Quadtree Representation & Compression of Spatial Data
نویسنده
چکیده
Spatial data representation and compression has become a focus issue in computer graphics and image processing applications. Quadtrees, as one of hierarchical data structures, basing on the principle of recursive decomposition of space, always offer a compact and efficient representation of an image. For a given image, the choice of quadtree root node plays an important role in its quadtree representation and final data compression. The goal of this thesis is to present a heuristic algorithm for finding a root node of a region quadtree, which is able to reduce the number of leaf nodes when compared with the standard quadtree decomposition. The empirical results indicate that, this proposed algorithm has quadtree representation and data compression improvement when in comparison with the traditional method.
منابع مشابه
Planelet Transform: A New Geometrical Wavelet for Compression of Kinect-like Depth Images
With the advent of cheap indoor RGB-D sensors, proper representation of piecewise planar depth images is crucial toward an effective compression method. Although there exist geometrical wavelets for optimal representation of piecewise constant and piecewise linear images (i.e. wedgelets and platelets), an adaptation to piecewise linear fractional functions which correspond to depth variation ov...
متن کاملQuadtree and Octree Grid Generation
Engineering analysis often involves the accurate numerical solution of boundary value problems in discrete form. Hierarchical quadtree (or octree) grid generation offers an efficient method for the spatial discretisation of arbitrary-shaped two- (or three-) dimensional domains. It consists of recursive algebraic splitting of sub-domains into quadrants (or cubes), leading to an ordered hierarchi...
متن کاملAdaptive transforms for image coding using spatially varying wavelet packets
We introduce a novel, adaptive image representation using spatially varying wavelet packets (WPs), Our adaptive representation uses the fast double-tree algorithm introduced previously (Herley et al., 1993) to optimize an operational rate-distortion (R-D) cost function, as is appropriate for the lossy image compression framework. This involves jointly determining which filter bank tree (WP freq...
متن کاملLossless Compression for Raster Maps Based On Mobile
In this paper, the combination of quadtree and block encoding compression approach is proposed for lossless compression of raster maps. This application is implemented on the mobile phone. Firstly, this approach iteratively split the raster map into quarter sections and the quadtree structure will construct. To index the spatial data, quadtree uses Morton encoding method. This approach defined ...
متن کاملLinkless Octree Using Multi-Level Perfect Hashing
The standard C/C++ implementation of a spatial partitioning data structure, such as octree and quadtree, is often inefficient in terms of storage requirements particularly when the memory overhead for maintaining parentto-child pointers is significant with respect to the amount of actual data in each tree node. In this work, we present a novel data structure that implements uniform spatial part...
متن کامل