基于裁剪区的地图注记自动压盖处理技术

A Clip Board-Based Technique on the Annotations' Automatic Laying Over Process

地图注记与图形同色压盖关系处理是地图出版编辑的重要内容之一。本文引入了绘图设备的裁剪区原理,建立了注记裁剪区及其分色对应表模型,基于"图层-要素-图元"地图文档结构,实现了一种自动计算注记裁剪区范围并压盖同色线划和填充点符的处理方法。该方法可快速更新裁剪区,快速检索分色对应表,在每次地图绘制过程应用裁剪区。较传统的图形剪断、蒙版等方法,该方法具有不增加地图文档存储数据量,压盖效果好,不限制地图出版编辑工序的特点。

The process of annotations＇ laying over its same colored graphics is one of the most important contents of map publication edit. The principle of clip board was introduced, and an annotation clip region model as well as its color-separation mapping table model was built up. Based on a ＂layer-feature-graphic element＂ document struc- ture, a method of annotations clip region automatic computing and annotation laying over its same colored lines and point symbols filled in region was realized. By applied the way in each map drawing, the clip board could be upda- ted quickly and the color-separation mapping table could be indexed fast. Compared with the method of graphics clipping and mask board, there were three advantages as follows： without increasing map document data bytes, perfect overlay appearance and unlimited map publication edit workflow.