Results 1 - 10 of 746

The Contourlet Transform: An Efficient Directional Multiresolution Image Representation

by Minh N. Do, Martin Vetterli - IEEE TRANSACTIONS ON IMAGE PROCESSING
"... The limitations of commonly used separable extensions of one-dimensional transforms, such as the Fourier and wavelet transforms, in capturing the geometry of image edges are well known. In this paper, we pursue a “true” two-dimensional transform that can capture the intrinsic geometrical structure t ..."
Abstract - Cited by 513 (20 self) - Add to MetaCart
The limitations of commonly used separable extensions of one-dimensional transforms, such as the Fourier and wavelet transforms, in capturing the geometry of image edges are well known. In this paper, we pursue a “true” two-dimensional transform that can capture the intrinsic geometrical structure

The Local Discontinuous Galerkin Method For Time-Dependent Convection-Diffusion Systems

by Bernardo Cockburn, Chi-wang Shu
"... In this paper, we study the Local Discontinuous Galerkin methods for nonlinear, time-dependent convection-diffusion systems. These methods are an extension of the Runge-Kutta Discontinuous Galerkin methods for purely hyperbolic systems to convection-diffusion systems and share with those methods the ..."
Abstract - Cited by 300 (34 self) - Add to MetaCart
their high parallelizability, their high-order formal accuracy, and their easy handling of complicated geometries, for convection dominated problems. It is proven that for scalar equations, the Local Discontinuous Galerkin methods are L2-stable in the nonlinear case. Moreover, in the linear case, it is shown

Multi-Chart Geometry Images

by P. V. Sander, Z. J. Wood, S. J. Gortler, J. Snyder, H. Hoppe , 2003
"... We introduce multi-chart geometry images, a new representation for arbitrary surfaces. It is created by resampling a surface onto a regular 2D grid. Whereas the original scheme of Gu et al. maps the entire surface onto a single square, we use an atlas construction to map the surface piecewise onto c ..."
Abstract - Cited by 117 (4 self) - Add to MetaCart
We introduce multi-chart geometry images, a new representation for arbitrary surfaces. It is created by resampling a surface onto a regular 2D grid. Whereas the original scheme of Gu et al. maps the entire surface onto a single square, we use an atlas construction to map the surface piecewise onto

Simplifying Surfaces with Color and Texture using Quadric Error Metrics

by Michael Garland, Paul S. Heckbert , 1998
"... There are a variety of application areas in which there is a need for simplifying complex polygonal surface models. These models often have material properties such as colors, textures, and surface normals. Our surface simplification algorithm, based on iterative edge contraction and quadric error m ..."
Abstract - Cited by 208 (2 self) - Add to MetaCart
metrics, can rapidly produce high quality approximations of such models. We present a natural extension of our original error metric that can account for a wide range of vertex attributes. CR Categories: I.3.5 [Computer Graphics]: Computational Geometry and Object Modeling---surface and object

A DISCONTINUOUS GALERKIN FINITE ELEMENT METHOD FOR HAMILTON-JACOBI EQUATIONS

by Changqing Hu, Chi-wang Shu , 1998
"... In this paper, we present a discontinuous Galerkin finite element method for solving the nonlinear Hamilton-Jacobi equations. This method is based on the Runge-Kutta discontinuous Galerkin finite element method for solving conservation laws. The method has the flexibility of treating complicated geo ..."
Abstract - Cited by 90 (16 self) - Add to MetaCart
In this paper, we present a discontinuous Galerkin finite element method for solving the nonlinear Hamilton-Jacobi equations. This method is based on the Runge-Kutta discontinuous Galerkin finite element method for solving conservation laws. The method has the flexibility of treating complicated

Method of characteristics in spherical geometry applied to a Harang discontinuity situation

by O. Amm - Ann. Geophys , 1998
"... Abstract. The method of characteristics for obtaining spatial distributions of ionospheric electrodynamic parameters from ground-based spatial observations of the ground magnetic disturbance and the ionospheric electric ®eld is presented in spherical geometry. The method includes tools for separatio ..."
Abstract - Cited by 15 (10 self) - Add to MetaCart
Abstract. The method of characteristics for obtaining spatial distributions of ionospheric electrodynamic parameters from ground-based spatial observations of the ground magnetic disturbance and the ionospheric electric ®eld is presented in spherical geometry. The method includes tools

The depth discontinuity occlusion camera

by Voicu Popescu, Daniel Aliaga - In Proceedings of the symposium on Interactive 3D graphics and games , 2006
"... Figure 1 Depth image, DDOC reference image, and corresponding pair of frames. The DDOC reference image alleviates disocclusion errors, which are quantified as number of missing pixels. Figure 2 Additional examples with the disocclusion errors highlighted in white. Rendering a scene using a single de ..."
Abstract - Cited by 16 (7 self) - Add to MetaCart
depth image suffers from disocclusion errors as the view translates away from the reference view. We present the depth discontinuity occlusion camera (DDOC), a non-pinhole camera that samples surfaces which are hidden in the reference view, but are likely to become visible in nearby views. The DDOC

On the Fourier Properties of Discontinuous Motion

by Steven Beauchemin, John L. Barron - Journal of Mathematical Imaging and Vision , 2000
"... . Retinal image motion and optical ow as its approximation are fundamental concepts in the eld of vision, perceptual and computational. However, the computation of optical ow remains a challenging problem as image motion includes discontinuities and multiple values mostly due to scene geometry, surf ..."
Abstract - Cited by 10 (0 self) - Add to MetaCart
. Retinal image motion and optical ow as its approximation are fundamental concepts in the eld of vision, perceptual and computational. However, the computation of optical ow remains a challenging problem as image motion includes discontinuities and multiple values mostly due to scene geometry

DISCONTINUITY FACTORS FOR NON-MULTIPLYING MATERIAL IN TWO-DIMENSIONAL HEXAGONAL REACTOR GEOMETRY

by Petko Petkov, Ulrich Grundmann, See Profile, Siegfried Mittag, Petko Petkov, Ulrich Grundmann
"... Discontinuity factors for non-multiplying material in two-dimensional hexagonal reactor geometry ..."
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Discontinuity factors for non-multiplying material in two-dimensional hexagonal reactor geometry

Nodal discontinuous Galerkin methods on graphics processors,

by A Klöckner , T Warburton , J Bridge , J S Hesthaven - J. Comp. Phys., , 2009
"... Abstract Discontinuous Galerkin (DG) methods for the numerical solution of partial differential equations have enjoyed considerable success because they are both flexible and robust: They allow arbitrary unstructured geometries and easy control of accuracy without compromising simulation stability. ..."
Abstract - Cited by 52 (4 self) - Add to MetaCart
Abstract Discontinuous Galerkin (DG) methods for the numerical solution of partial differential equations have enjoyed considerable success because they are both flexible and robust: They allow arbitrary unstructured geometries and easy control of accuracy without compromising simulation stability
Results 1 - 10 of 746