Abstract: In traditional large scale mapping,the method of obtaining the building's line is inefficient with high-precision or efficient with low-precision.According to the analysis of the oblique 3D model,the paper proposes a fast feature extraction method of building's feature line based on the linear axiom.In view of the status that elevation points are acquisited manually,a new method for the automatic generation of elevation points is proposed.It can be realized by the classification and interpolation of the laser point cloud data.Study proves that the method can get good results in both accuracy and efficiency and improve the degree of automation.

Key words: oblique photography, laser point cloud, feature line extraction, automatic generation of feature points, mapping automation