Research On Map Decoration Elements Based On Quadtree Theory

The map is the most frequently-used and effective media to transfer geographicinformation. The map decoration elements is a requisite part of the map whichcontains maptitle,mapsheet no,adjoining sheets,administrative subject,scalebar,slopediagram,the three-north direction,degree of secrets and technical specification．It canimprove the map’s readability and make people get useful information quickly andexactly．This article analyzes the problems which present in domestic and foreign GISsoftware on the function of map decoration, are "too much manual interaction,lowwork efficiency and low mapping precision "．Aimed at these questions,we proposethe automatic thoughts of decoration elements, and realize the function based on thevisual studio.net development platform,with the using of C#programming languageand ArcGIS Engine component library.The function can be used on map decoration ofthe national basic scale map decoration．The automation of map decoration must take the database as the basis．Theinformation of each scale’s decoration elements should be stored in a relationaldatabase, due to the need to store spatial data, we take use of geodatabase model．Considering that the national basic scale map is a huge amount of information, if weuse the traditional way to store data,the redundancy is serious and fetrieval speed isslowly,this paper presents a spatial data frame structure based on the thought ofquadtree,and proposes a new solution for the storage, retrieval, management ofdecoration elements．The module can be used as a separate map decoration software and also can beused as a plug-in which can be integrated into other GIS software．It is mainly used inthe national basic scale maps and can be extended according to actual needs．So longas the scale and scope of the map is known,the graphic and attribute information ofthe decoration elements can be obtained from the database and add the elements to themap automatically．At the same time it provides the editing interface,which can beused when the decoration elements should be modified．...