Current Search:   image reconstruction (x)

View All Items

  • CSV Spreadsheet
(1 - 3 of 3)
Curvelets and the Radon Transform
Title
Curvelets and the Radon Transform.
Creator
Dickerson, Jill, Katsevich, Alexander, Tamasan, Alexandru, Moore, Brian, University of Central Florida
Abstract / Description
Computed Tomography (CT) is the standard in medical imaging field. In this study, we look at the curvelet transform in an attempt to use it as a basis for representing a function. In doing so, we seek a way to reconstruct a function from the Radon data that may produce clearer results. Using curvelet decomposition, any known function can be represented as a sum of curvelets with corresponding coefficients. It can be shown that these corresponding coefficients can be found using the Radon data...
Show moreComputed Tomography (CT) is the standard in medical imaging field. In this study, we look at the curvelet transform in an attempt to use it as a basis for representing a function. In doing so, we seek a way to reconstruct a function from the Radon data that may produce clearer results. Using curvelet decomposition, any known function can be represented as a sum of curvelets with corresponding coefficients. It can be shown that these corresponding coefficients can be found using the Radon data, even if the function is unknown. The use of curvelets has the potential to solve partial or truncated Radon data problems. As a result, using a curvelet representation to invert radon data allows the chance of higher quality images to be produced. This paper examines this method of reconstruction for computed tomography (CT). A brief history of CT, an introduction to the theory behind the method, and implementation details will be provided.
Show less
Date Issued
2013
Identifier
CFE0004674, ucf:49852
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0004674
EFFICIENT CONE BEAM RECONSTRUCTION FOR THE DISTORTED CIRCLE AND LINE TRAJECTORY
Title
EFFICIENT CONE BEAM RECONSTRUCTION FOR THE DISTORTED CIRCLE AND LINE TRAJECTORY.
Creator
Konate, Souleymane, Katsevich, Alexander, University of Central Florida
Abstract / Description
We propose an exact filtered backprojection algorithm for inversion of the cone beam data in the case when the trajectory is composed of a distorted circle and a line segment. The length of the scan is determined by the region of interest , and it is independent of the size of the object. With few geometric restrictions on the curve, we show that we have an exact reconstruction. Numerical experiments demonstrate good image quality.
Date Issued
2009
Identifier
CFE0002530, ucf:47669
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0002530
ELECTRICAL CAPACITANCE VOLUME TOMOGRAPHY OF HIGH CONTRAST DIELECTRICS USING A CUBOID GEOMETRY
Title
ELECTRICAL CAPACITANCE VOLUME TOMOGRAPHY OF HIGH CONTRAST DIELECTRICS USING A CUBOID GEOMETRY.
Creator
Nurge, Mark, Schelling, Patrick, University of Central Florida
Abstract / Description
An Electrical Capacitance Volume Tomography system has been created for use with a new image reconstruction algorithm capable of imaging high contrast dielectric distributions. The electrode geometry consists of two 4 x 4 parallel planes of copper conductors connected through custom built switch electronics to a commercially available capacitance to digital converter. Typical electrical capacitance tomography (ECT) systems rely solely on mutual capacitance readings to reconstruct images of...
Show moreAn Electrical Capacitance Volume Tomography system has been created for use with a new image reconstruction algorithm capable of imaging high contrast dielectric distributions. The electrode geometry consists of two 4 x 4 parallel planes of copper conductors connected through custom built switch electronics to a commercially available capacitance to digital converter. Typical electrical capacitance tomography (ECT) systems rely solely on mutual capacitance readings to reconstruct images of dielectric distributions. This dissertation presents a method of reconstructing images of high contrast dielectric materials using only the self capacitance measurements. By constraining the unknown dielectric material to one of two values, the inverse problem is no longer ill-determined. Resolution becomes limited only by the accuracy and resolution of the measurement circuitry. Images were reconstructed using this method with both synthetic and real data acquired using an aluminum structure inserted at different positions within the sensing region. Comparisons with standard two dimensional ECT systems highlight the capabilities and limitations of the electronics and reconstruction algorithm.
Show less
Date Issued
2007
Identifier
CFE0001591, ucf:47119
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0001591