Wavelet transform (WT) is an important tool to analyze the time-frequency structure of a signal. The WT relies on prototype signal that called mother wavelet. However, there no single universal wavelet fits all signals. Thus, selection function might be challenging represent achieve optimum performance. There are some studies determine optimal for other biomedical signals; however, exists evalu...

We analyze the feedback-induced destabilization process of a single-mode laser diode with the wavelet transform ~WT!. We consider transients following an abrupt switch on of the feedback, for feedback levels strong enough so that the final state of operation of the laser is the coherence-collapsed state. The transient regime involves multiscale interactions that exhibit strong localization in b...

A novel adaptive VQ based subband coding scheme for very low bit rate coding of video sequences is presented. Overlapped block motion estimation/compensation is employed to exploit interframe redundancy. A 2D wavelet transform (WT) is applied to the resulting displaced frame diierence (DFD) signal. The WT coee-cients are encoded using an adaptive vector quantization scheme in combination with a...

In this paper, an effective and reliable skew estimation technique for machine printed documents and photos using radon transform is proposed and is compared with other methods used for skew estimation such as Fast Fourier Transform (FFT), Hough Transform (HT), combination of Horizontal Projection Profile (HPP) and Hough Transform, combination of Gabor filter and Radon transform, combination of...

In the proposed work, the techniques of wavelet transform (WT) and neural network were introduced for speech based text-independent speaker identification and Arabic vowel recognition. The linear prediction coding coefficients (LPCC) of discrete wavelet transform (DWT) upon level 3 features extraction method was developed. Feature vector fed to probabilistic neural networks (PNN) for classifica...

This paper proposes an N stage "non-separable" two-dimensional (2D) wavelet transform (WT) for lossless / lossy unified coding of digital images. The proposed method achieves better coding performance especially at high bit rate since it has fewer rounding operations. We convert the conventional "separable" 2D WT into "non-separable" one without changing its frequency characteristics so that th...

In this correspondence a novel adaptive VQ based subband coding scheme for very low bit rate coding of video sequences is presented. Overlapped block motion estimation/compensation is employed to exploit interframe redundancy. A 2D wavelet transform (WT) is applied to the resulting displaced frame diierence (DFD) signal. The WT coeecients are encoded using an adaptive subband vector quantizatio...

Digital signal processing and data analysis are very often used methods in a biomedical engineering research. In this work, the descriptions of two detection algorithms for ECG characteristic points are enclosed. The detection algorithms presented in this work are based on Pan and Tompkins’ algorithm and wavelet transform for signal de-noising and detection of QRS complexes. In the first approa...

Signal denoising is the process of reducing the unwanted noise in order to restore the original signal. Donoho and Johnstone’s denoising algorithm based on wavelet thresholding replace the small coefficients by zero and keep or shrink the coefficients with absolute value above the threshold. So the threshold selection becomes more important in signal denoising. In this paper the threshold selec...