基于几何信息熵的面状要素注记配置

Automatic Name Placement of Area Feature:A Metric Information Approach

注记配置直接影响GIS地图制图子系统的显示效果,其中面状注记配置的首要问题是寻找注记配置点。本文认为面状注记配置的实质是2维符号的"降维处理",亦即使用低维符号(0维配置点或1维配置线)表达高维(2维)符号的主要特征。通过基于图形认知的推导,作者认为注记配置位置应使得其与面状符号边界竞争形成的Voronoi图形内部面积最大。由于该原则可由Li&Huang提出的几何信息熵阐明,因此在Li&Huang信息量量测方法集上,引入"熵心"、"双熵心"、"熵线"的概念,提出了基于几何信息熵的面状符号注记配置方案。

sue for sence o n f , Name placement affects the cartographic subsystem of GIS software directly, and the most important isame placement of area feature is to decide where the annotation places. The authors argue that the esautomatic name placement in area feature is a ‘reducing dimension processing for 2-D symbols, i,e. name placement means that a point of 0- dimension or a placement line of 1-dimension is used to describe the main characteristics of area feature. Following this direction of thought, the authors suppose that all the points in the area will be the candidate for name placement, and each point will generate a Voronoi diagram with the border of area feature. Via deduction, this paper puts forward that the more reasonable placement position is the one which make the area of internaIVoronoi-cellmaximum. Because that Li ＆ Huang＇s Geometric lnformation Entropy can be used to describe this phenomena conveniently, a set of concepts named ＇Entropy Center’, ‘ Double Entropy Centers’ and ‘Entropy Line’ have been introduced, of cause, which based on （geo）metric information,. Finally, an algorithm of automatic name placement has been proposed.