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31.
镶嵌图像上拼接缝的消除方法 总被引:1,自引:0,他引:1
分析了基于小波变换的拼接缝消除方法的不足,提出了拼接缝消除的强制改正方法,并用实际图像进行了试验。结果表明文中提出的方法具有较好的拼接缝消除效果,算法简单,易于实现,可以处理彩色和黑白等多种图像。 相似文献
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The single spatial parameter in the spatial autoregressive model affects both the estimation of spillovers and the estimation
of spatial disturbances. Consequently, the spatial autoregressive model has the undesirable property that if the degree of
spatial dependence in the disturbances differs from that in the spillovers, neither may be estimated correctly. We show theoretically
that the dependence structure for the spillovers and disturbances can differ and conduct a Monte Carlo experiment that verifies
these findings. In contrast, estimates from a simple separable model show little bias in all the scenarios. We also show differences
between the spatial autoregressive model and the separable model on five empirical examples. 相似文献
34.
为解决目前医院地理信息服务系统在信息共享、空间分析等方面的不足,采用ArcGIS Server组件、C#编程语言、SQL Server数据库研发了医院网络地理信息服务系统。该系统以天地图作为基础地理数据,融合医院空间与医疗信息,并部署到互联网环境中。除具有医疗专题信息的网络浏览与查询外,系统还实现了诸多空间分析、地学统计等功能,既可为市民就医提供更全面的信息查询,又可为医疗事故的突发与应急提供技术支撑。 相似文献
35.
GeoStar is the registered trademark of GIS software made by WTUSM in China. By means of the GeoStar, multi-scale images, DEMs, graphics and attributes integrated in very large seamless databases can be created, and the multi-dimensional dynamic visualization and information extraction are also available. This paper describes the fundamental characteristics of such huge integrated databases, for instance, the data models, database structures and the spatial index strategies. At last, the typical applications of GeoStar for a few pilot projects like the Shanghai CyberCity and the Guangdong provincial spatial data infrastructure (SDI) are illustrated and several concluding remarks are stressed. 相似文献
36.
Data refinement refers to the processes by which a dataset’s resolution, in particular, the spatial one, is refined, and is thus synonymous to spatial downscaling. Spatial resolution indicates measurement scale and can be seen as an index for regular data support. As a type of change of scale, data refinement is useful for many scenarios where spatial scales of existing data, desired analyses, or specific applications need to be made commensurate and refined. As spatial data are related to certain data support, they can be conceived of as support-specific realizations of random fields, suggesting that multivariate geostatistics should be explored for refining datasets from their coarser-resolution versions to the finer-resolution ones. In this paper, geostatistical methods for downscaling are described, and were implemented using GTOPO30 data and sampled Shuttle Radar Topography Mission data at a site in northwest China, with the latter’s majority grid cells used as surrogate reference data. It was found that proper structural modeling is important for achieving increased accuracy in data refinement; here, structural modeling can be done through proper decomposition of elevation fields into trends and residuals and thereafter. It was confirmed that effects of semantic differences on data refinement can be reduced through properly estimating and incorporating biases in local means. 相似文献
37.
乔柱 《测绘与空间地理信息》2013,(3):157-159
随着城市建设的飞速发展,社会对城市基础信息的需求日益增加,传统的数字化测绘难以满足现代信息化测绘的需求。佛山市信息化测绘基础软件在实现信息数据的集成化、信息处理自动化、信息应用社会化等方面做出了巨大的贡献,本文从该软件在大比例尺测绘中针对房屋的切片管理及属性管理展开,重点论述了信息数据的集成化管理及应用。 相似文献
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On the basis of the authors' experiences of setting up an NGDC Web site, this paper attempts to present some significant aspects about the security of NGDC based on ASP. They include data storing, database maintenance, new technical support and so on. Firstly, this paper discusses how to provide the security of data which is saved in the hosts of NGDC. The security model of “Networks-DB Server-DB-DB Object” is also presented. In Windows NT Server, Internet Information Server (i. e., IIS) is in charge of transferring message and the management of Web sites. ASP is also based on IIS. The advantages of virtual directory technique provided by IIS are emphasized. 相似文献
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