Abstract: Aiming at the problem of low rendering efficiency of large-scale linear element map when the scale level of single vector tile data of geographic information is low, this paper proposes a large-scale linear element map synthesis method supported by geometric feature importance algorithm. In this method, the importance index of geometric features of line elements is proposed as the ranking basis when line elements are deleted, so as to realize the automatic synthesis of line elements taking into account the global characteristics of data, which not only retains the main geometric information on a single vector tile, but also effectively improves the efficiency of map rendering. The experimental results show that the rendering speed of line elements is increased by 3 times by applying this method to the vector data of “MapWorld Gansu”.

Key words: geometric importance, large scale, linear elements, map synthesis, vector tile technology