Scanning Topographic Map The Midpoint Symbols And Buildings Automatic Identification

Pattern recognization of topographic map presents development tendence and forehead in map-made field for a number of pattern recognizationg ,map-made and geographic information system(gis) have been studied. Paper's map will be long time to apply to gis in information science and date source.At present, as an important component of information science and information manufacture.Gis have alreadly been payed a great attention to for many countries and achieved high-speed development . Map vectorization is one of primary ways to capture digital spacial information from topographic map . However ,the traditional tracing vectorizatoin methods have some defects in slowly ,low accurray and automatic , litter reliabilibities,working hard ect, and does not match on the development of gis . Recognization and extraching digitized geo-information from map image opens a new way for map digitization and it is achieved signaficant for geographic information constuction and application. In this paper ,the following four aspects are explored and discussed.(1) Topographic map scanned is pre-settled for facing automatic recognization, It includes option of binary image, elimination of noise, thinning of symbols, modificatoin of intermittent points and deletion of error ect.(2) The paper arise two strategys of topographic map,one is integral classification, another is breaking up symbol from a map. It analyse traits of symbol structure and design a store of recognization and extraching .It discusses certain position about symbol. That can save greatly speed and effect for recognization symbol.(3) Base on the mingling method of statistics and structure, paper is studied in automatic recognization for point symbols and building symbols-Accoding to traits of point symbols,it adopts combination method to recognize. Acceding to traits of right angle of building image,it adopts statistics recognization when first ,at late it is structure recognization.(4) Frame and contents of topographic map pattern recognization system are designed. Branch system is simply designed too.At last, point symbol achieved has tested with image match.lt will improve a reference for topographic map pattern automatic recognization,It has significance of theory and practice.