scholarly journals Edge Detection in Radar Images Using Weibull Distribution

2013 ◽  
Author(s):  
Ali El-Zaart ◽  
Wafaa Kamel Al-Jibory
Keyword(s):  
Edge Detection ◽  
Weibull Distribution ◽  
Radar Images

scholarly journals A Proposed Approach to Determine the Edges in SAR images

2020 ◽  
pp. 185-192
Author(s):  
Rabab Farhan Abbas
Keyword(s):  
Edge Detection ◽  
Electromagnetic Waves ◽  
Operator Method ◽  
Bézier Curve ◽  
Bezier Curve ◽  
Edge Image ◽  
Sar Images ◽  
Wavelet Method ◽  
Radar Images ◽  
Sobel Operator

Radar is the most eminent device in the prolonged scattering era The mechanisms involve using electromagnetic waves to take Synthetic Aperture Radar (SAR) images for long reaching. The process of setting edges is one of the important processes used in many fields, including radar images, which assists in showing objects such as mobile vehicles, ships, aircraft, and meteorological and terrain forms. In order to accurately identify these objects, their edges must be detected. Many old-style methods are used to isolate the edges but they do not give good results in the  determination process. Conservative methods use an operator to detect the edges, such as the Sobel operator which is used to perform edge detection where the edge does not appear well.      The proposed method which combines Ridgelet transform, Bezier curve and Sobel operator is used to detect edges very efficiently. Ridghelet transform resolves the harms in the wavelet transform and it can well detect the edges in images. Bezier curve can profit gradual variation of the data and their mutability. Hence, the efficiency of the edged image is improved and, when used with Sobel operator, the quality of the edge image become very good. The data show that the advocated method has superior fallouts over the Sobel edge detection and the wavelet method in both subjective and impartial experiments. While the Peak Signal to Noise Ratio(PSNR) values were equal to 9.3812, 9.8918, 9.6521 and 9.0743using the Sobel operator method and to10.2564, 10.7927, 10.5612and 10.8633 using the wavelet method, they were increased in the proposed method to 12.6542, 12.9514, 12.8574 and 12.3013 respectively.

Neural network based edge detection in two-look and dual-polarization radar images

2014 ◽  
Author(s):  
Alexey V. Naumenko ◽  
Vladimir V. Lukin ◽  
Benoit Vozel ◽  
Kacem Chehdi ◽  
Karen Egiazarian
Keyword(s):  
Neural Network ◽  
Edge Detection ◽  
Dual Polarization ◽  
Radar Images

scholarly journals Speckle Reduction by Directional Coherent Anisotropic Diffusion

2019 ◽  
Vol 11 (23) ◽  
pp. 2768
Author(s):  
Guo Zhang ◽  
Fengcheng Guo ◽  
Qingjun Zhang ◽  
Kai Xu ◽  
Peng Jia ◽  
...  
Keyword(s):  
Edge Detection ◽  
Anisotropic Diffusion ◽  
Speckle Reduction ◽  
Simulated Image ◽  
Diffusion Filter ◽  
Anisotropic Diffusion Filter ◽  
Radar Images ◽  
Inaccurate Estimation ◽  
Series Of Experiments ◽  
Diffusion Function

To effectively balance speckle smoothing and preservation of edges and radiation, a novel anisotropic diffusion filter was developed that uses a directional coherent coefficient. The proposed filter effectively improves the edge detection operator of a traditional anisotropic diffusion filter. The new edge detection operator calculates 16 direction coherence coefficients to avoid the interference of the edge direction. For the diffusion function, the proposed method directly uses the detected directional coherent edge as the diffusion coefficient, which simplifies the calculation of the diffusion function and avoids the adverse effects of inaccurate estimation of the diffusion function threshold for a traditional anisotropic diffusion filter. The influence of the number of iterations and time steps on the proposed filter was analyzed. A series of experiments was conducted with a simulated image and three real synthetic-aperture radar images from different sensors. The results confirmed that the proposed method not only significantly reduces speckle but also effectively preserves the edge and radiation information of images.

scholarly journals Optical images-based edge detection in Synthetic Aperture Radar images

2015 ◽  
Vol 87 ◽  
pp. 38-46 ◽  
Author(s):  
Gilberto P. Silva ◽  
Alejandro C. Frery ◽  
Sandra Sandri ◽  
Humberto Bustince ◽  
Edurne Barrenechea ◽  
...  
Keyword(s):  
Edge Detection ◽  
Synthetic Aperture Radar ◽  
Synthetic Aperture ◽  
Radar Images ◽  
Optical Images ◽  
Aperture Radar

Brownian motion with quadratic killing and some implications

1986 ◽  
Vol 23 (04) ◽  
pp. 893-903 ◽  
Author(s):  
Michael L. Wenocur
Keyword(s):  
Brownian Motion ◽  
Weibull Distribution ◽  
Special Function ◽  
Function Theory ◽  
Killing Rate

Brownian motion subject to a quadratic killing rate and its connection with the Weibull distribution is analyzed. The distribution obtained for the process killing time significantly generalizes the Weibull. The derivation involves the use of the Karhunen–Loève expansion for Brownian motion, special function theory, and the calculus of residues.

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