大幅面地图的快速自动地形晕渲  

Rapid Automated Hill-Shading for Very Large Map

作　　者：胡卫明[1] 凌海滨[2] 

机构地区：[1]中国科学院自动化研究所模式识别国家重点实验室,北京100080 [2]北京大学文字信息处理技术国家重点实验室,北京100871

出　　处：《计算机学报》2000年第8期852-856,共5页Chinese Journal of Computers

基　　金：国家"九五"重中之重科技攻关项目!( 96-B0 2 -0 3 -12 )

摘　　要：在提出一个建立三维规则数据场的新算法的基础上 ,提出了一个可用于大幅面地图的快速实用的地形自动晕渲算法 .与传统数据网格化的方法不同 ,本算法采用了用网格点相邻等高线的高程值插值计算出网格点高程值的新思想 ,并且提出了相应的网格点相邻等高线的识别方法 ,该方法充分利用等高线所具有的先验知识 ,得到的网格点高程值质量很高 .另外 ,该规则数据场的建立方法经改进后 ,其时间复杂性与数据点数 (m)和网格点数 (n)成线性关系 O(m+n) ,因此计算速度很快 .文中还介绍了本算法所特有的三角面剖分、法向量计算等技巧 .本算法已用 Visual C++6 .0编程实现 ,嵌入到方正智绘地图出版系统中 .This paper proposes a new hill shading algorithm for the very large map. The elevation of grid is calculated with the elevations of contours being adjacent to the grid, and the approach for recognizing contours being adjacent to grid is presented. The prior knowledge of contours is used sufficiently for improving the quality of the calculated elevation of grid. The run time complexity of the approach for establishing the three dimensional regular data field is linear to the number of data points( m ) and the number of grid points( n), O(m+n ). In addition, the skills of dividing trigonal area, and calculating normal vector, which are particular in the algorithm, are introduced. The algorithm is programmed with Visual C++ 6.0, and is included in the large software product——Founder map publishing and geographical information system, which is developed by Founder research center.

关 键 词：地图 快速自动地形晕渲 地图制图 计算机 

分 类 号：P283.7[天文地球—地图制图学与地理信息工程]