain are solved.
Owner:ZHEJIANG UNIV

Camera calibration method and device, electronic equipment and storage medium

The invention is suitable for the technical field of image processing, and provides a camera calibration method and device, electronic equipment and a storage medium, and the camera calibration methodcomprises the steps: obtaining a first image, photographed by a camera, of a calibration plate at a first preset position and a second image, photographed by the camera, of the calibration plate at asecond preset position, acquiring a second preset position by rotating the calibration plate around a preset rotating shaft for a preset angle at the first preset position, wherein the preset rotating shaft is perpendicular to a preset plane, detecting an angular point in the first image and an angular point in the second image, and calculating a homography matrix according to the angular point in the first image and the angular point in a second image, using the homography matrix for describing the mapping relation between the second image and the first image, calculating the vanishing lineof the preset plane according to the homography matrix so that the calculation accuracy of the vanishing line of the preset plane is improved, calibrating the camera according to the vanishing line ofthe preset plane so that calibration precision of the camera is improved.
Owner:UBTECH ROBOTICS CORP LTD
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