Given a compressed image in the restricted quadtree and shading format, this paper presents a fast algorithm for computing 2D discrete cosine transform (DCT) on the compressed grey image directly without the need to decompress the compressed image. The proposed new DCT algorithm takes O(K2 logK + N2) time where the decompressed image is of size N × N and K denotes the number of nodes in the res...

Data-parallel primitives for performing operations on the PM1 quadtree, bucket PMR quadtree, and R-tree spatial data structures are presented using the scan model. Algorithms are described for building these three data structures that make use of these primitives. The data-parallel algorithms are assumed to be main memory resident. The algorithms were implemented on a minimally con gured Thinki...

The Support Vector Classification (SVC) is a powerful machine learning technique for pattern recognition purposes, whose efficiency depends significantly on its parameters selection. This paper proposes an algorithm that integrates the quadtree data structure with the grid search to select the optimal (C,) SVC parameters. The goal is to reduce computational operations and processing time from ...

In this paper, we present a method for synthesizing photorealistic visual speech using a parametric model based on quadtree splines. In an image-based visual speech synthesis system, visemes are used for generating an arbitrary new image sequence. The images between visemes are usually synthesized using a certain mapping. Such a mapping can be characterized by motion parameters estimated from t...

In this paper, a path planner is proposed for a fixed wing micro air vehicle (MAV), in the framework of fuzzy quadtrees. It is shown that a fuzzy version of the quadtree planner is apt for micro air vehicle applications with severe space, power and budgetary constraints. The algorithm can significantly reduce both space and time complexity and still yield an optimal and safe path for the vehicl...

The quadtree data structure is extensively used in representing 2dimensional data in many applications like image processing, cartographic data processing. VLSI embedding, graphics, computer animation, computer-aided architecture, etc. The data structure employs the divideand-conquer technique to recursively decompose the planar region. This paper addresses the problem of planar tessellation wh...

We present a quadtree-based decomposition of the interior of a polygon with holes. The complete decomposition yields a constant factor approximation of the minimum weight Steiner triangulation (MWST) of the polygon. We show that this approximate MWST supports ray shooting queries in the query-sensitive sense as deened by Mitchell, Mount and Suri. A proper truncation of our quadtree-based decomp...

In this paper a novel technique for rotation independent template matching via Quadtree Zernike decomposition is presented. Both the template and the target image are decomposed by using a complex polynomial basis. The template is analyzed in block-based manner by using a quad tree decomposition. This allows the system to better identify the object features. Searching for a complex pattern into...

A novel spatial data structure called the orientation adaptive quadtree (OAQ) is presented. The data structure takes advantage oflarge second-order moments of inertia of planar objects by aligning the quad tree axes with the object's principal axis of inertia. This provides a reduction in the number of leaf nodes necessary to store the quadtree compared to quadtrees aligned with the object coor...

Random binary search trees, b-ary search trees, median-of-(2k+1) trees, quadtrees, simplex trees, tries, and digital search trees are special cases of random split trees. For these trees, we offer a universal law of large numbers and a limit law for the depth of the last inserted point, as well as a law of large numbers for the height.