scholarly journals Speckle noise suppression method using multi-azimuth SAR images.

2021 ◽  
Vol 2083 (3) ◽  
pp. 032053
Author(s):  
Yingru Shi ◽  
Yang Liu ◽  
Peili Xi ◽  
Wei Yang ◽  
Hongcheng Zeng
Keyword(s):  
Noise Suppression ◽  
Speckle Noise ◽  
Image Sequences ◽  
Sar Images ◽  
Radar Images ◽  
Local Means ◽  
Structural Details ◽  
Novel Method ◽  
Non Local ◽  
Suppression Method

Abstract Synthetic aperture radar images play an important role in military and civilian fields, but the presence of speckle noise has an impact on subsequent tasks such as target detection and target interpretation. With the development of multi-azimuth observation mode, the obtained multi-azimuth image sequences have high similarities. Therefore, combined with multi-azimuth image sequences, a novel method of SAR image speckle noise suppression based on clustering is proposed in this paper. In this method, multi-azimuth joint filtering framework based on two-level filtering is proposed, in which pre-filtering for single image and joint filtering based on Non-local Means algorithm for multi-azimuth image are used to suppress the noise. And k-means clustering is used to optimize the search area in the multi-azimuth joint filtering, so as to effectively suppress speckle noise while retaining structural 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.

scholarly journals Wavelet Based Non-Local Means Filtering for Speckle Noise Reduction of SAR Images

2010 ◽  
Vol 23 (3) ◽  
pp. 595-607
Author(s):  
Dea-Gun Lee ◽  
Min-Jea Park ◽  
Jeong-Uk Kim ◽  
Do-Yun Kim ◽  
Dong-Wook Kim ◽  
...  
Keyword(s):  
Noise Reduction ◽  
Speckle Noise ◽  
Sar Images ◽  
Local Means ◽  
Non Local ◽  
Speckle Noise Reduction

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 Speckle Denoising With NL Filter and Stochastic Distances Under the Haar Wavelet Domain

2019 ◽  
Author(s):  
Pedro A. A. Penna ◽  
Nelson D. A. Mascarenhas
Keyword(s):  
State Of The Art ◽  
Speckle Noise ◽  
Haar Wavelet ◽  
Imaging Systems ◽  
Wavelet Domain ◽  
Sar Images ◽  
Local Means ◽  
Current State ◽  
Gamma Distributions ◽  
Non Local

Synthetic aperture radar SAR imaging systems have a coherent processing that causes the appearance of the multiplicative speckle noise. This noise gives a granular appearance to the terrestrial surface scene impairing its interpretation. The similarity between patches approach is applied by the current state-of-the-art filters in remote sensing area. The goal of this manuscript is to present a method to transform the non-local means (NLM) algorithm capable to mitigate the noise. Singlelook speckle and the NLM under the Haar wavelet domain are considered in our research with intensity SAR images. To achieve our goal, we used the Exponential-Polynomial (EP) and Gamma distributions to describe the Haar coefficients. Also, stochastic distances based on these two mentioned distributions were formulated and embedded in the original NLM technique. Finally, we present analyses and comparisons of real scenarios to demonstrate the competitive performance of the proposed method with some recent filters of the literature.

scholarly journals Synthetic-Aperture Radar Image Despeckling based on Improved Non-Local Means and Non-Subsampled Shearlet Transform

2020 ◽  
Vol 49 (3) ◽  
pp. 299-307
Author(s):  
Zengguo Sun ◽  
Rui Shi ◽  
Wei Wei
Keyword(s):  
Synthetic Aperture Radar Image ◽  
Synthetic Aperture ◽  
Sar Image ◽  
Sar Images ◽  
Shearlet Transform ◽  
Local Means ◽  
New Type ◽  
Non Local ◽  
Homogeneous Regions ◽  
Transform Domains

When Synthetic-Aperture (SAR) image is transformed into wavelet domain and other transform domains, most of the coefficients of the image are small or zero. This shows that SAR image is sparse. However, speckle can be seen in SAR images. The non-local means is a despeckling algorithm, but it cannot overcome the speckle in homogeneous regions and it blurs edge details of the image. In order to solve these problems, an improved non-local means is suggested. At the same time, in order to better suppress the speckle effectively in edge regions, the non-subsampled Shearlet transform (NSST) is applied. By combining NSST with the improved non-local means, a new type of despeckling algorithm is proposed. Results show that the proposed algorithm leads to a satisfying performance for SAR images.

A Novel Method with Adaptive Non-local Means for Image Denoising

2012 ◽  
Vol 4 (16) ◽  
pp. 251-257
Author(s):  
Wenhui Li ◽  
Bo Fu ◽  
Chunri Cui ◽  
Huiying Li ◽  
Ying Wang ◽  
...  
Keyword(s):  
Image Denoising ◽  
Local Means ◽  
Novel Method ◽  
Non Local

scholarly journals An Unbiased SPHERE-IFS Survey of Nearby Herbig Ae/Be Stars: Are All Group I Disks Transitional?

2018 ◽  
Vol 14 (S345) ◽  
pp. 250-251
Author(s):  
Maria Giulia Ubeira Gabellini ◽  
Mario E. van den Ancker ◽  
Davide Fedele ◽  
Giuseppe Lodato ◽  
Carlo Felice Manara
Keyword(s):  
Noise Suppression ◽  
Scattered Light ◽  
Speckle Noise ◽  
Be Stars ◽  
Systematic Survey ◽  
Spatially Resolved ◽  
Group I ◽  
Novel Method

AbstractUsing a novel method for speckle noise suppression from SPHERE-IFS data, we performed a systematic survey for disks in 22 Herbig Ae/Be stars, spatially resolving five disks and detecting seven new companion candidates. The fraction of sources with spatially resolved disks is systematically higher in the Meeus et al. (2001) group I sources, showing that disks are indeed more easily seen in scattered light in this sub-class of Herbig stars, consistent with the interpretation of group I sources having large gaps in their disks.

Efficient non-local means denoising for image sequences with dimensionality reduction

2018 ◽  
Vol 77 (23) ◽  
pp. 30595-30613
Author(s):  
Hemalata Bhujle ◽  
Basavaraj H. Vadavadagi ◽  
Shivanand Galaveen
Keyword(s):  
Dimensionality Reduction ◽  
Image Sequences ◽  
Local Means ◽  
Non Local
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