Results 1 
8 of
8
The quadtree and related hierarchical data structures
 ACM Computing Surveys
, 1984
"... A tutorial survey is presented of the quadtree and related hierarchical data structures. They are based on the principle of recursive decomposition. The emphasis is on the representation of data used in applications in image processing, computer graphics, geographic information systems, and robotics ..."
Abstract

Cited by 541 (12 self)
 Add to MetaCart
(Show Context)
A tutorial survey is presented of the quadtree and related hierarchical data structures. They are based on the principle of recursive decomposition. The emphasis is on the representation of data used in applications in image processing, computer graphics, geographic information systems, and robotics. There is a greater emphasis on region data (i.e., twodimensional shapes) and to a lesser extent on point, curvilinear, and threedimensional data. A number of operations in which such data structures find use are examined in greater detail.
Pyramidal parametrics
 Computer Graphics (SIGGRAPH ’83 Proceedings
, 1983
"... The mapping of images onto surfaces may substantially increase the realism and information content of computergenerated imagery. The projection of a flat source image onto a curved surface may involve sampling difficulties, however, which are compounded as the view of the surface changes. As the pr ..."
Abstract

Cited by 304 (1 self)
 Add to MetaCart
(Show Context)
The mapping of images onto surfaces may substantially increase the realism and information content of computergenerated imagery. The projection of a flat source image onto a curved surface may involve sampling difficulties, however, which are compounded as the view of the surface changes. As the projected scale of the surface increases, interpolation between the original samples of the source image is necessary; as the scale is reduced, approximation of multiple samples in the source is required. Thus a constantly changing sampling window of viewdependent shape must traverse the source image. To reduce the computation implied by these requirements, a set of prefiltered source images may be created. This approach can be applied to particular advantage in animation, where a large number of frames using the same source image must be generated. This paper advances a "pyramidal parametric " prefiltering and sampling geometry which minimizes aliasing effects and assures continuity within and between target images. Although the mapping of texture onto surfaces is an excellent example of the process and provided the original motivation for its development, pyramidal parametric data structures admit of wider application. The aliasing of not only surface texture, but also highlights and even the surface representations themselves, may be minimized by pyramidal parametric means.
Pyramid Computer Solutions of the Closest Pair Problem
, 1982
"... Given an N x N array of OS and Is, the closest pair problem is to determine the minimum distance between any pair of ones. Let D be this minimum distance (or D = 2N if there are fewer than two Is). Two solutions to this problem are given, one requiring O(log ( N) + D) time and the other O(log ( N)). ..."
Abstract

Cited by 2 (0 self)
 Add to MetaCart
Given an N x N array of OS and Is, the closest pair problem is to determine the minimum distance between any pair of ones. Let D be this minimum distance (or D = 2N if there are fewer than two Is). Two solutions to this problem are given, one requiring O(log ( N) + D) time and the other O(log ( N)). These solutions are for two types of parallel computers arranged in a pyramid fashion with the base of the pyramid containing the matrix. The results improve upon an algorithm of Dyer that requires o(N) time on a more pOWerfd COmpUter. 0 19135 Academic Press. Inc. 1.
Iowa State University From the SelectedWorks of Sarah A. Rajala
, 1992
"... Segmentationbased motion estimation and residual coding for packet video: a goaloriented approach ..."
Abstract
 Add to MetaCart
(Show Context)
Segmentationbased motion estimation and residual coding for packet video: a goaloriented approach
i •'immmmmmmmmmmil' * f ■ 0^0 y * 3 UNFORCED IMAGE PARTITIONING BY WEIGHTED PYRAMID LINKING
"... This paper describes a method of image segmentation that creates a partition of the image into compact, homogeneous regions using a parallel, iterative approach that does not require immediate forced choices. The approach makes use of a "pyramid " of successively reducedresolution ' ..."
Abstract
 Add to MetaCart
(Show Context)
This paper describes a method of image segmentation that creates a partition of the image into compact, homogeneous regions using a parallel, iterative approach that does not require immediate forced choices. The approach makes use of a "pyramid " of successively reducedresolution ' ersions of the image. It defines link strengths between pairs of pixels at successive levels of this pyramid, based on proximity and similarity, and iteratively recomputes the pixel values and adjusts the link strengths. After a fev iterations, the link strengths stabilize, and the links that remain strong define a set of subtrees of the pyramid. Each such tree represents a compact
The Tasks of Vision for Brains and Machines
"... This excerpt is provided, in screenviewable form, for personal use only by ..."
Abstract
 Add to MetaCart
(Show Context)
This excerpt is provided, in screenviewable form, for personal use only by