All a b c d e f g h i j k l m n o p q r s t u v w x y z Other

Page 1 Next

Displaying 1 – 20 of 51

Showing per page

Image Compression with Schauder Bases

Zbigniew Ciesielski (2001)

Applicationes Mathematicae

As is known, color images are represented as multiple, channels, i.e. integer-valued functions on a discrete rectangle, corresponding to pixels on the screen. Thus, image compression, can be reduced to investigating suitable properties of such, functions. Each channel is compressed independently. We are, representing each such function by means of multi-dimensional, Haar and diamond bases so that the functions can be remembered, by their basis coefficients without loss of information. For, each...

Image Interpolation

Vicent Caselles, Simon Masnou, Jean-Michel Morel, Catalina Sbert (1997/1998)

Séminaire Équations aux dérivées partielles

We discuss possible algorithms for interpolating data given in a set of curves and/or points in the plane. We propose a set of basic assumptions to be satisfied by the interpolation algorithms which lead to a set of models in terms of possibly degenerate elliptic partial differential equations. The Absolute Minimal Lipschitz Extension model (AMLE) is singled out and studied in more detail. We show experiments suggesting a possible application, the restoration of images with poor dynamic range. We...

Image processing for old movies by filters with motion detection

Sławomir Skoneczny (2005)

International Journal of Applied Mathematics and Computer Science

Old movies suffer from various types of degradation: severe noise, blurred edges of objects (low contrast), scratches, spots, etc. Finding an efficient denoising method is one of the most important and one of the oldest problems in image sequence processing. The crucial thing in image sequences is motion. If the motion is insignificant, then any motion noncompensated method of filtering can be applied. However, if the noise is significant, then this approach gives most often unsatisfactory results....

Image retrieval based on hierarchical Gabor filters

Tomasz Andrysiak, Michal Choraś (2005)

International Journal of Applied Mathematics and Computer Science

Content Based Image Retrieval (CBIR) is now a widely investigated issue that aims at allowing users of multimedia information systems to automatically retrieve images coherent with a sample image. A way to achieve this goal is the computation of image features such as the color, texture, shape, and position of objects within images, and the use of those features as query terms. We propose to use Gabor filtration properties in order to find such appropriate features. The article presents multichannel...

Implementation of adaptive generalized sidelobe cancellers using efficient complex valued arithmetic

George-Othon Glentis (2003)

International Journal of Applied Mathematics and Computer Science

Low complexity realizations of Least Mean Squared (LMS) error, Generalized Sidelobe Cancellers (GSCs) applied to adaptive beamforming are considered. The GSC method provides a simple way for implementing adaptive Linear Constraint Minimum Variance (LCMV) beamformers. Low complexity realizations of adaptive GSCs are of great importance for the design of high sampling rate, and/or small size and low power adaptive beamforming systems. The LMS algorithm and its Transform Domain (TD-LMS) counterpart...

Implementation of the MR tractography visualization kit based on the anisotropic Allen-Cahn equation

Pavel Strachota (2009)

Kybernetika

Magnetic Resonance Diffusion Tensor Imaging (MR–DTI) is a noninvasive in vivo method capable of examining the structure of human brain, providing information about the position and orientation of the neural tracts. After a short introduction to the principles of MR–DTI, this paper describes the steps of the proposed neural tract visualization technique based on the DTI data. The cornerstone of the algorithm is a texture diffusion procedure modeled mathematically by the problem for the Allen–Cahn...

Improving the stability of discretization zeros with the Taylor method using a generalization of the fractional-order hold

Cheng Zeng, Shan Liang, Yuzhe Zhang, Jiaqi Zhong, Yingying Su (2014)

International Journal of Applied Mathematics and Computer Science

Remarkable improvements in the stability properties of discrete system zeros may be achieved by using a new design of the fractional-order hold (FROH) circuit. This paper first analyzes asymptotic behaviors of the limiting zeros, as the sampling period T tends to zero, of the sampled-data models on the basis of the normal form representation for continuous-time systems with a new hold proposed. Further, we also give the approximate expression of limiting zeros of the resulting sampled-data system...

Improving the Watermarking Process with Usage of Block Error-Correcting Codes

Berger, Thierry, Todorov, Todor (2008)

Serdica Journal of Computing

The emergence of digital imaging and of digital networks has made duplication of original artwork easier. Watermarking techniques, also referred to as digital signature, sign images by introducing changes that are imperceptible to the human eye but easily recoverable by a computer program. Usage of error correcting codes is one of the good choices in order to correct possible errors when extracting the signature. In this paper, we present a scheme of error correction based on a combination of Reed-Solomon...

Incertidumbre (información a priori) condicionada por una experiencia.

Teófilo Brezmes, Pedro Gil Alvarez (1985)

Trabajos de Estadística e Investigación Operativa

Se introduce en este trabajo una axiomatización de las medidas de incertidumbre (información a priori) condicionada por una experiencia que generaliza la dada para la incertidumbre condicionada por un suceso. El concepto de medidas de incertidumbre condicionalmente componibles permite, en determinadas condiciones (componibilidad de tipo M), una construcción de las mismas. Por último se analizan diversos ejemplos (medidas de Shannon, Renyi, etc.), constatándose la igualdad de las construcciones dadas...

Infinite probabilistic secret sharing

Laszlo Csirmaz (2023)

Kybernetika

A probabilistic secret sharing scheme is a joint probability distribution of the shares and the secret together with a collection of secret recovery functions. The study of schemes using arbitrary probability spaces and unbounded number of participants allows us to investigate their abstract properties, to connect the topic to other branches of mathematics, and to discover new design paradigms. A scheme is perfect if unqualified subsets have no information on the secret, that is, their total share...

Currently displaying 1 – 20 of 51

Page 1 Next