Abstract: According to the fact that the traditional building simplify algorithm can not accurately maintain the details of the local geometric characteristics of buildings,introducing a sharp convex angle and other issues,a building polygon simplification method is proposed based on the adjacent five points in this paper.By defining the adjacent five points on the boundary of the polygon as the basic processing unit,the basic unit is divided into 4 types:Z parallel,Z non-parallel,U parallel and U non-parallel,to simplify progressively,and sharpen the corners generated during the reduction process taking into account the angular constraints.Experiments are conducted with the polygon data of a 1:10 000 actual building in a certain area.The results show that the proposed algorithm can avoid sharp corners as much as possible on the basis of maintaining the basic geometry features of the building,and results are more in line with human visual perception.

Key words: adjacent five-point approach, building polygon simplification, sharp corners, progressive simplification