658 results about "Quadtree" patented technology

A flat file data organization technique is used for storing and retrieving geospatially organized data. The invention reduces transfer time by transferring a few large files in lieu of a large number of small files. It also moves the process of locating a given data file away from the file system to a proprietary code base. Additionally, the invention simplifies database management by having quadtree packets generated on demand.

The invention provides a three-dimensional digital earth-space data organizing and rendering method based on a quad-tree index, which belongs to the technical fields of cartography, geography information systems and virtual reality. The method comprises the following steps of: unifying common spatial data formats under multi-scale and multi-projection conversion, multispectral, multi-temporal and high-resolution remote sensing satellite images and aerial images as well as digital thematic maps with different scales into same coordinate system, carrying out operation on the attribute of each element and the parameter regulation of quad-tree tiles, outputting in the form of the quad-tree tiles, carrying out quad-tree cutting on three-dimensional landscape map data, leading spatial data into a relevant database, and carrying out unified management. By using the method, common vector data, raster data, altitude data and three-dimensional map data are organically integrated and issued into a three-dimensional digital earth prototype, thereby shortening the time of data preprocessing, improving the execution efficiency and providing a new integration method for three-dimensional digital earth fundamental geographic data dissemination.

An apparatus and method for video coding based on flexible slice structure are disclosed. In the recent high efficiency video coding (HEVC) development, the slice may contain multiple LCUs instead of macroblocks. The LCU size being considered is 64×64 pixels which is much larger than the macroblock size of 16×16 pixels. Compared with the macroblock aligned slice for H.264, the LCU-aligned slice for HEVC does not provide enough granularities for dividing video frames. Consequently, a flexible slice structure is developed where slice partition is based on smaller coding units. In the flexible slice structure, the first LCU and the last LCU of the slice are allowed to be a fractional LCU, which is derived from a whole LCU using quadtree partition. Syntax elements are also developed to enable conveyance of flexible slice structure between an encoder and a decoder efficiently.

Three block concepts are introduced in HEVC: coding unit (CU), prediction unit (PU), and transform unit (TU). The overall coding structure is characterized by the various sizes of CU, PU and TU in a recursive fashion. For transform processing in current HEVC, a hierarchy RQT (Residual Quad Tree) is used and the TU size is related to the CU size, but independent of the PU size. This results in high encoding complexity and also causes increased processing time to process the syntax of residual quad tree. Accordingly a modified transform unit partition with reduced complexity is disclosed. According to an embodiment, the TU size may be restricted to the minimum of PU width and height, except for a 2N×2N coding unit with the 2N×2N partition type. In another embodiment, the maximum TU size equals to maximum of PU width and height, and the minimum TU size equals to minimum of the PU width and height, except for a 2N×2N coding unit with the 2N×2N partition type. In yet another embodiment, the TU size is selected between 2N×2N and N×N for the 2N×2N, 2N×N, N×2N and N×N partition types. The syntax element, split_transform_flag, is used to indicate the selection of 2N×2N or N×N TU size when needed. Furthermore, a method with reduced complexity of selecting the best merge candidate for the 2N×2N CU merge mode is disclosed. The method relies on R-D cost associated with the motion vector of merge candidate to reduce required computation.

The invention discloses a clustering method based on mobile object spatiotemporal information trajectory subsections. The clustering method based on mobile object spatiotemporal information trajectory subsections comprises the steps that the three attributes of time, speed and direction are introduced, and a similarity calculation formula of the time, speed and direction is provided for analyzing an internal structure and an external structure of a mobile object trajectory; firstly, according to the space density of the trajectory, the trajectory is divided into a plurality of trajectory subsections, then the similarities of the trajectory subsections are judged by calculating differences of the trajectory subjections on the space, time, speed and direction, finally, trajectory subsections in a non-significant cluster are deleted or are merged into adjacent significant clusters on the basis of a first cluster result, and therefore an overall moving rule is displayed on the clustering spatial form. According to the clustering method based on the mobile object spatiotemporal information trajectory subsections, the clustering result is improved, higher application value is provided, a space quadtree is adopted to conduct indexing on the trajectory subsections, clustering efficiency is greatly improved under the environment of a large-scale trajectory number set, and trajectories can be effectively clustered.

A method of determining density of a map is described along with an apparatus and computer-readable medium comprising instructions therefore. The method comprises determining one or more nodes of a quad tree applied to a map with which a predetermined query region intersects, calculating a cumulative data size of the query region based on a data size of the one or more intersecting nodes, and determining an average density of the query region based on the query region area and the cumulative data size.

The present invention relates to an on line 3D visualization method and system of natural resource data. The method mainly includes a step of natural resource data organization and storage and a step of natural resource data processing and 3D visualization. The step of natural resource data organization and storage includes: according to natural resource data characteristics and service characteristics, dividing data types, and making the natural resource data as tile image data formed by a plurality of tiles by adopting a pyramid model, then encoding each tile, and establishing a tile data set based on an embedded database technology, storing the tile data set in database, and establishing a quadtree index of space for each tile. The step of natural resource data processing and 3D visualization includes site and position 3D visualization and natural environment object dynamic 3D visualization. The method achieves real time on line 3D rendering display for all kinds of natural resources and geographic space information data in a high-performance 3D visualization environment.

A method for locating neighbor objects of a query object in a database. A query tile set is defined including a plurality of tiles that define an initial query radius that the query object is grouped within. Neighbor objects are located within the initial query radius. A number of neighbor objects within the initial query radius is determined. The query radius is expanded beyond the initial query radius by defining an expanded query tile set beyond the query tile set if the number of neighbor objects is less than a target number. Neighbor objects are located within the expanded query radius. It is determined whether a number of neighbor objects within the expanded radius corresponds to a target number. The query radius is expanded and neighbor objects located within the expanded radius until the number of neighbor objects equals or exceeds the target number.

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.

The invention discloses a method and a system for dynamically updating geographic space data based on a remote sensing image. The method comprises the steps of preprocessing an image, identifying change information, performing filtering to eliminate noise, extracting the boundary of a changed area, generating a vector boundary diagram of an image change feature, regularizing the boundary of the feature, segmenting update data based on the principle of quad-tree spatial index to locate the changed area quickly, identifying the change type of elements based on a neural decision tree method, extracting the change type, and updating and storing the change information in an original database. According to the invention, a simple, quick and accurate change detection method is obtained. By adoption of the quad-tree grid partition mode, the speed and precision of retrieval are improved. The boundary of the changed area extracted by an IGAC-based extraction method is more accurate.

In a communication network (20), a video encoder/decoder system (114) and an encoding method (150) facilitate transmission of video frames (116) over multiple low-data-rate channels (46). Frame data (204) is generated for each video frame (116). The frame data (204) is transformed (172) to obtain transform coefficients (212), which are assembled (174) into quadtrees (216) and separately coded (178). In addition, motion vectors (166) are split into coding blocks (188) and separately coded (190). The quadtrees (126) and the motion vectors (166) are independently distributed among the multiple channels (46) for transmission. A decoding method (360) facilitates error resilient reception of transform coefficient packets (222) and motion vector packets (244) so that lost transform coefficients (374) and/or lost motion vectors (384) can be estimated at a receiving video encoder/decoder system (114) to reconstruct a received video frames 144.

The invention discloses a method for quick inter-frame transcoding from H. 264/AVC standard to HEVC standard. The method comprises the following steps: imbedding an H.264/AVC standard code stream into a decoder for decoding, abstracting various information of subblocks during a decoding process, converting extracted information of the subblocks into CU and PU information for HEVC standard in ways of direct correspondence and small blocks forming large blocks, and finally using CU and PU information in HEVC standard coding directly. Since definite CU and PU information is available, quadtree division of CU, performed according to original encoding mode, is not required, ergodic of all possible PU modes under the depth of each CU is not required, and all that is needed is to calculate a PU mode and an intra-frame predicting mode under the depth of a corresponding CU. Therefore, calculating complexity in quadtree division of CU and ergodic under PU mode during transcoding is avoided. According to the transcoding method in the invention, the coding calculation complexity and coding time can be lowered and reduced considerably under the condition of very small loss of bit rate and video quality.

The invention aims at the problem that a traditional data structure cannot support the network multidimensional space data expression and provides a MDDRQ-Tree index structure for the network multidimensional space data expression. The MDDRQ-Tree index structure is characterized in that: (1) a primary tree is transformed from an area quadtree index structure divided through a rule of a pyramid hierarchy structure, (2) an overlapping sub-tree structure for supporting the multidimensional data is provided, (3) the change of spatial resolution is reflected by the depth of the tree, and (4) all the nodes of the tree are space object carriers. The invention organically integrates the multidimensional space data such as frequently-used vector data, gridded data, process data, three-dimensional landscape map data, and the like. In the manner of data organization, scheduling and searching fit for the network conditions, the invention can efficiently and rapidly support the web publishing of the multidimensional data for mass data. Compared with the traditional method, the index method of the invention can efficiently express and search the scale of the mass multidimensional data. The more the data volume is, the more obvious the promoted efficiency is.

The invention discloses a nowcasting method and system of a thunder cloud cluster based on the boundary recognition and tracer technique. The method performs the cloud cluster boundary recognition and topology process to establish the relationship between cloud cluster life timing and clan pedigree by using the pattern recognition technique. The method comprises the steps of performing the boundary recognition on the pre-processed radar data; respectively recognizing the life timing of each cloud cluster and the information of moving direction, velocity, area and strong center and the like ofeach cloud cluster through the six judging factors of the quadtree matching analysis factor, the overlap factor, the area factor, the circum-rectangle factor, the outline comprehensive factor and thelocal similarity determination factor; and performing linear extrapolation on the moving direction, velocity, area and the strength of the cloud cluster. The preliminary result indicates that the system and the method of the invention can realize better recognition and extrapolation forecast of the thunder cloud cluster.

A new effective and fast method and apparatus for still image compression implements an embedded progressive sorting scheme in a quadtree-like structure. In contrast to zerotree-based methods for wavelet coding, the invented embedded quadtree wavelet (EQW) method exploits the inherent spatial self-similarity within individual layers of the multiresolution decomposition hierarchy. This self-similarity offers higher predictability of the data within the same resolution level, and therefore usually provides a higher performance in seeking a compact code. The computation involved in the EQW method is more efficient than in the zerotree wavelet coding, and the produced bitstream is more robust to channel noise. The present invention can effectively be used for object-oriented shape coding or region coding in image and video compression coding systems.

The invention relates to an HEVC (High Efficiency Video Coding) intraframe coding mode selection method based on texture division features. The method includes steps of 1, inputting a CTU (Coding Tree Unit) with a to-be-selected coding mode; 2, performing texture feature analysis on original pixel brightness value of the current CTU and obtaining texture division marks of CUs of different sizes and a texture feature value of a 32*32 CU (Coding Unit) through calculation; 3, utilizing the texture division marks and the texture feature values of CUs, predicting a depth range of the current CTU and calculating an early termination coding division mark of the CUs and an early termination predication division mark of a PU (Predication Unit);4, utilizing the depth range of the current CTU, the early termination coding division mark of the CUs and the early termination predication division mark of the PU, implementing quadtree division of the current CTU. According to the invention, in a condition of maintaining good coding rate distortion performance, HEVC intraframe coding processing time is reduced effectively and at the same time, a comparatively good parallel treatment characteristic is achieved.

The invention provides a graphics processing unit (GPU)-orientated large-scale terrain fast drawing method. The method comprises the following steps of: generating an out-of-core file of original terrain, wherein the out-of-core file stores a plurality of terrain blocks containing original terrain data, an indexing serial number of each terrain block and compressed texture blocks corresponding to the terrain blocks, and the terrain data comprises texture data and altitude data; determining the level of detail (LOD) hierarchical distribution of the terrain according to a predetermined view point, establishing a terrain quadtree structure, traversing the terrain quadtree structure, selecting a corresponding quadtree node for different LODs, and adding the selected quadtree node to a rendering scheduling queue, wherein each node of the terrain quadtree structure corresponds to the corresponding compressed terrain block in the out-of-core file and is used for storing the LOD and the altitude data of the corresponding compressed terrain block; and acquiring the node to be scheduled from the rendering scheduling queue, and rendering the node to be scheduled to finish the drawing of the original terrain.

A method and apparatus for scalable video coding are disclosed, wherein the video data is configured into a Base Layer (BL) and an Enhancement Layer (EL) and wherein the EL has higher spatial resolution or better video quality than the BL. According to embodiments of the present invention, information from the base layer is exploited for coding the enhancement layer. The information coding for the enhancement layer includes CU structure, motion information, motion information, MVP/merge candidates, intra prediction mode, residual quadtree information, texture information, residual information, context adaptive entropy coding, Adaptive Lop Filter (ALF), Sample Adaptive Offset (SAO), and deblocking filter.

The invention provides a fractal multi-resolution simplified method used for large-scale terrain rendering. The method comprises the following steps: (1) determining a terrain grid rendering region in a scene, firstly carrying out equidistant grid resampling on DEM (digital elevation model) data of coarser grids to form a terrain quadtree node; (2) projecting a view point to an XOZ plane, creating a terrain multi-resolution frame, and setting a plurality of different resolution levels from 1 to n on the terrain by adopting the multi-resolution LOD (level of detail) technology according to the view point; and (3) determining the level of the terrain according to the distances between the view point and different regions of a model, extracting characteristic parameters from an original DEM data set, adopting a DEM-based fractal random midpoint displacement interpolation to generate a continuous real terrain, and realizing reconstruction of a large-scale terrain. The terrain realized by adopting the method in the invention has good space continuity, cracks between different levels in a common multi-resolution model can be avoided, and smooth transition of different resolution models can be realized.