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IEEE Signal Processing Letters

Issue 12 • Date Dec. 1999

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Displaying Results 1 - 15 of 15
  • Biased reconstruction for JPEG decoding

    Publication Year: 1999, Page(s):297 - 299
    Cited by:  Papers (25)  |  Patents (7)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (114 KB)

    Assuming a Laplacian distribution, there exists a well known method for optimally biasing the reconstruction levels for the quantized ac discrete cosine transform (DCT) coefficients in the JPEG decoder. This, however, requires an estimate of the Laplacian distribution parameter. We derive a new, maximum likelihood estimate of the Laplacian parameter using only the quantized coefficients available ... View full abstract»

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  • Low-complexity image denoising based on statistical modeling of wavelet coefficients

    Publication Year: 1999, Page(s):300 - 303
    Cited by:  Papers (415)  |  Patents (9)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (84 KB)

    We introduce a simple spatially adaptive statistical model for wavelet image coefficients and apply it to image denoising. Our model is inspired by a recent wavelet image compression algorithm, the estimation-quantization (EQ) coder. We model wavelet image coefficients as zero-mean Gaussian random variables with high local correlation. We assume a marginal prior distribution on wavelet coefficient... View full abstract»

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  • On the existence of discrete Wigner distributions

    Publication Year: 1999, Page(s):304 - 306
    Cited by:  Papers (16)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (73 KB)

    Among the myriad of time-frequency distributions, the Wigner distribution stands alone in satisfying many desirable mathematical properties. Attempts to extend definitions of the Wigner distribution to discrete signals have not been completely successful. In this letter, we propose an alternative definition for the Wigner distribution, which has a clear extension to discrete signals. Under this de... View full abstract»

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  • About a multiperiodic sampling scheme

    Publication Year: 1999, Page(s):307 - 308
    Cited by:  Papers (7)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (113 KB)

    For a stationary bandlimited process sampled at periodic times t/sub n/=nT, exact reconstruction is possible when the spectral band is (-/spl pi//T, /spl pi//T). We give a proof of an exact formula (the Lagrange interpolation formula) when the sampling set is a mixture of periodic times. View full abstract»

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  • Minimum error bound of signal reconstruction

    Publication Year: 1999, Page(s):309 - 311
    Cited by:  Papers (6)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (111 KB)

    In signal processing, reconstruction of a bandlimited signal from finite samples is complicated by the underdetermined nature of the problem and the unavoidable noise in the measurement. A sensitivity function was recently formulated assuming noise-free data, which provides point-wise information about reliability of the reconstructed signal before actual samples of the signal are taken. In this c... View full abstract»

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  • Equalization of recursive polynomial systems

    Publication Year: 1999, Page(s):312 - 314
    Cited by:  Papers (8)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (127 KB)

    This letter presents some theorems for the exact and pth-order equalization of nonlinear systems described by recursive polynomial input-output relationships. It is shown that the nonlinear equalizers derived on the basis of this theory have simple and computationally efficient structures. Furthermore, the pth-order equalizers can be shown to operate in a stable manner for a finite range of values... View full abstract»

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  • New methods for Fourier analysis and Fourier synthesis

    Publication Year: 1999, Page(s):315 - 317
    Cited by:  Papers (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (117 KB)

    A basic and important relation between square wave and sine-cosine function is presented. This relation leads to completely new methods for Fourier analysis and Fourier synthesis. View full abstract»

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  • Hyperspherical parametrization for unit-norm based adaptive IIR filtering

    Publication Year: 1999, Page(s):318 - 320
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (96 KB)

    The bias problem associated with equation error based adaptive infinite impulse response (IIR) filtering can be surmounted by imposing a unit-norm constraint on the autoregressive (AR) coefficients. We propose a hyperspherical parameterization to convert the unit-norm-constrained optimization into an unconstrained optimization. We show that the hyperspherical parameterization does not introduce an... View full abstract»

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  • What should we say about the kurtosis?

    Publication Year: 1999, Page(s):321 - 322
    Cited by:  Papers (20)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (125 KB)

    In this work, we point out some important properties of the normalized fourth-order cumulant (i.e., the kurtosis). In addition, we emphasize the relation between the signal distribution and the sign of the kurtosis. One should mention that in many situations, authors claim that the sign of the kurtosis depends on the nature of the signal (i.e., over- or sub-Gaussian). For a unimodal probability de... View full abstract»

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  • A frequency domain deterministic approach to channel identification

    Publication Year: 1999, Page(s):323 - 326
    Cited by:  Papers (30)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (144 KB)

    This letter studies the problem of identifying a single-input single-output channel by linearly precoding the input. Although it is known that filterbanks induce cyclostationarity if the input is stationary, this work demonstrates that filterbanks induce a special form of spectral redundancy even if the input is deterministic. This frequency domain interpretation of filterbanks nicely characterize... View full abstract»

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  • Blind phase recovery in general QAM communication systems using alternative higher order statistics

    Publication Year: 1999, Page(s):327 - 329
    Cited by:  Papers (29)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (82 KB)

    Blind phase recovery for square QAM communication systems using higher order statistics is well established. It is demonstrated that this method can be adapted for cross QAM constellations, if alternative fourth-order statistics are used. However, a four quadrant inverse tangent function must now be used. Monte Carte simulation provides evidence of the usefulness of the approach. View full abstract»

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  • Removal of ocular artifacts from EEG using an efficient neural network based adaptive filtering technique

    Publication Year: 1999, Page(s):330 - 332
    Cited by:  Papers (14)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (46 KB)

    The electroencephalogram (EEG) is susceptible to various large signal contaminations or artifacts. Ocular artifacts act as major source of noise, making it difficult to distinguish normal brain activities from the abnormal ones. In this letter, an efficient technique that combines two popular adaptive filtering techniques, namely adaptive noise cancellation and adaptive signal enhancement, in a si... View full abstract»

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  • List of reviewers

    Publication Year: 1999, Page(s):333 - 335
    Request permission for commercial reuse | PDF file iconPDF (14 KB)
    Freely Available from IEEE
  • Author index

    Publication Year: 1999, Page(s):1 - 3
    Request permission for commercial reuse | PDF file iconPDF (202 KB)
    Freely Available from IEEE
  • Subject index

    Publication Year: 1999, Page(s):3 - 12
    Request permission for commercial reuse | PDF file iconPDF (223 KB)
    Freely Available from IEEE

Aims & Scope

The IEEE Signal Processing Letters is a monthly, archival publication designed to provide rapid dissemination of original, cutting-edge ideas and timely, significant contributions in signal, image, speech, language and audio processing.

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Meet Our Editors

Editor-in-Chief
Peter Willett
University of Connecticut
Storrs, CT 06269
peter.willett@uconn.edu