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Visualizing local vector field topology

JOURNAL OF ELECTRONIC IMAGING 2000年第4期9卷 356-367页

作者： Scheuermann, G Hamann, B Joy, KI Kollmann, W Univ Calif Davis Dept Comp Sci Ctr Image Proc & Integrated Computing Davis CA 95616 USA Univ Calif Davis Dept Mech & Aeronaut Engn Davis CA 95616 USA

The visualization of vector fields has attracted much attention over the last decade due to the vast variety of applications in science and engineering. Topological methods have been used intensively for global structure extraction and analysis. Recently, there has been a growing interest in local structure analysis due to its connection to automatic feature extraction and speed. We present an algorithm that extracts local topological structure of arbitrary regions in a two-dimensional vector field. It is based on a mathematical analysis of the topological vector field structure in these regions. The algorithm deals with piecewise linear vector fields and arbitrary polygonal regions. We have tested the algorithm for well known analytic Vector fields and data sets resulting from computational fluid dynamics. (C) 2000 SPIE and IS&T. [S1017-9909(00)01104-1].

关键词： Visualization Visual analytics Computational fluid dynamics Lead Mechanics 3D image processing algorithm development Analytical research Image processing Standards development

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Extensible mark-up language file definition for structured acquisition data storage and transfer

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MEASUREMENT 2008年第3期41卷 320-326页

作者： Bras, Nuno B. Ramos, Pedro M. Serra, A. Cruz Univ Tecn Lisbon Inst Super Tecn Inst Telecommun IST P-1049001 Lisbon Portugal Univ Tecn Lisbon Inst Super Tecn Dept Elect & Comp Engn IST P-1049001 Lisbon Portugal

In many measuring applications where several acquisitions are needed, resulting measurement data could be more useful if measuring information is included as part of resulting data. For example, in advanced measurement algorithms development, it is common to acquire large amounts of organized data that should be clearly identified for automatic post processing. This paper proposes a new eXtensible Mark-up Language (XML) file structure, to be used as a data log file in generic measurement procedures. Benefits like web easiness, low file size requirements and flexible handling by several software platforms are introduced. Specifically developed software to work with the proposed XML structure is presented and the typical acquisition and processing architecture is presented. To demonstrate the proposed XML structure ability, a simple application example applied to power quality assessment was developed. (C) 2006 Elsevier Ltd. All rights reserved.

关键词： measurement software extensible mark-up language (XML) algorithm development

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Comparison between MERIS and regional high-level products in European seas

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REMOTE SENSING OF ENVIRONMENT 2014年 140卷 378-395页

作者： D'Alimonte, Davide Zibordi, Giuseppe Kajiyama, Tamito Berthon, Jean-Francois Univ Nova Lisboa Fac Ciencias & Tecnol Dept Informat Ctr Inteligencia Artificial Quinta Da Torre Caparica Portugal Commiss European Communities Joint Res Ctr Inst Environm & Sustainabil I-21020 Ispra Italy Univ Nova Lisboa Fac Ciencias & Tecnol Ctr Invest Informat & Tecnol Informaca Quinta Da Torre Caparica Portugal

Standard ocean color data products from the Medium Resolution Imaging Spectrometer (MERIS) are compared with equivalent regional products in European seas exhibiting different bio-optical properties: the northern Adriatic Sea, the Baltic Sea and the Western Black Sea (ADRS, BLTS and BLKS, respectively). Investigated quantities are: 1) the algal-2 pigment index, alg2;2) the composite-absorption coefficient of yellow substance and non-pigmented particles at 442 nm, a(dg);and 3) the concentration of the total suspended matter, TSM. Regional data products are created using ocean color inversion schemes based on MultiLayer Perceptron (MLP) neural nets trained with field measurements from the Coastal Atmosphere and Sea Time Series (CoASTS) and Bio-Optical mapping of Marine Properties (BiOMaP) programs. MLP input is the remote sensing reflectance Res at MERIS center-wavelengths specifically selected for different water types in view of minimizing the perturbing effects of inaccurate atmospheric correction on the retrieval of regional data products. A new method is also proposed to define the applicability of regional MLPs to input Res. Results indicate that MERIS alg2 values tend to overestimate the equivalent quantity computed with MLP regional algorithms. The agreement between MERIS and regional TSM data products is significantly better than that reported for alg2 and ad, especially for BLKS. Findings highlight the relevance of using regional inversion schemes to evaluate standard products over extended oceanographic regions as a complement to the analysis of match-ups between marine products measured in situ and derived from space-born data. (C) 2013 Elsevier Inc. All rights reserved.

关键词： Ocean color remote sensing Regional algorithms algorithm development

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Digital Filter Design Using Computer Algebra Systems

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CIRCUITS SYSTEMS AND SIGNAL PROCESSING 2010年第1期29卷 51-64页

作者： Lutovac, Miroslav D. Certic, Jelena D. Milic, Ljiljana D. Univ Belgrade Sch Elect Engn Belgrade 11000 Serbia State Univ Novi Pazar Novi Pazar 36300 Serbia

Digital filter design can be performed very efficiently using modern computer tools. The drawback of the numeric-based tools is that they usually generate a tremendous amount of numeric data, and the user might easily lose insight into the phenomenon being investigated. The computer algebra systems successfully overcome some problems encountered in the traditional numeric-only approach. In this paper, we introduce an original approach to algorithm development and digital filter design using a computer algebra system. The main result of the paper is the development of an algorithm for an infinite impulse response (IIR) filter design that, theoretically, is impossible to be implemented using the traditional approach. We present a step-by-step procedure which includes derivations of closed-form expressions for (1) the transfer functions of the implemented digital filter which contains the algebraic loop;(2) the closed-form expression for computing the number of requested iteration steps;and (3) the error function representing the difference of the output sample values of the new filter and that of the conventional filter. We demonstrate how one can use some already-known multiplierless digital filter as a start-up filter to design a new digital filter whose passband edge frequency can be simply moved by using a single parameter. As a result, we obtain a multiplierless IIR filter, which belongs to the family of low-power digital filters where multipliers are replaced with a small number of adders and shifters.

关键词： Symbolic signal processing Algebraic loop algorithm development Modeling Implementation Multiplierless IIR filter

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Fast algorithm for motion estimation under the varying interframe brightness characteristics

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JOURNAL OF ELECTRONIC IMAGING 2005年第4期14卷 043013.1-043013.7页

作者： Ahmadianpour, F Ahmad, MO Concordia Univ Dept Elect & Comp Engn Montreal PQ H3G 1M8 Canada

A fast two-stage scheme for the search of the motion vectors under varying interframe brightness characteristics, referred to as enhanced motion vectors, is devised. In the first stage of the scheme, a given block and the corresponding blocks in the search window are mapped into the sum-of-pixel value domain, where two subsets of candidate blocks, one consisting the blocks having the DC values closest to the DC value of the block of interest and the other consisting of those having the farthest DC values are selected. In the second stage, the motion vector is determined by employing these subsets and using the mean square error as the matching criterion. Experimental results show that the proposed technique provides a high prediction accuracy with a low computational load. (c) 2005 SPIE and IS&T.

关键词： Motion estimation Video algorithm development Computer engineering Computer simulations

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Stereo matching via selective multiple windows

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JOURNAL OF ELECTRONIC IMAGING 2007年第1期16卷 013012.1-013012.1页

作者： Adhyapak, Satyajit Anil Kehtarnavaz, Nasser Nadin, Mihai Univ Texas Dept Elect Engn Richardson TX 75080 USA

Window-based correlation algorithms are widely used for stereo matching due to their computational efficiency as compared to global algorithms. In this paper, a multiple window correlation algorithm for stereo matching is presented which addresses the problems associated with a fixed window size. The developed algorithm differs from the previous multiple window algorithms by introducing a reliability test to select the most reliable window among multiple windows of increasing sizes. This ensures that at least one window is large enough to cover a region of adequate intensity variations while at the same time small enough to cover a constant depth region. A recursive computation procedure is also used to allow a computationally efficient implementation of the algorithm. The outcome obtained from a standard set of images with known disparity maps shows that the generated disparity maps are more accurate as compared to two popular stereo matching local algorithms. (c) 2007 SPIE and IS&T.

关键词： algorithm development Reliability Venus Image processing Cameras Volume rendering Distortion Light sources and illumination Visualization Electrical engineering

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FLIR ATR using location uncertainty

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JOURNAL OF ELECTRONIC IMAGING 2000年第2期9卷 178-193页

作者： Liu, G Haralick, RM Univ Washington Dept Elect Engn Intelligent Syst Lab Seattle WA 98195 USA

A model-based FLIR ATR algorithm is described. It utilizes boundary contrast for target detection and recognition. Boundary contrast is related to the location uncertainty at target boundary points. A polygon model is used for deriving target centroid location uncertainty caused by the boundary point location uncertainty. The significance of the work lies in the sound mathematical models used in deriving the relationship between contrast and location uncertainty for the boundary points and the relationship between boundary point location uncertainty and centroid location uncertainty Experiment results show significantly improved performance in detection, recognition, and localization. (C) 2000 SPIE and IS&T. [S1017-9909(00)01602-0].

关键词： Detection and tracking algorithms Forward looking infrared Automatic target recognition Target detection Target recognition Signal to noise ratio Image segmentation algorithm development Error analysis Sensors

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Progressive coding of error-diffused bilevel images

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JOURNAL OF ELECTRONIC IMAGING 2003年第1期12卷 173-178页

作者： Lee, CS Park, HW Korea Adv Inst Sci & Technol Dept Elect Engn Taejon 305701 South Korea

We propose a new method to compress error-diffused bilevel images with resolution scalability. This method is a combination of inverse halftoning and rehalftoning. For the inverse halftoning, we combine 2 x 2 dots into a single pixel of a resolution-reduced image, where each pixel has a multilevel value of 0, 1, 2, 3, and 4. After the inverse halftoning, the resolution-reduced multilevel image is halftoned by using an error diffusion algorithm. Thus, the resolution of the error-diffused bilevel images can be reduced by repetition of the inverse halftoning and rehalftoning processes. After reducing the image size, we encode an error-diffused bilevel image progressively from the lowest resolution image to the highest resolution image. To encode higher resolution images, we use the information in the previously coded lower resolution image. Though the compression ratios of the proposed algorithm are similar to those of progressive Joint Bilevel Image Processing Group (JBIG), the image quality of the resolution-reduced image from the proposed algorithm is much better than that from the progressive JBIG. (C) 2003 SPIE and IST.

关键词： Image resolution Image compression Diffusion Binary data Image quality Image processing Quantization algorithm development Computer programming Image filtering

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Developing Multiagent algorithms for Tactical Missions Using Simulation

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IEEE INTELLIGENT SYSTEMS 2013年第1期28卷 42-49页

作者： Komenda, Antonin Vokrinek, Jiri Cap, Michal Pechoucek, Michal Czech Tech Univ Fac Elect Engn Agent Technol Ctr CR-16635 Prague Czech Republic Czech Tech Univ Dept Comp Sci CR-16635 Prague Czech Republic Czech Tech Univ Agent Technol Ctr CR-16635 Prague Czech Republic

The development process and simulation architecture presented here help narrow the gap between how theoretical AI algorithms are traditionally designed and validated and how practical algorithms for controlling roboti... 详细信息

关键词： Digital Simulation Military Systems Mobile Robots Multi Agent Systems Multi Robot Systems Telerobotics Simulated Tactical Missions Robotic Asset Control AI algorithms Simulation Architecture Multiagent algorithm development Actuators Computational Modeling Robot Kinematics Adaptation Models algorithm Design And Analysis Heuristic algorithms Intelligent Systems Multiagent Simulation Tactical Mission Coalition Operations algorithm development

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Method for the automatic detection and segmentation of the spinal canal in computed tomographic images

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JOURNAL OF ELECTRONIC IMAGING 2006年第3期15卷 033007.1-033007.9页

作者： Rangayyan, Rangaraj M. Deglint, Hanford J. Boag, Graham S. Univ Calgary Schulich Sch Engn Dept Elect & Comp Engn Calgary AB T2N 1N4 Canada Univ Calgary Schulich Sch Engn Dept Radiol Calgary AB T2N 1N4 Canada Alberta Childrens Prov Gen Hosp Calgary AB T2T 5C7 Canada

A method for the automatic 3-D segmentation of the spinal canal in computed tomographic (CT) images is presented. The method uses a priori radiological and anatomical information, mathematical morphology, and region-growing methods. The skin and peripheral fat structures are determined by delineating the air and other materials external to the body. Using the fat layer as a reference, the bone structure is segmented. The Hough transform for the detection of circles is applied to a cropped bone edge map that includes the thoracic vertebral structure. The centers of the detected circles are used to derive the information required for the fuzzy connectivity algorithm that is employed to segment the spinal canal. In a preliminary study, the method successfully segmented the spinal canal in eight CT volumes of four patients, with Hausdorff distances with reference to contours drawn independently by a radiologist in the range 1.7 +/- 0.8 mm. (c) 2006 SPIE and IS&T.

关键词： Image segmentation Bone Computed tomography Fuzzy logic 3D image processing Skin Feature extraction Hough transforms Tomography algorithm development

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