作者机构：
[杨敏; 艾廷华; 成晓强] School of Resources and Environment Science, Wuhan University, Wuhan 430072, China;[刘鹏程] College of Urban and Environment Science, Central China Normal University, Wuhan 430079, China
通讯机构：
[Yang, M.] S;School of Resources and Environment Science, Wuhan University, China
作者机构：
[刘鹏程; 李畅] College of Urban and Environmental Science, Huazhong Normal University, 152 Luoyu Road, Wuhan 430079, China;[李奇] Center for Earth Observation and Digital Earth Airborne Remote Sensing Center, Chinese Academy of Sciences, A 3 Datun Road, Beijing 100101, China;[李芳芳] Science and Technology on Information Systems Engineering Laboratory, National University of Defense Technology, 47 Yanwachizheng Street, Changsha 410073, China
通讯机构：
College of Urban and Environmental Science, Huazhong Normal University, 152 Luoyu Road, China
摘要：
Building 3D reconstruction based on ground remote sensing data (image, video and lidar) inevitably faces the problem that buildings are always occluded by vegetation, so how to automatically remove and repair vegetation occlusion is a very important preprocessing work for image understanding, compute vision and digital photogrammetry. In the traditional multispectral remote sensing which is achieved by aeronautics and space platforms, the Red and Near-infrared (NIR) bands, such as NDVI (Normalized Difference Vegetation Index), are useful to distinguish vegetation and clouds, amongst other targets. However, especially in the ground platform, CIR (Color Infra Red) is little utilized by compute vision and digital photogrammetry which usually only take true color RBG into account. Therefore whether CIR is necessary for vegetation segmentation or not has significance in that most of close-range cameras don't contain such NIR band. Moreover, the CIE L*a*b color space, which transform from RGB, seems not of much interest by photogrammetrists despite its powerfulness in image classification and analysis. So, CIE (L, a, b) feature and support vector machine (SVM) is suggested for vegetation segmentation to substitute for CIR. Finally, experimental results of visual effect and automation are given. The conclusion is that it's feasible to remove and segment vegetation occlusion without NIR band. This work should pave the way for texture reconstruction and repair for future 3D reconstruction.
作者机构：
[罗静; 刘鹏程; 李畅] College of Urban and Environmental Science, Central-China Normal University, 152 Luoyu Road, Wuhan 430079, China;[艾廷华] School of Resource and Environmental Science, Wuhan University, 129 Luoyu Road, Wuhan 430079, China
通讯机构：
College of Urban and Environmental Science, Central-China Normal University, 152 Luoyu Road, China
作者机构：
[黄亚锋; 艾廷华] School of Resources and Environmental Science, Wuhan University, 129 Luoyu Road, Wuhan 430079, China;[刘鹏程] College of Urban and Environment Science, Central-China Normal University, 152 Luoyu Road, Wuhan 430079, China;[黄亚锋; 艾廷华] Key Laboratory of Geographic Information System, Ministry of Education, Wuhan University, 129 Luoyu Road, Wuhan 430079, China
通讯机构：
School of Resources and Environmental Science, Wuhan University, 129 Luoyu Road, China
作者机构：
[Liu Pengcheng; Zhang Hailin; Zhang Xuesong] Huazhong Normal Univ, Sch City & Environm Sci, Wuhan, Peoples R China.
会议名称：
International Conference on Future Computers in Education (ICFCE 2011)
会议时间：
JUN 25-26, 2011
会议地点：
Xiamen, PEOPLES R CHINA
会议主办单位：
[Zhang Xuesong;Zhang Hailin;Liu Pengcheng] Huazhong Normal Univ, Sch City & Environm Sci, Wuhan, Peoples R China.
关键词：
geographic information technology;secondary school geography curriculum;teaching methods
摘要：
Rapid development and wide application of geographic information technology in recent years results in geographic information technology's being included in secondary school geography curriculum standards for the first time. Facing the new teaching tasks, geography teachers need to adopt appropriate teaching methods. Based on teaching theory of geography, this paper firstly analyses the characteristics of the "3S" technology course in "Geography curriculum standards of full-time regular senior secondary schools", such as teaching objectives, teaching materials and knowledge background of students etc. Moreover, some teaching methods of the "3S"technology course are introduced. In addition, the paper gives various corresponding cases to describe the above methods. It is shown that these methods are effective in practice.
作者机构：
[刘鹏程] College of Urban and Environmental Science, Central-China Normal University, 152 Luoyu Road, Wuhan 430079, China;[胡晋山] School of Geodesy and Geomatics, Xuzhou Normal University, 101 Shanghai Road, Xuzhou 221116, China;[成晓强; 艾廷华] School of Resource and Environmental Science, Wuhan University, 129 Luoyu Road, Wuhan 430079, China
通讯机构：
College of Urban and Environmental Science, Central-China Normal University, 152 Luoyu Road, China
作者机构：
[Li, Chang; Liu, Pengcheng] Huazhong Normal Univ, Coll Urban & Environm Sci, Wuhan 430079, Peoples R China.;[Yang, Ling] Henan Univ, China Australia Cooperat Res Ctr Geoinformat Anal, Coll Environ & Planning, Kaifeng 475004, Peoples R China.;[Hu, Min] Peoples Liberat Army Commun Command Acad, Wuhan 430010, Peoples R China.;[Hu, Min] China Univ Geosci, Sch Econom & Management, Wuhan 430074, Peoples R China.
通讯机构：
[Li, Chang] H;Huazhong Normal Univ, Coll Urban & Environm Sci, Wuhan 430079, Peoples R China.
会议名称：
International Conference on Advanced Measurement and Test (AMT 2010)
会议时间：
MAY 15-16, 2010
会议地点：
Sanya, PEOPLES R CHINA
会议主办单位：
[Li, Chang;Liu, Pengcheng] Huazhong Normal Univ, Coll Urban & Environm Sci, Wuhan 430079, Peoples R China.^[Yang, Ling] Henan Univ, China Australia Cooperat Res Ctr Geoinformat Anal, Coll Environ & Planning, Kaifeng 475004, Peoples R China.^[Hu, Min] Peoples Liberat Army Commun Command Acad, Wuhan 430010, Peoples R China.^[Hu, Min] China Univ Geosci, Sch Econom & Management, Wuhan 430074, Peoples R China.
会议论文集名称：
Key Engineering Materials
关键词：
vanishing point;line clustering;RANSAC;condition adjustment with parameters;error ellipse
摘要：
In close-range digital photogrammetry and computer vision, a major challenge is the automation of 3D reconstruction from 2D-images. And single image calibration is a fundamental task in these areas for research. It is known that camera parameters can be recovered by the vanishing points of three orthogonal directions. However, three reliable and well-distributed vanishing points are not always available. Therefore, how to estimate the error of two vanishing points is very significant for us to analyze the precision of camera calibration. New methods for vanishing point detection and error estimation are presented, which can be illustrated as follows. Firstly, the line clustering, which parallel to object lines and correspond to the vanishing points, are detected based on RANSAC (Random Sample Consensus). Secondly, "condition adjustment with parameters" is utilized to estimate a nonlinear error equation. Thirdly, the error of vanishing point is expressed by error ellipse that is derived by co-factor matrix according to adjustment principle. Finally, experimental results of vanishing points coordinates and their errors are shown and analyzed.
作者机构：
[Li, Chang; Liu, Pengcheng] Huazhong Normal Univ, Coll Urban & Environm Sci, Wuhan 430079, Peoples R China.;[Hu, Min] Peoples Liberat Army Commun Command Acad, Wuhan 430010, Peoples R China.;[Hu, Min] China Univ Geosci, Sch Econom & Management, Wuhan 430074, Peoples R China.
通讯机构：
[Li, Chang] H;Huazhong Normal Univ, Coll Urban & Environm Sci, Wuhan 430079, Peoples R China.
会议名称：
International Conference on Advanced Measurement and Test (AMT 2010)
会议时间：
MAY 15-16, 2010
会议地点：
Sanya, PEOPLES R CHINA
会议主办单位：
[Li, Chang;Liu, Pengcheng] Huazhong Normal Univ, Coll Urban & Environm Sci, Wuhan 430079, Peoples R China.^[Hu, Min] Peoples Liberat Army Commun Command Acad, Wuhan 430010, Peoples R China.^[Hu, Min] China Univ Geosci, Sch Econom & Management, Wuhan 430074, Peoples R China.
会议论文集名称：
Key Engineering Materials
关键词：
line extraction;Wallis filtering;LoG;Canny;Hough transform;perceptual organization;LSTM;aerial image
摘要：
Line and plane feature can provide more information than point feature, thus 3D reconstruction based on high-level features, such as line and plane, is an important development trend in Digital Photogrammetry and Computer Vision. Several methods for extracting straight line are researched, and the main procedures can be introduced as follows. Firstly, image is preprocessed by Wallis filtering that is used to enhance the image contrast and reduce the noise, so it is easy to extract more lines. Secondly, Laplacian of Gaussian operator (LoG) and Canny operator algorithms are compared to locate the edge by detecting discontinuity variation in image. Thirdly, Hough transform or perceptual organization based on hypothesis testing are compared and tested for combining and fitting fractured short line segments into a whole line. Lastly, the least square template matching algorithm (LSTM) is done to get higher precise (sub-pixel) located lines. In the experiment, different algorithms for straight line extraction of aerial images are realized and compared, in order to faster achieve richer and higher accurate straight line information, which can pave the way of image understanding and image matching.
