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IEEE Signal Processing Letters

Issue 7 • Date July 1999

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Displaying Results 1 - 10 of 10
  • Image segmentation by tree-structured Markov random fields

    Publication Year: 1999, Page(s):155 - 157
    Cited by:  Papers (18)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (160 KB)

    We propose a new algorithm, based on a tree-structured Markov random field (MRP) model, to carry out the unsupervised classification of images. It presents several appealing features; due to the MRF model, it takes into account spatial dependencies, yet is computationally light because only binary MRFs are used and a progressive refinement of information takes place. Moreover, it is adaptive to th... View full abstract»

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  • Wavelet image coding using trellis coded space-frequency quantization

    Publication Year: 1999, Page(s):158 - 161
    Cited by:  Papers (17)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (220 KB)

    The progress in wavelet image coding have brought the field into its maturity. Major developments in the process are rate-distortion (R-D) based wavelet packet transformation, zerotree quantization, subband classification and trellis-coded quantization, and sophisticated context modeling in entropy coding. Drawing from past experience and recent in sights, we propose a new wavelet image coding tec... View full abstract»

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  • A functional for compressible or incompressible elastic deformation estimation

    Publication Year: 1999, Page(s):162 - 164
    Cited by:  Papers (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (102 KB)

    When deformable motion is considered, the conventional "smoothness" constraints are not suitable since the deformation information lies on the derivatives of the displacement components. So we propose to use the small displacement theory of elasticity to define a new penalty function for two-dimensional (2-D) or three-dimensional (3-D) deformable motion estimation. This penalty function depends on... View full abstract»

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  • Generalized Perona-Malik equation for image restoration

    Publication Year: 1999, Page(s):165 - 167
    Cited by:  Papers (62)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (306 KB)

    This article introduces generalizations of the Perona-Malik (1990) equation. An edge enhancing functional is proposed for direct edge enhancement. A number of super diffusion operators is introduced for fast and effective smoothing. Statistical information is utilized for robust edge-stopping. Numerical integration is conducted by using a previously developed quasi-interpolating wavelet method. Co... View full abstract»

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  • A context based adaptive arithmetic coding technique for lossless image compression

    Publication Year: 1999, Page(s):168 - 170
    Cited by:  Papers (12)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (50 KB)

    Significant progress has recently been made in lossless image compression using discrete wavelet transforms. The overall performance of these schemes may be further improved by properly designing efficient entropy coders. A new technique is introduced for the implementation of context based adaptive arithmetic entropy coding. This technique is based on the prediction of the value of the current tr... View full abstract»

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  • SNR estimation of speech signals using subbands and fourth-order statistics

    Publication Year: 1999, Page(s):171 - 174
    Cited by:  Papers (19)  |  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (84 KB)

    This article addresses the problem of instantaneous signal-to-noise ratio (SNR) estimation during speech activity for the purpose of improving the performance of speech enhancement algorithms. It is shown that the kurtosis of noisy speech may be used to individually estimate speech and noise energies when speech is divided into narrow bands. Based on this concept, a novel method is proposed to con... View full abstract»

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  • Output distributions of recursive stack filters

    Publication Year: 1999, Page(s):175 - 178
    Cited by:  Papers (8)  |  Patents (11)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (69 KB)

    In this letter, we provide a method for deriving the output distribution function of any recursive stack filter. In particular, we give the output distribution of the recursive median filter. The method used relies on finite automata and Markov chain theory. The distribution of any recursive stack filter is expressed as a vector multiplication of steady-state probabilities by the truth table vecto... View full abstract»

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  • Order statistics approach for determining the number of sources using an array of sensors

    Publication Year: 1999, Page(s):179 - 182
    Cited by:  Papers (19)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (74 KB)

    A new approach for estimating the number of radiating, not fully correlated sources using the data received by an array of sensors is presented. The common approach is to apply information theoretic criteria, such as the minimum description length (MDL) or the Akaike information criterion (AIC), on the received data. Alternatively, we suggest to apply these criteria on the ordered eigenvalues of t... View full abstract»

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  • On the McClellan transformation of 1-D even-length linear phase filterbanks

    Publication Year: 1999, Page(s):183 - 185
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (59 KB)

    It was shown by Wei et al. (1997) that by applying the extended McClellan transformation on one-dimensional (1-D) even length linear phase perfect reconstruction (PR) filterbanks (FBs), the resulting multidimensional (M-D) FB does not have the PR property. The two types of extended McClellan transformation that were considered in Wei et al. were originally proposed by Mersereau et al. (1976) and K... View full abstract»

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  • Vector median-rational hybrid filters for multichannel image processing

    Publication Year: 1999, Page(s):186 - 190
    Cited by:  Papers (15)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (315 KB)

    In this letter, a new class of nonlinear filters called vector median-rational hybrid filters (VMRHFs) for multispectral image processing is introduced and applied to the color image filtering problem. These filters are based on rational functions (RFs) offering a number of advantages. First, a rational function is a universal approximator and a good extrapolator. Second, it can be trained by a li... View full abstract»

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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