Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 14 of 14 for “"distortion correction"”.
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Distortion Correction in LODOX StatScan X-Ray Images
… a background and description of a method of distortion correction in x-ray images produced by the LODOX StatScan machine. The distortion correction of an object's x-ray image is of particular interest in the medical field, particularly for prosthetics, implants, and orthopedic work. It is …
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Distortion correction in LODOX Statscan X-ray images
Word Processed copy. Includes bibliographical references (leaves 55-56).
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Distortion correction in magnetic resonance imaging using the simulated point spread function
Geometric distortion is a highly prevalent issue for echo-planar imaging (EPI), due to long readout times and field inhomogeneity. Previously, the measured point spread function (PSF) has been shown to be effective in correcting this distortion. In this work, we reconstruct an image quickly and …
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Quantitative susceptibility mapping and susceptibility-based distortion correction of echo planar images
… of EPI and structural images is difficult due to distortions in EPI data. These distortions are caused by magnetic field perturbations that arise from changes in magnetic susceptibility throughout the object of interest. Distortion is typically corrected by acquiring an additional scan called a …
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Distortion Correction for Non-Planar Deformable Projection Displays through Homography Shaping and Projected Image Warping
… for projection comes geometric and radiometric distortions. This work dwells on correcting geometric distortions occurring when images or video frames are projected onto static and deformable non-planar display surfaces. The distortion-correction process involves (i) detecting feature points …
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Gradient characterization in magnetic resonance imaging
… the MR gradient system that may cause gradient distortion. Additionally, high field MR scans are prone to inhomogeneities that disturb the gradient system. Regardless of the source, gradient characterization provides a simple tool for distortion correction. An improved method, named the …
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Reconstruction of 3D scenes from pairs of uncalibrated images. Creation of an interactive system for extracting 3D data points and investigation of automatic techniques for generating dense 3D data maps from pairs of uncalibrated images for remote sensing applications.
… In addition, a contribution to estimating lens distortion correction by a Levenberg Marquard based method is presented; generating data strings for straight lines which are essential input for estimating lens distortion correction. The remainder of the thesis presents correlation based methods …
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Reconstruction of 3D scenes from pairs of uncalibrated images. Creation of an interactive system for extracting 3D data points and investigation of automatic techniques for generating dense 3D data maps from pairs of uncalibrated images for remote sensing applications
… In addition, a contribution to estimating lens distortion correction by a Levenberg Marquard based method is presented; generating data strings for straight lines which are essential input for estimating lens distortion correction. The remainder of the thesis presents correlation based methods …
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Robust Video Object Tracking via Camera Self-calibration
… camera self-calibration and automatic radial distortion correction based on tracking of walking persons is designed to convert multiple object tracking into 3D space. (2) An adaptive model that learns online a relatively long-term appearance change of each target is proposed for robust 3D …
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Real-Time Implementation of Vision Algorithm for Control, Stabilization, and Target Tracking for a Hovering Micro-UAV
… homography, color segmentation, radial distortion correction, and an extended Kalman filter with a standard-deviation outlier rejection technique (SORT). This implementation was designed specifically for use as an on-board vision solution in determining movement of small unmanned air …
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Material-Specific Computed Tomography for Molecular X-Imaging in Biomedical Research
… photon counting CT, and photon counting CT data distortion correction approach based on deep learning. X-ray fluorescence molecular imaging (XFMI) has shown great promise as a low-cost molecular imaging modality for clinical and pre-clinical applications with high sensitivity. In this study, the …
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SCALABLE MATCHING OF DEFORMED IMAGES
… to ex-vivo hemisphere registration, geometry distortion correction for echo-planar MRI, and gradient-free landmark-guided registration for lung CT scans.
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Geometry model for marker-based localisation
… context. Amain contribution is in perspective distortion correction in which distortions aremodeled in all its forms with correction process. This is essential when dealingwith measurements and shapes in images. Because of the lack of robustness indepth sensing using monocular vision-based …
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Strategies for Artifact Correction and Motion Monitoring in MRI Through Innovations in Radiofrequency Coil Design
… and result in image artifacts such as geometric distortions and signal loss. B_0 inhomogeneities can be corrected through a process called shimming, which generates magnetic field patterns that have a similar spatial distribution but are opposite in polarity. 2\nd order spherical harmonic …