In this paper, we address the problem of finding the best time-varying filter bank tree-structured representation for a signal. The tree is allowed to vary at regular intervals, and the spacing of these changes can be arbitrarily short. The question of how to choose tree-structured representations of signals based on filter banks has attracted considerable attention. Wavelets and their adaptive...

Sub-band decomposition independent component analysis (SDICA) assumes that wide-band source signals can be dependent but some of their sub-components are independent. Thus, it extends applicability of standard independent component analysis (ICA) through the relaxation of the independence assumption. In this paper, firstly, we introduce novel wavelet packets (WPs) based approach to SDICA obtain...

In this paper the wavelet packet transform is used for processing of rolling element bearing fault signals. The effectiveness of the envelope analysis technique is combined with the flexibility of the wavelet packet transform, helping in the minimization of interventions by the end user. According to the proposed method, a time-frequency decomposition of a vibration signal is provided and the c...

Recently, it was suggested that spectrum estimation can be accomplished by applying wavelet denoising methodology to wavelet packet coefficients derived from the logarithm of a spectrum estimate. The particular algorithm we consider consists of computing the logarithm of the multitaper spectrum estimator, applying an orthonormal transform derived from a wavelet packet tree to the log multitaper...

In attempt to enhance the discrimination ability of present speaker verification systems, we study alternative ways for parameterization of human voice. Utilizing the flexibility provided by wavelet packet analysis, and rendering an account of the most recent psycho-acoustical studies, the authors investigate in an objective way the relative importance of constituent disjoint frequency subbands...

We analyze and discuss encryption schemes for JPEG2000 based on the wavelet packet transform with a keydependent subband structure. These schemes have been assumed to reduce the runtime complexity of encryption and compression. In addition to this “lightweight” nature, other advantages like encrypted domain signal processing have been reported. We systematically analyze encryption approaches ba...

Image Fusion, a technique which combines complimentary information from different images of the same scene so that the fused image is more suitable for segmentation, feature extraction, object recognition and Human Visual System. In this paper, a simple yet efficient algorithm is presented based on contrast using wavelet packet decomposition. First, all the source images are decomposed into low...

Baseline wander elimination is considered as a classical problem. We present a wavelet based search algorithm using the energy of the signal in different scales to isolate baseline wander from ECG signal. The algorithm calculates the wavelet packet coefficients. In each scale the energy of the signal is calculated. Comparison is made and the branch of the wavelet binary tree corresponding to hi...

POL-SAR data acquired from the two 1994 ights of the SIR-C/X-SAR platform has illustrated the variability of measurements due to seasonal, spectral, and angular changes. Consequently, statistical techniques for terrain classi cation make robust, unsupervised classi cation problematic. We present an algorithm for classifying terrain that accounts for variability in terrain signatures by deriving...