Search results for " three-dimensional"
showing 10 items of 323 documents
Hybrid Procedure for Automated Detection of Cracking with 3D Pavement Data
2016
Pavement cracks are considered a major indicator of pavement performance. Because traditional manual crack surveys are dangerous, time consuming, and expensive, technologies have been developed to collect high-speed pavement images, and numerous algorithms have been proposed to detect cracks on pavement surface. The latest PaveVision3D Ultra system (3D Ultra) has been implemented to achieve 30-kHz three-dimensional (3D) scanning rate for 1-mm resolution pavement surface data at highway speed up to 100 km/h (60 mi/h). This paper presents the application of a hybrid procedure for automated crack detection on 3D pavement data collected using 3D Ultra. The procedure combines three different me…
Taking Advantage of Selective Change Driven Processing for 3D Scanning
2013
This article deals with the application of the principles of SCD (Selective Change Driven) vision to 3D laser scanning. Two experimental sets have been implemented: one with a classical CMOS (Complementary Metal-Oxide Semiconductor) sensor, and the other one with a recently developed CMOS SCD sensor for comparative purposes, both using the technique known as Active Triangulation. An SCD sensor only delivers the pixels that have changed most, ordered by the magnitude of their change since their last readout. The 3D scanning method is based on the systematic search through the entire image to detect pixels that exceed a certain threshold, showing the SCD approach to be ideal for this applicat…
Imaging Evaluation of Facial Complex Strut Fractures
2012
High-resolution multidetector computed tomography with multiplanar reformations and 3-D postprocessing often provides the detail necessary for preoperative assessment of facial injuries. Maxillofacial fractures are classified in the following manner: upper face fractures, midface fractures (the most frequent), Le Fort fractures, and lower face or mandible fractures. The facial skeleton is a framework of vertical and horizontal buttresses that ensures a better resistance to trauma, but serves also as reference for maxillofacial surgery to restore facial size and shape. Radiologists should know how to diagnose and report the main types of facial fracture.
A new system for the representation of places hit by disasters
2010
This paper analyses a new system for data collection and management after a disaster. In particular, the system enables to represent what exists in a place, and to visualize the preceding state, in a synoptic vision before and after the event; and also enables the consultation of synthetic information, the possibility of connections to internet sites for further in depth analysis and then the possibility of archiving and retrieving data through researching specific items. This is carried out in a simple and quick way, utilizing a portable device. The obtained product is consultable on site, or otherwise memorized and archived. Because of all these functions, it could be a useful instrument …
Gadoxetate disodium-enhanced magnetic resonance cholangiography for the noninvasive detection of an active bile duct leak after laparoscopic cholecys…
2010
Abstract We report a case of an endoscopically confirmed biliary leak of the common hepatic duct after laparoscopic cholecystectomy that was prospectively diagnosed on gadoxetate disodium-enhanced magnetic resonance cholangiography. Whereas dynamic contrast-enhanced magnetic resonance images during the early vascular phases helped to rule out the causes of possible complications such as seroma, hematoma, or abdominal abscess, delayed hepatobiliary phase imaging was crucial for unequivocal diagnosis and location of the biliary leak. The diagnosis prompted therapeutic endoscopic retrograde cholangiography whereby a polytetrafluoroethylene-covered nitinol stent graft was successfully placed to…
Characterization of a fractured basement reservoir using high-resolution 3D seismic and logging datasets: A case study of the Sab'atayn Basin, Yemen.
2018
The Sab'atayn Basin is one of the most prolific Mesozoic hydrocarbon basins located in central Yemen. It has many oil producing fields including the Habban Field with oil occurrences in fractured basement rocks. A comprehensive seismic analysis of fractured basement reservoirs was performed to identify the structural pattern and mechanism of hydrocarbon entrapment and reservoir characteristics. A 3D post-stack time migration seismic cube and logging data of 20 wells were used and several 2D seismic sections were constructed and interpreted. Depth structure maps were generated for the basement reservoir and overlying formations. The top of the basement reservoir is dissected by a set of NW-S…
Donor/recipient algorithm for management of the middle hepatic vein in right graft live donor liver transplantation
2010
Abstract Background The aim of this study was to delineate an algorithm for donor and recipient criteria and middle hepatic vein (MHV) management in right-graft live-donor liver transplantation (LDLT) on the basis of computerized 3-dimensional computed tomographic image analysis. Methods Data on 94 consecutive right-graft LDLTs were prospectively collected. Graft and remnant data for the first 23 cases were retrospectively evaluated by means of 3-dimensional computed tomographic reconstructions, and on the basis of that preliminary series, a graft selection algorithm using 3 parameters—hepatic vein dominance classification, graft and remnant graft volume/body weight ratios, and congestion v…
Roadmap on digital holography [Invited]
2021
This Roadmap article on digital holography provides an overview of a vast array of research activities in the field of digital holography. The paper consists of a series of 25 sections from the prominent experts in digital holography presenting various aspects of the field on sensing, 3D imaging and displays, virtual and augmented reality, microscopy, cell identification, tomography, label-free live cell imaging, and other applications. Each section represents the vision of its author to describe the significant progress, potential impact, important developments, and challenging issues in the field of digital holography.
Software for automated application of a reference-based method fora posterioridetermination of the effective radiographic imaging geometry
2005
Objectives: Presentation and validation of software developed for automated and accurate application of a reference-based algorithm (reference sphere method: RSM) inferring the effective imaging geometry from quantitative radiographic image analysis. Methods: The software uses modern pattern recognition and computer vision algorithms adapted for the particular application of automated detection of the reference sphere shadows (ellipses) with subpixel accuracy. It applies the RSM algorithm to the shadows detected, thereby providing threedimensional Cartesian coordinates of the spheres. If the three sphere centres do not lie on one line, they uniquely determine the imaging geometry. Accuracy …
Multifacet structure of observed reconstructed integral images.
2005
Three-dimensional images generated by an integral imaging system suffer from degradations in the form of grid of multiple facets. This multifacet structure breaks the continuity of the observed image and therefore reduces its visual quality. We perform an analysis of this effect and present the guidelines in the design of lenslet imaging parameters for optimization of viewing conditions with respect to the multifacet degradation. We consider the optimization of the system in terms of field of view, observer position and pupil function, lenslet parameters, and type of reconstruction. Numerical tests are presented to verify the theoretical analysis.