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The market for digital video is growing, with compression as a core enabling technology. Standardized methods as motion-compensated DCT, which have reached a level of maturity over decades, are dominating today's products. During the past years, another wave of innovation has occurred in video compression research and development, which leads to the assumption that it is still far from reaching its...
This document describes a haptic application that allows blind people recognize three-dimensional (3D) objects that exist in virtual environment. The system allows blind people to touch, grasp and manipulate objects that exist in the haptic enabled VE. The system is designed in order to provide an alternative way of human computer interaction to blind users.
In this paper, we present two versions of a demonstrator for gaze direction estimation. The first version is based on the analysis and the interpretation of head movements, especially in case of important head rotations. In such a case, we suppose that the gaze direction coincides with the head orientation. The second version of the demonstrator is based on the analysis of the iris centres positions...
Automatic real-time translation of gestured languages for hearing-impaired would be a major advance on disabled integration path. In this paper, we present a demonstrator on Cued Speech hand gesture recognition.
In this paper, we address the blind separation problem of binaural mixed signals, and propose a novel blind separation method using Single-Input-Multiple-Output-model-based independent component analysis (SIMO-ICA) with a self-generator (SG) for the initial filter. SIMO-ICA which has been proposed by the authors can separate mixed signals, not into monaural source signals but into SIMO-model-based...
In adaptive signal processing, joint process estimation plays an important role in various estimation problems. It is well known that a joint process estimator consists of two structures, namely the orthogonalizer and the regression filter. In literature, orthogonalization step is performed either by orthogonal transformations or by linear predictors. While the orthogonal transformations do not preserve...
In this paper, we present a dynamic programming approach to voice transformation (VT). The goal of VT is to modify the speech of a source speaker such that it is perceived as if spoken by a target speaker. The speech model used in this work is based on MELP (Mixed Excitation Linear Prediction) speech coding algorithm. The designed system obtains speaker-specific codebooks of line spectral frequencies...
Programmability with its associated flexibility will be increasingly important in future multi-standard radio systems. We are presenting a fully programmable and flexible DSP platform capable of efficiently performing channel estimation and MRC-based channel equalization for several CDMA based wireless transmission systems in software. Our processor is based on a DSP core with SIMD-computing clusters...
In multi-class problems, within- and between-class scatters should be considered in classification criterion. The common vector approach (CVA) uses the discriminative information obtained from within-class scatter of any class. It has been shown that this classical CVA method gives high recognition rates in multi-class problems. In this study, improvements on the CVA method that consider both within-...
Coset-based codes are often proposed as an alternative to the theoretical probabilistic random binning in network coding. In this paper nested lattice codes recently proposed for multiterminal binning are used to devise a structured high dimensional Costa scheme for data hiding. The resulting embedding scheme overcomes both the famous Scalar Costa Scheme (SCS) and regular Quantization Index Modulation...
A new iterative speech enhancement scheme that can be seen as an approximation to the Expectation-Maximization (EM) algorithm is proposed. The algorithm employs a Kalman filter that models the excitation source as a spectrally white process with a rapidly time-varying variance, which calls for a high temporal resolution estimation of this variance. A Local Variance Estimator based on a Prediction...
In this paper, the pulse shape design for various communication systems including PAM, FSK, and PSK is considered. The pulse is designed by imposing constraints on the time and frequency domains constraints on the autocorrelation function of the pulse shape. Intersymbol interference, finite duration and spectral mask restrictions are a few examples leading to convex sets in L2. The autocorrelation...
We consider cyclically prefixed block transmission over frequency selective wireless multiple input multiple output (MIMO) channels. We make a bit rate comparison between MIMO cyclically prefixed single carrier (CP-SC) and MIMO orthogonal frequency division multiplexing (OFDM) systems. We analytically prove that MIMO CP-SC with decision feedback equalization (DFE) outperforms MIMO OFDM with linear...
The goal of partial encryption of a bit stream is to make the entire stream somehow useless for anyone that cannot decrypt its ciphered subset. In this paper we present the effects of the partial encryption of some H.264/AVC coding parameters, in order to obtain a moderate degradation of the video content, which can be appealing for commercial applications, like pay-per-view systems and others, without...
In this paper a new class of filters designed for the removal of impulsive noise in color images is presented. The proposed filter class is based on the nonparametric estimation of the density probability function of pixels in a sliding filtering window. The comparison of the new filtering method with the standard techniques used for impulsive noise removal, indicates good noise removal capabilities...
Most edge detection algorithms include three main stages: smoothing, differentiation, and labeling. In this paper, we evaluate the performance of algorithms in which competitive learning is applied first to enhance edges, followed by an edge detector to locate the edges. In this way, more detailed and relatively more unbroken edges can be found as compared to the results when an edge detector is applied...
Internet traffic primarily consists of packets from Transmission Control Protocol (TCP) flows. Based on passive, flow level TCP network measurements, our previous work has focused on using the principal component method to perform factor analysis on flow class throughput correlation matrices in order to infer which classes of TCP flows are sharing bottlenecks in the network. In this paper, we present...
Amplifier nonlinearities affect drastically the performance of OFDM systems. A new carrier allocation method that reduces the intermodulation distortion between different carriers for multiuser OFDM system is presented. Using this allocation technique and transmit beamforming a bit error rate improvement is obtained in a low or medium load system. Comparison of this proposal with Block and Interleaved...
Text-to-phoneme mapping is a very important preliminary step in any text-to-speech synthesis system. In this paper, we study the performances of the multilayer perceptron (MLP) neural network for the problem of text-to-phoneme mapping. Specifically, we study the influence of the input letter encoding in the conversion accuracy of such system. We show, that for large network complexities the orthogonal...
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