quad tree

(redirected from Quadtree)
Also found in: Wikipedia.

quad tree

A tree structure used to search a database. There are always four branches attached to a branch point (node). The search continually divides the available records by four until the desired record is found. See splay tree.
Mentioned in ?
References in periodicals archive ?
Firstly, in view of the fact that the 3D scene is far greater than the radar beam and there generally exists plenty of objects which are definitely can not be detected by radar, this paper adopts quadtree to establish and query the 3D scene.
A noval fragile watermarking method for medical images using quadtree structure", Conf.
Each CTU is recursively partitioned into coding units (CUs) using a quadtree structure.
The Quadtree algorithm seems to be the best one, having the best compression rate, the best memory usage and some good compression and decompression times.
It uses three levels of quadtree partition for motion estimation, which provides good balance degree of variation to picture content and helps to improve the compression ratio.
Los SABDE evaluados utilizan diferentes tipos de estructuras de indices espaciales: PostGIS utiliza el indice de arbol R implementado sobre un arbol de busqueda llamado GiST (Generalized Search Tree, Arbol Generalizado de Busqueda), mientras que SQL Server aprovecha las ideas del arbol quadtree para la creacion de etiquetas y los usa posteriormente en la estructura del arbol B+.
Query and Visualization of extremely large network datasets over the web using Quadtree based KML Regional Network Links , 17th International Conference on Geoinformatics, pp.
The right panel of figure 1 shows the quadtree stixel size averaged across 100 partitions.
El uso de grafos que codifican las relaciones de dependencia entre vertices para evitar la aparicion de grietas en las superficies multi-resolucion, constituye una de las principales contribuciones en lo que se conoce como Triangulaciones Quadtree Restringidas (RQT) (Lindstrom et al, 1996).
For this, any system that uses a hierarchical data structure to organize a geographical object space may be used, such as for example a region quadtree [12], [13].
In [27] a watermarking technique based on the quadtree is proposed.
This is implemented by constructing a quadtree of the image, progressing down the tree, splitting as necessary when inhomogeneities exist.

Full browser ?