Automatic Road Extraction from Color Road Map

This paper introduces an automatic road extraction method from color road maps.Firstly,the sign symbols,which are very important for later road extraction,are identified from the map by using Labeling and rule-based extraction；Secondly,based on the grades of the roads,road layers are extracted according to color features of the objects on the map,and the extracted roads are thinned.Finally,based on the characteristics of the roads and the relationships between the roads and the sign symbols,this paper also establishes several rules to examine the precision of the roads and mend them if necessary,thus making the road extraction a feedback close looped automatic process.The experiments also demonstrate the method’s attectiveness in terms of precision,automation and broad use.