Impulse noise

About: Impulse noise is a research topic. Over the lifetime, 4816 publications have been published within this topic receiving 63970 citations.

Robust adaptive filtering algorithms for /spl alpha/-stable random processes

Abstract: A new class of algorithms based on the fractional lower order statistics is proposed for finite impulse response adaptive filtering in the presence of a stable processes. It is shown that the normalized least mean p-norm (NLMP) and Douglas' family of normalized least mean square algorithms are special cases of the proposed class of algorithms. A convergence proof for the new algorithm is given by showing that it performs a descent-type update of the NLMP cost function. Simulation studies indicate that the proposed algorithms provide superior performance in impulsive noise environments compared to the existing approaches.

Impulse noise removal in speech using wavelets

Abstract: A new method for removing impulse noise from speech in the wavelet transform domain is proposed. The method utilizes the multi-resolution property of the wavelet transform, which provides finer time resolution at the higher frequencies than the short-time Fourier transform (STFT), to effectively identify and remove impulse noise. It uses two features of speech to discriminate speech from impulse noise: one is the slow time-varying nature of speech and the other is the Lipschitz regularity of the speech components. On the basis of these features, an algorithm has been developed to identify and suppress wavelet coefficients that correspond to impulse noise. Experiment results show that the new method is able to significantly reduce impulse noise without degrading the quality of the speech signal or introducing any audible artifacts.

A direction-finding technique for wide-band impulsive noise source

Abstract: A direction-finding technique for wide-band impulsive electromagnetic interference is presented. An experimental investigation was performed using a spark generator as the impulsive noise source. The signals were captured using a two-antenna array directly sampled at 1 Gs/s. A digital signal processing based correlation technique allowed assessment of the time delay between the antennas. The results in a nonideal radio propagation environment show the bearing can be estimated to an accuracy of 20.

Quaternion-Based Impulse Noise Removal From Color Video Sequences

Abstract: In this paper, a new quaternion vector filter for removal of random impulse noise in color video sequences is presented. First, luminance distances and chromaticity differences that are represented in quaternion form are combined together to measure color distances between color pixels. Then, based on this new color distance mechanism, the samples along horizontal, vertical, and diagonal directions in current frame and the samples of adjacent frames on motion trajectory are used to detect whether each pixel is noisy or not. By analyzing the spatiotemporal order-statistic information about these directional samples, the video pixels are classified into noise free and noisy. Finally, 3-D weighted vector median filtering is performed on the pixels that are judged as noisy, and the other pixels remain unchanged. The experimental results show that the proposed algorithm significantly outperforms other state-of-the-art video denoising methods in terms of both objective measure and visual evaluation.