In this paper, a novel image zooming scheme for indexed color images is proposed. In the proposed scheme, the bilinear interpolation technique is employed to enlarge the original image. Then, the pixel grouping process is executed to classify the pixels in the enlarged image. From the experimental results, it is shown that the proposed scheme provides better image quality than the pixel copy te...

This paper presents an approach for the effective combination of interpolation with binarization of gray level text images to reconstruct a high resolution binary image from a lower resolution gray level one. We study two nonlinear interpolative techniques for text image interpolation. These nonlinear interpolation methods map quantized low dimensional 2 x 2 image blocks to higher dimensional 4...

Downsampling and upsampling are widely used in image display, compression, and progressive transmission. In this paper we examine new down/upsampling methods using frequency response analysis and experimental evaluation. We consider six classes of filters for down/upsampling: decimation/duplication, bilinear interpolation, least-squares filters, orthogonal wavelets, biorthogonal wavelets, and a...

This paper deals with light sources in computer graphics. Different kinds of light sources and different types of solutions generally used are first described. Then, a new solution for directionally dependent light sources based on Noé and Péroche’s model[NP00] is proposed to avoid drawbacks of bilinear interpolation. The use of singular integrals with locally supported functions allows a fast ...

Abstract. A hybrid stress finite volume method is proposed for linear elasticity equations. In this new method, a finite volume formulation is used for the equilibrium equation, and a hybrid stress quadrilateral finite element discretization, with continuous piecewise isoparametric bilinear displacement interpolation and two types of stress approximation modes, is used for the constitutive equa...

The problem of computing Bilinear-Diffie-Hellman maps is considered. It is shown that the problem of computing the map is equivalent to computing a diagonal version of it. Various lower bounds on the degree of any polynomial that interpolates this diagonal version of the map are found that shows that such an interpolation will involve a polynomial of large degree, relative to the size of the se...

One way to visualize vector elds was based on their qualitative structure by showing the eld topology after linear or bilinear interpolation. This paper extends this to cases of nonlinear behavior in the grid cells. It uses new ideas about the analysis of some polynomial vector elds which have been proved by using Cliiord algebra and analysis. They are used as local model for the visualization ...

In a separable complex Hilbert space endowed with an isometric conjugate-linear involution, we study sequences orthonormal with respect to an associated bilinear form. Properties of such sequences are measured by a positive, possibly unbounded angle operator which is formally orthogonal as a matrix. Although developed in an abstract setting, this framework is relevant to a variety of eigenvecto...

The paper considers a problem of consensus-based synchronization of uncertain parameter varying multi-agent systems. We present a method for constructing consensus-based synchronization protocol schedules for each agent to ensure it synchronizes with a reference parameter-varying system. The proposed protocol guarantees a specified level of H∞ transient consensus between the agents. The algorit...

Formulated in terms of velocity, pressure and the extra stress tensor, the incompressible Navier-Stokes equations are discretized by stabilized finite element methods. The stabilized methods proposed are analyzed for a linear model and extended to the Navier-Stokes equations. The numerical tests performed confirm the good stability characteristics of the methods. These methods are applicable to...