86 results about "Point correspondence" patented technology

Camera motion is determined in a three-dimensional image capture system using a combination of two-dimensional image data and three-dimensional point cloud data available from a stereoscopic, multi-aperture, or similar camera system. More specifically, a rigid transformation of point cloud data between two three-dimensional point clouds may be more efficiently parameterized using point correspondence established between two-dimensional pixels in source images for the three-dimensional point clouds.

Camera motion is determined in a three-dimensional image capture system using a combination of two-dimensional image data and three-dimensional point cloud data available from a stereoscopic, multi-aperture, or similar camera system. More specifically, a rigid transformation of point cloud data between two three-dimensional point clouds may be more efficiently parameterized using point correspondence established between two-dimensional pixels in source images for the three-dimensional point clouds.

A monocular motion stereo-based automatic free parking space detection system is disclosed. The system acquires image sequences with a single rearview fisheye camera, three-dimensionally reconstructs the vehicle rearview by using point correspondences, and recovers metric information from a known camera height to estimate the positions of adjacent vehicles thereby detecting the free parking spaces. By using de-rotation-based feature selection and 3D structure mosaicking the degradation of the 3D structure near the epipole is solved and it is not necessary to use the unreliable odometry due to its accuracy depending on road conditions.

A method and system for building a statistical four-chamber heart model from 3D volumes is disclosed. In order to generate the four-chamber heart model, each chamber is modeled using an open mesh, with holes at the valves. Based on the image data in one or more 3D volumes, meshes are generated and edited for the left ventricle (LV), left atrium (LA), right ventricle (RV), and right atrium (RA). Resampling to enforce point correspondence is performed during mesh editing. Important anatomic landmarks in the heart are explicitly represented in the four-chamber heart model of the present invention.

A method for calibrating real and virtual views includes tracking a calibration screen, wherein a real reference point, generated by a real reference point generator, is projected on the calibration screen, aligning a view of a virtual reference point to a view of the real reference point in a display, wherein the real reference point generator and the display have a fixed relative position, determining a point correspondence between the virtual reference point and the real reference point, and determining one or more parameters for rendering a virtual object in the real scene.

A method for calibrating real and virtual views includes tracking a calibration screen, wherein a real reference point, generated by a real reference point generator, is projected on the calibration screen, aligning a view of a virtual reference point to a view of the real reference point in a display, wherein the real reference point generator and the display have a fixed relative position, determining a point correspondence between the virtual reference point and the real reference point, and determining one or more parameters for rendering a virtual object in the real scene.

Methods and apparatus for camera calibration based on multiview image geometry. A lens profiling module may estimate two or more mathematical models for correcting aberrations in images in a single pass from a set of calibration images captured with a camera / lens combination. For example, the module may estimate the lens aberrations of geometric distortion, lateral chromatic aberration, and vignette models in a single pass. The module may determine point correspondences, 3D transformations, and camera intrinsics for views of calibration charts captured in the images. The module estimates the mathematical models for the two or more types of aberrations from the information determined from the views of the calibration charts. The module may automatically determine an optimal model complexity when estimating the mathematical models. The estimated models may be written or appended to a lens profile for the camera / lens combination used to captured the calibration images.

The invention relates to a method for estimating an image relation model for two or more related images based on a plurality of point correspondences. The method includes using a weighted random sampling algorithm to repeatedly draw subsets of point correspondences for generating model estimates, evaluating said model estimates for the full plurality of the point correspondences, and updating weights associated with each of the point correspondences in the random sampling algorithm based on information obtained in said evaluating.

Robust techniques for self-calibration of a moving camera observing a planar scene. Plane-based self-calibration techniques may take as input the homographies between images estimated from point correspondences and provide an estimate of the focal lengths of all the cameras. A plane-based self-calibration technique may be based on the enumeration of the inherently bounded space of the focal lengths. Each sample of the search space defines a plane in the 3D space and in turn produces a tentative Euclidean reconstruction of all the cameras that is then scored. The sample with the best score is chosen and the final focal lengths and camera motions are computed. Variations on this technique handle both constant focal length cases and varying focal length cases.

A method for processing an anaglyph image to produce an enhanced image is described. The method includes receiving an anaglyph image; determining first and second feature locations from the first and second digital image channels and producing feature descriptions of the feature locations; and using the feature descriptions to find feature point correspondences between the first and second feature locations of the first and second digital image channels. The method further includes determining a warping function for the second digital image channel based on the feature point correspondences; producing an enhanced second digital image channel by applying the warping function to the second digital image channel; and producing an enhanced image from the first digital image channel and the enhanced second digital image channel.

Poses of a movable camera relative to an environment are obtained by determining point correspondences from a set of initial images and then applying 2-point motion estimation to the point correspondences to determine a set of initial poses of the camera. A point cloud is generated from the set of initial poses and the point correspondences. Then, for each next image, the point correspondences and corresponding poses are determined, while updating the point cloud.

A system for generating a ground truth dataset for motion planning is disclosed. The system includes sensors for data acquisition for motion planning of a vehicle, the sensors including a LiDAR; a calculating module configured to calculate LiDAR poses in response to data from the sensors and generate undistorted LiDAR scans; an extracting module configured to extract static points from a target undistorted LiDAR scan and generate a LiDAR static-scene point cloud; and a generating module configured to generate sparse image point correspondences for each pair of images, using the LiDAR static-scene point cloud.

A monocular motion stereo-based automatic free parking space detection system is disclosed. The system acquires image sequences with a single rearview fisheye camera, three-dimensionally reconstructs the vehicle rearview by using point correspondences, and recovers metric information from a known camera height to estimate the positions of adjacent vehicles thereby detecting the free parking spaces. By using de-rotation-based feature selection and 3D structure mosaicking the degradation of the 3D structure near the epipole is solved and it is not necessary to use the unreliable odometry due to its accuracy depending on road conditions.

A method and apparatus for determining camera pose from point correspondences. Specifically, an efficient solution to the classical five-point relative pose problem is presented. The problem is to find the possible solutions for relative camera motion between two calibrated views given five corresponding points. The method consists of computing the coefficients of a tenth degree polynomial and subsequently finding its roots. The method is well suited for numerical implementation that also corresponds to the inherent complexity of the problem. The method is used in a robust hypothesize- and-test framework to estimate structure and motion in real-time.

The invention discloses a model base for craniofacial reconstruction and a craniofacial reconstruction method. The model base for craniofacial reconstruction comprises a craniofacial standard model base and a craniofacial PLSR shape relation model base, wherein physiological points are defined on the craniofacial standard model base. According to the craniofacial reconstruction method, a craniofacial three-dimensional surface model base, on which physiological point corresponding relations are defined, is established through a skin layer point correspondence method and a skull point correspondence method, wherein the skin layer point correspondence method combines partition deformation and multiple restrictions, and the skull point correspondence method is base on TPS overall deformation and multiple restrictions. A craniofacial partial shape relation model based on PLSR is established on the basis of the craniofacial three-dimensional surface model base, and thus the craniofacial PLSR shape relation model base is obtained. By means of a craniofacial standard model, which has the same forensic anthropological information with a to-be-reconstructed skull, in the craniofacial reconstruction model base and the craniofacial PLSR shape relation model, the face of the skull is reconstructed. The craniofacial reconstruction model base is established in the craniofacial partial shape relation modeling method based on PLSR, and the problems that samples are small and variables have multiple correlations in the craniofacial reconstruction method based on statistical theory are solved.

Method and apparatus for estimating relative three-dimensional (3D) camera rotations, focal lengths, and radial (lens) distortions from point-correspondences in pairwise (two image) image alignment. A core estimator takes a minimal (three) number of point-correspondences and returns a rotation, lens (radial) distortion and two focal lengths. The core estimator solves relative 3D camera rotations, and lens distortions from 3-point-correspondences in two images in the presence of noise in point-correspondences. A robust estimator may be based on or may be “wrapped around” the core estimator to handle noise and errors in point-correspondences. The robust estimator may determine an alignment model for a pair of images from the rotation, distortion, and focal lengths.

The invention proposes an underwater 3D reconstruction device and method based on the multilayer refractive model of light field, belonging to the research field of computer vision, and the typical application is the high-precision 3D reconstruction in underwater. This device adopts multilayer refractive model of light field to calibrate binocular stereo vision. The center point correspondence algorithm of laser stripe adopts the underwater laser stripe matching algorithm based on the multilayer refractive model of light field and the singular value decomposition method based on the corresponding points under the multilayer refractive model of light field is adopted to calculate the 3D points. The whole system device is composed of two high-speed camera packaging storehouses and laser scanning computing unit packaging storehouses. The packaging storehouse adopts high-voltage resistance design. The high-speed camera packaging storehouse and the laser scanning system and the computing unit packaging storehouse are connected by high-voltage resistance tubes. The high-pressure resistant tube contains a high speed USB3.0 cables connected to the camera and the computing unit. The high speed camera package storehouse is symmetrically distributed at both ends of the device, and the laser scanning computing unit package storehouse is in the middle of the device. The invention can be applied to the high-precision three-dimensional reconstruction in the deep-water area, and the deepest depth can reach 4000 meters below water.

The invention discloses automatic image alignment. A method for automatically aligning images includes (a) determining initial correspondent point features between a first image and a second image, (b) creating a triangular meshes for the images from the initial correspondent point features within the images, and (c) refining point correspondence between the first and second images based on affine transformation estimation using the triangular meshes. The method may also include (d) creating refined triangular meshes for the images from the point correspondence refined in (c), and (e) determining coordinate alignment within the areas of pairs of correspondent triangles in the refined triangular meshes through interpolation of affine transformation on the pairs of correspondent triangles.

A method for determining motion vectors from one point in one image frame of a scene to corresponding points in at least two other image frames of the scene, wherein the frames are obtained in a capture process utilizing one or more cameras, wherein the method employs an iterative and hierarchical dense motion estimation that computes the geometry-consistent and appearance-consistent motion fields between three images simultaneously by enforcing both a trilinear constraint and a constant-brightness constraint. This method includes the steps of: providing first, second and third images of a scene under perspective projection with unconstrained motion of the camera, wherein points (x′,y′) and (x″,y″) in the second and third frames are projections of the same spatial points (x,y) in the first frame; specifying a system of trifocal tensors and optical flow equations that describe point correspondence across the three images; and applying both a geometric constraint of trilinearity and an appearance constraint of constant brightness, thereby utilizing a trilinear constraint and a constant brightness constraint to obtain the pointwise displacement between the three frames simultaneously.

The subject matter of the invention is a method for determining the imaging equation for self calibration with regard to performing stereo-PIV methods on visualized flows, said method being comprised of at least two cameras and one image sector, with the cameras viewing approximately the same area of the illuminated section but from different directions, the point correspondences between the two cameras being determined by measuring the displacement of the respective interrogation areas in the camera images using optical cross-correlation, the imaging equation being determined by means of approximation methods, using known internal and external camera parameters.

Systems, methods and computer program products for mapping coordinates of various imaging stations are described. In some implementations, cells (e.g.., red blood cells) in a biological specimen (112) can be used for determining the mapping information between the imaging stations (120a, 120b). The use of cells allows a target image (e.g., an image of a sub-region of cells in the biological specimen) taken by one imaging station (120b) to be pattern -matched to a reference image (e.g., an image showing a larger region of cells in the biological specimen that also includes the sub -region) taken by another imaging station (120a). Once the target image is matched to the reference image, point by point correspondence (and therefore coordinates) between the target image and the reference image can be established for computing the coordinate transformation to map the imaging stations.

Poses of a movable camera relative to an environment are obtained by determining point correspondences from a set of initial images and then applying 2-point motion estimation to the point correspondences to determine a set of initial poses of the camera. A point cloud is generated from the set of initial poses and the point correspondences. Then, for each next image, the point correspondences and corresponding poses are determined, while updating the point cloud.

A system for generating a ground truth dataset for motion planning of a vehicle is disclosed. The system includes an internet server that further includes an I / O port, configured to transmit and receive electrical signals to and from a client device; a memory; one or more processing units; and one or more programs stored in the memory and configured for execution by the one or more processing units, the one or more programs including instructions for: a corresponding module configured to correspond, for each pair of images, a first image of the pair to a LiDAR static-scene point cloud; and a computing module configured to compute a camera pose associated with the pair of images in the coordinate of the point cloud.

A method of generating a ground truth dataset for motion planning of a vehicle is disclosed. The method includes: corresponding, for each pair of images, a first image of the pair to a LiDAR static-scene point cloud; and computing a camera pose associated with the pair of images in the coordinate of the point cloud.

The invention discloses a pedestrian space-time outline presenting method based on ellipse Fourier decomposition. The method comprises the following three steps of: firstly, updating a background model by using a multi-distribution model, and then extracting time-space outline of original pedestrian to be processed by a binaryzation, morphology operator and 8-communication outline tracking method; confirming the point correspondence based on MDL (Master Data Library), increasing CDI (Comprehensive Dissertation Index) feature representing the grayscale distribution feature for the target function to obtain accurate point correspondence; and finally analyzing the closure of pedestrian outline, considering the periodicity characteristic that any point returns to the original position finally by moving along the outline, using the ellipse Fourier decomposition, neglecting the high-frequency shape detain section and keeping the low-frequency overall situation shape information so as to represent the high-dimensional 2D+time outline vector to be the low-dimensional EFCShape vector. The invention maintains the effective information of the outline analysis, realizes effective compression of outline data and provides an efficient outline representing method for application such as the subsequent gait identification.

The present invention discloses a computer system utilizing a knowledge-based mode, and relates to a method of deducing and authenticating the knowledge and the capability of the people. The method comprises the steps of 1 dividing the professional knowledge into the theoretical knowledge and the skill knowledge; 2 classifying the professional knowledge in detail to classify and design the knowledge points; 3 setting questions according to the knowledge points, dividing the question types into the true or false questions and the choice questions, and inputting in the computer system to form a massive question base; 4 enabling each person to log in the computer system to examine, and setting the questions randomly via the computer system to form the examination papers of certain question numbers, for example 100 questions, wherein the knowledge points of the same examination paper are not repeated, and the examination papers are different every time each person logs in the computer system; 5 according to the achievement of an examinee of answering each question, deducing whether the examinee grasp the knowledge corresponding to the knowledge points, thereby concretely calculating the level of the theoretical knowledge and the skill knowledge of each person, namely a talent report. The method changes the situation that the previous paper-based examination only can calculate the scores, but can not calculate the levels of the knowledge and the capability of the people.

The invention discloses a single photo based three-dimensional face modeling method and system. The modeling method is characterized in that a deformation model is acquired through dense point correspondence and principal component analysis, and then a face model is built through feature point alignment. The beneficial effects are that 1) compared with a three-dimensional scanner, the modeling method is good in universality and flexibility, simple to operate, low in cost and applicable to the general public; 2) compared with multi-face-photo modeling, the modeling method simplifies manual operation steps and reduces the computation time; and 3) compared with traditional single-face-photo modeling, the modeling method only needs simple manual initialization, the computation amount is small, the face modeling speed is high, and an acquired face model is high in sense of reality. The modeling system comprises an image acquisition module, a conversion module, an analysis module, a molding module and a Face++API interface. The modeling system further has the beneficial effects that 1) a generated face model has a strong sense of reality, the modeling time is short, and the automation degree is high.

A method for determining a conjugate distance equation for automatic calibration in the execution of stereo-PIV(Particle Image Velocimetry) is provided to execute calibration of stereo-PIV even in a closed space or micro-channel. A method for determining a conjugate distance equation includes ate least two cameras and a single light slit. The cameras observe a region of the light slit in different directions, and point-to-point correspondence between the cameras is determined by moving and measuring each interrogation field in camera images according to optical correlation. The conjugate equation is decided using an approximation method according to internal and external camera parameters.

The invention discloses the hole repairing method and device of a three-dimensional crown mesh model and relates to the oral cavity technology field. In the prior art, the accuracy of the automatic repairing of a three-dimensional crown mesh model hole is low. In the invention, the above problem can be solved. The method comprises the following steps of acquiring the specific dimension of each three-dimensional tooth mesh model from multiple sets of three-dimensional tooth mesh models with a consistent topological structure of the same three-dimensional tooth mesh model; using a maximum posterior estimation method to construct a target three-dimensional tooth mesh model matching with the shape of the three-dimensional scanning crown model to be repaired based on the specific dimension; carrying out deformation from a target three-dimensional crown mesh model intercepted by the target three-dimensional tooth mesh model to a three-dimensional scanning crown model; repairing the three-dimensional scanning crown model according to the point correspondence relation of the deformed target three-dimensional crown mesh model and the three-dimensional scanning crown model; carrying out meshsmoothing on the repaired three-dimensional scanning crown model and acquiring a final result. The method and the device are mainly suitable for the scene of automatically repairing tooth holes.