排序方式: 共有22条查询结果,搜索用时 78 毫秒
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针对现有的配准方法用于多光谱影像与SAR遥感影像配准时,存在受SAR图像斑纹噪声影像大、手工选取配准控制点精度低、利用图像景物特征配准时获取区域和边沿困难等问题,以SPOT5影像与RADARSATSAR影像配准进行实验,提出了一种利用改进的SIFT在提取的特征图像上寻找匹配点进行粗配准,然后利用交叉累积剩余熵作为相似性测度结合原始影像信息寻找光学特征图像的角点在SAR影像上的匹配点并进行精配准的方法,配准精度达到了子像素级水平。实验结果表明该方法对多源遥感影像有很强的适应性,配准精度高。 相似文献
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Automatic 3D point cloud registration is a main issue in computer vision and remote sensing. One of the most commonly adopted solution is the well-known Iterative Closest Point (ICP) algorithm. This standard approach performs a fine registration of two overlapping point clouds by iteratively estimating the transformation parameters, assuming good a priori alignment is provided. A large body of literature has proposed many variations in order to improve each step of the process (namely selecting, matching, rejecting, weighting and minimizing). The aim of this paper is to demonstrate how the knowledge of the shape that best fits the local geometry of each 3D point neighborhood can improve the speed and the accuracy of each of these steps. First we present the geometrical features that form the basis of this work. These low-level attributes indeed describe the neighborhood shape around each 3D point. They allow to retrieve the optimal size to analyze the neighborhoods at various scales as well as the privileged local dimension (linear, planar, or volumetric). Several variations of each step of the ICP process are then proposed and analyzed by introducing these features. Such variants are compared on real datasets with the original algorithm in order to retrieve the most efficient algorithm for the whole process. Therefore, the method is successfully applied to various 3D lidar point clouds from airborne, terrestrial, and mobile mapping systems. Improvement for two ICP steps has been noted, and we conclude that our features may not be relevant for very dissimilar object samplings. 相似文献
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Close-range terrestrial digital photogrammetry and terrestrial laser scanning for discontinuity characterization on rock cuts 总被引:9,自引:0,他引:9
This paper reviews the application of close-range terrestrial digital photogrammetry and terrestrial laser scanning for discontinuity characterization on rock cuts. Terrestrial remote sensing techniques are being increasingly used as a complement to traditional scanline and window mapping methods. They provide more comprehensive information on rock cuts, allow surveying of inaccessible outcrops, and increase user safety. Selected case studies are used to estimate the accuracy of several 3D model registration approaches and the most time-, effort- and cost-effective methods are highlighted. It is shown that simple registration networks are able to provide adequate measurement of discontinuity orientation for engineering purposes. The case studies presented also illustrate the effects of sampling bias and limitations related to discontinuity characterization using remote sensing techniques. Vertical orientation bias and occlusion can be of particular concern when persistent discontinuities dip at the same angle as the camera/scanner line-of-sight. Major advantages of the techniques are presented illustrating how terrestrial remote sensing techniques provide rapid spatial measurements of discontinuity location, orientation and curvature and are well suited to the quantification of persistence magnitudes greater than 3 m. 相似文献
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City model enrichment 总被引:1,自引:0,他引:1
Philip D. Smart Jonathan A. Quinn Christopher B. Jones 《ISPRS Journal of Photogrammetry and Remote Sensing》2011,66(2):223-234
The combination of mobile communication technology with location and orientation aware digital cameras has introduced increasing interest in the exploitation of 3D city models for applications such as augmented reality and automated image captioning. The effectiveness of such applications is, at present, severely limited by the often poor quality of semantic annotation of the 3D models. In this paper, we show how freely available sources of georeferenced Web 2.0 information can be used for automated enrichment of 3D city models. Point referenced names of prominent buildings and landmarks mined from Wikipedia articles and from the OpenStreetMaps digital map and Geonames gazetteer have been matched to the 2D ground plan geometry of a 3D city model. In order to address the ambiguities that arise in the associations between these sources and the city model, we present procedures to merge potentially related buildings and implement fuzzy matching between reference points and building polygons. An experimental evaluation demonstrates the effectiveness of the presented methods. 相似文献
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The representation of similarity transformation in three-dimensional (3D) space, especially of orientation, is a crucial issue in navigation, geodesy, photogrammetry, robot arm manipulation, etc. Considering the large amount of computer resources required by iterative algorithms designed for spatial similarity transformation, the high dependence on initial values of unknown parameters, and the instability of solving transformation parameters for large-angle registration, a closed-form solution for pairwise light detection and ranging (LiDAR) point cloud registration is proposed. In this solution, dual-number quaternions are used to represent the 3D rotation. The relationship between the rotation matrix-based representation of similarity transformation and the dual quaternion-based representation is described first. Considering that the same features from two neighboring stations coincide after pairwise registration, a dual quaternion-based error norm, which is associated with the sum of the position errors, is constructed. Based on theory of least squares and by extreme value analysis of the error norm, detailed derivations of the model and the main formulas are obtained. Once the similarities between the same features from the two neighboring LiDAR stations are constructed, the rotation matrix, the scale parameter, and the translation vector are simultaneously derived. Two experiments are conducted to verify the feasibility and effectiveness of the proposed algorithm. The proposed algorithm has the advantages of simplicity and ease of implementation, making it better than the traditional methods that use matrices to describe spatial rotation. Moreover, it solves the transformation parameters without the initial estimates of unknown parameters, making it better than iterative algorithms. Most importantly, in contrast to unit quaternion-based algorithms, the proposed algorithm solves seven unknown parameters simultaneously. Therefore, it effectively avoids the accumulation of introduced error in calculation and the negative impact from the inappropriate choice of initial values. 相似文献
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基于SIFT特征的SAR图像配准方法在玉树地震中的应用 总被引:1,自引:0,他引:1
本文针对SAR图像特点, 提出了基于改进SIFT(尺度不变特征变换)算法的SAR图像配准方案: ① 对待配准图像进行ISEF(无限对称指数滤波器)滤波处理, 降低图像的斑点噪声; ② 采用SIFT算法提取特征点, 略过差分金字塔第一层的特征点检测, 提高时间效率; ③ 在欧氏空间内剔除误匹配点, 提高配准精度。 实验表明, 本文提出的SAR图像配准方案检测到的匹配点对的数量和稳健性都有提高, 精度能够满足亚像元级SAR图像的应用需求, 且用时比传统SIFT方法减少60%以上。 最后对精配准的SAR图像进行震害变化检测, 得到的震害分布与高分辨率光学图像上判读的建筑物毁坏情况基本一致。 相似文献
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基于B/S模式,采用面向服务、多层架构的方式,莒县不动产登记平台开发了登记子系统、权籍调查子系统、查询分析子系统、信息共享交换子系统、档案管理子系统,为不动产统一登记工作的开展提供技术支撑。用GDAL/OGR技术标准,按照采集、建库、管理一体化的模式,根据系统各类核心数据的生产、更新特点,确定每类数据的更新技术路线和日常运行机制,将权籍调查流程纳入系统管理,做到了权籍调查、登记发证、档案归档一体化管理的作业模式,满足了不动产统一登记发证工作的要求。 相似文献
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