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 ...

An algorithm is presented for reconstructing a quadtree from its quadtree medial axis transform (QMAT). It is useful when performing operations for which the QMAT is well suited (e.g., thinning of an image). The algorithm is a postorder tree traversal which propagates the subsumption of each BLACK QMAT node in the eight possible directions. Analysis of the algorithm shows that its average execu...

This article presents a quadtree-based data structure for effective indexing of images. An image is represented by a multi-level feature vector, computed by a recursive decomposition of the image into four quadrants and stored as a full fixed-depth balanced quadtree. A node of the quadtree stores a feature vector of the corresponding image quadrant. A more general quadtree-based structure calle...

Recently, more research has been conducted on moving object databases (MOD). Typically, there are three kinds of data for dynamic attributes in MOD, i.e., historical, current and future. Although many index structures have been developed for the former two types of data, there is not much work to deal with the future data. In particular, the problem of index update has not been addressed with e...

In this paper, we propose an algorithm for neighbors finding in images represented by quadtree data structure. We first present a scheme for addressing image pixels that takes into account the order defined on a quadtree blocks. We study various properties of this method, and then we develop a formula that establishes links between quadtree blocks. Based on these results, we present an efficien...

We consider the problem of building a quadtree subdivision for a set E of n non-intersecting edges in the plane. Our approach is to first build a quadtree on the vertices corresponding to the endpoints of the edges, and then compute the intersections between E and the cells in the subdivision. For any k ≥ 1, we call a K-quadtree a linear compressed quadtree that has O(n/k) cells with O(k) verti...

The quadtree data structure is commonly used in image coding to decompose an image into separate spatial regions to adaptively identify the type of quantizer used in various regions of an image. The authors describe the theory needed to construct quadtree data structures that optimally allocate rate, given a set of quantizers. A Lagrange multiplier method finds these optimal rate allocations wi...

An algorithm is presented to answer window queries in a quadtree-based spatial database environment by retrieving all of the quadtree blocks in the underlying spatial database that cover the quadtree blocks that comprise the window. It works by decomposing the window operation into sub-operations over smaller window partitions. These partitions are the quadtree blocks corresponding to the windo...

In this paper, we present a fractal image compression algorithm employing a new quadtree recomposition (QR) approach. In this approach, quadtree subblocks of an image are iteratively recombined into larger blocks for fractal coding. For complex images, this approach exhibits superior runtime performance, when compared to a classical quadtree decomposition (QD) scheme, while maintaining high del...