Quantitative and qualitative comparison of SAR images from incomplete measurements using compressed sensing and nonuniform FFT

2011 ◽  
Author(s):  
Hamed Kajbaf ◽  
Joseph T. Case ◽  
Yahong Rosa Zheng ◽  
Sergey Kharkovsky ◽  
Reza Zoughi
Keyword(s):  
Compressed Sensing ◽  
Sar Images ◽  
Qualitative Comparison ◽  
Nonuniform Fft

Distributed compressed sensing for despeckling of SAR images

2018 ◽  
Vol 81 ◽  
pp. 138-154 ◽  
Author(s):  
Ahmad Shafiei ◽  
Mojtaba Beheshti ◽  
Ehsan Yazdian
Keyword(s):  
Compressed Sensing ◽  
Sar Images ◽  
Distributed Compressed Sensing

scholarly journals Sparse-View Ultrasound Diffraction Tomography Using Compressed Sensing with Nonuniform FFT

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Shaoyan Hua ◽  
Mingyue Ding ◽  
Ming Yuchi
Keyword(s):  
Inverse Problem ◽  
Fourier Transform ◽  
Compressed Sensing ◽  
Reconstruction Method ◽  
Diffraction Tomography ◽  
Computation Complexity ◽  
Robustness To Noise ◽  
Nonuniform Fft ◽  
Simulation Results ◽  
The Cost

Accurate reconstruction of the object from sparse-view sampling data is an appealing issue for ultrasound diffraction tomography (UDT). In this paper, we present a reconstruction method based on compressed sensing framework for sparse-view UDT. Due to the piecewise uniform characteristics of anatomy structures, the total variation is introduced into the cost function to find a more faithful sparse representation of the object. The inverse problem of UDT is iteratively resolved by conjugate gradient with nonuniform fast Fourier transform. Simulation results show the effectiveness of the proposed method that the main characteristics of the object can be properly presented with only 16 views. Compared to interpolation and multiband method, the proposed method can provide higher resolution and lower artifacts with the same view number. The robustness to noise and the computation complexity are also discussed.

scholarly journals A Hue‐domain filtering technique for enhancing spatial sampled compressed sensing‐based SAR images

2019 ◽  
Vol 13 (3) ◽  
pp. 357-367
Author(s):  
Kadir Sabanci ◽  
Enes Yigit ◽  
Abdurrahim Toktas ◽  
Ahmet Kayabasi
Keyword(s):  
Compressed Sensing ◽  
Sar Images ◽  
Filtering Technique

The Contribution of Phonon-Scattered Electrons to High-Resolution Electron Micrographs of Crystals

1990 ◽  
Vol 48 (1) ◽  
pp. 62-63
Author(s):  
H. Kohl
Keyword(s):  
High Resolution ◽  
Spherical Aberration ◽  
High Resolution Electron Microscopy ◽  
Static Potential ◽  
Qualitative Comparison ◽  
The Past ◽  
Resolution Electron ◽  
High Resolution Images ◽  
High Resolution Electron Micrographs ◽  
Extract Information

High-Resolution Electron Microscopy is able to determine structures of crystals and interfaces with a spatial resolution of somewhat less than 2 Å. As the image is strongly dependent on instrumental parameters, notably the defocus and the spherical aberration, the interpretation of micrographs necessitates a comparison with calculated images. Whereas one has often been content with a qualitative comparison of theory with experiment in the past, one is currently striving for quantitative procedures to extract information from the images [1,2]. For the calculations one starts by assuming a static potential, thus neglecting inelastic scattering processes.We shall confine the discussion to periodic specimens. All electrons, which have only been elastically scattered, are confined to very few directions, the Bragg spots. In-elastically scattered electrons, however, can be found in any direction. Therefore the influence of inelastic processes on the elastically (= Bragg) scattered electrons can be described as an attenuation [3]. For the calculation of high-resolution images this procedure would be correct only if we had an imaging energy filter capable of removing all phonon-scattered electrons. This is not realizable in practice. We are therefore forced to include the contribution of the phonon-scattered electrons.

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