Symmetric quadrature mirror lters (QMF's) ooer several advantages for wavelet-based image coding. Symmetry and odd-length contribute to eecient boundary handling and preservation of edge detail. Symmetric QMF's can be obtained by mildly relaxing the lter bank orthogonality conditions. We describe a computational algorithm for these lter banks which is also symmetric in the sense that the analys...

Many of the despeckling lters currently available (Mean, Median, Lee Sigma, Lee MMSE, Kuan, Frost, etc.) operate by smoothing over a xed window, whose size must be decided by two competing factors. Over homogeneous regions large window sizes are needed to improve speckle reduction by averaging. However, a large window size reduces the fundamental resolution of the algorithm, as with multi-looki...

Filtering is used to select a subset, corresponding to the information interests of a user, from a set of information items. The information interests are described in a lter which is created to control the selection. In our earlier work we have described a theoretical framework for specifying lters to express content-based and structure-oriented constraints on structured text. In the lters, th...

The GCE web site has been set up and is available online at http://gcelter.marsci.uga.edu/lter/. Data sets from the Georgia Rivers LMER as well as new data from the LTER are being organized in the database associated with this web site. We have made presentations about the GCE LTER at local and coastal schools and to a meeting of the research coordinators from NOAA’s National Estuarine Research...

Line integral convolution (LIC) has become a well-known and popular method for visualizing vector elds. The method works by convolving a random input texture along the integral curves of the vector eld. In order to accelerate image synthesis signiicantly, an eecient algorithm has been proposed that utilizes pixel coherence in eld line direction. This algorithm, called \fast LIC", originally was...

We have implemented a four-tap adaptive lter in a continuous-time analog VLSI circuit. Since an ideal delay is impossible to implement in continuous-time hardware, we implemented the delay line as a cascade of low-pass lters (called the gamma lter). Since many years of research in our lab has shown that the gamma lter outperforms the ideal delay line for a wide range of applications, the gamma ...

Three adaptive multichannel L-lters based on marginal data ordering are proposed. They rely on well-known algorithms for the iterative minimization of the mean square error (MSE), namely, the least mean squares (LMS), the normalized LMS (NLMS), and the LMS-Newton (LMSN) algorithms. We treat both the unconstrained minimization of the MSE and the minimization of the MSE when structural constraint...

|In this paper, a novel lter structure is introduced for multispectral image processing, the vector median-rational hybrid lter's (VMRHF's), which constitute an extension of the nonlinear rational type hybrid lters called medianrational hybrid lter's (MRHF's) recently introduced for 1-D and 2-D signal processing. The VMRHF is a two-stages lter, which exploits in an e ective way the features of ...

| Weighted Myriad Filters have been proposed recently as a class of robust, nonlinear lters based on the statistical properties of-stable processes. These processes are very eeective in modeling many real-world signals that are impulsive in nature. The class of Weighted Myriad Filters includes linear normalized FIR lters and is inherently more powerful than weighted median lters (which are cons...