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Overview of image reconstruction

Description: Image reconstruction (or computerized tomography, etc.) is any process whereby a function, f, on R/sup n/ is estimated from empirical data pertaining to its integrals, ..integral..f(x) dx, for some collection of hyperplanes of dimension k < n. The paper begins with background information on how image reconstruction problems have arisen in practice, and describes some of the application areas of past or current interest; these include radioastronomy, optics, radiology and nuclear medicine, elect… more
Date: April 1, 1980
Creator: Marr, R.B.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Compression of fingerprint data using the wavelet vector quantization image compression algorithm. 1992 progress report

Description: This report describes the development of a Wavelet Vector Quantization (WVQ) image compression algorithm for fingerprint raster files. The pertinent work was performed at Los Alamos National Laboratory for the Federal Bureau of Investigation. This document describes a previously-sent package of C-language source code, referred to as LAFPC, that performs the WVQ fingerprint compression and decompression tasks. The particulars of the WVQ algorithm and the associated design procedure are detailed … more
Date: April 11, 1992
Creator: Bradley, J. N. & Brislawn, C. M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Sloan digital sky survey

Description: The Sloan Digital Sky Survey will produce a detailed digital photometric map of half the northern sky to about 23 magnitude using a special purpose wide field 2.5 meter telescope. From this map we will select {approximately} 10{sup 6} galaxies and 10{sup 5} quasars, and obtain high resolution spectra using the same telescope. The imaging catalog will contain 10{sup 8} galaxies, a similar number of stars, and 10{sup 6} quasar candidates.
Date: April 1, 1994
Creator: Kent, S. M.; Stoughton, C.; Newberg, H.; Loveday, J.; Petravick, D.; Gurbani, V. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Energy & Technology Review, April 1994

Description: The Lawrence Livermore National Laboratory was established in 1952 to do research on nuclear weapons and magnetic fusion energy. Since then, other major programs have been added, including technology transfer, laser science, biology and biotechnology, environmental research and remediation, arms control and nonproliferation, advanced defense technology, and applied energy technology. These programs in turn require research in basic scientific disciplines including chemistry, and materials scien… more
Date: April 1, 1994
Creator: Quirk, W. J.; Canada, J.; de Vore, L.; Gleason, K.; Kirvel, R. D; McElroy, L. et al.
Item Type: Refine your search to only Journal/Magazine/Newsletter
Partner: UNT Libraries Government Documents Department
open access

Virtually distortion-free imaging system for large field, high resolution lithography using electrons, ions or other particle beams

Description: Virtually distortion free large field high resolution imaging is performed using an imaging system which contains large field distortion or field curvature. A reticle is imaged in one direction through the optical system to form an encoded mask. The encoded mask is then imaged back through the imaging system onto a wafer positioned at the reticle position. Particle beams, including electrons, ions and neutral particles, may be used as well as electromagnetic radiation.
Date: April 10, 1991
Creator: Hawryluk, A. M. & Ceglio, N. M.
Item Type: Refine your search to only Patent
Partner: UNT Libraries Government Documents Department
open access

Environment reconstruction for robot navigation

Description: The United State Department of Energy (DOE) is facing a large task in characterizing and remediating waste tanks and their contents. Because of the hazardous materials inside the waste tanks, all of the work must be done remotely. The purpose of this paper is to show how to reconstruct an enclosed environment from various scans of a Laser Range Finder (LRF). The reconstructed environment can then be used by a robot for path planning, and by an operator to monitor the progress of the waste remed… more
Date: April 1, 1994
Creator: Bohn, S. & Thornton, E.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Estimation of fractal dimensions from transect data

Description: Fractals are a useful tool for analyzing the topology of objects such as coral reefs, forest canopies, and landscapes. Transects are often studied in these contexts, and fractal dimensions computed from them. An open question is how representative a single transect is. Transects may also be used to estimate the dimensionality of a surface. Again the question of representativeness of the transect arises. These two issues are related. This note qualifies the conditions under which transect data m… more
Date: April 1, 1994
Creator: Loehle, C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Quantitative autoradiographic microimaging in the development and evaluation of radiopharmaceuticals

Description: Autoradiographic (ARG) microimaging is the method for depicting biodistribution of radiocompounds with highest spatial resolution. ARG is applicable to gamma, positron and negatron emitting radiotracers. Dual or multiple-isotope studies can be performed using half-lives and energies for discrimination of isotopes. Quantitation can be performed by digital videodensitometry and by newer filmless technologies. ARG`s obtained at different time intervals provide the time dimension for determination … more
Date: April 1, 1994
Creator: Som, P. & Oster, Z. H.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Simulation of stellar speckle imaging

Description: Standard FFT-based phase screen generation methods do not accurately model low frequency turbulence characteristics. This paper introduces a new phase screen generation technique which uses low frequency subharmonic methods. The structure functions for this new method match very closely the structure functions of Kolmogorov turbulence theory.
Date: April 1, 1994
Creator: Johansson, E. M. & Gavel, D. T.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Texture splats for 3D vector and scalar field visualization

Description: Volume Visualization is becoming an important tool for understanding large 3D datasets. A popular technique for volume rendering is known as splatting. With new hardware architectures offering substantial improvements in the performance of rendering texture mapped objects, we present textured splats. An ideal reconstruction function for 3D signals is developed which can be used as a texture map for a splat. Extensions to the basic splatting technique are then developed to additionally represent… more
Date: April 6, 1993
Creator: Crawfis, R. A. & Max, N.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Structural and Morphological Properties of Carbon Supports: Effect of Catalyst degradation, ECS Transactions 33(1), 425 (2010)

Description: The object of this work was to identify correlations between performance losses of Pt electrocatalysts on carbon support materials and the chemical and morphological parameters that describe them. Accelerated stress testing, with an upper potential of 1.2 V, was used to monitor changes to cathode properties, including kinetic performance and effective platinum surface area losses. The structure and chemical compositions were studied using X-ray Photoelectron Spectroscopy and Scanning Electron M… more
Date: April 1, 2011
Creator: Patel, A.; Artyushkova, K.; Atanassov, P.; Young, A.; Dutta, M.; Ahmad, Z. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Linear adaptive noise-reduction filters for tomographic imaging: Optimizing for minimum mean square error

Description: This thesis solves the problem of finding the optimal linear noise-reduction filter for linear tomographic image reconstruction. The optimization is data dependent and results in minimizing the mean-square error of the reconstructed image. The error is defined as the difference between the result and the best possible reconstruction. Applications for the optimal filter include reconstructions of positron emission tomographic (PET), X-ray computed tomographic, single-photon emission tomographic,… more
Date: April 1, 1993
Creator: Sun, W. Y.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries Government Documents Department
open access

New formulation for interferometric synthetic aperture radar for terrain mapping

Description: The subject of interferometric synthetic aperture radar (IFSAR) for high-accuracy terrain elevation mapping continues to gain importance in the arena of radar signal processing. Applications to problems in precision terrain-aided guidance and automatic target recognition, as well as a variety of civil applications, are being studied by a number of researchers. Not unlike many other areas of SAR processing, the subject of IFSAR can at first glance appear to be somewhat mysterious. In this paper … more
Date: April 1, 1994
Creator: Jakowatz, C. V. Jr.; Wahl, D. E.; Eichel, P. H. & Thompson, P. A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

The wavelet/scalar quantization compression standard for digital fingerprint images

Description: A new digital image compression standard has been adopted by the US Federal Bureau of Investigation for use on digitized gray-scale fingerprint images. The algorithm is based on adaptive uniform scalar quantization of a discrete wavelet transform image decomposition and is referred to as the wavelet/scalar quantization standard. The standard produces archival quality images at compression ratios of around 20:1 and will allow the FBI to replace their current database of paper fingerprint cards w… more
Date: April 1, 1994
Creator: Bradley, J. N. & Brislawn, C. M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Final Report 2007: DOE-FG02-87ER60561

Description: This project involved a multi-faceted approach to the improvement of techniques used in Positron Emission Tomography (PET), from radiochemistry to image processing and data analysis. New methods for radiochemical syntheses were examined, new radiochemicals prepared for evaluation and eventual use in human PET studies, and new pre-clinical methods examined for validation of biochemical parameters in animal studies. The value of small animal PET imaging in measuring small changes of in vivo bioch… more
Date: April 26, 2007
Creator: Kilbourn, Michael R
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Volumetric Video Motion Detection for Unobtrusive Human-Computer Interaction

Description: The computer vision field has undergone a revolution of sorts in the past five years. Moore's law has driven real-time image processing from the domain of dedicated, expensive hardware, to the domain of commercial off-the-shelf computers. This thesis describes their work on the design, analysis and implementation of a Real-Time Shape from Silhouette Sensor (RT S{sup 3}). The system produces time-varying volumetric data at real-time rates (10-30Hz). The data is in the form of binary volumetric i… more
Date: April 1, 2002
Creator: SMALL, DANIEL E.; LUCK, JASON P. & CARLSON, JEFFREY J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Asynchronous global optimization techniques for medium and large inversion problems

Description: We discuss global optimization procedures adequate for seismic inversion problems. We explain how to save function evaluations (which may involve large scale ray tracing or other expensive operations) by creating a data base of information on what parts of parameter space have already been inspected. It is also shown how a correct parallel implementation using PVM speeds up the process almost linearly with respect to the number of processors, provided that the function evaluations are expensive… more
Date: April 1, 1995
Creator: Pereyra, V.; Koshy, M. & Meza, J.C.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Reconstruction of mechanically recorded sound from an edison cylinder using three dimensional non-contact optical surface metrology

Description: Audio information stored in the undulations of grooves in a medium such as a phonograph disc record or cylinder may be reconstructed, without contact, by measuring the groove shape using precision optical metrology methods and digital image processing. The viability of this approach was recently demonstrated on a 78 rpm shellac disc using two dimensional image acquisition and analysis methods. The present work reports the first three dimensional reconstruction of mechanically recorded sound. Th… more
Date: April 20, 2004
Creator: Fadeyev, V.; Haber, C.; Maul, C.; McBride, J.W. & Golden, M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Final report: SIAM [Society for Industrial and Applied Mathematics] Conference on Linear Algebra and its Applications, October 23-26, 2000

Description: The Society for Industrial and Applied Mathematics (SIAM) and the SIAM Activity Group in Linear Algebra in conjunction with the International Linear Algebra Society (ILAS) held the SIAM Conference on Linear Algebra and its applications on October 23-26, 2000 at the McKimmon Conference Center on the campus of North Carolina State University in Raleigh, North Carolina. The goals of this conference were to highlight the central role of linear algebra in many problems of mathematics and the applied… more
Date: April 6, 2001
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

An Adaptive B-Spline Method for Low-order Image Reconstruction Problems - Final Report - 09/24/1997 - 09/24/2000

Description: A common problem in signal processing is to estimate the structure of an object from noisy measurements linearly related to the desired image. These problems are broadly known as inverse problems. A key feature which complicates the solution to such problems is their ill-posedness. That is, small perturbations in the data arising e.g. from noise can and do lead to severe, non-physical artifacts in the recovered image. The process of stabilizing these problems is known as regularization of which… more
Date: April 11, 2000
Creator: Li, Xin; Miller, Eric L.; Rappaport, Carey & Silevich, Michael
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Multispectral image fusion for detecting land mines

Description: This report details a system which fuses information contained in registered images from multiple sensors to reduce the effects of clutter and improve the ability to detect surface and buried land mines. The sensor suite currently consists of a camera that acquires images in six bands (400nm, 500nm, 600nm, 700nm, 800nm and 900nm). Past research has shown that it is extremely difficult to distinguish land mines from background clutter in images obtained from a single sensor. It is hypothesized, … more
Date: April 1, 1995
Creator: Clark, G. A.; Sengupta, S. K.; Aimonetti, W. D.; Roeske, F.; Donetti, J. G.; Fields, D. J. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Membrane separation systems---A research and development needs assessment

Description: Industrial separation processes consume a significant portion of the energy used in the United States. A 1986 survey by the Office of Industrial Programs estimated that about 4.2 quads of energy are expended annually on distillation, drying and evaporation operations. This survey also concluded that over 0.8 quads of energy could be saved in the chemical, petroleum and food industries alone if these industries adopted membrane separation systems more widely. Membrane separation systems offer si… more
Date: April 1, 1990
Creator: Baker, R.W. (Membrane Technology and Research, Inc., Menlo Park, CA (USA)); Cussler, E.L. (Minnesota Univ., Minneapolis, MN (USA). Dept. of Chemical Engineering and Materials Science); Eykamp, W. (California Univ., Berkeley, CA (USA)); Koros, W.J. (Texas Univ., Austin, TX (USA)); Riley, R.L. (Separation Systems Technology, San Diego, CA (USA)) & Strathmann, H. (Fraunhofer-Institut fuer Grenzflaech
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Looking at large data sets using binned data plots

Description: This report addresses the monumental challenge of developing exploratory analysis methods for large data sets. The goals of the report are to increase awareness of large data sets problems and to contribute simple graphical methods that address some of the problems. The graphical methods focus on two- and three-dimensional data and common task such as finding outliers and tail structure, assessing central structure and comparing central structures. The methods handle large sample size problems … more
Date: April 1, 1990
Creator: Carr, D. B.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

(Manufacturing of the 40/30 mm gated image intensifier tube)

Description: One of EG G's customers is attempting to find a manufacturer to make the 40/30 mm gated image intensifier tube. A request for quotation had been sent out to a number of manufacturers. The tube performance required was not fully defined and the replies, as expected, came back with caveats to cover the areas of uncertainty. The trip was undertaken to discuss the project, to more clearly define the areas of uncertainty and to evaluate the capabilities of the manufacturers.
Date: April 27, 1990
Creator: Vine, B. H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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