共查询到20条相似文献,搜索用时 46 毫秒
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提出了一种从彩色扫描地形图中提取等高线的方法。其中,在等高线细化方面采用局部细化的策略,在智能跟踪中提出了方向式搜索,不仅避免了像素点的重复判断,而且保证了追踪过程的正确性。采用了一些有代表性的国家标准地形图进行测试,通过计算具体度量指标对提取结果作了定量分析。实验表明该方法在实际应用中具有很好的实用性。 相似文献
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扫描地形图等高线自动提取 总被引:1,自引:0,他引:1
扫描矢量化是地形图等高线数字化录入的一种常用方法,但现有的数字化方法存在一些不足:①无法处理公里网格线等干扰信息;②等高线密集区域识别困难。从扫描地形图的灰度信息出发,通过阈值过滤后将图像进行二值化处理,然后采用两边同步行走夹比取中矢量化算法进行栅格向矢量的自动转化,最后根据生成的线的长度信息将公里网格线一次删除。结果表明:基于线的长度信息可以去除95%以上的公里网格线;在地形起伏较大的山区可以自动提取80%以上的等高线,而其他相对平坦区域可自动提取95%以上的等高线,自动化程度高。 相似文献
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本文对Geoway软件在数字化1:1万地形图中的软硬环境,作业工艺流程、作业方案等进行了介绍,对如何采集地物要素,矢量化等高线的实际操作做了详细的描述,仅为测绘界同仁提供参考。 相似文献
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关于地形图与地籍图的探讨 总被引:1,自引:0,他引:1
在当代的各种建设和经济活动中,地形图和地籍图为各项工作打下了坚实的基础,发挥了相当大的作用,但两者的众多共性和具体特征,大家未能十分明确,相应的测量组织工作亦出现盲乱现象,在此笔者浅略对地籍图、地形图绘予探讨。一、关于地形图的认识地形图——表示地面点... 相似文献
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CAIZhongliang WUHehai DUQingyun LIAOChujiang 《地球空间信息科学学报》2003,6(4):17-26
This paper makes a study on the interactive digital generalization, where map generalization can be divided into intellective reasoning procedure and operational procedure, which are done by human and computer, respectively. And an interactive map generalization environment for large scale topographic map is then designed and realized. This research focuses on: ① the significance of researching an interactive map generalization environment,② the features of large scale topographic map and interactive map generalization, ③ the construction of map generalization-oriented database platform. 相似文献
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This paper makes a study on the interactive digital generalization, where map generalization can be divided into intellective reasoning procedure and operational procedure, which are done by human and computer, respectively. And an interactive map generalization environment for large scale topographic map is then designed and realized. This research focuses on: ¹ the significance of researching an interactive map generalization environment, ² the features of large scale topographic map and interactive map generalization, ³ the construction of map generalization-oriented database platform. 相似文献
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利用ArcGIS构建地形图分幅空间数据库 总被引:1,自引:0,他引:1
本文利用ArcGIS绑定的脚本语言Python和AML及其空间分析功能,设计了简单可行的算法,并编制了相应的程序,构建了国家基本比例尺地形图分幅空间数据库。首先生成图幅分幅格网,以及对应的网格标识点、图幅编号文件,将标识点与图幅编号文件关联后再与图幅网格叠加即可。该方法充分利用了GIS的空间叠加功能,仅用了极少量的程序代码,没有编程经验的人员可以比较容易掌握,对于各行业应用领域的工作者有很大帮助。 相似文献
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Aggregation method is seriously impacted by the landscape characteristics, which has been emphasized due to proportional errors. This research proposed an uncertainty weighted majority rule-based aggregation method (UWMRB) to upscale the cropland/non-cropland map. The Cropland Data Layer for 2016 at 30m resolution, with its corresponding confidence level data, were collected to conduct the experiment using UWMRB and majority rule-based aggregation method. Proportional errors of crop/non-crop were used to assess the accuracy of the two methods. Ordinal logistic regression was used to obtain the probability of an error occurring to predict the uncertainty of both methods. The results show that UWMRB can achieve the lower proportional errors with lower uncertainty. Also, it can reduce the influence of complexity and fragmentation of landscape on aggregation performance. Additionally, the examination of UWMRB provides an important view of application of uncertainty information for upscaling land cover maps in an efficient way. 相似文献
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等高线的空间关系规则和渐进式图形简化方法 总被引:6,自引:0,他引:6
详细讨论了等高线表达地形的规则和以此为基础自动建立等高线关系的方法,对地形特征点、线的提取改进了已有较成熟的方法,建立了一套实用的等高线图形简化的渐进式方法,并对其特殊情况的处理提 出了具体的算法。这种方法把不同比例尺跨度的等高线图形综合融为一体,易于实现,等高线图形简化时的等高线相交可在综合过程中控制。 相似文献
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矿区地形图动态自动修正系统初探 总被引:1,自引:0,他引:1
由于矿区特殊性,其地形图变化十分频繁,及时对变化区域或新测绘区域地形图进行修绘是一项十分重要的工作.通过对地形图计算机绘图理论的分析,开发一个矿区地形图动态自动修正系统.该系统特色之处首先是建立一个提取DXF格式地形图控制数据提取接口,并能根据提取数据和修正区域控制数据进行修正区域搜寻、开窗显示、TIN的生成、等高线追踪平滑,以及与原有地形图接边等功能;其次系统力求做到该功能模块的独立性,以能够成为数字化绘图平台或GIS系统绘图功能的补充,或为其该项功能的完善提供具体思路.最后,通过具体实例验证该系统功能的可行性和实用性. 相似文献
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Quantitative relations between spatial similarity degree and map scale change of individual linear objects in multi-scale map spaces 总被引:1,自引:0,他引:1
Haowen Yan 《国际地球制图》2015,30(4):472-482
Quantitative relations between spatial similarity degree and map scale change in multi-scale map spaces play important roles in map generalization and construction of spatial data infrastructure. Nevertheless, no achievements have been made regarding this issue. To fill the gap, this paper firstly proposes a model for calculating spatial similarity degrees between an individual linear object at one scale and its generalized counterpart at the other scale. Then psychological experiments are designed to validate the new model, taking four different individual linear objects at five different scales as test samples. The experiments have shown that spatial similarity degrees calculated by the new model can be accepted by a majority of the subjects. After this, it constructs a formula that can calculate spatial similarity degree using map scale change (and vice versa) for individual linear objects in multi-scale map spaces by the curve fitting method using the point data from the psychological experiments. Both the formula and the model can calculate quantitative relations between spatial similarity degree and map scale change of individual linear objects in multi-scale map spaces, which facilitates automation of map generalization algorithms for linear features. 相似文献
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乔柱 《测绘与空间地理信息》2015,(7)
地图自动综合缩编问题一直以来都是个难题。伴着信息化测绘技术的发展,地图自动综合问题逐渐成为热点。随着社会经济与城市建设的飞速发展,城市管理越来越精细化,大比例尺地图的自动综合显得特别的迫切,特别是由1∶500综合到1∶1 000,1∶2 000在城市规划、土地管理等行业的应用具有广泛的需求。 相似文献