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3478 results about "Feature matching" patented technology

Improved method of RGB-D-based SLAM algorithm

InactiveCN104851094AMatching result optimizationHigh speedImage enhancementImage analysisPoint cloudEstimation methods
Disclosed in the invention is an improved method of a RGB-D-based simultaneously localization and mapping (SLAM) algorithm. The method comprises two parts: a front-end part and a rear-end part. The front-end part is as follows: feature detection and descriptor extraction, feature matching, motion conversion estimation, and motion conversion optimization. And the rear-end part is as follows: a 6-D motion conversion relation initialization pose graph obtained by the front-end part is used for carrying out closed-loop detection to add a closed-loop constraint condition; a non-linear error function optimization method is used for carrying out pose graph optimization to obtain a global optimal camera pose and a camera motion track; and three-dimensional environment reconstruction is carried out. According to the invention, the feature detection and descriptor extraction are carried out by using an ORB method and feature points with illegal depth information are filtered; bidirectional feature matching is carried out by using a FLANN-based KNN method and a matching result is optimized by using homography matrix conversion; a precise inliners matching point pair is obtained by using an improved RANSAC motion conversion estimation method; and the speed and precision of point cloud registration are improved by using a GICP-based motion conversion optimization method.
Owner:XIDIAN UNIV

Method and system for authenticating shielded face

The invention discloses a method and a system for authenticating a shielded face, wherein the method comprises the following steps: S1) collecting a face video image; S2) preprocessing the collected face video image; S3) performing detection calculation on the shielded face, evaluating a position of a face image by utilizing a three-frame difference method according to motion information of a video sequence, and further confirming the position of the face according to an Adaboost algorithm; and S4) performing authenticating calculation on the shielded face, dividing a face sample into a plurality of sub-blocks, performing shielding distinguishment on the sub-blocks of the face by adopting a SVM(Support Vector Machine) binary algorithm combined with a supervising 1-NN k-Nearest neighbor method, if the sub-blocks are shielded, directly abandoning the sub-blocks, and if the sub-blocks are not shielded, extracting a corresponding LBP (Length Between Perpendiculars) textural feature vector for performing weighting identification, and then using a classifier based on a rectangular projection method to reduce feature matching times. According to the method for authenticating the shielded face, the detection rate and the detection speed for the local shielded face are effectively increased.
Owner:SUZHOU UNIV

Method and system for tracking, three-dimensionally superposing and interacting target object without special mark

The invention belongs to the technical field of computer application, and provides a method and a system for tracking, three-dimensionally superposing and interacting a target object without a special mark. The method comprises the following steps of: firstly, segmenting the target object from an image shot by a camera, and creating a characteristic template of the target object automatically; next, directly identifying the target object by utilizing the characteristics of the target object, and calculating three-dimensional information (relative to the camera) of the target object; and finally, superposing a virtual object or an animated picture in a three-dimensional coordinate system in a realistic space through a graphics engine in real time. According to the method disclosed by the invention, video images and template images are subjected to characteristic matching via a surf algorithm so as to finish the calibration on the camera, so that real-time tracking and real-time three-dimensional superposing of the target object without the special mark are realized; for each frame of video image, three-dimensional coordinate information of the target is calculated in real time, so that interaction of a person or an object in reality with a virtual person or a virtual object is realized; and therefore, the method and the system disclosed by the invention are relatively high in degree of automation and have relatively popularization and application values.
Owner:樊晓东

Unmanned aerial vehicle aerial photography sequence image-based slope three-dimension reconstruction method

InactiveCN105184863AReduce in quantityReduce texture discontinuities3D modellingVisual technologyStructure from motion
The invention relates to an unmanned aerial vehicle aerial photography sequence image-based slope three-dimension reconstruction method. The method includes the following steps that: feature region matching and feature point pair extraction are performed on un-calibrated unmanned aerial vehicle multi-view aerial photography sequence images through adopting a feature matching-based algorithm; the geometric structure of a slope and the motion parameters of a camera are calculated through adopting bundle adjustment structure from motion and based on disorder matching feature points, and therefore, a sparse slope three-dimensional point cloud model can be obtained; the sparse slope three-dimensional point cloud model is processed through adopting a patch-based multi-view stereo vision algorithm, so that the sparse slope three-dimensional point cloud model can be diffused to a dense slope three-dimensional point cloud model; and the surface mesh of the slope is reconstructed through adopting Poisson reconstruction algorithm, and the texture information of the surface of the slop is mapped onto a mesh model, and therefore, a vivid three-dimensional slope model with high resolution can be constructed. The unmanned aerial vehicle aerial photography sequence image-based slope three-dimension reconstruction method of the invention has the advantages of low cost, flexibility, portability, high imaging resolution, short operating period, suitability for survey of high-risk areas and the like. With the method adopted, the application of low-altitude photogrammetry and computer vision technology to the geological engineering disaster prevention and reduction field can be greatly prompted.
Owner:TONGJI UNIV

Target object recognition and positioning method based on color images and depth images

ActiveCN106826815AImprove the efficiency of finding the target objectEffective reflection of the characteristicsProgramme-controlled manipulatorScene recognitionColor imageColor recognition
The invention relates to a target object recognition and positioning method based on color images and depth images. The method is characterized by comprising the following steps that (1), a target region is confirmed by a robot by the adoption of the remote HSV color recognition, the distance between the robot and the target region is obtained according to the RGB color images and the depth images, and the robot conducts navigation and path planning and moves to the portion near the target region; (2), when the robot reaches the portion near the target region, through the SURF feature point detection, the RGB feature information of the target object is obtained, feature matching is conducted on the RGB feature information and the pre-stored RGB feature information of the target object, and if the feature of the target object accords with an existing object model, the target object is positioned; and (3), the RGB color images are collected to an imaging plane, the two-dimensional coordinates of the target object in the imaging plane are obtained, and the relative distance between the target object and a camera is obtained through the depth images, so that the three-dimensional coordinates of the target object are obtained. By the adoption of the target object recognition and positioning method, the category of the object can be judged quickly, and the three-dimensional coordinates of the object can be determined quickly.
Owner:JIANGSU CAS JUNSHINE TECH

Robot positioning and map construction system based on binocular vision features and IMU information

Disclosed is a robot positioning and map construction system based on binocular vision features and IMU information, comprising a binocular information collection, feature extraction and matching module, an improved IMU initialization and motion module, a visual SLAM algorithm initialization and tracking module, a local mapping module and a loop detection and optimization module. The binocular information collection, feature extraction and matching module comprises a binocular ORB feature extraction sub-module, a binocular feature matching sub-module and an IMU information collection sub-module. The improved IMU initialization and motion module includes an IMU angular rate deviation estimation sub-module, a gravity acceleration prediction sub-module, an IMU acceleration deviation estimation sub-module and an IMU pre-integration sub-module. The visual SLAM algorithm initialization and tracking module includes a tracking inter-frame motion sub-module and a key frame generation sub-module. The local mapping module includes a new key frame insertion sub-module, a local BA optimization sub-module and a redundant key frame elimination sub-module. The loop detection and optimization module includes a loop detection sub-module and a global optimization sub-module. The invention provides a robot positioning and map construction system based on binocular vision features and IMU information, which has good robustness, high accuracy and strong adaptability.
Owner:ZHEJIANG UNIV OF TECH

A fast monocular vision odometer navigation and positioning method combining a feature point method and a direct method

ActiveCN109544636AAccurate Camera PoseFeature Prediction Location OptimizationImage enhancementImage analysisOdometerKey frame
The invention discloses a fast monocular vision odometer navigation and positioning method fusing a feature point method and a direct method, which comprises the following steps: S1, starting the vision odometer and obtaining a first frame image I1, converting the image I1 into a gray scale image, extracting ORB feature points, and constructing an initialization key frame; 2, judging whether thatinitialization has been carry out; If it has been initialized, it goes to step S6, otherwise, it goes to step S3; 3, defining a reference frame and a current frame, extracting ORB feature and matchingfeatures; 4, simultaneously calculating a homography matrix H and a base matrix F by a parallel thread, calculating a judgment model score RH, if RH is great than a threshold value, selecting a homography matrix H, otherwise selecting a base matrix F, and estimating a camera motion according to that selected model; 5, obtaining that pose of the camera and the initial 3D point; 6, judging whetherthat feature point have been extracted, if the feature points have not been extracted, the direct method is used for tracking, otherwise, the feature point method is used for tracking; S7, completingthe initial camera pose estimation. The invention can more precisely carry out navigation and positioning.
Owner:GUANGZHOU UNIVERSITY
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