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Conference on algorithms and Technologies for Multispectral, Hyperspectral, and Ultraspectral Imagery VIII

作者： Abel, MD Zenner, JM Petrick, GA Buswell, AT Pilati, ML Czyzewski, WR Alessandro, LP Weaver, SK Ball Aerospace & Technologies Corp. (United States) U.S. Air Force National Air Intelligence Ctr. (United States)

ISBN: (纸本)0819444758

A combined radiative transfer model and statistical approach to atmospheric correction of hyperspectral data, called MODFULL, has been developed and tested. MODFULL retrieves in-scene water vapor and aerosol (without the aid of dark pixels) which it uses for atmospheric correction. It also provides the user with checks on spectral registration of the hyperspectral data being processed. A description of this model will be given along with an analysis of its strengths and weaknesses. A summary of test results using comparisons with an industry standard Empirical Line Method (ELM) correction will also be presented.

关键词： Aerosols Atmospheric corrections Data modeling Atmospheric modeling Reflectivity Absorption Data corrections Atmospheric particles algorithm development Sensors

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Optimal multi-tone bit allocation for fixed rate video transmission over ADSL

Optimal multi-tone bit allocation for fixed rate video trans...

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Conference on Visual Communications and Image Processing 2002

作者： Antonini, M Moureaux, I Lecuire, V CNRS and Univ. de Nice-Sophia Antipolis (France) CNRS and Univ. Henri Poincare (France)

ISBN: (纸本)0819444111

In this paper we propose a novel approach for the bit allocation performed in an ADSL modulator. This new method is based on the observation that the transmission speed using ADSL strongly depends on the distance between the central office and the subscriber's side and does not permit real-time transmission for high bitrate video on long distances. The algorithm we develop takes into account the characteristics of a video sequence and distributes the channel error according to visual sensitivity. This method involves variable transmission Bit Error Rate.

关键词： Video Signal to noise ratio Modulation Visualization Quadrature amplitude modulation algorithm development Computer programming Semantic video Modulators Standards development

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Retinex processing for automatic image enhancement

Retinex processing for automatic image enhancement

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Conference on Human Vision and Electronic Imaging VII

作者： Rahman, ZU Jobson, DJ Woodell, GA Coll William & Mary Dept Comp Sci Williamsburg VA 23187 USA

ISBN: (纸本)0819444022

In the last published concept (1986) for a Retinex computation, Edwin Land introduced a center/surround spatial form, which was inspired by the receptive field structures of neurophysiology. With this as our starting point we have over the years developed this concept into a full scale automatic image enhancement algorithm the 'Multi-Scale Retinex with Color Restoration (MSRCR) which combines color constancy with local contrast/lightness enhancement to transform digital images into renditions that approach the realism of direct scene observation. The MSRCR algorithm has proven to be quite general purpose, and very resilient to common forms of image pre-processing such as reasonable ranges of gamma and contrast stretch transformations. More recently we have been exploring the fundamental scientific implications of this form of image processing namely: (i) the visual inadequacy of the linear representation of digital images, (ii) the existence of a canonical or statistical ideal visual image, and (iii) new measures of visual quality based upon these insights derived from our extensive experience with MSRCR enhanced images. The lattermost serves as the basis for future schemes for automating visual assessment-a primitive first step in bringing visual intelligence to computers.

关键词： Visualization Image enhancement Image processing Information visualization Image quality Image visualization Digital image processing Human vision and color perception Light sources and illumination algorithm development

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Feedback control of an active material adaptive tuned vibration absorber using relative phase.

Feedback control of an active material adaptive tuned vibrat...

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Smart Structures and Materials 2002 Conference

作者： Williams, KA Chiu, GTC Bernhard, RJ Univ Alabama Dept Mech Engn Tuscaloosa AL 35487 USA

ISBN: (纸本)0819444499

Adaptive tuned vibration absorbers for attenuation of harmonic vibration may be realized through the use of active materials in absorber designs. For example, the variable elastic modulus of shape memory alloy may be used to incorporate variable springs in an absorber, such that the absorber natural frequency may be on-line tuned. The difficulty then becomes the control of the tuned condition of the absorber. One method for controlling the tuned condition of the absorber is to drive the relative phase between the primary system and the absorber to a desired value. The classical phase-locked loop is one method that might be used to achieve this control goal. An alternative method is to utilize a simple PI controller that uses the relative phase as an error signal. The map between the control input to the active material elements and the resulting relative phase can be modeled as a first-order linear system in series with a static nonlinearity with certain characteristics. This paper presents an analysis of the stability of the phase tracking of an adaptive tuned vibration absorber made of active material. The necessary characteristics for the map between the control signal and the resulting relative phase are presented. A control algorithm is developed that results in asymptotic stability of the system in the presence of an uncertain fixed excitation frequency. Results of implementation of an experimental ATVA on a primary system are presented.

关键词： Shape memory alloys Control systems algorithm development Calcium Data modeling Systems modeling Feedback control Mathematical modeling Signal attenuation Mechanical engineering

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Pattern recognition in the database of a mask layout

Pattern recognition in the database of a mask layout

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Conference on Photomask and Next-Generation Lithography Mask Technology IX

作者： Chen, SY Lynn, EC Shin, JJ Mentor Graphics Taiwan Ltd. (Taiwan) Taiwan Semiconductor Manufacturing Co. Ltd. (Taiwan)

ISBN: (纸本)0819445177

The request of pattern recognition has been frequently brought up by both mask and wafer engineers. Despite of different intentions, pattern recognition is usually the first step of many applications and hence plays a major role to accomplish certain tasks. For the purpose of this work, pattern recognition is defined as searching a specific polygon or a group of particular patterns from a chip layout. Operator scan is truly not an efficient approach of pattern recognition, in particular, for cases with huge design database of advanced semiconductor integrated circuits. Obviously, an automation system of pattern recognition is necessary and benefits the data preparation process. Two categories of pattern recognition are discussed in the present study, "fuzzy search" and "exact match." Each category has its own application, but the searching algorithms could be much different. Details of searching algorithms are given for both categories of pattern recognition. Due to the nature of industrial standard, the scope of the present application is limited to database with GDSII format. Hence, coordinate searching is internally used inside the searching engine.

关键词： Pattern recognition Genetic algorithms Fuzzy logic Detection and tracking algorithms Optical proximity correction Databases Photomasks Semiconducting wafers algorithm development Visualization

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Retrieval of trace species profiles using balloon-borne occultation spectra.

Retrieval of trace species profiles using balloon-borne occu...

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8th International Symposium on Atmospheric and Ocean Optics - Atmospheric Physics

作者： Eremenko, MN Payan, S Camy-Peyret, C Kataev, MY Mitsel, AA Tomsk Univ Automat Control Syst & Radioelect Tomsk Russia

ISBN: (纸本)0819444332

Remote sensing of atmospheric state parameters (such as temperature and mixing ratio profiles, trace gas column amounts) requires fast and accurate radiative transfer calculations. For the retrieval of a large number of species, a set of micro-windows containing single lines of the target species is generally used. However, spectral signatures of several species like CFCs are often covering large micro-windows and a forward calculation in a wide spectral region must be performed to access the concentration of these species in the atmosphere using remote sensing techniques. If line-by-line calculation of the absorption cross section is used, the calculation time is important and not dedicated to operational analysis of spectral atmospheric measurements. A new retrieval algorithm has been developed at LPMA to determine vertical profiles in such conditions. In order to decrease the calculation time, pre-calculated absorption cross section look-up tables are used, allowing quick generation of absorption cross section without significant loss of accuracy. The simulation of the measurements on wide spectral region is very sensitive to instrumental characteristics like spectral variation of the instrument line shape or accurate calibration of the spectra and the corresponding modelling problems will be carefully examined. A description of the new version of the LPMA atmospheric retrieval algorithm will be presented illustrated by results obtained from balloon solar occultation spectra recorded in the stratosphere. Retrievals of ClONO2 using independent spectroscopic input will be presented and analysis in term of inorganic chlorine burden.

关键词： Absorption algorithm development Databases Chlorine Spectroscopy Atmospheric sensing Remote sensing Sun Clouds Fourier transforms

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Computer simulation of line profile and data processing in diffraction experiments

Computer simulation of line profile and data processing in d...

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5th International Workshop on Nondestructive Testing and Computer Simulations in Science and Engineering

作者： Gurova, T Teodósio, JR Assis, JT Monin, VI Titovets, YF Fed Univ Rio De Janeiro Rio De Janeiro Brazil

ISBN: (纸本)0819443662

Data processing of a line profile is one of the most important procedures in a diffraction experiment. The main problem is connected with the presence of K-alpha1 and K-alpha2 wave components in X-ray radiation that produces the principal errors while determining the angular position or width of a diffraction line. By using computer methods in data processing, it is possible to realize effectively the Rachinger method of separation of K-alpha1 and K-alpha2 components. In this paper, computer simulation of diffraction profiles was used to analyze the possibilities of the Rachinger method. A separation criterion based on searching true principal parameters, namely the distance and intensity interrelation between K-alpha1 and K-alpha2 components, was proposed. The separation method is incorporated into the data processing for a portable diffractometer developed by authors from Polytechnical Institute (UERJ). The data processing includes control of an experimental procedure for the case of macro and microstress measurements.

关键词： Diffraction Data processing Computer simulations X-rays Analytical research algorithm development Nondestructive evaluation Process control X-ray diffraction Physics

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Parallel implementation of the adaptive neighborhood contrast enhancement technique using histogram-based image partitioning

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JOURNAL OF ELECTRONIC IMAGING 2001年第3期10卷 804-813页

作者： Rangayyan, RM Alto, H Gavrilov, D Univ Calgary Dept Elect & Comp Engn Calgary AB Canada Univ Calgary Netera Alliance Calgary AB Canada

An adaptive neighborhood contrast enhancement (ANCE) technique was developed to improve the perceptibility of features in digitized mammographic images for use in breast cancer screening. The computationally intensive algorithm was implemented on a cluster of 30 COMPAQ Alpha processors using the message passing interface. The parallel implementation of the ANCE technique utilizes histogram-based image partitioning with each partition consisting of a list of gray-level values. The master processor allots one set of gray-level values to each slave processor. Each slave locates all possible seed pixels in the image with the designated gray-level values, grows a region around each pixel, enhances the contrast of the seed and any redundant seed pixels if required, and returns the results to the master. The master then sends a new set of gray-level values to the slave for processing. The subdivision of the original image based on gray-level values guarantees that slave processors do not process the same pixel, and is particularly well suited to the characteristics of the ANCE algorithm. The parallelism value of the problem is in the range of 16-20;the performance did not improve significantly when more than 16 processors were used. The performance declined when more than 20 processors were used. The result is a substantial improvement in processing time, leading to the enhancement of 4 Kx4 K pixel images in the range of 30-90 s. (C) 2001 SPIE and IS&T.

关键词： Image processing Mammography Image enhancement Breast cancer Biopsy Sun Cancer algorithm development Breast Image contrast enhancement

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Identity-plus-row matrix decomposition and its application in design of parallel projection algorithms

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JOURNAL OF ELECTRONIC IMAGING 2001年第3期10卷 814-824页

作者： Li, HZ Shi, HC Univ Missouri Dept Comp Engn & Comp Sci Columbia MO 65211 USA

Many image processing operations can be abstracted into matrix operations. With the help of matrix analysis, we can understand the inherent properties of the operations and thus design better algorithms. In this paper, we propose a matrix decomposition method referred to as identity-plus-row decomposition, The decomposition is particularly useful in design of parallel projection algorithms on mesh-connected computers. Projection is a frequently used process in image processing and visualization. In volume graphics, projection is used to render the essential content of a three-dimensional volume onto a two-dimensional image plane. For Radon transform, projection is used to transform the image space into a parameter space. By applying the identity-plus-row matrix decomposition method, we solve the data redistribution problem due to the irregular data access patterns present in those applications on single instruction stream, multiple data stream (SIMD) mesh-connected computers, developing fast algorithms for volume rendering and Radon transform on SIMD mesh-connected computers. (C) 2001 SPIE and IS&T.

关键词： Image processing Radon transform Array processing 3D image processing Matrices Binary data Imaging systems algorithm development Computing systems Visualization

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Efficiently tracking a moving object in two-dimensional image space

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JOURNAL OF ELECTRONIC IMAGING 2001年第3期10卷 785-793页

作者： Barrett, SF Wright, CHG Zwick, H Wilcox, M Rockwell, BA Naess, E Univ Wyoming Dept Elect Engn Laramie WY 82071 USA USAF Acad Dept Elect Engn Colorado Springs CO 80840 USA USA Res Detachment Walter Reed Army Inst Res Brooks AFB TX 78235 USA USAF Acad Dept Biol Colorado Springs CO 80840 USA USAF Human Effectiveness Directorate Opt Radiat Branch Brooks AFB TX 78235 USA

A tracking algorithm has been developed to efficiently track a moving object in two-dimensional image space. The algorithm employs a limited exhaustive template matching scheme that combines the accuracy of an exhaustive search with the computational efficiency of a coarse-fine template matching scheme, The overall result is an accurate, time-efficient tracking algorithm. After providing a theoretical discussion of the algorithm, three separate biomedical applications of the algorithm are described. (1) stabilizing an irradiating laser on the retinal surface for photocoagulation treatment, (2) measuring target fixation eye movement to construct pattern densities at the retina, and (3) tracking a rat swimming in a Morris Water Maze for psychophysiological studies. Results for each application is provided, The paper concludes Vith a discussion of the relative merits of the tracking algorithm and recommendations for methods to improve the performance of the algorithm. (C) 2001 SPIE and IS&T.

关键词： Detection and tracking algorithms Retina algorithm development Video Eye Head Cameras Laser coagulation Scanning laser ophthalmoscopy Electrical engineering

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