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Proceedings ArticleDOI

Denoising and Robust Non-Linear Wavelet Analysis,

TLDR
In this paper, the authors developed outlier resistant wavelet transforms, in which outliers and outlier patches are localized to just a few scales, and improved upon the Donoho and Johnstone nonlinear signal extraction methods.
Abstract
In a series of papers, Donoho and Johnstone develop a powerful theory based on wavelets for extracting non-smooth signals from noisy data. Several nonlinear smoothing algorithms are presented which provide high performance for removing Gaussian noise from a wide range of spatially inhomogeneous signals. However, like other methods based on the linear wavelet transform, these algorithms are very sensitive to certain types of non-Gaussian noise, such as outliers. In this paper, we develop outlier resistant wavelet transforms. In these transforms, outliers and outlier patches are localized to just a few scales. By using the outlier resistant wavelet transform, we improve upon the Donoho and Johnstone nonlinear signal extraction methods. The outlier resistant wavelet algorithms are included with the 'S+WAVELETS' object-oriented toolkit for wavelet analysis.

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Book

Wavelet Methods for Time Series Analysis

TL;DR: Wavelet analysis of finite energy signals and random variables and stochastic processes, analysis and synthesis of long memory processes, and the wavelet variance.
Journal ArticleDOI

Despeckling of medical ultrasound images

TL;DR: A simple preprocessing procedure is introduced, which modifies the acquired radio-frequency images, so that the noise in the log-transformation domain becomes very close in its behavior to a white Gaussian noise, which allows filtering methods based on assuming the noise to be white and Gaussian, to perform in nearly optimal conditions.
Journal ArticleDOI

Robust wavelet denoising

TL;DR: This work proposes a robust wavelet-based estimator using a robust loss function, solving a nontrivial optimization problem and appropriately choosing the smoothing and robustness parameters.
Journal ArticleDOI

Flexible empirical Bayes estimation for wavelets

TL;DR: In this article, the authors proposed empirical Bayes (EB) prior selection methods for various error distributions including the normal and the heavier-tailed Student t-distribution, and obtained threshold shrinkage estimators based on model selection, and multiple-shrinkage estimator based on a model averaging.
Journal ArticleDOI

Multiscale analysis and modeling using wavelets

TL;DR: An overview of multiscale data analysis and empirical modeling methods based on wavelet analysis, which exploit the ability of wavelets to extract events at different scales, compress deterministic features in a small number of relatively large coefficients, and approximately decorrelate a variety of stochastic processes.
References
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Journal ArticleDOI

Adapting to Unknown Smoothness via Wavelet Shrinkage

TL;DR: In this article, the authors proposed a smoothness adaptive thresholding procedure, called SureShrink, which is adaptive to the Stein unbiased estimate of risk (sure) for threshold estimates and is near minimax simultaneously over a whole interval of the Besov scale; the size of this interval depends on the choice of mother wavelet.
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Singularity detection and processing with wavelets

TL;DR: It is proven that the local maxima of the wavelet transform modulus detect the locations of irregular structures and provide numerical procedures to compute their Lipschitz exponents.
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Image compression through wavelet transform coding

TL;DR: If pictures can be characterized by their membership in the smoothness classes considered, then wavelet-based methods are near-optimal within a larger class of stable transform-based, nonlinear methods of image compression.
Journal ArticleDOI

Estimation of time series parameters in the presence of outliers

TL;DR: An iterative procedure is proposed for detecting IO and AO in practice and for estimating the time series parameters in autoregressive-integrated-moving-average models in the presence of outliers.
Journal ArticleDOI

Robust bayesian estimation for the linear model and robustifying the Kalman filter

TL;DR: In this article, robust Bayesian estimates of the vector x are constructed for the following two distinct situations: (1) the state x is Gaussian and the observation error v is (heavy-tailed) non-Gaussian and (2) the states x and v are Gaussian.