Now showing items 490-508 of 508

  • Wavelet-Based Deconvolution Using Optimally Regularized Inversion for Ill-Conditioned Systems 

    Neelamani, Ramesh; Choi, Hyeokho; Baraniuk, Richard G. (1999-07-20)
    We propose a hybrid approach to wavelet-based deconvolution that comprises Fourier-domain system inversion followed by wavelet-domain noise suppression. In contrast to conventional wavelet-based deconvolution approaches, ...
  • Wavelet-Based Denoising Using Hidden Markov Models 

    Borran, Mohammad Jaber; Nowak, Robert David (2001-05-20)
    Hidden Markov models have been used in a wide variety of wavelet-based statistical signal processing applications. Typically, Gaussian mixture distributions are used to model the wavelet coefficients and the correlation ...
  • Wavelet-Based Post-Processing of Low Bit Rate Transform Coded Images 

    Gopinath, Ramesh A.; Lang, Markus; Guo, Haitao; Odegard, Jan E. (1994-01-15)
    In this paper we propose a novel method based on wavelet thresholding for enhancement of decompressed transform coded images. Transform coding at low bit rates typically introduces artifacts associated witht he basis ...
  • Wavelet-Based Post-Processing of Low Bit Rate Transform Coded Images 

    Gopinath, Ramesh A.; Lang, Markus; Guo, Haitao; Odegard, Jan E. (1994-11-01)
    In this paper we propose a novel method based on wavelet thresholding for enhancement of decompressed transform coded images. Transform coding at low bit rates typically introduces artifacts associated witht he basis ...
  • Wavelet-based queuing analysis of Gaussian and non-Gaussian long-range-dependent network traffic 

    Ribeiro, Vinay Joseph (1999-05-20)
    In this thesis, we develop a simple and powerful multiscale model for the synthesis of nonGaussian, long-range-dependent (LRD) network traffic. The wavelet transform effectively doecorrelates LRD signals and hence is ...
  • Wavelet-based Rician noise removal for magnetic resonance imaging 

    Nowak, Robert David (1999-10-20)
    It is well-known that the noise in magnetic resonance magnitude images obeys a Rician distribution. Unlike additive Gaussian noise, Rician noise is signal-dependent and consequently spearating signal from noise is a ...
  • A Wavelet-Based Statistical Model for Image Restoration 

    Wan, Yi; Nowak, Robert David (2001-10-20)
    In this paper we develop a wavelet-based statistical method for solving the image restoration problem. In this approach, a signal prior is set up by modeling the image wavelet coefficients as independent Gaussian mixture ...
  • Wavelet-Based Transformations for Nonlinear Signal Processing 

    Nowak, Robert David; Baraniuk, Richard G. (1999-07-01)
    Nonlinearities are often encountered in the analysis and processing of real-world signals. In this paper, we introduce two new structures for nonlinear signal processing. The new structures simplify the analysis, design, ...
  • Wavelet-Based Transformations for Nonlinear Signal Processing 

    Nowak, Robert David; Baraniuk, Richard G. (2001-07-01)
    Nonlinearities are often encountered in the analysis and processing of real-world signals. We introduce two new structures for nonlinear signal processing. The new structures simplify the analysis, design, and implementation ...
  • Wavelet-Based Transformations for Nonlinear Signal Processing 

    Nowak, Robert David; Baraniuk, Richard G. (1997-04-01)
    Nonlinearities are often encountered in the analysis and processing of real-world signals. This paper develops new transformations for nonlinear signal processing. The theory of tensor norms is employed to show that wavelets ...
  • Wavelet-Domain Approximation and Compression of Piecewise Smooth Images 

    Wakin, Michael; Romberg, Justin; Choi, Hyeokho; Baraniuk, Richard G. (2006-05-01)
    The wavelet transform provides a sparse representation for smooth images, enabling efficient approximation and compression using techniques such as zerotrees. Unfortunately, this sparsity does not extend to piecewise smooth ...
  • Wavelet-domain Approximation and Compression of Piecewise Smooth Images 

    Wakin, Michael; Romberg, Justin; Choi, Hyeokho; Baraniuk, Richard G. (2005-01-15)
    The wavelet transform provides a sparse representation for smooth images, enabling efficient approximation and compression using techniques such as zerotrees. Unfortunately, this sparsity does not extend to <i>piecewise ...
  • Wavelet-Domain Filtering for Photon Imaging Systems 

    Nowak, Robert David; Baraniuk, Richard G. (1999-05-01)
    Many imaging systems rely on photon detection as the basis of image formation. One of the major sources of error in these systems is Poisson noise due to the quantum nature of the photon detection process. Unlike additive ...
  • Wavelet-Domain Regularized Deconvolution for Ill-Conditioned Systems 

    Neelamani, Ramesh; Choi, Hyeokho; Baraniuk, Richard G. (1999-10-01)
    We propose a hybrid approach to wavelet-based image deconvolution that comprises Fourier-domain system inversion followed by wavelet-domain noise suppression. In contrast to conventional wavelet-based deconvolution approaches, ...
  • Wavelets and Multifractals for Network Traffic Modeling and Inference 

    Ribeiro, Vinay Joseph; Riedi, Rudolf H.; Baraniuk, Richard G. (2001-05-01)
    This paper reviews the multifractal wavelet model (MWM) and its applications to network traffic modeling and inference. The discovery of the fractal nature of traffic has made new models and analysis tools for traffic ...
  • When does interval coding occur? 

    Johnson, Don; Glantz, Raymon (2003-07-20)
    During the stationary portion of neuron's spiking response to a stimulus, the stimulus could be coded in the average rate and, more elaborately, in the statistics of the sequence of interspike intervals. We use information ...
  • Wigner-Based Formulation of the Chirplet Transform 

    Baraniuk, Richard G.; Jones, Douglas L. (1996-12-01)
    Using the Wigner distribution, we derive and analyze a matrix formulation for the chirplet transform, a signal analysis tool that generalizes the wavelet and short-time Fourier transforms. The formulation expresses the ...
  • Wigner-Ville Spectrum Estimation via Wavelet Soft-Thresholding 

    Baraniuk, Richard G. (1994-10-01)
    The high noise sensitivity of the Wigner distribution makes smoothing a necessity for producing readable time-frequency images of noise corrupted signals. Since linear smoothing suppresses noise at the expense of considerable ...
  • WInHD: Wavelet-based Inverse Halftoning via Deconvolution 

    Neelamani, Ramesh; Nowak, Robert David; Baraniuk, Richard G. (2002-10-20)
    We propose the <i>Wavelet-based Inverse Halftoning via Deconvolution</i> (WInHD) algorithm to perform inverse halftoning of error-diffused halftones. WInHD is motivated by our realization that inverse halftoning can be ...