The Research Of Automatic Map Labeling On Linear Features

Automatic map labeling is an intelligent action, which uses the names, font sizes, font styles, coordinates of map objects and the rules of map labeling to calculate the proper location. It's simulates the process of manual work and expects to obtain the effect that is as good as the cartographic professional's manual work.Linear features are the important element of map and GIS. There are many linear features in spatial information, and the figures of linear features are very complex. The linear feature's map labeling researches take an important position in the researches on automatic map labeling, which is difficult and flexible. At present, there are relatively fewer researches on linear features.Firstly, the author analyzes and compares the situation of the linear feature's automatic map labeling researches, then summarizes the rules of linear feature's automatic map labeling. Secondly, the author explains the data structures of automatic map labeling and analyzes the basic factors which influence label's quality. Thirdly, the author proposes a linear feature's labeling model which based on greedy search. And then put forwards a label quality evaluate model, which considers label's clash and the shape of linear features. It's from several aspects which include label's clash, overlay, position level, monotonic segment and visual range to evaluate label's quality. Lastly, the author gives the experiments on linear features, analyses of the result and the outlook of linear feature's automatic map labeling.