311 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 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 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.

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 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 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 discloses a method for correcting the measurement vibration of a deformation video of a multi-constrained wind tunnel test model. The method comprises the following steps: arranging a video observation camera; establishing an image point projection observation equation; establishing rigid body and extreme line constraint equations; constructing an iterative equation; iteratively solving an optimal solution of an equation set; and reconstructing a current camera posture and a model posture. The method has the positive effects that rigid body constraint conditions of body feature points of the test model and rigid body constraint conditions of wallboard feature points of a wind tunnel test section are simultaneously utilized, collinear constraint conditions of wing feature points of the test model in multi-view measurement geometry are further increased, and all the constraint conditions are creatively changed into uniform iterative equations; the method has the advantages that the iterative convergence is rapid, the solving accuracy is high, the position and posture of the test model cane be simultaneously solved, and the like.

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.

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.