360 results about "Regular grid" patented technology

A method and computer graphics system capable of super-sampling and performing programmable real-time filtering or convolution are disclosed. In one embodiment, the computer graphics system may comprise a graphics processor, a sample buffer, and a sample-to-pixel calculation unit. The graphics processor may be configured to generate a plurality of samples. The sample buffer, which is coupled to the graphics processor, is configured to store the samples and may be configured to double-buffer at least part of the stored samples. The sample-to-pixel calculation unit is programmable to select a variable number of stored samples from the sample buffer to filter into an output pixel. The sample-to-pixel calculation unit performs the filter process in real-time, and may be programmable to use a number of different filter types in.a single frame. The sample buffer may be super-sampled, and the samples may be positioned according to a regular grid, a perturbed regular grid, or a stochastic grid.

A method and computer graphics system for rendering images using programmable sample positions is disclosed. In one embodiment, the computer graphics system may comprise a graphics processor, a sample buffer, and a sample-to-pixel calculation unit. The graphics processor may be configured to generate a plurality of samples using a sample positioning algorithm selected from a programmable memory or generated by programmable hardware. The sample buffer, which is coupled to the graphics processor, may be configured to store the samples. The sample buffer may be super-sampled and double buffered. The sample-to-pixel calculation unit is programmable to select a variable number of stored samples from the sample buffer to filter into an output pixel. The sample-to-pixel calculation unit performs the filter process in real-time, and may use a number of different filter types. The algorithms used to position the samples may position the samples according to a regular grid, a perturbed regular grid, or a stochastic grid.

A method for determining a sail plan for a towed-array marine seismic survey, includes: dividing a survey area into a regular grid of tiles; and identifying a subset of the tiles as nodes around which continuously curved sail lines are defined. The nodes define regular pattern further including: a first subpattern of nodes; and a second subpattern of nodes offset from the first subpattern. In alternative aspects, a computer-readable program storage medium may be encoded with instructions that, when executed by a processor, perform the method, or a computing apparatus may be programmed to perform the method. A method for conducting a towed array marine survey includes: traversing a plurality of continuously curved sail lines across a survey area, each sail line being relative to a node; and acquiring seismic data while traversing the continuously curved sail lines. The set of nodes defining a regular pattern further including: a first subpattern of nodes; and a second subpattern of nodes offset from the first subpattern.

The present invention provides a browser based mass three-dimensional point cloud data release method. The method comprises the following steps that S1. a bounding box of original three-dimensional point cloud data is calculated, and block division is carried out on the original three-dimensional point cloud data according to the bounding box and a regular grid division theory, so as to divide a plurality of block point cloud bounding boxes; S2. an octree is established for each block point cloud bounding box, and a description file is configured for each octree; S3. regular grid division is carried out on a point cloud octree, and a quadtree structure is established for the octree contained in each regular grid; and S4. a browser sends in real time a query request to a server, the server returns in real time an octree query result to the browser, the browser carries out visibility determination on the octree query result, and the visible octree is loaded, so as to complete dynamic loading and scheduling of mass three-dimensional point cloud data. According to the method disclosed by the present invention, web based release and visualization of mass large point cloud files are realized, and the problem that point cloud data is difficult to release is solved.

A method having application for petroleum exploration or geological storage of generating a mesh of a faulted underground medium, comprising generating a hex-dominant mesh from faults and horizons in a form of a 3D triangulated surfaces. Each 3D triangulated surface is converted to a 2D triangulated surface onto which the faults are projected by an isometric unfolding technique. A regular two-dimensional grid pattern is generated for each 2D triangulated surface. The faults are accounted for by deforming quadrilaterals of the grid pattern intersected by projected faults. The deformed regular grid pattern is then converted to a 3D gridded surface and each quadrilateral which is crossed by a fault is converted into two triangles at a level of a diagonal. Finally, after iterating for all the 3D triangulated surfaces, the mesh is generated by creating links between the nodes of neighboring three-dimensional gridded surfaces with respect to the faults.

Systems and methods for imaging a 3D volume of geometrically irregular grid data. The systems and methods utilize various types of probes and displays to render the geometrically irregular grid data, in real-time, and analyze the geometrically irregular grid data.

The invention relates to a method and a system for estimating population density in urban built-up areas coordinated by spatial big data. The method comprises the following steps: obtaining a buildingrange based on an object-oriented classification method by utilizing high-resolution optical remote sensing data; dividing urban blocks through a spatial topology algorithm by utilizing spatial big data of an urban fine road network, and dividing the urban blocks into residential areas and non-residential areas by combination with spatial big data of points of interest; obtaining building heightby utilizing remote sensing optical three-dimensional imaging data; constructing a population density estimation model by utilizing a multiple regression analysis method according to the building height and the building range and by combination with population statistical data; and inputting the building range and the building height as input variables into the population density estimation model,performing calculation to obtain population density, and then, assigning the population density to regular grid space corresponding to urban built-up areas by utilizing a spatial statistical analysismethod. The method and the system can precisely and accurately realize estimation of the population density in the built-up urban areas, are more suitable for requirements of urban planning, disasterprevention and reduction and business decision for fine population data, and are beneficial to further popularization and application.

The invention discloses a LiDAR point cloud filter method based on gradient and area growth. The method mainly includes the steps of firstly, acquiring the original LiDAR point cloud data; secondly, rejecting gross errors; thirdly, gridding rules; fourthly, selecting ground seed points; fifthly, performing area growth; sixthly, using the grids where the new ground points satisfying the conditions as centers and using the point, with the lowest elevation, in the grids as the new seed points for growing according to the fourth step until no points satisfy the conditions, and stopping growing; seventhly, sequentially performing area growth on seed points and centralized seed points according to the fourth step and the fifth step until the whole process is finished. By the method, the elevation threshold size is limited effectively, the calculation quantity of the whole method is lowered effectively, and the ground points and non-ground points in LiDAR point cloud data of complex cities can be separated fast. In addition, the method is simple, and the result obtained by the method is relatively small.

A method and computer graphics system capable of super-sampling and performing real-time convolution are disclosed. In one embodiment, the computer graphics system may comprise a graphics processor, a sample buffer, and a sample-to-pixel calculation unit. The graphics processor may be configured to generate a plurality of samples. The sample buffer, which is coupled to the graphics processor, may be configured to store the samples. The sample-to-pixel calculation unit is programmable to select a variable number of stored samples from the sample buffer to filter into an output pixel. The sample-to-pixel calculation unit performs the filter process in real-time, and may use a number of different filter types in a single frame. The sample buffer may be super-sampled, and the samples may be positioned according to a regular grid, a perturbed regular grid, or a stochastic grid.

A method and apparatus for three-dimensional visualization and analysis for automatic non-destructive examination of a solid Rotor using ultrasonic phased array is disclosed. Data is acquired by scanning a solid rotor with a phased array ultrasound transducer producing a plurality of two dimensional ultrasound scans. Each of a plurality of sample points of a plurality of two dimensional ultrasound scans are associated with a corresponding 3D image point of a regular grid. A kernel function for each of the plurality of sample points defining a size and shape of a kernel located at the corresponding image point is determined. A weight is assigned to each kernel which, in one embodiment, is based on the sample point value. A value for each image point of the regular 3D grid is determined based on kernels overlapping each image point. A three-dimensional volume representing the solid rotor is then visualized.

The invention discloses a high-fidelity digital modeling method of terrain elevation, the steps are as follows: the first step is to carry out push-broom data acquisition; the second step is to carry out grid segmentation of the acquired vector terrain feature data; the third step is to carry out similar DEM grid data organization of PLA, organization management is carried out to the PLA data after the grid segmentation treatment according to grid data structure; the fourth step is to generate a new digital elevation model file to carry out the seamless embedding of the vector feature data; a feature embedded digital elevation model data structure is composed of three sub-files which comprise a grid file, a feature identification file and a feature file; the grid file is a regular grid data structure; the feature identification file is used for spatial data index of a vector grid integrated organization, the structure thereof is consistent with the current national DEM data structure and only records the grids with the features; the feature file records terrain feature information which is contained in one grid unit, and the information comprises feature points and feature lines.

The invention discloses a three-dimensional city model self-adaption scheduling method, and belongs to the field of three-dimensional digital city and three-dimensional geographical information systems. By means of the three-dimensional city model self-adaption scheduling method, regular gridding indexes are graded, the grading thinking is adopted, the two grades including the fine granularity and the thick granularity are used, the regular gridding indexes are respectively constructed, the problem of scheduling disorders of three-dimensional models in different sizes is solved, and the scheduling efficiency is improved. The self-adaption scheduling method is provided by calculating model request importance degree factors according to the distance between the centers of the models and a current viewpoint, the sizes of the models themselves, and the current states of the models, the model request time, the model request time number and the model request importance degree factors are sufficiently considered to conduct dynamic adjustment, and the high efficiency and the vision coincidence of dynamic adjustment are accordingly achieved. Compared with the scheduling method that only the viewpoint distance is considered, the model scheduling process of the three-dimensional city model self-adaption scheduling method is high in response speed and smooth, and the good view effect is achieved; meanwhile, asynchronous collaboration between scheduling threads and rendering threads is achieved, and therefore the scheduling efficiency is greatly improved.

For the purpose of preventing a situation in which the fiber density looks as if it suddenly decreases in a specific view direction, a method comprises: specifying a region of interest R1 in MR image data collected by a diffusion tensor method; defining regular grid points in the region of interest R1; defining points obtained by randomly moving the grid points as tracking start points S1, S2, . . . ; performing diffusion tensor analysis on each tracking start point S1, S2, . . . in the image data to determine a direction of a principal axis vector; tracking a fiber by repeatedly selecting a neighbor point along the direction of the principal axis vector and performing diffusion tensor analysis on the neighbor point to determine the direction of the principal axis vector; and producing and displaying an image of the tracked fibers as viewed in a desired view direction.

The invention is a prestack depth migration method for seismic data processing of a relief land surface, determining an imaging reference plane according to the highest point of a collection region, and projecting the relief land surface to a regular grid to fill a constant speed approaching to the near land surface in the relief land surface; using Fourier finite extrapolation operators of one-way wave equation to make wave field extrapolation on shot seismic source wave fields and detector received wave fields along the depth axis, and keeping the wave field between input and output datum equal to zero; imaging the extrapolated shot and detector wave field record by conjugate related imaging conditions, and stacking the related results of each frequency and processing the imaging result into a section image by routine display software, and the invention has an obvious imaging effect of complex construction on the condition of relief land surface.

The present invention discloses a new path planning method based on regular grid DEM data. According to the new path planning method, the distance and the slope are used as the evaluation indexes of the path search; in order to balance the interaction between the distance and the slope, the complete function g(n) of a DA* algorithm is designed based on the distance function of the space path and the slope function constructed with the exponential function; the parameter in the function is calculated with the DEM data, and the new complete function g(n) is optimized so as to be adapted to the change of different resolutions of the DEM data; based on the same strategy and the function construction method, the new heuristic function h(n) of the DA* algorithm is constructed; and in order to improve the search efficiency of the algorithm, by setting the initial weight and dynamically adjusting the weight in the search process, the influence of the complete function and the heuristic function on the evaluation result is changed, such that the new constructed DA* path finding algorithm can efficiently search the appropriate path. According to the preset invention, the new path planning method can self-adapt to the DEM data resolution, and can be used in different application environments.

The triangular mesh generating portion divides the surface of geometry model to be meshed in a meshed manner according to a target element dimension and generates a triangular mesh on the surface of geometry model. The regular mesh generating portion assumes a shaped parallelpiped enclosing the shape to be meshed. The parallelpiped is divided in a meshed manner by the hexahedral element whose distance between the nodes has the substantially same density as the triangular mesh on the surface. The resulting regular mesh located inside the triangular mesh on the surface of geometry model is divided into a tetrahedral meshed manner. The shell meshing area extracting portion extracts a shell-like space between the inner tetrahedral mesh and the triangular mesh on the surface of geometry model. The shell mesh generating portion generates the tetrahedral mesh in the overall shape to be meshed.

The invention discloses a method of filtering an airborne LiDAR (Light Detection and Ranging) point cloud. The method comprises the following steps of firstly, carrying out gross error elimination and regular grid transformation on LiDAR point cloud data so as to generate a depth image; secondly, computing a segmented elevation threshold through an Otsu algorithm in an image threshold segmentation technology, and carrying out iterative rough classification of ground points and non-ground points on the point cloud data, which are obtained before regular grid transformation and resampling, through the threshold; lastly, respectively carrying out progressive triangulation network filtering on the classified ground points and non-ground points through the two different thresholds, and outputting network construction point cloud data, namely, ground point data. According to the method, the point cloud data, which participate in a filtering process, are data, which are obtained before regular grid transformation and resampling, so that the problem of accuracy loss of the point cloud due to regular grid transformation can be effectively avoided; a categorical attribute guidance is provided for the progressive triangulation network filtering, a filtering strategy is correspondingly adjusted for different terrain conditions, so that a better filtering effect is obtained.

A method of forming a hybrid mesh representation of an object surface is provided, along with the hybrid mesh representation and data structures corresponding to various polygons in the hybrid mesh representation. The hybrid mesh representation comprises a base mesh and one or more higher level meshes. At least one of the higher level meshes representing a patch is an irregular mesh. The method of forming the hybrid mesh representation comprises the steps of forming a base mesh, and then forming one or more higher level meshes from the base mesh through one or more regular refinement operations in combination with at least one irregular operation.

The invention discloses a method for manufacturing a digital elevation model by using data of a laser altimeter. The method comprises the following steps of: acquiring elevation measurement data by using the laser altimeter; filtering the elevation measurement data of the laser altimeter; and filtering, and interpolating the laser elevation measurement data subjected to singular point removal, and manufacturing the digital elevation model (DEM) with full moon regular grids. Because full moon data is used, the data accuracy and the resolution of the moon DEM manufactured by using the method are obviously increased by using the filtering and interpolating process.