Study On Internet Based Cartographic Symbolization

The structure of map symbol is discussed at first in this thesis which points out it is the important part of GIS system. The symbol structure is made based on composite pattern. Then the general algorithms of symbol drawing is introduced, a circulating block line entity drawing algorithms and a polygon entity fill algorithms based on seed fill are developed.To building a map symbol editor, a framework which several design pattern are associated with is constructed which manage symbols by STL container in memory. Then three symbol serialization based on files, database and compound document are pointed out.To the symbols managing system, the symbols' online editor and browser by Web Service and ISAPI are realized which improve the runtime efficiency by the method of Lazy Loading and Database Gateway.Map visualization is made deep study in this thesis. A map server system is constructed based on SLD and pipeline pattern. The map layer style information is saved in the SLD XML document. The pipeline is divided into four filters to finish the data extraction, displaying entity generator, rendering and presentation. The system runs on COM+ environment.At last two projects are developed by using the outcome of the thesis.