检索结果-内蒙古大学图书馆

Error factors in the rotational symmetric triangulation sensor

Yi Qi Yi Biao Xue Bao/Chinese Journal of Scientific Instrument 2007年第SUPPL. 3期28卷 9-13页

作者： Wang, Lei Gao, Jun Wang, Xiaojia Eckstein, Johannes Ott, Peter Lab. of Image Information Processing School of Computer and Information Hefei University of Technology Hefei 230009 China Hochschule Heilbronn Heilbronn D-74081 Germany Dept. of Mechanical and Electrical Engineering Xiamen University Xiamen 361005 China

Rotationally symmetric triangulation (RST) sensor has more flexibility and less uncertainty than traditional laser triangulation because of the abaxial rotationally symmetric optical system. Error and uncertain factors in this kind of sensors are studied in this paper, especially the system uncertainty factors from the error of manufacturing and adjustment. Geometric error model of RST which met the Scheimpflug condition is presented. Based on this model, it is shown that an incident laser spot which departures the rotational axis of the optical system will influent the measurement result quite a lot, and also a tilt detector and optical system aberration will have a smaller effect. At last, Simulation and experiment results are given to verify the analysis.

关键词： Error factors Laser triangulation sensor Optical measurement Rotational symmetric

来源：评论

学校读者我要写书评

暂无评论

Vignetting and illumination compensation for omni-directional image generation on spherical coordinate

Vignetting and illumination compensation for omni-directiona...

引用

16th International Conference on Artificial Reality and Telexistence - Workshops, ICAT 2006

作者： Kim, Yu-Na Sim, Dong-Gyu Image Processing Systems Laboratory Dept. of Computer Engineering Kwangwoon University

ISBN: (纸本)076952754X

This paper presents an omni-directional image generation algorithm on spherical coordinates by compensating vignetting and illumination effects. The algorithm generates an omni-directional image by transforming each planar image to the spherical image. In this paper, vignetting and illumination compensation methods are proposed for realistic and seamless omni-directional video systems. We can synthesize any point of view from the stitched omnidirectional image on the spherical coordinates. Experimental results show that the proposed algorithm can effectively generate the omni-directional image and with real video sequences. Furthermore, the proposed omni-directional system with vignetting and illumination compensation is shown to be approximately 14 dB better than that which does not consider the said effects. © 2006 IEEE.

关键词： Spheres

来源：评论

学校读者我要写书评

暂无评论

Rule-based reasoning for semantic image segmentation and interpretation

Rule-based reasoning for semantic image segmentation and int...

引用

1st International Conference on Semantic and Digital Media Technologies, SAMT 2006

作者： Berka, Petr Athanasiadis, Thanos Avrithis, Yannis Dept. of Information and Knowledge Engineering University of Economics Prague Czech Republic Image Video and Multimedia Systems Laboratory National Technical University Athens Greece

In this paper, we propose the application of rulebased reasoning for knowledge assisted image segmentation and object detection. A region merging approach is proposed based on fuzzy labeling and not on visual descriptors, while reasoning is used in evaluation of dissimilarity between adjacent regions according to rules applied on local information.

关键词： Semantics

来源：评论

学校读者我要写书评

暂无评论

LANDING AN UNMANNED AIR VEHICLE: VISION BASED MOTION ESTIMATION AND NONLINEAR CONTROL

引用

Asian Journal of Control 2008年第3期1卷

作者： Omid Shakernia Yi Ma T. John Koo Shankar Sastry Dept. of Electrical Engineering & Computer Science University of California at Berkeley Berkeley CA94720-1774 U.S.A. Tak-Kuen John Koo received the B.Eng. degree in 1992 in Electronic Engineering and the M.Phil. in 1994 in Information Engineering both from the Chinese University of Hong Kong. From 1994 to 1995 he was a graduate student in Signal and Image Processing Institute at the University of Southern California. He is currently a Ph.D. Candidate in Electrical Engineering and Computer Sciences at the University of California at Berkeley. His research interests include nonlinear control theory hybrid systems inertial navigation systems with applications to unmanned aerial vehicles. He received the Distinguished M.Phil. Thesis Award of the Faculty of Engineering The Chinese University of Hong Kong in 1994. He was a consultant of SRI International in 1998. Currently he is the team leader of the Berkeley AeRobot Team and a delegate of The Graduate Assembly University of California at Berkeley. He is a student member of IEEE and SIAM. S. Shankar Sastry received his Ph.D. degree in 1981 from the University of California Berkeley. He was on the faculty of MIT from 1980-82 and Harvard University as a Gordon McKay professor in 1994. He is currently a Professor of Electrical Engineering and Computer Sciences and Bioengineering and Director of the Electronics Research Laboratory at Berkeley. He has held visiting appointments at the Australian National University Canberra the University of Rome Scuola Normale and University of Pisa the CNRS laboratory LAAS in Toulouse (poste rouge) and as a Vinton Hayes Visiting fellow at the Center for Intelligent Control Systems at MIT. His areas of research are nonlinear and adaptive control robotic telesurgery control of hybrid systems and biological motor control. He is a coauthor (with M. Bodson) of “Adaptive Control: Stability Convergence and Robustness Prentice Hall 1989.” and (with R. Murray and Z. Li) of “A Mathematical Introduction to Robotic Manipulati

In this paper, we use computer vision as a feedback sensor in a control loop for landing an unmanned air vehicle (UAV) on a landing pad. The vision problem we address here is then a special case of the classic ego-motion estimation problem since all feature points lie on a planar surface (the landing pad). We study together the discrete and differential versions of the ego-motion estimation, in order to obtain both position and velocity of the UAV relative to the landing pad. After briefly reviewing existing algorithm for the discrete case, we present, in a unified geometric framework, a new estimation scheme for solving the differential case. We further show how the obtained algorithms enable the vision sensor to be placed in the feedback loop as a state observer for landing control. These algorithms are linear, numerically robust, and computationally inexpensive hence suitable for real-time implementation. We present a thorough performance evaluation of the motion estimation algorithms under varying levels of image measurement noise, altitudes of the camera above the landing pad, and different camera motions relative to the landing pad. A landing controller is then designed for a full dynamic model of the UAV. Using geometric nonlinear control theory, the dynamics of the UAV are decoupled into an inner system and outer system. The proposed control scheme is then based on the differential flatness of the outer system. For the overall closed-loop system, conditions are provided under which exponential stability can be guaranteed. In the closed-loop system, the controller is tightly coupled with the vision based state estimation and the only auxiliary sensor are accelerometers for measuring acceleration of the UAV. Finally, we show through simulation results that the designed vision-in-the-loop controller generates stable landing maneuvers even for large levels of image measurement noise. Experiments on a real UAV will be presented in future work.

关键词： Motion estimation computer vision based control unmanned air vehicle differential flatness

来源：评论

学校读者我要写书评

暂无评论

Moving object detection based on a new level set algorithm using directional speed function

引用

16th International Conference on Artificial Reality and Telexistence, ICAT 2006

作者： Sim, Dong-Gyu Image Processing Systems Laboratory Dept. of Computer Engineering Kwangwoon University 447-1 Wolgye-dong Nowon-gu Seoul 139-701 Korea Republic of

ISBN: (纸本)3540497765

In this paper, a moving object detection method is proposed based on a level set algorithm of which speed function employs three properties based on human visual characteristics. The speed function is composed of three factors: directional filtered difference, proximity weighted spatial edgeness, and directional intensity consistency. For the directional filtered difference factor, directional filtering of the difference image between background and current images is introduced to utilize temporal edgeness along a detected contour. The edgeness in the current image is also employed for an initial estimation of moving object regions. The last factor, directional intensity consistency, is based on the continuity assumption of gray-level intensities along an estimated contour. The effectiveness of the proposed algorithm is shown with four real image sequences in terms of objective detection accuracies for various experimental conditions. Keywords: object detection, level set, segmentation. © 2006 Springer-Verlag Berlin/Heidelberg.

关键词： Object detection

来源：评论

学校读者我要写书评

暂无评论

Measurement of Net Ocean Surface Heat Flux, Solar Irradiance and Near-Surface Temperature using a Novel Surface Contact Lagrangian Buoy

Measurement of Net Ocean Surface Heat Flux, Solar Irradiance...

引用

OCEANS

作者： J. P. Boyle Michael Herman J. D. DePasqua Physics & Meteorology Dept. Western Connecticut State University Danbury CT USA Senior Electrical Engineering Consultant Embedded Signal & Image Processing Chicago IL

Development of a 3 rd generation light, wave-following surface contact multi-sensor float (SCMsF) is underway. This instrument is designed to simultaneously measure net ocean surface heat flux, solar irradiance, near-surface water temperature and sea state. Whereas the 2 nd generation SCMsF design is tethered to a WOCE-type Lagrangian drifter, the 3 rd generation is designed to be autonomous. This paper reports preliminary results from a series of experiments performed at a wind-wave-current tank under a variety of meteorological and sea state conditions to assess SCMsF flux and temperature accuracy and operational limits. Comparisons suggest SCMsF net surface fluxes are in generally good agreement with values measured or derived using standard instruments and methods. These experiments also indicate the latest design has significantly improved wave-following characteristics, potentially allowing measurement of net ocean surface heat flux up to wind speeds of 10 m s -1 . Infrared imagery of the SCMsF in the wind-wave-current tank and in a rooftop pool suggests the region containing the flux measuring thermopiles is typically 0.5 to 0.9degC cooler than the cool water skin surface. This SCMsF surface temperature offset is relatively insensitive to environmental conditions - even during strong insolation

关键词： Ocean temperature Sea surface Sea measurements Solar heating Lagrangian functions Solar power generation Surface waves Instruments Water heating Meteorology

来源：评论

学校读者我要写书评

暂无评论

Study on geo-information modelling

引用

WSEAS Transactions on Systems 2006年第5期5卷 1108-1113页

作者： Klimešová, Dana Czech University of Agriculture Faculty of Economics and Management Dept. of Information Engineering Kamýcká 129 165 21 Praha 6 - Suchdol Czech Republic Czech Academy of Sciences Institute of Information Theory and Automation Dept. of Image Processing Pod vodarenskou vezi 4 182 00 Prague 8 Czech Republic

The paper is devoted to the geo-information modelling in the context of Web services model, dynamic geographic information systems (GIS) and the problem of spatial data uncertainty. GIS Web services offer wide spectrum of data sources resulting in very heterogeneous data that are in disposal to meet the demands of users and can bring significant benefit to knowledge-based approaches. The use of heterogeneous data available on Web-multi-sensor, multi-band and others in the combination with multi-criteria conditions evaluation causes increasing of uncertainty we meet in the processes and consequently in results. The contribution discusses the possibility of context incorporation (temporal, spatial, local, objective, attribute oriented, relation oriented) on the level of knowledge-based system to decrease the uncertainty of data, classification process and analytical functions and increase the information value of decision support.

关键词： Systems science

来源：评论

学校读者我要写书评

暂无评论

Lossless video coding based on selective residual DPCM

Lossless video coding based on selective residual DPCM

引用

25th PCS: Picture Coding Symposium 2006, PCS2006

作者： Nam, Jung-Hak Sim, Dong-Gyu Lee, Yung-Lyul Oh, Seoung-Jun Ahn, Chang-Beom Seo, Jeong-Il Kang, Kyeong-Ok Kim, Kyuheon Image Processing Systems Laboratory Dept. of Computer Engineering Kwangwoon University 447-1 Wolgye-dong Nowon-gu Seoul 139-701 Korea Republic of DMS Lab. Dept. of Internet Eng. Sejong University 98 Kunja-dong Kwangjin-gu Seoul Korea Republic of VIA-Multimedia Center Kwangwoon University 447-1 Wolgye-dong Nowon-gu Seoul 139-701 Korea Republic of Broadcasting Media Research Group ETRI 161 Gajeong-dong Yuseong-gu Daejeon 305-600 Korea Republic of

ISBN: (纸本)300018726X

In this paper, we propose an efficient lossless intra coding by embedding a pixel-wise residual prediction into the H.264/AVC. The H.264/AVC was designed for lossy video coding so that it could not yield the best performance for lossless video coding. In this paper, we applied a pixel-wise prediction to the residual signal generated by the H.264 intra prediction. We found that the proposed method is better than the conventional H.264/AVC FREXT lossless coding mode in terms of coding efficiency. The proposed lossless coding algorithm achieves around 12-21% bit saving against the H.264/AVC FREXT high profile for several test sequences.

关键词： image coding

来源：评论

学校读者我要写书评

暂无评论

ROAD CENTRAL CONTOUR EXTRACTION FROM HIGH RESOLUTION SATELLITE image USING TENSOR VOTING FRAMEWORK

ROAD CENTRAL CONTOUR EXTRACTION FROM HIGH RESOLUTION SATELLI...

引用

2006 International Conference on Machine Learning and Cybernetics(IEEE第五届机器学习与控制论坛)

作者： SHENG ZHENG JIAN LIU WEN-ZHONG SHI GUANG-XI ZHU Electronic & Information Engineering Dept. Huazhong University of Science and Technology Wuhan 430 State Education Commission Key Laboratory for Image Processing and Intelligent Control Inst.for Pat Advanced Research Center for Spatial Information Technology Department of Land Surveying and Geo-In Chinese Key lab of optic & electronics Huazhong University of Science and Technology Wuhan 430074

In this paper, a unique road contour extraction approach from high resolution satellite image is proposed, in which the road contour was extracted in two steps. Firstly, support vector machines (SVM) was employed merely to classify the image into two groups of categories: a road group and a non-road group. The identified road group images are the discrete and irregularly distributed sampled points, and they are an uncompleted data set for the road. Secondly, the road contour was extracted from the road group images using the tensor voting framework, since the tensor voting technique is superior to the traditional methods in extracting the geometrical structure from the uncompleted data set. The experimental results on the high resolution satellite image demonstrate that the proposed approach worked well with images comprised by both rural and urban area features.

关键词： Tensor voting framework Road central line extraction High-resolution satellite image

来源：评论

学校读者我要写书评

暂无评论

Semantics, Web and Mining: Preface

Lecture Notes in Computer Science (including subseries Lectu...

引用

Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) 2006年 4289 LNAI卷 v-vi页

作者： Berendt, Bettina Hotho, Andreas Mladenič, Dunja Semeraro, Giovanni Spiliopoulou, Myra Stumme, Gerd Van Someren, Maarten Ackermann, Markus Grobelnik, Marko Svátek, Vojtěch Institute of Information Systems Humboldt University Berlin Germany Knowledge and Data Engineering Group University of Kassel Germany J. Stefan Institute Ljubljana Slovenia Department of Informatics University of Bari Italy Faculty of Computer Science Otto-von-Guericke-Univ. Magdeburg Germany Informatics Institute University of Amsterdam Netherlands Dept. of Natural Language Processing Institute for Computer Science University of Leipzig Germany University of Economics Prague Czech Republic

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：