scholarly journals Speckle Noise Suppression in SAR Images Using a Three-Step Algorithm

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3643 ◽  
Author(s):  
Ze Yu ◽  
Wenqi Wang ◽  
Chunsheng Li ◽  
Wei Liu ◽  
Jian Yang
Keyword(s):  
Noise Suppression ◽  
Minimum Mean Square Error ◽  
Image Interpretation ◽  
Speckle Noise ◽  
Bias Reduction ◽  
Edge Preservation ◽  
Improved Performance ◽  
Step Algorithm ◽  
The Impact ◽  
Speckle Suppression

Speckle noise can reduce the image quality of synthetic aperture radar (SAR) and complicate image interpretation. This study proposes a novel three-step approach based on the conventional probabilistic patch-based (PPB) algorithm to minimize the impact of bright structures on speckle suppression. The first step improves the calculation accuracy of the weight by pre-processing speckle noise with a linear minimum mean-square error filter and reassessing similarity between pixels. In the second step, an iterative method is developed to avoid interfering with bright structures and acquires a more accurate homogeneous factor by adaptively changing the size of the search window. In the final step, the spreading and blurring of bright structures is corrected using a modified bias-reduction technique. Experimental results demonstrate the proposed algorithm has improved performance for both speckle suppression and preservation of edges and textures, evaluated by indicators including the equivalent number of looks, the edge preservation index, the mean, and standard deviation of ratio images.

scholarly journals COMPARISON OF FILTERS DEDICATED TO SPECKLE SUPPRESSION IN SAR IMAGES

2016 ◽  
Vol XLI-B7 ◽  
pp. 269-276 ◽  
Author(s):  
P. Kupidura
Keyword(s):  
Land Cover ◽  
Noise Suppression ◽  
Speckle Noise ◽  
Sar Images ◽  
Structuring Element ◽  
Radar Images ◽  
Artificial Image ◽  
Salt And Pepper ◽  
Image Details ◽  
Speckle Suppression

This paper presents the results of research on the effectiveness of different filtering methods dedicated to speckle suppression in SAR images. The tests were performed on RadarSat-2 images and on an artificial image treated with simulated speckle noise. The research analysed the performance of particular filters related to the effectiveness of speckle suppression and to the ability to preserve image details and edges. Speckle is a phenomenon inherent to radar images – a deterministic noise connected with land cover type, but also causing significant changes in digital numbers of pixels. As a result, it may affect interpretation, classification and other processes concerning radar images. Speckle, resembling “salt and pepper” noise, has the form of a set of relatively small groups of pixels of values markedly different from values of other pixels representing the same type of land cover. Suppression of this noise may also cause suppression of small image details, therefore the ability to preserve the important parts of an image, was analysed as well. In the present study, selected filters were tested, and methods dedicated particularly to speckle noise suppression: Frost, Gamma-MAP, Lee, Lee-Sigma, Local Region, general filtering methods which might be effective in this respect: Mean, Median, in addition to morphological filters (alternate sequential filters with multiple structuring element and by reconstruction). The analysis presented in this paper compared the effectiveness of different filtering methods. It proved that some of the dedicated radar filters are efficient tools for speckle suppression, but also demonstrated a significant efficiency of the morphological approach, especially its ability to preserve image details.

scholarly journals COMPARISON OF FILTERS DEDICATED TO SPECKLE SUPPRESSION IN SAR IMAGES

2016 ◽  
Vol XLI-B7 ◽  
pp. 269-276 ◽  
Author(s):  
P. Kupidura
Keyword(s):  
Land Cover ◽  
Noise Suppression ◽  
Speckle Noise ◽  
Sar Images ◽  
Structuring Element ◽  
Radar Images ◽  
Artificial Image ◽  
Salt And Pepper ◽  
Image Details ◽  
Speckle Suppression

This paper presents the results of research on the effectiveness of different filtering methods dedicated to speckle suppression in SAR images. The tests were performed on RadarSat-2 images and on an artificial image treated with simulated speckle noise. The research analysed the performance of particular filters related to the effectiveness of speckle suppression and to the ability to preserve image details and edges. Speckle is a phenomenon inherent to radar images – a deterministic noise connected with land cover type, but also causing significant changes in digital numbers of pixels. As a result, it may affect interpretation, classification and other processes concerning radar images. Speckle, resembling “salt and pepper” noise, has the form of a set of relatively small groups of pixels of values markedly different from values of other pixels representing the same type of land cover. Suppression of this noise may also cause suppression of small image details, therefore the ability to preserve the important parts of an image, was analysed as well. In the present study, selected filters were tested, and methods dedicated particularly to speckle noise suppression: Frost, Gamma-MAP, Lee, Lee-Sigma, Local Region, general filtering methods which might be effective in this respect: Mean, Median, in addition to morphological filters (alternate sequential filters with multiple structuring element and by reconstruction). The analysis presented in this paper compared the effectiveness of different filtering methods. It proved that some of the dedicated radar filters are efficient tools for speckle suppression, but also demonstrated a significant efficiency of the morphological approach, especially its ability to preserve image details.

Relay Selection-aware Non-orthogonal Multiple Access Networks: Direct and Relaying Mode

2020 ◽  
Vol 13 (3) ◽  
pp. 348-354
Author(s):  
Dinh-Thuan Do ◽  
Minh-Sang V. Nguyen
Keyword(s):  
Relay Selection ◽  
Multiple Access ◽  
Decode And Forward ◽  
Selection Scheme ◽  
Fixed Power ◽  
Transmission Quality ◽  
Improved Performance ◽  
Outage Probabilities ◽  
Future Work ◽  
The Impact

Objective: In this paper, Decode-and-Forward (DF) mode is deployed in the Relay Selection (RS) scheme to provide better performance in cooperative downlink Non-orthogonal Multiple Access (NOMA) networks. In particular, evaluation regarding the impact of the number of multiple relays on outage performance is presented. Methods: As main parameter affecting cooperative NOMA performance, we consider the scenario of the fixed power allocations and the varying number of relays. In addition, the expressions of outage probabilities are the main metric to examine separated NOMA users. By matching related results between simulation and analytical methods, the exactness of derived formula can be verified. Results: The intuitive main results show that in such cooperative NOMA networks, the higher the number of relays equipped, the better the system performance can be achieved. Conclusion: DF mode is confirmed as a reasonable selection scheme to improve the transmission quality in NOMA. In future work, we will introduce new relay selections to achieve improved performance.

scholarly journals The Influence of Video Format on Engagement and Performance in Online Learning

2021 ◽  
Vol 11 (2) ◽  
pp. 128
Author(s):  
Sergej Lackmann ◽  
Pierre-Majorique Léger ◽  
Patrick Charland ◽  
Caroline Aubé ◽  
Jean Talbot
Keyword(s):  
Student Performance ◽  
Cognitive Engagement ◽  
Emotional Engagement ◽  
Emotional States ◽  
Lecture Capture ◽  
Improved Performance ◽  
And Performance ◽  
Subject Experiment ◽  
The Impact ◽  
Video Format

Millions of students follow online classes which are delivered in video format. Several studies examine the impact of these video formats on engagement and learning using explicit measures and outline the need to also investigate the implicit cognitive and emotional states of online learners. Our study compared two video formats in terms of engagement (over time) and learning in a between-subject experiment. Engagement was operationalized using explicit and implicit neurophysiological measures. Twenty-six (26) subjects participated in the study and were randomly assigned to one of two conditions based on the video shown: infographic video or lecture capture. The infographic video showed animated graphics, images, and text. The lecture capture showed a professor, providing a lecture, filmed in a classroom setting. Results suggest that lecture capture triggers greater emotional engagement over a shorter period, whereas the infographic video maintains higher emotional and cognitive engagement over longer periods of time. Regarding student learning, the infographic video contributes to significantly improved performance in matters of difficult questions. Additionally, our results suggest a significant relationship between engagement and student performance. In general, the higher the engagement, the better the student performance, although, in the case of cognitive engagement, the link is quadratic (inverted U shaped).

scholarly journals Firm Level Strategy, Organization Culture and Performance of Food and Beverage Manufacturing Firms in Kenya

2018 ◽  
Vol 13 (8) ◽  
pp. 224 ◽  
Author(s):  
Zachary B. Awino ◽  
Dominic C. Muteshi ◽  
Reginah K. Kitiabi ◽  
Ganesh P. Pokhariyal
Keyword(s):  
Policy Formulation ◽  
Manufacturing Firms ◽  
Organization Culture ◽  
Hierarchical Regression ◽  
Firm Level ◽  
Food And Beverage ◽  
Improved Performance ◽  
And Performance ◽  
The Impact ◽  
The Relationship

The study tested the impact of organization culture on the on the relationship between firm-level strategy and performance of food and beverage manufacturing firms in Kenya. The opinion of the CEO/MDs from 125 firms in this sector was sought by application of a structured questionnaire; the collected data was analysed using hierarchical regression analysis. The paper stated hypothesis that organizational culture has a significant effect on the relationship between firm-level strategy and performance. The results supported the hypothesis. Therefore, firm development of strong organization culture to support firm-level strategy for higher performance is paramount. These findings will contribute to government policy formulation for sector’s expansion and competitiveness and management drives in building a positive organization culture to support firm-level strategy for improved performance.

Speckle noise suppression of digital holographic microscopy with diffusion glass rotation

2021 ◽  
Author(s):  
Bingcai Liu ◽  
Rui Niu ◽  
Ailing Tian ◽  
Hongjun Wang ◽  
Xueliang Zhu ◽  
...  
Keyword(s):  
Noise Suppression ◽  
Speckle Noise ◽  
Digital Holographic Microscopy ◽  
Holographic Microscopy

New directional wave observations from CFOSAT : impact on ocean/wave coupling in the Southern Ocean

2021 ◽  
Author(s):  
Lotfi Aouf ◽  
Daniele Hauser ◽  
Stephane Law-Chune ◽  
Bertrand chapron ◽  
Alice Dalphinet ◽  
...  
Keyword(s):  
Southern Ocean ◽  
Surface Wind ◽  
Bias Reduction ◽  
Ocean Wave ◽  
Wave Number ◽  
Geophysical Research ◽  
Wave Coupling ◽  
Ocean Region ◽  
Directional Wave ◽  
The Impact

<p>The Southern ocean is a complex ocean region with uncertainties related to surface wind forcing and fluxes exchanges at the air/sea interface. The improvement of wind wave generation in this ocean region is crucial for climate studies. With CFOSAT satellite mission, the SWIM instrument provides directional wave spectra for wavelengths from 70 to 500 m, which shed light on the role of correcting the wave direction and peak wave number of dominant wave trains in the wind-waves growth phase. This consequently induced a better energy transfer between waves and a significant bias reduction of wave height in the Southern Ocean (Aouf et al. 2020). The objective of this work is to extend the analysis of the impact of the assimilation of wave number components from SWIM wave partitions on the ocean/wave coupling. To this end, coupled simulations of the wave model MFWAM and the ocean model NEMO are performed during the southern winter period of 2019 (May-July). We have examined the MFWAM/NEMO coupling with and without the assimilation of the SWIM mean wave number components. Several coupling processes related to Stokes drift, momentum flux stress and wave breaking inducing turbulence in the ocean mixing layer have been analyzed. We also compared the coupled runs with a control run without wave forcing in order to evaluate the impact of the assimilation. The results of coupled simulations have been validated with satellite Sea Surface Temperature and available surface currents data over the southern ocean. We also investigated the impact of the assimilation during severe storms with unlimited fetch conditions.</p><p>Further discussions and conclusions will be commented in the final paper.</p><p>Aouf L., New directional wave satellite observations : Towards improved wave forecasting and climate description in Southern Ocean, Geophysical Research Letters, DOI: 10.1029/2020GL091187 (in production).</p><p> </p><div> <div> <div></div> <div>What do you want to do ?</div> New mail</div> </div><div><img></div>

scholarly journals Firm Performance: Does Mastering a Foreign Language Matter?

10.29007/dkzg ◽  
2018 ◽  
Author(s):  
Remedios Hernández Linares ◽  
María José Naranjo ◽  
Héctor Sánchez Santamaría ◽  
Mercedes Rico García ◽  
Laura Fielden Burns ◽  
...  
Keyword(s):  
Foreign Language ◽  
Organizational Performance ◽  
Small And Medium Enterprises ◽  
Language Education ◽  
Foreign Language Education ◽  
Primary Data ◽  
First Semester ◽  
Improved Performance ◽  
Medium Enterprises ◽  
The Impact

Over the last twenty years the impact of language in international and multinational companies has attracted significant scholarly attention, which is reflected in the growing literature. However, and despite the fact that small and medium enterprises (SMEs) constitute the engine of numerous economies worldwide, the impact of foreign languages on SMEs’ performance remains understudied. This is especially intricate because, considering that SMEs often have fewer resources, the commitment of such resources to language acquisition and foreign language education can only be justified in the case of improved performance. To address this gap, the objective of our research aims to get insights whether and how the domain of a foreign language (mainly English) affects SMEs’ performance. For this purpose, we perform an exploratory empirical study based on data collected through a telephone questionnaire during the first semester of 2017. A group of private Spanish SMEs constitutes our sample. Our work presents the results of the statistical analysis of these primary data, and contributes to a more nuanced perspective on language utility for organizational performance.

scholarly journals Denoising of Medical Ultrasound Images using Wavelet Transform with Bilateral Filter

2019 ◽  
Vol 8 (4) ◽  
pp. 8113-8116
Keyword(s):  
Wavelet Transform ◽  
Bilateral Filter ◽  
Intrinsic Noise ◽  
Speckle Noise ◽  
Computer Assisted ◽  
Ultrasound Images ◽  
Medical Ultrasound ◽  
Edge Preservation ◽  
Neighborhood Relationship ◽  
Speckle Filtering

Medical image degradation contains a significant impact on image quality and therefore affects the human interpretation and also the accuracy of computer assisted diagnostics techniques, unfortunately ultrasound images are principally degraded by an intrinsic noise known as speckle noise. Therefore, de- speckle filtering may be pre-processing step in medical ultrasound images. During this paper we propose a new image de-noising technique is the combination of bilateral filter and wavelet transform. The main contribution of this paper is within the use of a new neighborhood relationship to develop a new multi-scale bilateral filter. Experimental outcomes validate the usefulness and also the correctness of the proposed filter in edge preservation and speckle noise reduction for medical ultrasound images.

Analysis and Mechanism of Impact of GPR Detection Effect Result from Soil Water Content

2012 ◽  
Vol 226-228 ◽  
pp. 2098-2102 ◽  
Author(s):  
Xin Jing Wang ◽  
Zhen Qi Hu ◽  
Yan Ling Zhao ◽  
Yu Ming Guo ◽  
Pei Jun Wang
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Amplitude Spectrum ◽  
Image Interpretation ◽  
Soil Taxonomy ◽  
Underground Pipe ◽  
Mechanism Of Impact ◽  
The Impact ◽  
Detection Effect

Using the ground-penetrating radar (GPR) system with the different frequencies and neutron probe, combing with radar image interpretation and the amplitude spectrum, the impact of GPR detection effects on the soil taxonomy and underground pipe were analyzed. The results indicate that when the soil content is 17.02%, the effect on soil taxonomy of 750MHZ antenna is better than 400MHZ, but the effect on underground pipe is same. As soil water content increases to 25.333%, the soil taxonomy of two antennas’ detection tends to same, and “fake stratifications” existed. The soil water content accelerates to 36.389%, the detection effect on soil taxonomy and underground pipe is so poor. Attenuation mechanism and propagation characteristics of the high electromagnetic wave were presented to interpret those phenomena. The above analysis shows that the soil water content is one of the main prerequisites for the applications of GPR. Some indicators could be provided to nondestructive test in land consolidation project quality by GPR from this research.

Sign in / Sign up

Export Citation Format

Share Document