Patches Automatic Generalization Method For Geographical Conditions Census Map

Geographical conditions census is the mapping area of the natural geographical situation and socioeconomic elements of the spatial distribution of the situation and the distribution of the law and the relationship between the map.The main data source for the geographical conditions of the census is the geographical conditions results.As the surface coverage in the space with no overlap and gaps,rich information and other characteristics,the study of high precision and rapid automatic generalization of the map has become a large number of geographical conditions of the important comprehensive protection.Based on the WJ-III map workstations,this paper has established a set of geo-national census cartography merger and simplification method,independent research and development of the corresponding algorithm model,to achieve the geographical conditions of the census results fast,high-precision automatic synthesis.Based on the analysis and research of the existing methods of maps at home and abroad,this paper proposes and establishes a method of merging the patches under multi-mode conditions.The method is used to classify and extract the small patches on the map,and the area threshold is used as the criterion of the combination of the patches.Based on the rule of the patches,the merging pattern of semantic priority,area first and shared priority is established.The physical reconstruction of the data is realized.A method of simplification of the topological relation and feature feature is proposed and established.Based on the classification of the shared arc and the topological relation of the constructed arc,the method is based on the classification of the shared arc,and the different methods are used to separate the natural and artificial objects,taking into account the contours of the features of the map,to maximize the topographic relationship between the patches.The algorithm of automatic pattern synthesis is developed,and the example is verified by the surface coverage map data of Chishui City,Guizhou Province.The efficiency of automatic processing is higher than that of the existing manual processing.The results show the effectiveness and reliability of the method.