Current digital image/video storage, transmission and display technologies use uniformly sampled images. On the other hand, the human retina has a nonuniform sampling density that decreases dramatically as the solid angle from the visual fixation axis increases. Therefore, there is sampling mismatch between the uniformly sampled digital images and the retina. This paper introduces retinally rec...

A novel irregular and nonuniform sampling scheme for image data is presented in this paper. Its main characteristics are the particular distribution of the samples along image edges and in textured areas, which is obtained following a multiresolution approach, and the low computational complexity. As an example of application, an image coding system is proposed which, thanks to both the peculia...

This paper presents a lossy compression method for motion capture data. Each degree of freedom of a motion clip is smoothed by an anisotropic diffusion process and then divided into segments at feature discontinuities. Feature discontinuities are identified by the zero crossings of the second derivative in the smoothed data. Finally, each segment of each degree of freedom is approximated by a c...

An adaptive nonuniform sampling technique for alias-free image representation is presented. It is both fast, thanks to the use of pseudo-Poisson disks (PPDs), and eeective, because a higher sample density is used in areas which are rich in details; these zones of the image are located using a skewness-based operator, which is both simple and accurate, and gradient information. Experimental resu...

Original scientific paper In this paper, the possibility to create uniform porous structure for nonsymmetric precursor heating was investigated together with changes in collapse stress and their reproducibility. The statistic relative standard deviation (RSD) of pore size was used to determine the structural uniformity. It was shown that proper adjustment of the foaming parameters leads to form...

0022-3093/$ see front matter 2008 Elsevier B.V. A doi:10.1016/j.jnoncrysol.2008.06.014 * Corresponding author. Tel.: +609 258 5680; fax: + E-mail address: [email protected] (G.W. Sche The Young’s moduli of a set of silica aerogels have been measured by two techniques: 3-point bending and uniaxial compression. The data found by the two methods differ strongly. The uniaxial compression test g...

image compression, JPEG, companding The use of a compander (compressor-expander) in conjunction with scalar uniform high-resolution quantization, so as to obtain an overall effect of an improved nonuniform quantization, has been widespread for many years and embedded in standards of digitization and compression of audio waveforms (μ-law in the U.S., and A-law in Europe). However, there is almos...

In this paper high dynamic range nonuniform two-dimensional vector quantization model for Laplacean source was provided. Semilogarithmic A-law compression characteristic was used as radial scalar compression characteristic of two-dimensional vector quantization. Optimal number value of concentric quantization domains (amplitude levels) is expressed in the function of parameter A. Exact distorti...

Most of image compression methods are based on frequency domain transforms that are followed by a quantization and rounding approach to discard some coefficients. It is obvious that the quality of compressed images highly depends on the manner of discarding these coefficients. However, finding a good balance between image quality and compression ratio is an important issue in such manners. In t...

An SPICE compatible model for multiple coupled nonuniform lossless transmission lines (TL's) is presented. The method of the modeling is based on the steplines approximation of the nonuniform TLs and quasi-TEM assumptions. Using steplines approximation the system of coupled nonuniform TLs is subdivided into arbitrary large number of coupled uniform lines (steplines) with different characteristi...