ArcGIS与AutoCAD结合在1:50 000数据库更新工程中的应用

由于GIS软件平台与CAD软件平台各自具有的优势不一样,如何把ArcGIS和AutoCAD相结合,利用各自优势,快速有效地进行地形图数据库内业编辑、数据分析;本文重点讨论了GIS和CAD数据交换的问题.     

发扬夏坚白院士精神,倡导尊重知识、重视知识产权的行业之风

前不久,报章上出现了这样一条消息:国家信息产业部、国家版权局、商务部、财政部四部委联合下发了<关于计算机预装正版操作系统软件有关问题的通知>.根据通知精神,从现在开始没有预装正版操作系统的PC产品将无法上市销售.     

搜酷

强悍的摄像机作为索尼XR系列摄像机的开篇之作,HDRXR520E集众多项级配置于一身,采用了在低光照环境下有着出色表现的Exmor R CMOS感光元件,     

电脑族每天必喝的四杯茶

1.上午一杯绿茶绿茶中含强效的抗氧化剂以及维生素C,不但可以清除体内的自由基,还能分泌出对抗紧张压力的荷尔蒙。绿茶中所含的少量咖啡因可以刺激中枢神经,振奋精神。不过最好在白天饮用,以免影响睡眠。2.下午一杯菊花茶菊花有明目清肝的作用,有些人就干脆用菊花加上枸杞一起泡来喝,或     

中国最美的古村落(十) 浙中奇绝 乌石古村

最吸引人的是这里的建筑,古民居外墙都由一小块一小块的乌石垒成,粗犷的外形与凝重的黑色相结合,结构精巧独特,给人以"鬼斧神工"的感觉,据说最早的乌石屋已有近三百年的历史.     

同江:一曲赫哲族船歌

同江位于三江平原北端,黑龙江与松花江汇流处南岸的三角地带,是有百年历史的国际口岸城市,由佳木斯市代管。清末设立临江州,1905年辟为通商口岸,1914年以黑龙江、松花江在此合一而改名同江。东接抚远,南邻饶河,北与俄列宁斯科耶隔水相望,边境线长166公里,设有国家一类口岸。同江有八岔、街津口两个赫哲族乡,这是一个只有四千人口,却在漫     

国家测绘局跨世纪青年学术带头人李清泉教授

李清泉教授生于1965年1月,安徽天长人,中共党员,工学博士,武汉大学副校长,湖北省第八、九届政协委员,第二届"湖北省五四青年奖章"获得者,湖北省青年联合会第十届委员会副主席,武汉市青年联合会第十届委员会副主席,李清泉教授先后承担了教学、科研、产业和财务管理以及大量社会工作.     

万维网GIS的若干关键技术及其实现

提出基于J2EE多层体系结构的WebGIS系统,能够平衡好服务器、应用服务器、客户端负载,极大地提高系统的响应速度;对海量的矢量数据与影像数据采用不同的压缩方式,在数据不失真的情况下尽量减少数据的传输量,减轻网络的负载;栅格数据与矢量数据的"无缝"叠加,更加形象清楚地发布空间数据;基于0racle Spatial关系数据库的WebGIS,使系统更加安全可靠.     

中国最美的古村落(一)千古太极奇村——俞源探秘

俞源的经典在于村落结构的设计:村中有大小七个水塘组成北斗七星的格局,村内的28幢主要建筑则按照天上的28星宿排布。     

阳光于丹不怕老

穿平底鞋,常蹦着走,累了就玩,少说消极话4月14日午后,著名学者于丹走进了人民日报社大院,应邀主讲"世界读书日"之青年讲堂的首场讲座。在这个春花烂漫的时节,于丹微笑着坐在怒放的梨花下,与记者聊起了自己的生活与健康心得。     

基于AMMGC三线阵影像多视匹配模型的DSM自动提取

提出了适用于三线阵数字影像多视匹配的AMMGC模型,该模型综合利用多张线阵影像,减少信息盲区,提高匹配成功率,较大程度上克服了传统双像匹配模型的不足。AMMGC模型通过金字塔影像传递匹配初值,利用匹配检查策略检验匹配结果,非常适用于特征点与格网点匹配。运用ADS40三线阵数字影像对AMMGC匹配模型进行系统试验,结果表明:该模型能够从影像上获取大量同名像点,生成密集DSM,在DSM自动采集方面具有较强的可行性与实用性。     

三线阵CCD影像的像点自动匹配技术研究

目前国内针对三线阵CCD影像像点自动量测技术研究比较少,主要采用常规影像匹配方法进行处理。本文在分析众多匹配方法的基础上,根据三线阵CCD影像的特点,在立体环境下对三线阵CCD影像空三加密像点自动量测的方法进行研究。用实验的方法研究了基于金字塔分层动态窗口匹配运算的相关系数法在三线阵CCD影像像点立体匹配中的应用,最后通过三线阵CCD数字模拟影像试验,得出结论:采用金字塔分层动态窗口匹配运算的相关系数法是解决三线阵CCD影像空三加密像点自动量测问题比较有效的途径。     

基于SIFT的宽基线立体影像密集匹配

提出基于对极几何和单应映射双重约束及SIFT特征的宽基线立体影像多阶段准密集匹配算法。算法包括三个阶段：①基于特征点的空间分布和信息熵选取一定数量的最优SIFT特征点集并进行最小二乘初始稀疏匹配及立体像对的基本矩阵和单应矩阵估计;②对于其余特征,利用同名核线倾斜角及SIFT特征的尺度信息对匹配窗口的仿射变换参数进行迭代优化及变形改正、提取仿射不变SIFT特征描述符,并基于双重约束信息及欧氏距离测度进行匹配;③考虑宽基线立体影像较低的特征提取重复率,对第②步左右影像中未能成功匹配的特征点,基于双向搜索策略,采用基于盒滤波加速计算的SSD测度在变形改正后的双重约束区域中进行匹配,并对匹配结果进行加权最小二乘拟合定位。实际的宽基线立体影像试验结果证明了算法的有效性,可为后续的三维重建提供较为可靠的密集或准密集匹配点。     

Tracking of facial deformations in multi-image sequences with elimination of rigid motion of the head

The paper deals with measurement of human facial deformations from synchronized image sequences taken with multiple calibrated cameras from different viewpoints. SIFT (Scale Invariant Feature Transform) keypoints are utilized as image feature points in the first place to determine spatial and temporal correspondences between images. If no temporal match is found for an image point by keypoint matching, then the tracking of the point is switched to least squares matching provided the point has one or more spatial corresponding points in the other views of the previous frame. For this purpose, a new method based on affine multi-image least squares matching is proposed where multiple spatial and temporal template images are simultaneously matched against each search image and part of the spatial template images also change during adjustment. A new method based on analyzing temporal changes in the image coordinates of the tracked points in multiple views is then presented for detecting the 3-D points which move only rigidly between consecutive frames. These points are used to eliminate the effect of rigid motion of the head and to obtain the changes in the 3-D points and in the corresponding image points due to pure deformation of the face. The methods are thoroughly tested with three multi-image sequences of four cameras including also quite large changes of facial deformations. The test results prove that the proposed affine multi-image least squares matching yields better results than another method using only fixed templates of the previous frame. The elimination of the effect of rigid motion works well and the points where the face is deforming can be correctly detected and the true deformation estimated. A method based on a novel adaptive threshold is also proposed for automated extraction and tracking of circular targets on a moving calibration object.     

三线阵影像多视匹配AMMGC优化模型

数字摄影测量中单立体影像匹配可能获取"病态解",匹配可靠性低、成功率不高,限制后续产品生产。在ADS40物方多视匹配模型基础上,给出了像方多视匹配AMMGC模型,该模型综合利用多张影像信息,减小信息盲区,获取匹配点的"确定解"。AMMGC模型利用匹配检查策略检验匹配结果,通过自适应窗口变换策略选取最佳大小与形状的匹配窗口,进一步提高匹配精度与成功率。实验结果表明:该模型匹配成功率高,能够可靠匹配相似特征点和地表不连续特征点,具有较强的实用性。     

嫦娥二号影像密集匹配及DEM制作方法

嫦娥二号卫星搭载了一台两线阵CCD立体相机,以线阵推扫成像方式获取了覆盖全月球的7 m分辨率影像。与嫦娥一号影像相比,影像分辨率大大提高,月表地貌细节更加丰富,制作高分辨率月表DEM更加复杂而困难,现有的基于嫦娥影像制作方法难以满足应用需求。针对嫦娥二号影像特点,在基于RPC模型生成近似核线影像基础上,进行金字塔影像匹配,实现了原始影像的逐像素匹配;计算匹配点的月面坐标后,采用基于反距离插值方法生成月表三维地形;对于图像阴影等地形漏洞,采用基于径向基函数进行插值填补。试验结果表明,该方法生成的月表三维地形DEM数据,能准确真实地表达高分辨率的月表地形地貌细节,并较好地应用于嫦娥二号全月球三维地形DEM数据产品的生产任务中。     

基于特征点的影像视差分析

本文介绍了一种基于特征点的数字立体影像匹配方法。该法采用Frstner算子提取特征点,然后应用一种松驰迭代算法,实现了同名特征点之间的立体匹配。为实现立体像对的自动相对定向和数字地形模型自动生成提供了一种切实可行的方法。     

SIFT特征匹配旋转补偿的影像匹配方法

本文针对较大旋转角度影像的匹配问题,提出一种基于SIFT特征匹配旋转补偿的影像匹配方法.即采用SIFT特征匹配方法估计影像问的旋转角度,对匹配窗口影像进行旋转补偿,最后采用带核线几何约束条件的相关系数法寻找同名点.在每层金字塔,采用带模型连接条件的相对定向来删除错误匹配点.通过对一组实际航摄影像进行试验,验证了所提出方...     

Towards 3D map generation from digital aerial images

This paper describes the fusion of information extracted from multispectral digital aerial images for highly automatic 3D map generation. The proposed approach integrates spectral classification and 3D reconstruction techniques. The multispectral digital aerial images consist of a high resolution panchromatic channel as well as lower resolution RGB and near infrared (NIR) channels and form the basis for information extraction.Our land use classification is a 2-step approach that uses RGB and NIR images for an initial classification and the panchromatic images as well as a digital surface model (DSM) for a refined classification. The DSM is generated from the high resolution panchromatic images of a specific photo mission. Based on the aerial triangulation using area and feature-based points of interest the algorithms are able to generate a dense DSM by a dense image matching procedure. Afterwards a true ortho image for classification, panchromatic or color input images can be computed.In a last step specific layers for buildings and vegetation are generated and the classification is updated.     

Geometric-constrained multi-view image matching method based on semi-global optimization

Targeting at a reliable image matching of multiple remote sensing images for the generation of digital surface models, this paper presents a geometric-constrained multi-view image matching method, based on an energy minimization framework. By employing a geometrical constraint, the cost value of the energy function was calculated from multiple images, and the cost value was aggregated in an image space using a semi-global optimization approach. A homography transform parameter calculation method is proposed for fast calculation of projection pixel on each image when calculating cost values. It is based on the known interior orientation parameters, exterior orientation parameters, and a given elevation value. For an efficient and reliable processing of multiple remote sensing images, the proposed matching method was performed via a coarse-to-fine strategy through image pyramid. Three sets of airborne remote sensing images were used to evaluate the performance of the proposed method. Results reveal that the multi-view image matching can improve matching reliability. Moreover, the experimental results show that the proposed method performs better than traditional methods.