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IEEE Signal Processing Letters

Issue 10 • Date Oct. 1999

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Displaying Results 1 - 8 of 8
  • Enhancement of document images using multiresolution and fuzzy logic techniques

    Publication Year: 1999, Page(s):249 - 252
    Cited by:  Papers (12)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (153 KB)

    This letter presents a method for enhancing document images based on the multiresolution decomposition and fuzzy logic approach. The document image to be enhanced is obtained from a scanner and is a blurred binary image that is corrupted by additive noise. This type of image occurs in many situations when documents such as checks and credit card receipts become noisy and low-contrast images after ... View full abstract»

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  • Euclidean distance transform by stack filters

    Publication Year: 1999, Page(s):253 - 256
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (101 KB)

    Euclidean distance transform (EDT) using a gray-scale morphological erosion with a large distance structuring element is difficult to implement in real-time. Herein, a stack filtering method that permits the implementation of EDT in real-time using only binary logic gates is proposed. This letter reports a fast errorless method for EDT implementation. View full abstract»

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  • Axiomatic approach for quantification of image resolution

    Publication Year: 1999, Page(s):257 - 258
    Cited by:  Papers (15)  |  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (67 KB)

    Image resolution is the primary parameter for performance characterization of any imaging system. In this work, we present an axiomatic approach for quantification of image resolution, and demonstrate that a good image resolution measure should be proportional to the standard deviation of the point spread function of an imaging system. View full abstract»

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  • Teager energy based feature parameters for speech recognition in car noise

    Publication Year: 1999, Page(s):259 - 261
    Cited by:  Papers (42)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (103 KB)

    In this letter, a new set of speech feature parameters based on multirate signal processing and the Teager energy operator is introduced. The speech signal is first divided into nonuniform subbands in mel-scale using a multirate filterbank, then the Teager energies of the subsignals are estimated. Finally, the feature vector is constructed by log-compression and inverse discrete cosine transform (... View full abstract»

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  • Optimum window design by semi-infinite quadratic programming

    Publication Year: 1999, Page(s):262 - 265
    Cited by:  Papers (10)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (147 KB)

    This letter presents a new extended active set strategy for optimum finite impulse response (FIR) window design by semi-infinite quadratic programming. The windows may be asymmetric corresponding to frequency responses with general nonlinear phase. The optimality criterion is to minimize the sidelobe energy (L/sub 2/-norm) subject to a peak sidelobe magnitude-constraint (L/sub /spl infin//-constra... View full abstract»

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  • An efficient implementation of the backward greedy algorithm for sparse signal reconstruction

    Publication Year: 1999, Page(s):266 - 268
    Cited by:  Papers (23)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (108 KB)

    Recent work in sparse signal reconstruction has shown that the backward greedy algorithm can select the optimal subset of unknowns if the perturbation of the data is sufficiently small. We propose an efficient implementation of the backward greedy algorithm that yields a significant improvement in computational efficiency over the standard implementation. Furthermore, we propose an efficient algor... View full abstract»

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  • Transfer function estimation using elemental sets

    Publication Year: 1999, Page(s):269 - 272
    Cited by:  Papers (3)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (115 KB)

    Nonlinear least-squares (NLS) fitting of rational transfer functions to frequency response data yields the maximum likelihood estimator (MLE) of the transfer function coefficient vector under mild conditions on the observation noise. Furthermore, the NLS approach is robust to errors in the modeling of data. However the NLS criterion is in general difficult to minimize. Here we show that an asympto... View full abstract»

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  • Maximum-likelihood DOA estimation by data-supported grid search

    Publication Year: 1999, Page(s):273 - 275
    Cited by:  Papers (56)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (77 KB)

    After reviewing the main existing methods for determining the maximum-likelihood (ML) estimates of the direction-of-arrival (DOA) parameters in array signal processing applications, we introduce a new conceptually simple and computationally effective approach that consists of maximizing the likelihood function (LF) over a set of points derived from the data. We show that the data-supported grid se... View full abstract»

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