scholarly journals Preprocessing of Ion Microtomography Data for Improved Reconstruction Quality

1990 ◽  
Vol 217 ◽  
Author(s):  
David L. Weirup ◽  
Arthur E. Pontau ◽  
Arlyn J. Antolak ◽  
Dan H. Morse ◽  
G. Bench ◽  
...  
Keyword(s):  
Mechanical Stability ◽  
Center Of Mass ◽  
Reconstruction Algorithm ◽  
Spatial Filter ◽  
Mass Motion ◽  
Ion Energy ◽  
Reconstruction Quality ◽  
Micron Size ◽  
Pass Through

ABSTRACTIn Ion Microtomography (IMT), material densities are determined from the energy lost by ions as they pass through a specimen. For fine-scale measurements with micron-size beams, mechanical stability and precision of motion can impact the quality of the reconstruction. We describe several preprocessing procedures used to minimize imperfect specimen manipulation, including adjustment of the center of mass motion in sinograms and correction for vertical translations. In addition, the amount of noise in the reconstruction is reduced by utilizing median (as opposed to mean) ion energy loss values for density determinations. Furthermore, particular portions of the sampled image can be enhanced with minimal degradation of spatial resolution by a judicial choice of spatial filter in the reconstruction algorithm. The benefits and limitations of these preprocessing techniques are discussed.

scholarly journals Improved Reconstruction Quality of Bioluminescent Images by Combining SP3Equations and Bregman Iteration Method

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Qiang Wu ◽  
Jinchao Feng ◽  
Kebin Jia ◽  
Xiangyu Wang
Keyword(s):  
Drug Development ◽  
Iteration Method ◽  
Tumor Therapy ◽  
Reconstruction Algorithm ◽  
Reconstruction Algorithms ◽  
Bregman Iteration ◽  
Bioluminescence Tomography ◽  
Practical Applications ◽  
Reconstruction Quality

Bioluminescence tomography (BLT) has a great potential to provide a powerful tool for tumor detection, monitoring tumor therapy progress, and drug development; developing new reconstruction algorithms will advance the technique to practical applications. In the paper, we propose a BLT reconstruction algorithm by combining SP3equations and Bregman iteration method to improve the quality of reconstructed sources. The numerical results for homogeneous and heterogeneous phantoms are very encouraging and give significant improvement over the algorithms without the use of SP3equations and Bregman iteration method.

A Modified Regularized Super-Resolution Reconstruction Algorithm

2014 ◽  
Vol 989-994 ◽  
pp. 2250-2253
Author(s):  
Qi Xie ◽  
Wei Yi Chen
Keyword(s):  
Detection System ◽  
Super Resolution ◽  
Reconstruction Algorithm ◽  
Modulation Transfer ◽  
Resolution Observation ◽  
Reconstruction Quality ◽  
Objective Indicators ◽  
Regularized Method ◽  
Optical Detection System

The super-resolution reconstruction technology is proposed in this paper to overcome the image degradation of shipboard optical detection system. Firstly, establish the super-resolution observation model, then analysis the inadequate of traditional regularized method through the modulation transfer function and proposed a modified regularized algorithm, experimental results shows that the proposed method has the better visual effect and objective indicators. It is a feasible method to enhance reconstruction quality of the system.

scholarly journals Dynamic optimal grasping of a circular object with gravity using robotic soft-fingertips

2016 ◽  
Vol 26 (2) ◽  
pp. 309-323 ◽  
Author(s):  
Rodolfo García-Rodríguez ◽  
Victor Segovia-Palacios ◽  
Vicente Parra-Vega ◽  
Marco Villalva-Lucio
Keyword(s):  
Essential Feature ◽  
Center Of Mass ◽  
Point Contact ◽  
Robotic Hands ◽  
Normal Forces ◽  
Circular Object ◽  
Robot Hands ◽  
Pass Through ◽  
And Control

Abstract Object manipulation usually requires dexterity, encoded as the ability to roll, which is very difficult to achieve with robotic hands based on point contact models (subject to holonomic constraints). As an alternative for dexterous manipulation, deformable contact with hemispherical shape fingertips has been proposed to yield naturally a rolling constraint. It entails dexterity at the expense of dealing with normal and tangential forces, as well as more elaborated models and control schemes. Furthermore, the essential feature of the quality of grasp can be addressed with this type of robot hands, but it has been overlooked for deformable contact. In this paper, a passivity-based controller that considers an optimal grasping measure is proposed for robotic hands with hemispherical deformable fingertips, to manipulate circular dynamic objects. Optimal grasping that minimizes the contact wrenches is achieved through fingertip rolling until normal forces pass through the center of mass of the object, aligning the relative angle between these normal forces. The case of a circular object is developed in detail, though our proposal can be extended to objects with an arbitrary shape that admit a local decomposition by a circular curvature. Simulation and experimental results show convergence under various conditions, wherein rolling and tangent forces become instrumental to achieve such a quality of grasp.

Single Image Dehazing by Predicting Atmospheric Scattering Parameters

2020 ◽  
Vol 2020 (1) ◽  
pp. 74-77
Author(s):  
Simone Bianco ◽  
Luigi Celona ◽  
Flavio Piccoli
Keyword(s):  
Reference Image ◽  
Single Image ◽  
Scattering Parameters ◽  
Image Dehazing ◽  
Atmospheric Scattering ◽  
Local Structures ◽  
Full Reference ◽  
Reconstruction Quality ◽  
Single Image Dehazing

In this work we propose a method for single image dehazing that exploits a physical model to recover the haze-free image by estimating the atmospheric scattering parameters. Cycle consistency is used to further improve the reconstruction quality of local structures and objects in the scene as well. Experimental results on four real and synthetic hazy image datasets show the effectiveness of the proposed method in terms of two commonly used full-reference image quality metrics.

scholarly journals New diagonal micropolarizer arrays designed by an improved model in fourier domain

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jia Hao ◽  
Yan Wang ◽  
Kui Zhou ◽  
Xiaochang Yu ◽  
Yiting Yu
Keyword(s):  
Stokes Parameters ◽  
Fourier Domain ◽  
Extended Model ◽  
Reconstruction Accuracy ◽  
Polarization Imaging ◽  
New Class ◽  
Reconstruction Quality ◽  
Improved Design ◽  
Improved Model

AbstractThe design of micropolarizer array (MPA) patterns in Fourier domain provides an efficient approach to reconstruct and investigate the polarization information. Inspired by Alenin’s works, in this paper, we propose an improved design model to cover both 2 × N MPAs and other original MPAs, by which an entirely new class of MPA patterns is suggested. The performance of the new patterns is evaluated through Fourier domain analysis and numerical simulations compared with the existing MPAs. Particularly, we analyze the reconstruction accuracy of the first three Stokes parameters and degree of linear polarization (DoLP) in detail. The experimental results confirm that the 2 × 2 × 2 MPA provides the highest reconstruction quality of s0, s1, s2 and DoLP in terms of quantitative measures and visual quality, while the 3 × 3 diagonal MPA achieves the state-of-the-art best results in case of single-snapshot systems. The guidance of this extended model and new diagonal MPAs show its massive potential for the division of focal plane (DoFP) polarization imaging applications.

NUCLEON IN NUCLEAR MEDIUM

2009 ◽  
Vol 18 (05n06) ◽  
pp. 1166-1175
Author(s):  
SHASHIKANT C. PHATAK
Keyword(s):  
Standard Procedure ◽  
Center Of Mass ◽  
Critical Density ◽  
Magnetic Interaction ◽  
Nuclear Medium ◽  
Mass Motion ◽  
Field Equations ◽  
Dielectric Model ◽  
Chiral Color Dielectric Model

The behavior of a nucleon in nuclear medium is discussed in Chiral Color Dielectric Model. It is assumed that the nucleons in nuclear medium produces a background dielectric field and the quark and dielectric field equations are solved self consistantly in presence of the dielectric field. A nucleon in nuclear medium is then constructed by means of standard procedure followed in chiral bag models. The corrections due to center of mass motion, color magnetic interaction and meson interaction are included. The calculations show that the nucleon becomes bigger in the medium but its mass does not change much. It is found that beyond a certian density, bound solutions in which quarks are bound in self-generated dielectric field are not possible. Thus, the calculations indicate that there is a critical density beyond which the matter consists of deconfined quarks.

Micro Line Quality Measurement Based on Normally Scanned Digital Image

2012 ◽  
Vol 236-237 ◽  
pp. 839-843
Author(s):  
Xiao Meng Cui ◽  
Guang Xue Chen ◽  
Huan Mei Wang ◽  
Lin Lin Chen
Keyword(s):  
Low Cost ◽  
Quality Measurement ◽  
Digital Printing ◽  
Quality Analysis ◽  
Output Performance ◽  
Micron Size ◽  
Measurement Principle ◽  
Analysis System ◽  
Detection Instrument

In this study we present a new framework to assess line micro quality of multicolor prints adapted to a low-cost image quality analysis system based on common flatbed scanner. The contribution elements including quality metrics, measurement principle, applying methods and detection instrument, which were complemented and sorted in terms of ISO 13660 standard, were described and a case experiment was conducted to survey the output performance of both inkjet printer and xerographic printer, two most popular digital printing technologies. Their qualities were compared in details rendering angle such as width and straightness of line, raggedness and blurriness in line edges, as well as darkness and contrast in color. The results verify the efficiency and shortcomings of the framework. Meanwhile, the metric values let us take an investigation in the character of each digital printing technology in micron size.

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