Matched ltering and adaptive beamforming are both necessary for e cient speech dereverberation and noise reduction by microphone arrays. This can be achieved by the identi cation of impulse responses. In this contribution, we show that adaptive microphone arrays are sensitive to identi cation errors of impulse responses, particularly due to speaker movements. We prove that adjusted matchedlteri...

Image Reduction is one of the most important image processing tasks. In this article, a new fuzzy filter is presented for the removal of impulse noise in gray and color images. The filter consists of two stages. In the first stage, using trapezoid membership function four values are used to detect whether a given pixel contains noise or not. In the second stage fuzzy enhanced classifier is appl...

This paper presents a novel two-stage adaptive noise reduction scheme for images corrupted by salt and pepper noise. The first stage identifies the impulse noise in the image by classifying the pixels into two classesthe 'noise-free pixels' and the 'noise corrupted pixels', based on the intensity values of the pixels. The second stage aims to reduce the impulse noise from th...

This paper presents a new method for suppressing noise in video sequences. The filter is an extension of the sigma filter. It uses local measurements to obtain noise reduction while preserving the image edges and details. By using a special defined weighting function, this filter can reduce both Gaussian and impulse noise effectively.

1 Introduction In a distant-talking environment, channel distortion drastically degrades speech recognition performance because of mismatches between the training and test environments. The current approaches focusing on robustness issues for automatic speech recognition (ASR) in noisy reverberant environments can be classified as speech enhancement, robust feature extraction, or model adaptati...

Background and objective: In the recent years image processing techniques are used as a tool to improve detection and diagnostic capabilities in the medical applications. Medical applications have been so much affected by these techniques which some of them are embedded in medical instruments such as MRI, CT and other medical devices. Among these techniques, medical image enhancement algorithms...

This paper presents a modified noise reduction algorithm for speech enhancement based on the scheme of null-forming. A fixed infinite-duration impulse response (IIR) filter is designed to calibrate the mismatch of the microphone pair. To weaken the performance degradation caused by narrow-band effect, the signal is decomposed into several specified sub-bands with auditory characters. This incre...

This paper presents a novel video enhancement system based on an adaptive spatio-temporal connective (ASTC) noise filter and an adaptive piecewise mapping function (APMF). For ill-exposed videos or those with much noise, we first introduce a novel local image statistic to identify impulse noise pixels, and then incorporate it into the classical bilateral filter to form ASTC, aiming to reduce th...

Averaging is one of the basic methods of statistical analysis of experimental data where the response of the system is periodic or quasi-periodic. As long as the noise are Gaussian, the standard averaging leads to good results and effective noise reduction. However, when the distortions have impulsive nature, then such an approach leads to a deterioration of the system. In this case the robust ...

Image is often degraded by more than one type of noise. In order to design an efficient filter to remove mixed noise from image, this paper proposes a weighted-linking pulse coupled neural network (PCNN) model so as to construct a two-channel parallel noise filter using four PCNNs of this model. This filter detects noise using the pulses generated by neurons, and iteratively removes noise by th...