314 results about "Point projection" patented technology

A method of displaying at least one point-of-interest of a body during an intra-body medical procedure. The method is effected by (a) establishing a location of the body; (b) establishing a location of an imaging instrument being for imaging at least a portion of the body; (c) defining at least one projection plane being in relation to a projection plane of the imaging instrument; (d) acquiring at least one point-of-interest of the body; and (e) projecting said at least one point-of-interest on said at least one projection plane; such that, in course of the procedure, the locations of the body and the imaging instrument are known, thereby the at least one point-of-interest is projectable on the at least one projection plane even in cases whereby a relative location of the body and the imaging instrument are changed.

A method for facilitating a medical or surgical procedure in an operating site in a body of a patient may involve: displaying a first point on a first two-dimensional image of the operating site into which an elongate, flexible catheter device is inserted in response to a first user input; mapping the first point on at least a second two-dimensional image of the operating site, the second two-dimensional image being oriented at a non-zero angle with respect to the first two-dimensional image; displaying a first line on the second image that projects from the first point; displaying a second point on the second image in response to a second user input; and determining a three-dimensional location within the operating site, based on the first line and the second point on the second image.

A method for image recognition of a material object that utilizes graphical modeling of the corner points of a vertex which includes projecting a point on a digital display to an inward depth, a one half pixel distance in the plane of the display, with a conic to a digital display, and a square block containing one half size child blocks that are scaled to depth, projecting the corner points of a vertex and replacing the bisecting points of edge features detected in a digital display scaled at an increasing rate of congruency to the dimensions of an object. The method may further include producing a digital image of the material object, providing a central processing unit, providing memory associated with a central processing unit; providing a display associated with a central processing unit; loading the digital image into the memory; defining the edges of features within the digital image; and a finding fight crucial points from registrations projected on to an edge feature display.

A projection system includes projection units configured to project an image on a projection body; a preparing unit configured to prepare calibration-use images; an extraction unit configured to extract, from each of the calibration-use images, at least grating points indicating a distortion in a projected image of one of the projection units and alignment points of the projected image of the one of the projection units or another one of the projection units; a conversion unit configured to convert, onto a common coordinate system, the grating points of the projected images of the projection units extracted from the calibration-use images, based on alignment points common to the calibration-use images; and a geometric correction coefficient calculation unit configured to calculate a geometric correction coefficient for providing a projection image to be projected from the projection units, based on the grating points on the common coordinate system.

The invention relates to a remote-sensing image matching method with combination of characteristic segmentation with topographic inequality constraint. The method comprises the following steps: partitioning a base image so as to obtain base image blocks; extracting the characteristic points of each base image block; calculating local contrasts of all the characteristic points; selecting a plurality of characteristic points with the large local contrasts as seed points; performing projection on the seed points so as to obtain a corresponding search region of each base image block on an image to be matched; calculating a scale difference factor and a rotation matrix of the base image and the image to be matched and balancing the scale and the rotation difference; introducing in data based on global SRTM (Shuttle Radar Topography Mission); performing hierarchical matching on each base image block based on the seed points and eliminating miss matching points; performing image segmentation and combination; and extracting edge characteristics and segmented regions, thereby obtaining dense matching point clouds. The method has the advantages that the remote-sensing image matching in different resolutions and different perspectives can be realized in a full-automation manner; and the reliable and dense homonymy points can also be obtained from the difficult-to-match regions which are poor and similar in textures, have discontinuous topographic surfaces and the like.

The invention provides a camera array calibration algorithm capable of calibrating a 3D camera and obtaining relatively precise extrinsic parameters between the 3D camera and a visible light camera. The algorithm comprises the following steps: firstly, internally calibrating the visible light camera and the 3D camera to obtain intrinsic parameters of the cameras; secondly, adopting the intrinsic parameters of and a depth map provided by the 3D camera to restore the spatial locations of corner points of calibration boards, adopting minimum corner point projection error to obtain the optimum extrinsic parameters from the 3D camera to the required visible light camera, thereby completing the calibration of the whole camera array.

The invention discloses a ground laser radar reflection intensity image generation method based on central projection. The ground laser radar reflection intensity image generation method based on central projection comprises the following steps that firstly, a ground laser radar is used for obtaining the laser point cloud of a detected object; secondly, the laser source of the ground laser radar serves as a projection center, a central point projection radial is determined through the projection center and the center of the laser point cloud, a plane which is perpendicular to the central point projection radial and passes through the central point serves as a projection plane, the laser point cloud is projected in the projection plane to obtain corresponding projection points; thirdly, a minimum wrapping rectangle and a rectangular graph of all the projection points are built and are divided through grids with the same intervals, and any grid unit of the rectangular graph has corresponding grid units in the minimum wrapping rectangle. For any grid unit of the rectangular graph, the reflection intensity value of the nearest projection point in the minimum wrapping rectangle is converted into a gray value, and the gray value is given to the grid unit.

The invention provides a frosted glass and a preparation method thereof, a glass back cover and an electronic device, wherein the frosted surface of frosted glass has a pointed projection structure. According to the present invention, based on the pointed projection structure of the frosted glass, the frosted glass has a frosted effect and achieves anti-fingerprint and anti-glare effect, and lightcan be subjected to mirror reflection on the surface having the pointed projection structure to form pearlescent effect, such that the frosted glass simultaneously has effects of fingerprint resistance, glare resistance and pearlescent effect, and pearlescent ink printing on the glass is not required so as to save the frosted glass production process and the frosted glass production cost.

The invention discloses an evaluation method of a part flatness error based on a minimum area method. The evaluation method comprises the steps of measuring and obtaining coordinates of measuring points on a measured plane, giving an initial parameter of the plane, enquiring the measuring points contacted with an error containing area according to the distances from the points to the plane, projecting the measuring points into a designated plane and converting into straightness error calculation in the designated plane by a coordinate system transformation method according to the quantity and the relative positions of the contact points, searching the measuring points contacted with the containing area and satisfying a straightness error discretion rule through the rotation change of the containing area in the projection plane, obtaining a rotated containing area, redefining a projection plane, conducting iterative calculation sequentially according to the straightness error calculation till a flatness discretion rule is satisfied, and outputting the flatness error and an optimal value corresponding to an ideal plane parameter. With the adoption of the evaluation method, the flatness error satisfying a minimum area discretion rule can be accurately calculated.

The invention provides a vehicle license character feature extracting and classifying method using projection symmetry as the precondition for judgment. The method comprises the following steps: firstly extracting character feature to 26 letters and 10 numbers which may appear in vehicle license characters by using projection symmetry as precondition to divide into four classes, namely vertical projection class, horizontal projection class, central point projection class and dissymmetric property class and realize the coarse classifications of vehicle license characters; and fining, performing normalization transformation, then extracting features of points and rings and completing the fine classification of vehicle license characters. The invention combines the projection symmetry with the feature extraction method of points and rings to set a vehicle license character classifier, thus laying the foundation of realizing the identification of vehicle license characters finally. The method has better identification effect on confusable characters, such as '0' and 'D', '8' and 'B', '7' and 'T' and the like, thus increasing the identification speed and accuracy of vehicle license characters.

The invention discloses an extraction method of a contour line of a clearance distance between an electric transmission line and the ground surface based on point cloud data. Through the steps of point could acquisition, point could classification, lead wire fitting, span length partition, clearance distance calculation, distance minimum point extraction, clearance distance minimum point projection and conversion, contour line generation and the like, a contour line of the clearance distance between an extra-high voltage direct-current electric transmission line and the ground surface of a line corridor below the extra-high voltage direct-current electric transmission line is extracted, the height of the contour line indicates the clearance distance between a lead wire and the ground, andconditions of the distance between the lead wire to ground objects below the lead wire under different working conditions of static or wind deviation can be visually displayed; and meanwhile, comparison of multi-period data of the ground surface of the line corridor can be realized based on the contour line, areas with changes of the ground objects below the lead wire or trees are discovered, andreference is provided for the control over the line corridor. According to the extraction method of the contour line, the design is scientific and reasonable, different working conditions can be fullytaken into account, and the minimum clearance distance between the whole section of the electric transmission line lead wire and the ground surface so as to realize the control over tree barriers.

The invention provides a mobile robot positioning method and system based on three-dimensional point cloud and visual fusion, and the method comprises the steps: building an environment map, carryingout the fusion of point cloud and visual features, matching a map, and carrying out the positioning. Wherein the environment map is a feature grid map for establishing an environment, each grid in thefeature grid map stores a point set composed of feature points extracted from the point cloud and feature points of the visual image, and a height value, an intensity value and a normal vector projection value are extracted; the point cloud and visual feature fusion is to project feature points extracted from the image to a point cloud space and form joint feature points with point cloud features. According to map matching and positioning, joint feature points are projected to a two-dimensional grid, feature vectors are extracted, the feature grid is matched with the map, a histogram filter is adopted to determine the posterior probability of each candidate pose, and the position of the robot in the map is determined based on the posterior probabilities.

A method and an apparatus for removing outliers from a main view of a scene during 3D reconstruction of a scene from multiple views of the scene. A 3D projection unit projects a 3D point of a pixel of the main view into neighboring views. A comparator then compares the distance of each of the projected 3D points in the neighboring views to the 3D point of the main view with a defined distance threshold. Based on the comparison a flagging unit assigns flags to the pixel in the main view. Finally, depending on values of the flags a rejecting unit rejects the pixel in the main view as an outlier.

The invention relates to a layered point cloud segmentation method based on DBSCAN. Firstly, a CSF is adopted to separate a ground point from a non-ground point; In a non-ground point segmentation process, point clouds in the vertical direction are layered according to a certain height, DBSCAN clustering is carried out on projection points of each layer on an XOY plane to obtain a central point ofeach cluster, all the clustered central points are projected to the XOY plane, and each object main body is clustered by utilizing DBSCAN to obtain a plurality of object main bodies; a judgment is made whether each main body point exists in each layer of each main body or not, judging the number of objects contained in each cluster, and finally, a cluster of multiple objects is segmented. For segmentation of side viewpoint cloud data, extraction of most of main bodies in a scene can be guaranteed, certain robustness is achieved, particularly, the invention has good performance in the scene with trees as the main component, and the result obtained through the method has certain significance in point cloud classification and point cloud three-dimensional reconstruction after point cloud segmentation.

The present invention provides a detection method of an unstructured point cloud feature point and an extraction method thereof. The extraction method includes (1) calculating the Harris response value of a sampling point in different scale space; (2) selecting the Harris response value of the optimal scale space as the Harris response value of the sampling point to obtain a feature point set Q; (3) selecting one maximum point of the Harris response values possessing maximality in both of the scale space neighborhood and a geometric neighborhood as a candidate feature point, at last, selecting the optimizing strategy to draw the final feature point. A tangent plane of the gained feature point is subjected to network segmentation under a polar coordinate system, and then a neighborhood point of the feature point is projected to the tangent plane, a feature information statistical matrix is generated by voting projected length corresponding to projective points from each grid to four peaks of the grid, then both of a row vector and a column vector are respectively subjected to the DCT transform and the DFT transform, the elements of the upper left corner after transform is a character description vector.

The invention discloses a steel member cylinder fitting algorithm which comprises the following steps: setting a plurality of measuring points on a to-be-measured section circle, arranging a high-precision laser instrument to acquire three-dimensional coordinates of the measuring points, and converting the three-dimensional coordinates measured at different measuring positions into a common coordinate system by adopting a transfer algorithm; calculating a fitting plane equation by utilizing the coordinate points after station transfer to obtain plane equation parameters, and taking the plane as an evaluation plane for the roundness of the section; projecting the coordinates of the measurement points to the evaluation plane, and calculating the projection coordinate of each point and the distance from each point to the evaluation plane; carrying out plane circle fitting on the coordinate points projected to the same plane by utilizing a linear least square method to obtain a fitting radius and a circle center of a circle; on the basis of plane circle fitting, calculating the cylinder roundness of a plurality of profile circles by adopting a least square method, namely carrying out cylinder fitting. A plurality of algorithms are integrated, so that the method has very strong pertinence on the dimension measurement of the large-scale cylindrical steel member.

The virtual three-dimensional image of an observed object is formed by arranging a plurality of sectional images and projected from a viewpoint fixed to a predetermined position onto a projection plane which is fixed to a predetermined position to form and display a perspective image. The pixel value on the sectional image which is transversed by a projection line extending from the viewpoint to the projection plane are read and, if the read value coincides with one of a plurality of predetermined values, pixel data are recorded in a pixel recording region corresponding to that value in pixel value memories. While the projection line scans the pixels one by one on the projection plane, for each coming scanned pixel the pixel data are recorded. After all the data are recorded, the pixel data recorded in the pixel value memories are read out and the data are displayed on a display as a perspective image.

The invention belongs to the technical field of space-to-ground observation, and particularly discloses a method for calculating a three-dimensional intersection angle of satellite images. The method comprises the following steps of A, acquiring image point coordinates of same-name points of a three-dimensional satellite image pair by using a manual measurement or automatic satellite image matching method; B, implementing an RFM (rational function model)-based area network compensation method by utilizing the coordinates of the same-name points of the satellite images to realize the optimization of RPC (rational polynomial coefficient) parameters; C, calculating spatial rectangular coordinates corresponding to object-space points formed by projecting the same-name points onto projection surfaces at different elevations by using a projection trajectory method to finish the spatial reconstruction of same-name light; and D, calculating the three-dimensional intersection angle of the same-name light by utilizing direction vectors of the reconstructed same-name light. The method is applied to the calculation of the three-dimensional intersection angle of any three-dimensional model formed by overlapped satellite images without any ground control point, can be used for the mapping accuracy evaluation of the three-dimensional model, and has remarkable economic and social benefits.

The invention relates to an intelligent terminal 3D watch try-on method and system based on augmented reality. Image information similar to hand color is extracted, hand image information is extracted from a background image, after contour extraction, convex hull detection is carried out, and according to a given threshold, whether it is a hand portion is determined; a contour is obtained again for the convex hull detection, and a convex hull at a waist is determined; according to internal parameters of different virtual scene video cameras, given by different intelligent terminal devices, relative transformation relations between coordinate points of the waist and the virtual scene video cameras are calculated; and a projection matrix is calculated, the obtained waist coordinate points are projected to a three-dimensional scene by use of the relative transformation relations between the coordinate points of the waist and the virtual scene video cameras, and a 3D model of a watch is projected to a waist position in the three-dimensional scene according to the projection matrix. According to the invention, application of pictures with identification information is unnecessary, what is needed is only one intelligent terminal, a waist image of a user is obtained in real time through a pick-up head, and after the waist image is processed through the intelligent terminal, a try-on effect can be displayed on a screen.

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.

The invention provides a multi-reflection inhibiting method in in-situ measurement of a high reflection metal structural component. With the adoption of the method, the in-situ measurement of the high reflection metal structural component is achieved. The method comprises eight major steps. The method specially comprises the steps of: firstly, calibrating a left camera, a right camera and a projector; secondly, calculating the relative position of the projector and a workpiece coordinate systems by using the parameters provided by an in-situ measuring machine; thirdly, measuring and planning based on the normal direction of each face of a model of a part (Computer-Aided Design); fourthly, projecting the points to be measured on the workpiece on a digital projector, and selectively projecting after determining an area required for projecting; and fifthly, calculating the phases of pictures from the cameras so as to complete the three-dimensional reproduction of an object. The multi-reflection inhibiting method has the advantages of fast speed, high precision, and dense three-dimensional point cloud and the like, and moreover, the multi-reflection inhibiting method achieves the full-automatic in-situ measurement without manual intervention, has high operability, and can meet the requirement on in-situ quick measurement of the field strong reflection metal structural component.

An apparatus is taught for draining static electrical charges build-up on a traveling web of dielectric material. The apparatus includes discharge means comprised of a metal member having one end formed into at least one needle point projection. The discharge means is connected to ground potential and mounted in close proximity to the traveling web. Responsive to concentrated static electrical charges the discharge means causes ionization of the gasses surrounding the discharge means, thereby draining the static electrical charges to the ground potential through the discharge means. The apparatus further includes means for sensing and reading the magnitude of static electrical charges drawn from the web of dielectric material and for applying the sensed information as digital signals to a manufacturing controller. The manufacturing controller uses the information to control manufacturing parameters that minimize the generation of static electrical charges during the manufacture of the dielectric material.

A computer system and method for simplifying annotations on a surface includes a tolerance process creates a tolerance window lying in a plane and centered on the query point at the end of a test edge and perpendicular to the test edge. The tolerance window is defined by a first tolerance that specifies an amount of first error measured by the distance from a simplified path to an original path in the plane tangent to the surface, and a second tolerance that specifies an amount of second error measure by the distance from the simplified path to the original path in the plane perpendicular to the surface. The original path is a set of original edges on the surface. A point projection process that projects a second end point of one or more second edges onto the plane of the tolerance window. The second edges has the query point also as an end point where the projection of the second end points are projected points. An invalidation process marks an edge as "invalid" and removes it both from the list of simplifiable edges and the final list of simplified edges. A selection process selects one of the second end points that has a projected point within the plane containing the tolerance window, deletes the query point, and connects the origin point to the respective second end point, to create a new edge that replaces the test edge and respective second edges in the set of original edges to create the simplified path.

The embodiment of the invention provides an acquisition device and method in 3D modeling. Aplurality of images of a target object are acquired by using the acquisition device; (2) the calibration device acquires the position and attitude information of the acquisition device when the acquisition device acquires each image; and (3) the processor synthesizes a three-dimensional model of the target object according to the plurality of images, and obtains three-dimensional coordinates corresponding to the homonymous image points according to the position and attitude information of the acquisitionequipment, thereby obtaining a three-dimensional model point cloud with accurate three-dimensional coordinates. The absolute size calibration of the target object is realized through a method for acquiring the position and the posture of the camera, and a homonymous image point resolving mode is adopted, so that the target object does not need to be subjected to calibration object placement or calibration point projection in advance.

A point projection type flood plasma source implements a magnetron sputter cold cathode electron source in a discharge cavity separated from a process chamber by a narrow conduit and a solenoid magnetic field. The solenoid magnetic field impedes radial electron flow in the nozzle and the process chamber. Process gas flows into the discharge cavity and through the nozzle to the process chamber. This gas is ionized in the nozzle and the process chamber by electrons trapped in the solenoid magnetic field. The result is a dense plasma plume in the process chamber useful for a number of applications. The source has particular advantages for reactive gas processes such as those requiring oxygen.

The invention relates to a method for measuring and calibrating a spatial position vector of a point projection optical measuring head. The method comprises the following steps of: measuring a standard ball on a rectangular coordinate system measuring machine by utilizing the point projection optical measuring head; acquiring measuring machine coordinate information of seven light spots on the surface of the standard ball and acquiring optical measuring head reading values of the corresponding light spots; establishing a relation equation by utilizing a space geometry relation between a beam linear vector and the surface of the standard ball; and solving beam position vector information of the point projection optical measuring head. The method has the advantages of simplicity, convenience, easiness for operation and high measurement accuracy. The invention gives a measuring principle, the measuring method, measuring steps, a calculating formula and the like.

Provided is a steel cord for reinforcing a rubber article, which has an improved durability against so-called cuts, such as notches and perforations, which are generated in the case of treading on an obtusely or sharply pointed projection, without decreasing the strength in the axial direction of the cord, and without increasing the thickness in the radial direction, namely without increasing the weight of a tire, as well as a tire using the steel cord for reinforcing a rubber article as a reinforcing material, especially a construction vehicle tire. Also provided is a steel cord for reinforcing rubber articles with a multi-twisted structure formed by twisting a plurality of sheath strands formed by twisting a plurality of wires around a core strand formed by twisting a plurality of wires, and the core strand being constituted of an at least three-layer-twisted structure formed by twisting core filaments and sheath filaments. The lowest tensile breaking strength of filament bs and the tensile breaking strength of steel cord Bc satisfy the relationship represented by the following formula:bs / Bc×100≧0.65.