Stencil operations are an important class of scientific computational kernels that are pervasive in scientific simulations as well as in image processing. A key characteristic of this class of computation is that they have a low operational intensity, i.e., the ratio of the number of memory accesses to the number of floating point operations it performs is high. As a result, the performance of ...

Because visual computations are very data intensive they are often limited by the bandwidth of the system rather than its peak computational performance. The trend towards many-core architectures exacerbates the problem because the parallel cores let the compute capability grow exponentially while the system bandwidth increases only linearly. At the core of the bandwidth problem in visual compu...

We describe a novel 3D finite difference method for solving the anisotropic inhomogeneous Poisson equation based on a multi-component additive implicit method with a 13-point stencil. The serial performance is found to be comparable to the most efficient solvers from the family of preconditioned conjugate gradient (PCG) algorithms. The proposed multicomponent additive algorithm is unconditional...

Two of the best methods to recognize silhouette to create real-time volume shadow in virtual environment are described in this paper. Volume shadow algorithm is implemented for virtual environment with moveable illuminated light source. Triangular method and the Visible-non visible method are introduced. The recent traditional silhouette detection and implementation techniques used in volume sh...

Considering matrices obtained by the application of a five-point stencil on a 2D rectangular grid, we analyse a preconditioning method introduced by Axelsson and Eijkhout, and by Brand and Heinemann. In this method, one performs a (modified) incomplete factorization with respect to a so-called ‘repeated’ or ‘recursive’ red– black ordering of the unknowns while fill-in is accepted provided that ...

The objective of this work is to predict the deviations between spectral measurements obtained by different devices for halftone prints. To describe the physics, the transport theory is considered, and to accurately solve the governing equations for arbitrary phase functions, a stochastic Monte Carlo method is employed. Recently, a stencil approach was developed, which allows to speed up such M...

We present a numerical method for the variable coefficient Poisson equation in three dimensional irregular domains and with interfacial discontinuities. The discretization embeds the domain and interface into a uniform Cartesian grid augmented with virtual degrees of freedom to provide accurate treatment of jump and boundary conditions. The matrix associated with the discretization is symmetric...

In geographical information systems vector data has important applications in the analysis and management of virtual landscapes. Therefore, methods that allow combined visualization of terrain and geospatial vector data are required. Such methods have to adapt the vector data to the terrain surface and to ensure a precise and efficient mapping. In this paper, a rendering method based on the ste...

In general, mesh smoothing is performed by minimizing the discrete energy function for the surface. One of the major problems in mesh smoothing is to prevent the mesh from shrinking. In this paper, we propose a novel volume constraint to address the shrinking problem in mesh smoothing. Our key observation is that the mesh can be efficiently smoothed patch by patch in a signal processing manner,...