Reduction of residual noise using directional median filter

2011 ◽  
Author(s):  
Ching-Ta Lu ◽  
Kun-Fu Tseng ◽  
Chih-Tsung Chen
Keyword(s):  
Median Filter ◽  
Residual Noise

The Study of Combination Filtering for Removing Mixed Noise of Remote Sensing Image

2014 ◽  
Vol 989-994 ◽  
pp. 3881-3884 ◽  
Author(s):  
Cui Zhou ◽  
Jing Hong Zhou ◽  
Dong Hao Fan
Keyword(s):  
Remote Sensing ◽  
Median Filter ◽  
Practical Method ◽  
Remote Sensing Image ◽  
Gaussian Mixture ◽  
Wiener Filtering ◽  
Filter Method ◽  
Practical Application ◽  
Residual Noise ◽  
Mixed Noise

The traditional combination filter method in the practical process is often two layers of composite filtering de-noising for the image containing the gaussian mixture noise and pulse noise. This paper proposes a three filter combination algorithm based on the two layers filters, To the Gaussian and pulse mixed noise of the remote sensing image, we use wavelet threshold de-nosing and adaptive median filter de-nosing, and then using the third layer adaptive Wiener filtering de-noising to remove the residual noise. Through theoretical analysis and practical application, the de-nosing results of this method is obvious in processing mixed noise of remote sensing image, this is a practical method of combination filtering de-noising, it can be widely used in the field of image processing.

The Effect of Kalman-Weighted Averaging and Artifact Rejection on Residual Noise During Auditory Brainstem Response Testing

2019 ◽  
Vol 28 (1) ◽  
pp. 114-124
Author(s):  
Linda W. Norrix ◽  
Julie Thein ◽  
David Velenovsky
Keyword(s):  
Repeated Measures ◽  
Auditory Brainstem ◽  
Weighted Averaging ◽  
Auditory Brainstem Responses ◽  
Residual Noise ◽  
Electrophysiological Recordings ◽  
Artifact Rejection ◽  
Brainstem Response ◽  
Active Motor ◽  
Averaging Time

Purpose Low residual noise (RN) levels are critically important when obtaining electrophysiological recordings of threshold auditory brainstem responses. In this study, we examine the effectiveness and efficiency of Kalman-weighted averaging (KWA) implemented on the Vivosonic Integrity System and artifact rejection (AR) implemented on the Intelligent Hearing Systems SmartEP system for obtaining low RN levels. Method Sixteen adults participated. Electrophysiological measures were obtained using simultaneous recordings by the Vivosonic and Intelligent Hearing Systems for subjects in 2 relaxed conditions and 4 active motor conditions. Three averaging times were used for the relaxed states (1, 1.5, and 3 min) and for the active states (1.5, 3, and 6 min). Repeated-measures analyses of variance were used to examine RN levels as a function of noise reduction strategy (i.e., KWA, AR) and averaging time. Results Lower RN levels were obtained using KWA than AR in both the relaxed and active motor states. Thus, KWA was more effective than was AR under the conditions examined in this study. Using KWA, approximately 3 min of averaging was needed in the relaxed condition to obtain an average RN level of 0.025 μV. In contrast, in the active motor conditions, approximately 6 min of averaging was required using KWA. Mean RN levels of 0.025 μV were not attained using AR. Conclusions When patients are not physiologically quiet, low RN levels are more likely to be obtained and more efficiently obtained using KWA than AR. However, even when using KWA, in active motor states, 6 min of averaging or more may be required to obtain threshold responses. Averaging time needed and whether a low RN level can be attained will depend on the level of motor activity exhibited by the patient.

A Novel Algorithm based on UBTMF for Colour Pictures

2018 ◽  
Vol 8 (4) ◽  
pp. 84
Author(s):  
Himanshu Rehani ◽  
Anuradha Saini
Keyword(s):  
Driving Forces ◽  
Median Filter ◽  
Main Stream ◽  
Points Of Interest ◽  
Novel Algorithm

The issue of picture denoising is one of the most established in the field, is as yet getting extensive focus from the exploration zone due to consistently expanding interest for sensibly valued great media and in additament its part as a pre-preparing venture for picture division, pressure, and so on, because of high spatial being without a vocation of mundane pictures, nearby averaging of the pixels impressively abate the commotion while bulwark the first structure of the picture. To enhance the execution of the essential channels, more compelling sifting calculations including the exchanging vector channels and the amalgamation vector. In spite of the fact that there are different sifting calculations to cull, the more preponderant part of them is not outfit predicated. Multifarious Median Filter (AMF) performs well at low commotion densities. Be that as it may, at high filter densities the window measure must be expanded which may prompt obscuring the picture. In exchanging middle channel the cull depends on Re-characterized limit esteem. The paramount downside of this technique is that characterizing a vigorous cull is onerous. Supplementally these channels won't consider the nearby highlights because of which points of interest and edges may not be recouped severely, concretely when the filter level is high. To vanquish the above downside, Decision Predicated Algorithm (DBA) is proposed. In this, the picture is denoised by utilizing a 3x3 window. On the off chance that the preparing pixel esteem is 0 or 255 it is handled or else it is left unaltered. At high commotion thickness the middle esteem will be 0 or 255 which is boisterous. The goal of disuniting is to expel the driving forces so the commotion free picture is planarity recouped with least flag bending. Filter (Clamor) expulsion can be accomplished by utilizing sundry subsisting direct dissevering procedures which are main stream as a result of their numerical straightforwardness and the presence of the assembling direct framework hypothesis. In spite of the fact that middle channels expel motivation clamor without harming the edges, the prodigious majority of them work consistently over the picture and in this way have a propensity to alter both commotion and clamor free pixels. Preferably, the disuniting ought to be connected just to debased pixels while leaving uncorrupted pixels in place. We propose a novel calculation for clamor diminishment in light of UBTMF for Colour pictures.

An Alternate Algorithm for (3x3) Median Filtering of Digital Images

2012 ◽  
Vol 2 (1) ◽  
pp. 7-9 ◽  
Author(s):  
Satinderjit Singh
Keyword(s):  
Median Filter ◽  
Computational Cost ◽  
Spatial Coherence ◽  
General Purpose ◽  
Median Filtering ◽  
Basic Algorithm ◽  
Temporal Complexity ◽  
Filter Kernel ◽  
One Step ◽  
High Computational Cost

Median filtering is a commonly used technique in image processing. The main problem of the median filter is its high computational cost (for sorting N pixels, the temporal complexity is O(N·log N), even with the most efficient sorting algorithms). When the median filter must be carried out in real time, the software implementation in general-purpose processorsdoes not usually give good results. This Paper presents an efficient algorithm for median filtering with a 3x3 filter kernel with only about 9 comparisons per pixel using spatial coherence between neighboring filter computations. The basic algorithm calculates two medians in one step and reuses sorted slices of three vertical neighboring pixels. An extension of this algorithm for 2D spatial coherence is also examined, which calculates four medians per step.

Enhancing the Performance of One Dimensional Median Filter

2019 ◽  
Vol 118 (7) ◽  
pp. 73-76
Author(s):  
Sharanabasappa ◽  
P Ravibabu
Keyword(s):  
Impulse Noise ◽  
Rank Order ◽  
Median Filter ◽  
Filter Method ◽  
Salt And Pepper Noise ◽  
Edge Preservation ◽  
Word Level ◽  
Look Ahead ◽  
Filter Architecture ◽  
Salt And Pepper

Nowadays, during the process of Image acquisition and transmission, image information data can be corrupted by impulse noise. That noise is classified as salt and pepper noise and random impulse noise depending on the noise values. A median filter is widely used digital nonlinear filter  in edge preservation, removing of impulse noise and smoothing of signals. Median filter is the widely used to remove salt and pepper noise than rank order filter, morphological filter, and unsharp masking filter. The median filter replaces a sample with the middle value among all the samples present inside the sample window. A median filter will be of two types depending on the number of samples processed at the same cycle i.e, bit level architecture and word level architecture.. In this paper, Carry Look-ahead Adder median filter method will be introduced to improve the hardware resources used in median filter architecture for 5 window and 9 window for 8 bit and 16 bit median filter architecture.

Dual Ascent Based Median Filter for Image Restoration

2019 ◽  
Author(s):  
Narendra Kumar ◽  
H. S. Shukla ◽  
Arvind Kumar Tiwari ◽  
Anil Kumar Dahiya
Keyword(s):  
Image Restoration ◽  
Median Filter ◽  
Dual Ascent

Double Line Clustering based Colour Image Segmentation Technique for Plant Disease Detection

2019 ◽  
Vol 15 (8) ◽  
pp. 769-776
Author(s):  
Kalaivani Subramani ◽  
Shantharajah Periyasamy ◽  
Padma Theagarajan
Keyword(s):  
Pattern Matching ◽  
Error Rate ◽  
Median Filter ◽  
Identification System ◽  
Double Line ◽  
Cultivation System ◽  
Matching Algorithm ◽  
Non Local ◽  
Mining Methods ◽  
Blight Disease

Background: Agriculture is one of the most essential industry that fullfills people’s need and also plays an important role in economic evolution of the nation. However, there is a gap between the agriculture sector and the technological industry and the agriculture plants are mostly affected by diseases, such as the bacterial, fungus and viral diseases that lead to loss in crop yield. The affected parts of the plants need to be identified at the beginning stage to eliminate the huge loss in productivity. Methods: In the present scenario, crop cultivation system depend on the farmers experience and the man power, but it consumes more time and increases error rate. To overcome this issue, the proposed system introduces the Double Line Clustering technique based disease identification system using the image processing and data mining methods. The introduced method analyze the Anthracnose, blight disease in grapes, tomato and cucumber. The leaf images are captured and the noise has been removed by non-local median filter and the segmentation is done by double line clustering method. The segmented part compared with diseased leaf using pattern matching algorithm. Methods: In the present scenario, crop cultivation system depend on the farmers experience and the man power, but it consumes more time and increases error rate. To overcome this issue, the proposed system introduces the Double Line Clustering technique based disease identification system using the image processing and data mining methods. The introduced method analyze the Anthracnose, blight disease in grapes, tomato and cucumber. The leaf images are captured and the noise has been removed by non-local median filter and the segmentation is done by double line clustering method. The segmented part compared with diseased leaf using pattern matching algorithm. Conclusion: The result of the clustering algorithm achieved high accuracy, sensitivity, and specificity. The feature extraction is applied after the clustering process which produces minimum error rate.

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