Development of Impulsive Noise Detection Schemes for Selective Filtering in Images

Development of Impulsive Noise Detection Schemes for Selective Filtering in Images
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Image Noise Suppression is a highly demanded approach in digital imaging systems design. Impulsive noise is one such noise, which is frequently encountered problem in acquistion, transmission and processing of images. In the area of image restoration, many state-of-the art filters consist of two main processes, classification (detection) and reconstruction (filtering). Classification is used to separate uncorrupted pixels from corrupted pixels. Reconstruction involves replacing the corrupted pixels by certain approximation technique. In this thesis such schemes of impulsive noise detection and filtering thereof are proposed. Impulsive noise can be Salt & Pepper Noise (SPN) or Random Valued Impulsive Noise (RVIN). Only RVIN model is considered in this thesis because of its realistic presence. In the RVIN model a corrupted pixel can take any value in the valid range. Adaptive threshold selection is emphasized for all the four proposed noise detection schemes. Incorporation of adaptive threshold into the noise detection process led to more reliable and more efficient detection of noise. Based on the noisy image characteristics and their statistics, threshold values are selected. To validate the efficacy of proposed noise filtering schemes, an application to image sharpening has been investigated under the noise conditions. It has been observed, if the noisy image passes through the sharpening scheme, the noise gets amplified and as a result the restored results are distorted. However, the prefiltering operations using the proposed schemes enhances the result to a greater extent. Extensive simulations and comparisons are done with competent schemes. It is observed, in general, that the proposed schemes are better in suppressing impulsive noise at different noise ratios than their counterparts.

On the Development of Impulsive Noise Removal Schemes

On the Development of Impulsive Noise Removal Schemes
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Noise Suppression from images is one of the most important concens in digital image porcessing. Impulsive noise is one such noise, which may corrupt images during their acquisitioni or transmission or storage etc. A variety of techniques are reported to remove this type of noise. It is observed that techniques which follow the two satage process of detection of noise and filtering of noisy pixels achieve better performance than others. In this thesis such schemes of impulsive noise detection and filtering thereof are proposed.

Proceedings of International Conference on Computer Vision and Image Processing

Proceedings of International Conference on Computer Vision and Image Processing
Author: Balasubramanian Raman
Publisher: Springer
Total Pages: 623
Release: 2016-12-22
Genre: Technology & Engineering
ISBN: 981102104X

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This edited volume contains technical contributions in the field of computer vision and image processing presented at the First International Conference on Computer Vision and Image Processing (CVIP 2016). The contributions are thematically divided based on their relation to operations at the lower, middle and higher levels of vision systems, and their applications. The technical contributions in the areas of sensors, acquisition, visualization and enhancement are classified as related to low-level operations. They discuss various modern topics – reconfigurable image system architecture, Scheimpflug camera calibration, real-time autofocusing, climate visualization, tone mapping, super-resolution and image resizing. The technical contributions in the areas of segmentation and retrieval are classified as related to mid-level operations. They discuss some state-of-the-art techniques – non-rigid image registration, iterative image partitioning, egocentric object detection and video shot boundary detection. The technical contributions in the areas of classification and retrieval are categorized as related to high-level operations. They discuss some state-of-the-art approaches – extreme learning machines, and target, gesture and action recognition. A non-regularized state preserving extreme learning machine is presented for natural scene classification. An algorithm for human action recognition through dynamic frame warping based on depth cues is given. Target recognition in night vision through convolutional neural network is also presented. Use of convolutional neural network in detecting static hand gesture is also discussed. Finally, the technical contributions in the areas of surveillance, coding and data security, and biometrics and document processing are considered as applications of computer vision and image processing. They discuss some contemporary applications. A few of them are a system for tackling blind curves, a quick reaction target acquisition and tracking system, an algorithm to detect for copy-move forgery based on circle block, a novel visual secret sharing scheme using affine cipher and image interleaving, a finger knuckle print recognition system based on wavelet and Gabor filtering, and a palmprint recognition based on minutiae quadruplets.

IETE Journal of Research

IETE Journal of Research
Author:
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Total Pages: 532
Release: 2002
Genre: Electronics
ISBN:

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Development of Iterative Minimum-maximum Filter for Reducing Impulse Noise from Highly Corrupted Images

Development of Iterative Minimum-maximum Filter for Reducing Impulse Noise from Highly Corrupted Images
Author: Amjad Najim Jabir
Publisher:
Total Pages: 408
Release: 2006
Genre: Image analysis
ISBN:

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Digital images are often corruted by impulse noise during acquisition or transmission through communication channels. Noisy pixels are characterized by having values that are subtantially different from their surroundingd. In an enviroment of fierce noise contamination, infected pixels tend to connect into noise blothes that colud give the filtering algorithm an illusion of being part of the original image data. Therefore, many impulses would be difficult to detect, with the consequence of a less chance for proper detection and thus, filtering. Different methods have been introduced in literature to filter images with high noise level, including non-linear, fuzzy and combined filters. Performances of some typical filters of each category is studied in detail and compared to that of the suggested filter. This study introduces an iterative minimum filter images highly corrupted with impulse noise, typically in the range 30-80%. Noise detection and filtering are done separately and iteratively, where the impulse detector with a threshold values and the scanning window size, are made proportional to a measure of noise level. Extensive testingm using different types of standard test images, has proved the effectiveness of the proposed filter to give lower Mean Square Error (MSE) of the filtered images, Higher Bit Correct Ratio (BCR) values with better visual quality images have also been recovered and compared to other studied filters such as non-fuzzy, fuzzy and combined filters. This study has verified that a reasonable tradeoff has been achieved between the two aspects of impulse noise suppresion and image edges preservation, which are considered as two inherently conflicting requirements. To facilitate use of the proposed filter, the algorithm has been implemented as a stand-alone application, in the form of an attractive graphical user interface.

Removal of Random Valued Impulsive Noise

Removal of Random Valued Impulsive Noise
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In digital Image Processing, removal of noise is a highly demanded area of research. Impulsive noise is common in images which arise at the time of image acquisition and or transmission of images. Impulsive noise can be classified into two categories, namely Salt & Pepper Noise (SPN) and Random Valued Impulsive Noise (RVIN). Removal SPN is easier as compared to RVIN due to its characteristics. The present work concentrates on removal of RVIN from images. Most of the nonlinear filters used in removal of impulsive noise work in two phases, i.e. detection followed by filtering only the corrupted pixels keeping uncorrupted ones intact. Performance of such filters is dependent on the performance of detection schemes. In this work, thrust has been put to devise an accurate detection scheme and a novel weighted median filtering mechanism. The proposed detection scheme utilizes double difference among the pixels in a test window. The difference is computed along four directions namely, horizontal, vertical, and two diagonals to capture the edge direction if any exists. This helps to identify, whether the test pixels under consideration is an edge pixel or a noisy one. Subsequently, the corrupted pixels are passed through in weighted median filter, where more weights are assigned to those pixels which lie in a minimum variance direction among all the four. Extensive simulation has been carried out at various noise conditions and with different standard images. Comparative analysis has been made with existing standard schemes with suitable parameters such as Peak Signal to Noise Ratio (PSNR), fault detection and misses. It has been observed in general that the proposed schemes outperforms its counterparts at low and medium noise conditions and performs at par at high noise conditions with low computational overhead. The low computational requirements have been substantiated with number of operations required for single window operation and overall time required for detection and f.

Development of Some Novel Nonlinear and Adaptive Digital Image Filters for Efficient Noise Suppression

Development of Some Novel Nonlinear and Adaptive Digital Image Filters for Efficient Noise Suppression
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Some nonlinear and adaptive digital image filtering algorithms have been developed in this thesis to suppress additive white Gaussian noise (AWGN), bipolar fixed-valued impulse, also called salt and pepper noise (SPN), random-valued impulse noise (RVIN) and their combinations quite effectively. The present state-of-art technology offers high quality sensors, cameras, electronic circuitry: application specific integrated circuits (ASIC), system on chip (SOC), etc., and high quality communication channels. Therefore, the noise level in images has been reduced drastically. In literature, many efficient nonlinear image filters are found that perform well under high noise conditions. But their performance is not so good under low noise conditions as compared to the extremely high computational complexity involved therein. Thus, it is felt that there is sufficient scope to investigate and develop quite efficient but simple algorithms to suppress low-power noise in an image. When ...

Impulsive Noise Detection and Mitigation in Communication Systems

Impulsive Noise Detection and Mitigation in Communication Systems
Author: Reza Barazideh
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Release: 2019
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Impulsive noise is a widespread and rapidly growing source of harmful interference in many applications such as vehicular communications, power line communication (PLC), underwater acoustic (UWA) communication, and Internet of Things (IoT). Noise of this type may originate from a variety of sources such as motors, high efficiency lighting, and even other wireless systems such as pulse-type or frequency-modulated continuous wave (FMCW) radars. Impulsive interference can reduce signal quality to the point of reception failure and increase bit errors resulting in degradation in system reliability. Multicarrier transmission techniques and, in particular, orthogonal frequency division multiplexing (OFDM), is proposed to cope with the frequency selectivity of the propagation channel. Although, OFDM provides some level of robustness against impulsivity by spreading the power of impulsive noise over multiple subcarriers, its performance degrades dramatically if the power of impulsive noise exceeds a certain threshold. Many mitigation techniques focus on reducing the interference before it reaches the receiver. In the context of this dissertation, the emphasis is on the reduction of interference that has already entered the signal path. Specifically, this dissertation aims to develop approaches to effectively detect and mitigate the severe impact of the impulsive noise. Here, we investigate two different categories of impulsive noise suppression techniques that can be used as a stand-alone solution or combined with other interference reduction techniques. First, we design and develop Blind Adaptive Intermittently Nonlinear Filters (BAINFs) for analog-domain mitigation of impulsive noise. The idea behind using analog domain mitigation is that insufficient processing bandwidth severely limits the effectiveness of digital nonlinear interference mitigation techniques. Therefore, the suppression of non-Gaussian noise in the analog domain before the analog to digital converter (ADC) where the outliers are more distinguishable can be helpful. The BAINFs can be implemented in many structures and we propose some sample realizations of BAINFs that can be used in different applications. In this dissertation, we consider PLC and UWA communication systems as case studies. The performance of the proposed BAINFs in these systems is quantified analytically and with experimental data. Secondly, in the classic threshold based outlier detection approaches, determining the optimum threshold is the main challenge as this threshold will vary in response to channel conditions and model mismatches. As always, there is a compromise between detection and false alarm probability in the traditional threshold based methods. To overcome this drawback, we propose a two stage impulsive noise mitigation approach. In the first stage, a machine learning approach such as a deep neural network (DNN) is used to detect the instances of impulsivity. Then, the detected impulsive noise can be mitigated in the suppression stage to alleviate the harmful effects of outliers. The robustness of the proposed DNN-based approach under (i) mismatch between impulsive noise models considered for training and testing, and (ii) bursty impulsive environment when the receiver is empowered with interleaving technique is evaluated.