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Image Enhancement is a process of improving the quality of an image by improving the contrast of the images. Images acquired underwater usually suffers from non-uniform illumination, low-contrast, motion blur effect due to turbulence in the flow of water, in under ocean environment, scattering of light from different particles of various sizes, diminished intensity and color level due to poor visibility...
Multichannel noise reduction techniques are commonly used in speech communication applications. In these applications, it is often desired to maintain a residual amount of background noise to avoid perceptually unpleasant artifacts, such as musical tones or time periods of complete silence. Noise reduction can be achieved by the parametric multichannel Wiener filter (PMWF), which provides a trade-off...
Multiscale error diffusion (MED) is superior to conventional error diffusion algorithm as it can eliminate directional hysteresis completely and possesses good blue noise characteristics. However, due to its filter design, it is not suitable for printing processes which suffer instable dot generation and large dot gain. This paper presents a multiscale error diffusion algorithm for green noise digital...
In this paper, an Adaptive Median Constant False Alarm Rate (AMCFAR) and multi-frame post detection integration algorithm is proposed for effective real time automatic target detection of boat-generated acoustic signals, in which, an observation space is created by sampling and dividing input analog acoustic signal into multiple frames and each frame is transformed into the frequency domain. In the...
High quality, reliable communications between public safety personnel is essential for accomplishing missions while maintaining their own health and safety. The SCBA mask air delivery system is essential equipment in some public service activities, and its effects on speech must be considered in public service communications system designs. An SCBA mask encloses the face and mouth and alters articulation...
Problem associated with biomedical signal like ECG is to extract noise cause by high frequency interference, electromagnetic fields, power line interference and body movement. It is difficult to apply filters with fixed coefficients to reduce random noises. Adaptive filter technique is required to overcome this problem. This paper presents an innovative technique for estimation of ECG waves using...
Here an attempt has been made for environmental noise cancellation using adaptive Neuro fuzzy inference system for mobile communication. The aim of present work is to reduce the environmental noise during the speech communication by using Adaptive Neuro Fuzzy Filtering. Now a day's many people are using mobile phones during their journey, as received signal is continuously corrupted by environmental...
Most Active Noise Control (ANC) systems use some form of the LMS [5] [9] algorithm due to its reduced computational complexity. However, the problems associated with it are well-known, namely slow convergence and high sensitivity to the eigenvalue spread [3] [9]. To overcome these problems the RLS algorithm is often used, but it is now widely known, that the RLS loses many of its good properties for...
We present a method for optimizing adaptation laws that are generalizations of the LMS algorithm. The proposed technique has been applied successfully for designing estimators of rapidly time-varying mobile radio channels. The estimators apply time-invariant filtering on the instantaneous gradient. Time-varying parameters of linear regression models are estimated in situations where the regressors...
The implementation of analog adaptive median filters for image processing is presented. The adaptive median filter is based on transconductance comparators, which saturation current is adapted to act as a local weight operator. Transistor level simulations, using 1.2mm parameters, have shown excellent results in high removing incidence noise. An image with 249 × 209 corrupted with 35% salt and pepper...
A multidimensional filtering technique is proposed using fuzzy logic ideas and based on local statistics. The local multivariate histogram of the mutlichannel image is computed using the Parzen estimation technique. The maximum and minimum of the histogram are used as parameters, to describe the signal shape. The method is organized around a fuzzy control system. Experimental results, in true color...
In this paper, we propose a frequency domain active noise control (ANC) system without a secondary path model. The proposed system is based on the frequency domain simultaneous perturbation (FDSP) method we have proposed. In this system, the coefficients of the adaptive filter are updated only by error signals. The conventional ANC system using the filtered-x algorithm becomes unstable due to the...
A novel median-based filter having the effectiveness in the removal of impulse noise with high probability is proposed in this paper. The proposed filter is a kind of switching scheme-based median filters, and consists of two main parts: one detects impulse noise (impulse detecotor), another removes impulse noise (noise removal filter). First, we propose a novel impulse detector based on the directional...
Two methods for multiplierless elliptic IIR filter implementation are discussed: cascade realization and parallel connection of two allpass networks. Elliptic IIR filters are selected because they fulfill the requirements with lower order, and, usually, they require fewer coefficient multipliers. The comparison is made on the basis of adder costs, amplitude characteristics in pass and stop bands,...
As the stochastic and time-varying underwater acoustic channels with serious multipath delays, energy loss and distortion factors, making the modeling and estimation of the underwater acoustic channel have been difficult problems in academic circles. As to the multiple-input multiple-output (MIMO) underwater acoustic communication, the system model with multiplicative noise is proposed to characterize...
Based on the adaptive filtering mode, we discussed and analyzed how to improve the quality of microphone array speech enhancement and reduce the complexity of the algorithm. This paper described a new variable step least mean square (LMS) algorithm which could reduce the effect of input noise to step factor, improve the performance of the algorithm. The algorithm smoothed the step factor in time domain...
Edge pixels are the key feature widely used for the processing of the digital images. Edges will be lost due to filtering operation carried out on digital images. The structure comprises of alpha trimmed mean filter and edges are preserved with the specialized technique. Lost edge details due to the mean filtering operation are restored with the help of the preserved edges. Balanced histogram technique...
Electrocardiogram (ECG) signals are affected by various types of noises that are differed based on frequency content. In order to improve accuracy and reliability, it is essential to remove such a disturbance. The denoising of ECG signals is challenging as it is difficult to apply filters with fixed coefficients. Adaptive filtering techniques can be used, in which the filter coefficients can be modified...
This paper proposes a modified approach to filter Salt & Pepper Noise by applying Fuzzy logic with auxiliary BDND algorithm and FSM filtering for grayscale images. Main purpose of this algorithm is to provide an efficient method to differentiate unwanted noise pixels with image edge pixels to restore the details and textures in grayscale images. The approach constitutes two phases: one phase detects...
In this paper, low complexity reconfigurable hardware architecture for adaptive median filter is proposed and a comparative study of hardware based median and adaptive median filter is presented. An efficient development of median & adaptive median filter is presented for removal of impulse noise mainly salt & pepper noise from digital Images. Performance measurement of mean square error (MSE)...
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