In this report, we propose combining the Total Variation denoising method with the high loss wavelet compression for high noise level images. Numerical experiments show that TV-denoising can bring more wavelet coeffic...
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ISBN:
(纸本)0819429163
In this report, we propose combining the Total Variation denoising method with the high loss wavelet compression for high noise level images. Numerical experiments show that TV-denoising can bring more wavelet coefficients closer to zero thereby making the compression more efficient while the salient features (edges) of the images can still be retained.
Preconditioning techniques for linear systems are widely used in order to speed up the convergence of iterative methods. Unfortunately, linear systems arising in image processing are highly ill-conditioned and precond...
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ISBN:
(纸本)0819450782
Preconditioning techniques for linear systems are widely used in order to speed up the convergence of iterative methods. Unfortunately, linear systems arising in image processing are highly ill-conditioned and preconditioners often give bad results, since the noise components on the data are strongly amplified already at the early iterations. In this work, we propose filtering strategies which allow to obtain preconditioners with regularization features for Toeplitz systems of image deblurring. Regularization preconditioners are able to speed up the convergence in the space less sensitive to the noise and, simultaneously, they slow down the restoration from components mainly corrupted by noise. A 2-d numerical simulation concerning astronomical image deblurring confirms the effectiveness of the arguments.
We present a number of methods that use image and signed processing techniques for removal of noise from a signal. The basic idea is to first construct a time-frequency density of the noisy signal. The time-frequency ...
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ISBN:
(纸本)0819432938
We present a number of methods that use image and signed processing techniques for removal of noise from a signal. The basic idea is to first construct a time-frequency density of the noisy signal. The time-frequency density, which is a function of two variables, can then be treated as an "image", thereby enabling use of image processing methods to remove noise and enhance the image. Having obtained an enhanced time-frequency density, one then reconstructs the signal. Various time frequency-densities are used and also a number of image processing methods are investigated. Examples of human speech and whale sounds are given. In addition, new methods are presented for estimation of signal parameters from the time-frequency density.
This Volume 5205 of the conference proceedings contains 59 papers. Topics discussed include time frequency and time scale analysis, adaptive sensor network, wireless communication, image processing, exploitation of st...
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This Volume 5205 of the conference proceedings contains 59 papers. Topics discussed include time frequency and time scale analysis, adaptive sensor network, wireless communication, image processing, exploitation of structured in imaging and signalprocessing, matrix algorithms, signalprocessing applications, computer arithmetic and arithmetic and architectures for real time applications.
We introduce a new space-time signalprocessing scheme that uses both transmitter diversity technique and beamforming technique for code-division multiple access (CDMA) systems. The introduced scheme achieves the dive...
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ISBN:
(纸本)0819450782
We introduce a new space-time signalprocessing scheme that uses both transmitter diversity technique and beamforming technique for code-division multiple access (CDMA) systems. The introduced scheme achieves the diversity gain over Rayleigh fading channel through the transmitter diversity technique, and the signal-to-noise ratio (SNR) gain by the beamforming technique. Bit error rate (BER) analyses are given each of the three cases in which the transmitter diversity, beamforming and introduced combined scheme are used, in the frequency-flat Rayleigh fading channel. The analytic results are shown to coincide with the Monte-Carlo simulation results. We show that the combined scheme is more robust to the channel correlation and the speed of mobile than the diversity and beamforming scheme. Furthermore, the combined scheme gives a reduced multiple-access-interference because of its beamforming capability.
The Jacobi method for singular value decomposition is well-suited for parallel architectures. Its application to signal subspace computations is well known. Basically the subspace spanned by singular vectors of large ...
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ISBN:
(纸本)0819425842
The Jacobi method for singular value decomposition is well-suited for parallel architectures. Its application to signal subspace computations is well known. Basically the subspace spanned by singular vectors of large singular values are separated from subspace spanned by those of small singular values. The Jacobi algorithm computes the singular values and the corresponding vectors in random order. This requires sorting the result after convergence of the algorithm to select the signal subspace. A modification of the Jacobi method based on a linear objective function merges the sorting into the SVD-algorithm at little extra cost. In fact, the complexity of the diagonal processor cells in a triangular array get slightly larger. In this paper we present these extensions, in particular the modified algorithm for computing the rotation angles and give an example of its usefulness for subspace separation.
In this paper, we present implementations of a pattern recognition algorithm which uses a RBF (Radial Basis Function) neural network. Our aim is to elaborate a quite efficient system which realizes real time faces tra...
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ISBN:
(纸本)0819445584
In this paper, we present implementations of a pattern recognition algorithm which uses a RBF (Radial Basis Function) neural network. Our aim is to elaborate a quite efficient system which realizes real time faces tracking and identity verification in natural video sequences. Hardware implementations have been realized on an embedded system developed by our laboratory. This system is based on a DSP (Digital signal Processor) TMS320C6x. The optimization of implementations allow us to obtain a processing speed of 4.8 images (240 x 320 pixels) per second with a correct rate of 95% of faces tracking and identity verification.
The proceedings contains 58 papers from the conference of SPIE: advancedsignalprocessingalgorithms, architectures, and implementations viII. The topics discussed include: blind channel identification and extraction...
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The proceedings contains 58 papers from the conference of SPIE: advancedsignalprocessingalgorithms, architectures, and implementations viII. The topics discussed include: blind channel identification and extraction of more sources than sensors;blind channel estimation for CDMA systems with orthogonal modulation;blind equalization and source separation with MSK inputs and adaptive blind channel estimation by least-squares smoothing for CDMA.
The Sensor-Angle Distribution (SAD) is a recently introduced tool representing the power arriving at each sensor as a function of angle (or spatial frequency). It can be used to characterize near-field scatter environ...
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ISBN:
(纸本)0819445584
The Sensor-Angle Distribution (SAD) is a recently introduced tool representing the power arriving at each sensor as a function of angle (or spatial frequency). It can be used to characterize near-field scatter environments. The SAD, as originally introduced, under-sampled the spatial correlation of the received signal (measured at each sensor) causing the SAD to be aliased for common source location cases. In this paper we indicate how this may be overcome. Additional results are provided showing that the SAD may be implemented as a multiple weighted subarray beamformer.
作者：
Hughes, DHUSAF
Res Lab Ctr Integrated Transmiss & Exploitat Rome NY 13441 USA
A femtosecond electromagnetic pulse propagating in a linear dispersive medium is analyzed in phase spaces of (space, wave number) and (time, frequency). First moment densities are computed as eigenvalues of differenti...
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ISBN:
(纸本)0819450782
A femtosecond electromagnetic pulse propagating in a linear dispersive medium is analyzed in phase spaces of (space, wave number) and (time, frequency). First moment densities are computed as eigenvalues of differential operators acting on Hilbert ray representations of the pulse in relevant domains. These moment densities are used as metrics in the relevant phase spaces to measure the local mean values and their deviations in position and wavenumber, and in time and frequency. For example, arrival times of the pulse over its spectral content are computed as the mean arrival time at a particular frequency to within one half the local deviation at that frequency. These metrics on the pulse are compared to the relevant phase space Wigner distribution.
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