Open Science Research Excellence

Alberto E Giraldez

Publications

2

Publications

2
3542
Kalman-s Shrinkage for Wavelet-Based Despeckling of SAR Images
Abstract:
In this paper, a new probability density function (pdf) is proposed to model the statistics of wavelet coefficients, and a simple Kalman-s filter is derived from the new pdf using Bayesian estimation theory. Specifically, we decompose the speckled image into wavelet subbands, we apply the Kalman-s filter to the high subbands, and reconstruct a despeckled image from the modified detail coefficients. Experimental results demonstrate that our method compares favorably to several other despeckling methods on test synthetic aperture radar (SAR) images.
Keywords:
Kalman's filter, shrinkage, speckle, wavelets.
1
9224
Microarrays Denoising via Smoothing of Coefficients in Wavelet Domain
Abstract:

We describe a novel method for removing noise (in wavelet domain) of unknown variance from microarrays. The method is based on a smoothing of the coefficients of the highest subbands. Specifically, we decompose the noisy microarray into wavelet subbands, apply smoothing within each highest subband, and reconstruct a microarray from the modified wavelet coefficients. This process is applied a single time, and exclusively to the first level of decomposition, i.e., in most of the cases, it is not necessary a multirresoltuion analysis. Denoising results compare favorably to the most of methods in use at the moment.

Keywords:
Directional smoothing, denoising, edge preservation,microarrays, thresholding, wavelets