摘要
缓冲区可分为空间物体与邻近对象只呈单一距离关系的静态缓冲区和空间物体对邻近对象的影响度随距离变化而呈不同强度的扩散或衰减的动态缓冲区 .缓冲区的生成包括单个目标缓冲区生成和多个目标重叠缓冲区多边形间的合并 .静态缓冲区生成是在空间物体周围建立一定宽度的带状区 ;动态缓冲区的生成则根据空间物体对周围对象的影响度随距离变化而变化的性质选择线性模型、二次模型和指数模型 .缓冲区的重叠合并有数学运算法、矢量栅格转换法和混合运算法 .混合运算法分别吸收了前两种方法的优点 ,对重叠缓冲区先由矢量转换成栅格 ,扫描栅格边界 ,提取扫描线上有效矢量边界弧段 ,再对它们进行求交运算 ,删除无效弧段 ,保留有效弧段 ,最后将它们根据结点连接信息进行连接 ,形成合并后的封闭缓冲区多边形 .
Buffer is a zone around a geographic entity to find out to what extent it influences the other objects around it. Static buffer is only a simple zone around the entity, but in dynamic buffer, the influence is changed alone with the distance between the entity and the around objects. It also needed to merge overlapping parts of several buffers. The mixing method first completes the changing from vector data to raster data, and then scans the border of the raster zone and extracts the vector arcs on the scan way which are necessary for the finally buffer polygon. Then put these vector arcs into a mathematics intersect operation, at last form a close buffer polygon with the rule of four arcs node.
出处
《科技通报》
2000年第5期356-360,共5页
Bulletin of Science and Technology
