In fractal coding technique, an image is encoded by making use of its self-similarity property. The image can be reconstructed with some well-defined contractive mappings based on this property and hence, in theory, the reconstructed image can be of any desirable size by using an initial image of appropriate size during the decoding process. However, in practice, the enlarged image is always de...

We obtain several formulas for the action of the bilinear Hilbert transform on pairs of Hermite and Laguerre functions. The result can be expressed as a linear combination of products of Hermite or Laguerre functions.

Single rows in STIS rectified spectral images are being analyzed in science programs where the highest obtainable spatial resolution is needed. Here we discuss a problem that limits the accuracy of rectified spectral images that contain spatially unresolved components. Because the point spread function is undersampled along the slit, interpolation between the rows of the distorted spectral imag...

Let M0 = G0/H be a (n+1)-dimensional Cahen-Wallach Lorentzian symmetric space associated with a symmetric decomposition g0 = h + m and let S(M0) be the spin bundle defined by the spin representation ρ : H → GLR(S) of the stabilizer H . This article studies the superizations of M0, i.e. its extensions to a homogeneous supermanifold M = G/H whose sheaf of superfunctions is isomorphic to Λ(S∗(M0))...

Various interpolated three-dimensional (3-D) digital waveguide mesh algorithms are elaborated. We introduce an optimized technique that improves a formerly proposed trilinearly interpolated 3-D mesh and renders the mesh more homogeneous in different directions. Furthermore, various sparse versions of the interpolated mesh algorithm are investigated, which reduce the computational complexity at ...

Let $A$ be an abelian topological group and $B$ a trivial topological $A$-module. In this paper we define the second bilinear cohomology with a trivial coefficient. We show that every abelian group can be embedded in a central extension of abelian groups with bilinear cocycle. Also we show that in the category of locally compact abelian groups a central extension with a continuous section can b...

Mesh-based motion estimation—also known as control grid interpolation or warping—provides a smoother estimated intensity field compared to the traditional block-matching algorithm (BMA), resulting in most cases in a more realistic motion field and smaller estimation error. In mesh-based motion, unlike BMA, the computation of a motion vector is affected by its neighboring vectors. This interdepe...

ABSTRACT Common motion compensated hybrid video coding standards such as H.263, MPEG-1, MPEG-2, MPEG-4 are based on a fractional-pel displacement vector resolution of 1/2-pel. Recent approaches like MPEG-4 ACE and H.26L (TML5) use a 1/4-pel displacement vector resolution. In order to estimate and compensate fractional-pel displacements, the image signal has to be interpolated. Therefore differe...

This paper describes the delay calculation method and the accuracy analysis of its interpolation for CMOS ASIC libraries which contain cell-based primitives and memories to be used during the pre-layout design phase of logic simulation, timing verification, and logic synthesis. The delay calculation method addressed in this paper is specified as IEC CDV 61523-2 standard which consists of the es...

A warping operator consists of an invertible axisdeformation applied either in the signal domain or in thecorresponding Fourier domain. Additionally, a warping trans-formation is usually required to preserve the signal energy, thuspreserving orthogonality and being invertible by its adjoint.Initially, the design of such operators has been motivated bythe idea of suitably...