Research Of Map Automatic Labeling And Its Application In Mapping By AutoCAD

In recent years, with the fast development of economy construction, the rateof maps updating becomes faster and faster. Otherwise, the information technologydevelopment, represented by computer and network, makes the world to quicken theprocess of geomatics technology informatization. The design and productionautomatization of maps have become a task needed imminently resolved, which isfaced by the persons whose work is geomatics. In the process of map design andproduction automatization, map labeling is the bottle-neck restricting its development.If map labeling automatization can come true, the efficiency of cartography will beenhanced greatly, the time, consumed by producing maps, will be shortened greatly, and it can be largely satisfied that every walk of life gives demands to the speed ofmap production.First, in the foundation of realizing the development of present situation of mapautomatic labeling around world, the paper has concluded the rules of map labeling.Then, all methods and material algorithms, used for labeling all kinds of mapelements, are discussed in detail in the paper. The calculation of candidate placementsof point element automatic labeling must be executed by corresponding methods, according to the shape of point elements, so we can get candidate placements whichhave strong relationship belonging to point elements. In addition, the paper alsointroduces two algorithms used for optimizing labeling placement, they are greedsearch and search based on trace, and can be used for optimizing labeling placementsof line element and area element. The calculating of candidate placement of line andarea elements is more complex than point element, there are suitable algorithms fordifferent line and area elements. The key points of the paper are putting forwardalgorithm ameliorated for labeling dual line element, a new method, center arraymethod, used for labeling area element, and ameliorating the search algorithm basedon Delaunay triangle network to label area element. The paper also gives us a newpredigesting algorithm, because some algorithm in existence can't meet our demands, the name of new algorithm is parallel method, it is not only simple, but also in highefficiency. At last, the map automatic labeling subsystem is developed by ObjectARXon the platform of AutoCAD which is famous software of cartography around world, and it is tested and applied by the example labeling the topography map and land mapof a town in QiongLai, SiChuan.