scholarly journals Median Filtering Using First-Order and Second-Order Neighborhood Pixels to Reduce Fixed Value Impulse Noise from Grayscale Digital Images

Electronics ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 2034
Author(s):  
Ali Salim Nasar Mursal ◽  
Haidi Ibrahim
Keyword(s):  
Impulse Noise ◽  
Digital Images ◽  
Noise Removal ◽  
Second Order ◽  
First Order ◽  
Information Preservation ◽  
Noisy Pixel ◽  
Detection Stage ◽  
The Difference ◽  
Two Stages

It is essential to restore digital images corrupted by noise to make them more useful. Many approaches have been proposed to restore images affected by fixed value impulse noise, but they still do not perform well at high noise density. This paper presents a new method to improve the detection and removal of fixed value impulse noise from digital images. The proposed method consists of two stages. The first stage is the noise detection stage, where the difference values between the pixels and their surrounding pixels are computed to decide whether they are noisy pixels or not. The second stage is the image denoising stage. In this stage, the original intensity value of the noisy pixels is estimated using only their first-order and second-order neighborhood pixels. These neighboring orders are based on the Euclidean distance between the noisy pixel and its neighboring pixels. The proposed method was evaluated by comparing it with some of the recent methods using 50 images at 18 noise densities. The experimental results confirm that the proposed method outperforms the existing filters, excelling in noise removal capability with structure and edge information preservation.

From First-Order Coherence to Higher-Order Coherence of Synchrotron Radiation

1998 ◽  
Vol 5 (3) ◽  
pp. 305-308 ◽  
Author(s):  
Tsuneaki Miyahara
Keyword(s):  
Synchrotron Radiation ◽  
Free Electron ◽  
Higher Order ◽  
Second Order ◽  
Free Electron Lasers ◽  
First Order ◽  
Noise Characteristics ◽  
The Difference

The difference between first-order and second-order coherence of synchrotron radiation is discussed in relation to how they can be measured and how they affect the noise characteristics of future free-electron lasers.

Decision Based Median Filter algorithm using Resource Optimized FPGA to Extract Impulse Noise

2014 ◽  
Vol 3 (1) ◽  
pp. 1
Author(s):  
Rutuja Nandkumar Kulkarni ◽  
Pradip C Bhaskar
Keyword(s):  
Impulse Noise ◽  
Median Filter ◽  
Noise Removal ◽  
Mean Value ◽  
Linear Filter ◽  
Noise Detection ◽  
Object Boundary ◽  
Typical Application ◽  
Impulse Noise Removal ◽  
Noisy Pixel

Median filter is a non-linear filter used in image processing for impulse noise removal. It finds its typical application in the situations where edges are to be preserved for higher level operations like segmentation, object recognition etc. This paper presents an accurate and efficient noise detection and filtering algorithm for impulse noise removal. The algorithm includes two stages: noise detection followed by noise filtering. The proposed algorithm replaces the noisy pixel by using  median value when other pixel values, 0’s or 255’s are present in the selected window and when all the pixel values are 0’s and 255’s then the noise pixel is replaced by mean value of all the elements present in the selected window. Similarly algorithm checks for five different conditions to preserve image details, object boundary in high level of noise densities. This median filter was designed, simulated and synthesized on the Xilinx family of FPGAs (XC3S500E of Spartan-3E). The VHDL was used to design the above 2-D median filter using ISE (Xilinx) tool & tested & compared for different grayscale images.

A Lagrangian solution for internal waves

1985 ◽  
Vol 152 ◽  
pp. 191-202 ◽  
Author(s):  
Brian Sanderson
Keyword(s):  
Internal Waves ◽  
Breaking Waves ◽  
Stratified Fluid ◽  
Second Order ◽  
First Order ◽  
Lagrangian Equations ◽  
Lagrangian Solution ◽  
Lagrangian Coordinate ◽  
Sinusoidal Shape ◽  
The Difference

A perturbation procedure is used to obtain first- and second-order solutions for small-amplitude internal waves in a Lagrangian coordinate system. The first-order Lagrangian equations are formally accurate to the same order as the first-order Eulerian equations; however, they are different and the Lagrangian solution gives a more realistic wave shape. First-order Lagrangian solutions for internal waves in uniformly stratified fluid have a shape similar to that found in the second-order Eulerian solution. Wave profiles in uniformly stratified fluid exhibit broad crests and narrow troughs near the surface, a sinusoidal shape at mid-depth, and narrow crests and broad troughs near the bottom. The difference between the shape of crests and troughs grows as the wave amplitude is increased. Solutions obtained in a uniformly stratified fluid with a small bottom slope yield plausible shapes for breaking waves.

A NEW LOOK AT THE DUAL DEPTH OF INVESTIGATION OF LWD PROPAGATION RESISTIVITY LOGGING

2021 ◽  
Author(s):  
Gong Li Wang ◽  
◽  
Dean Homan ◽  
David Maggs ◽  
David Allen ◽  
...  
Keyword(s):  
Phase Shift ◽  
Eddy Current ◽  
Second Order ◽  
Vertical Resolution ◽  
Shift Measurement ◽  
Attenuation Measurement ◽  
First Order ◽  
Dielectric Effect ◽  
The Difference ◽  
Resistivity Logging

It is well established that phase shift and attenuation measurements acquired by an electromagnetic propagation tool come with different depths of investigation (DOI). The attenuation measurement sees deeper into the formation than the phase shift measurement. This difference has been reported not only for the 2 MHz propagation resistivity tool, but also for the deep propagation tool that operates at 25 MHz. Although the difference has been demonstrated with modeling, test tank experiments and logs, a complete physical explanation has been notably absent since the introduction of the MHz-frequency propagation logging in 1980s. The question is so intriguing that it has been raised repeatedly over the past decades: what drives the difference of DOI for the two measurements that are acquired with the same electromagnetic field? In this paper, we revisit this problem with an aim of providing a physical insight to bridge the gap between theory and application. This is an extension of our recent work on the theory of apparent conductivity for propagation measurements. We address the problem by applying high-order geometric theory for low-frequency electromagnetic problems in lossy media in conjunction with the Taylor series expansion for the voltage ratio measured by a propagation tool. In so doing, we find that in a resistive formation where the dielectric effect is small: 1) the phase shift measurement is primarily due to the first-order eddy current induced in the formation; 2) in contrast, the leading source of the attenuation measurement is the second-order eddy current. Since the second-order eddy current is more spread out than the first-order eddy current, this explains why the DOI of attenuation resistivity is larger than that of phase shift resistivity. The difference in spatial distribution of two eddy currents is also the reason for the difference of vertical resolution between the two. The same root cause for the difference of DOI and vertical resolution also holds when comparing R-signal and X-signal from induction resistivity logging. Other properties shared by propagation and induction resistivity logging will be discussed, such as skin effect and dielectric effect, as well as their asymptotic properties in high-resistivity formations. We conclude that propagation and induction resistivity logging are essentially similar, even though the two measurement principles may seem rather different.

scholarly journals First- and Second-Order Full-Differential in Edge Analysis of Images

2014 ◽  
Vol 2014 ◽  
pp. 1-5
Author(s):  
Dong-Mei Pu ◽  
Yu-Bo Yuan
Keyword(s):  
Control Parameter ◽  
Second Order ◽  
Canny Operator ◽  
First Order ◽  
Good Selection ◽  
Pascal Voc ◽  
Uniform Definition ◽  
The Difference ◽  
Basic Ideas ◽  
Selection Of

Two concepts of first- and second-order differential of images are presented to deal with the changes of pixels. These are the basic ideas in mathematics. We propose and reformulate them with a uniform definition framework. Based on our observation and analysis with the difference, we propose an algorithm to detect the edge from image. Experiments on Corel5K and PASCAL VOC 2007 are done to show the difference between the first order and the second order. After comparison with Canny operator and the proposed first-order differential, the main result is that the second-order differential has the better performance in analysis of changes of the context of images with good selection of control parameter.

scholarly journals Kajian Wacana Percakapan di Facebook

2018 ◽  
Vol 3 (2) ◽  
pp. 164-176
Author(s):  
M. Afifulloh
Keyword(s):  
Spoken Language ◽  
Second Order ◽  
Written Language ◽  
Everyday Language ◽  
First Order ◽  
The Media ◽  
Discourse Studies ◽  
The Difference ◽  
Internet Networks

There are two types of languages currently used by humans, namely written language and spoken language. These two languages are used separately for different purposes. But in its development, written language and spoken language are used simultaneously so that now the term discussing chatting. This paper attempts to examine the development of these types of languages both from structuralist and functionalist glasses. The two major schools eventually brought this study to the point of problems regarding language, namely discourse. Discourse studies are able to examine languages ranging from words, phrases, clauses, and sentences comprehensively both first order meaning and second order meaning. The result of the study shows that the discourse on Facebook is a different discourse from other forms of discourse. The difference lies in its media, the shape of the text, and the nature of the text. The media is a forum that can be found in cyberspace through computer devices and internet networks. The form of text is in the form of a written conversation between two people or even more. In these conversations between the speaker and the partner do not deal directly but can directly comment, refute, criticize, or approve the opinions of the speaker. The grammatical elements of internet languages are very different which are shown through the structure of the sentence, the presentation of words, and inflection of words. Many choices of words or alphabet that are not everyday language. As an example appears @ (read at), dotcom which is more or less heard by the media

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