Line Feature Simplification Method Based on Bend Group Division

General line feature simplification methods have some defects on the simplification of the continuous small bends, as it failed to maintain the hierarchy of the simplification. Hierarchy of the simplification refers to that, under different threshold, the curves of different simplified results show a gradual change from complicated to simple. Analyses of morphological changes in the simplification based on bend shows that, the deletion of a basic bend will have an effect on the adjacent curved form. The rational use of the interaction between adjacent bending can maximize the retention of the original form of bending, under the premise of meeting the simplification threshold. Aiming at the simplification problem of continuous small bends, this paper puts forward the concept of three-element-bend group division, which re-plans the simplification process of continuous bend, dividing the road into three different element bend groups, simplifying the bend group in different way according to the different type of bend groups, and execute simplification process according to a circulating simplification strategy. Thus the interval simplification of line feature is realized, thus maintained the hierarchy of the simplification. The simplification experiment test shows that this method can maintain the morphological characteristics of the original road and a hierarchy between different threshold results.