scholarly journals SART-Type Image Reconstruction from a Limited Number of Projections with the Sparsity Constraint

2010 ◽  
Vol 2010 ◽  
pp. 1-9 ◽  
Author(s):  
Hengyong Yu ◽  
Ge Wang
Keyword(s):  
Image Reconstruction ◽  
Haar Wavelet ◽  
Reconstruction Technique ◽  
Algebraic Reconstruction Technique ◽  
Haar Wavelet Transform ◽  
Linear Inverse Problems ◽  
Sparsity Constraints ◽  
Sparsity Constraint ◽  
Simultaneous Algebraic Reconstruction Technique

Based on the recent mathematical findings on solving the linear inverse problems with sparsity constraints by Daubechiesx et al., here we adapt a simultaneous algebraic reconstruction technique (SART) for image reconstruction from a limited number of projections subject to a sparsity constraint in terms of an invertible compression transform. The algorithm is implemented with an exemplary Haar wavelet transform and tested with a modified Shepp-Logan phantom. Our preliminary results demonstrate that the sparsity constraint helps effectively improve the quality of reconstructed images and reduce the number of necessary projections.

scholarly journals SART-Type Image Reconstruction from Overlapped Projections

2011 ◽  
Vol 2011 ◽  
pp. 1-7
Author(s):  
Hengyong Yu ◽  
Changguo Ji ◽  
Ge Wang
Keyword(s):  
Image Reconstruction ◽  
Reconstruction Algorithm ◽  
Reconstruction Technique ◽  
Algebraic Reconstruction Technique ◽  
Multiple Sources ◽  
X Ray ◽  
Type Reconstruction ◽  
Soft Threshold ◽  
Simultaneous Algebraic Reconstruction Technique ◽  
Data Acquisition Process

To maximize the time-integrated X-ray flux from multiple X-ray sources and shorten the data acquisition process, a promising way is to allow overlapped projections from multiple sources being simultaneously on without involving the source multiplexing technology. The most challenging task in this configuration is to perform image reconstruction effectively and efficiently from overlapped projections. Inspired by the single-source simultaneous algebraic reconstruction technique (SART), we hereby develop a multisource SART-type reconstruction algorithm regularized by a sparsity-oriented constraint in the soft-threshold filtering framework to reconstruct images from overlapped projections. Our numerical simulation results verify the correctness of the proposed algorithm and demonstrate the advantage of image reconstruction from overlapped projections.

scholarly journals Variable Weighted Ordered Subset Image Reconstruction Algorithm

2006 ◽  
Vol 2006 ◽  
pp. 1-7 ◽  
Author(s):  
Jinxiao Pan ◽  
Tie Zhou ◽  
Yan Han ◽  
Ming Jiang
Keyword(s):  
Numerical Simulation ◽  
Iterative Reconstruction ◽  
Reconstruction Algorithm ◽  
Reconstruction Technique ◽  
Algebraic Reconstruction Technique ◽  
Reconstruction Algorithms ◽  
Ct Data ◽  
Simultaneous Algebraic Reconstruction Technique ◽  
Algebraic Reconstruction

We propose two variable weighted iterative reconstruction algorithms (VW-ART and VW-OS-SART) to improve the algebraic reconstruction technique (ART) and simultaneous algebraic reconstruction technique (SART) and establish their convergence. In the two algorithms, the weighting varies with the geometrical direction of the ray. Experimental results with both numerical simulation and real CT data demonstrate that the VW-ART has a significant improvement in the quality of reconstructed images over ART and OS-SART. Moreover, both VW-ART and VW-OS-SART are more promising in convergence speed than the ART and SART, respectively.

X-ray topo-tomography studies of linear dislocations in silicon single crystals

2018 ◽  
Vol 51 (6) ◽  
pp. 1616-1622 ◽  
Author(s):  
Victor Asadchikov ◽  
Alexey Buzmakov ◽  
Felix Chukhovskii ◽  
Irina Dyachkova ◽  
Denis Zolotov ◽  
...  
Keyword(s):  
Numerical Analysis ◽  
High Resolution ◽  
Single Crystals ◽  
Complete Characterization ◽  
Reconstruction Technique ◽  
Algebraic Reconstruction Technique ◽  
X Ray ◽  
Laboratory Setup ◽  
Simultaneous Algebraic Reconstruction Technique

This article describes complete characterization of the polygonal dislocation half-loops (PDHLs) introduced by scratching and subsequent bending of an Si(111) crystal. The study is based on the X-ray topo-tomography technique using both a conventional laboratory setup and the high-resolution X-ray image-detecting systems at the synchrotron facilities at KIT (Germany) and ESRF (France). Numerical analysis of PDHL images is performed using the Takagi–Taupin equations and the simultaneous algebraic reconstruction technique (SART) tomographic algorithm.

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