顾及三维形态特征的河流曲线化简方法

Line Simplification of River Considering Three-Dimensional Shape Characteristics

鉴于常规曲线化简方法应用于河流曲线化简时难以顾及河流要素的三维特征及其拓扑结构,提出了一种顾及三维形态特征的河流曲线化简方法。该方法利用河流曲线上散点的三维特征对散点进行选取进而实现河流曲线化简。在三维Douglas-Peucker(3D D-P)算法的基础上提出一种三维散点排队法,根据散点的三维特征对河流曲线的离散点集进行排队,并通过初始排队、'3合1'队列合并及约束点位置调整3个过程建立散点队列,然后根据压缩比从队列尾部删除相应比例的点数获得散点综合结果,将综合后的散点按照河流曲线的原始次序重构出化简后的河流曲线。实验结果表明,该方法既能最大程度地保留河流的三维形态特征,又能保证河流曲线之间的拓扑结构一致性。

In view of routine line simplification method less considering river curve’s three-dimensional shape and topological structure which is applied to line simplification of river,the paper proposes a method of river line simplification considering three-dimensional shape characteristics.On the basis of three-dimensional Douglas-Peucker(3D D-P)algorithm,a three-dimensional scatter point queuing method is proposed.In this algorithm,points set in river curves are queued by river curves’ three-dimensional feature,which would be divided into initial queue process,"3 in 1"combination queue process and adjusting constraint point position process.Then,some proportional points corresponding with compression ratio are deleted from queue’s rear.Finally,simplified river curves are reconstructed by points’ order in river curve.The results of experiment show that river curves’ three-dimensional shape feature could be maintained and the consistence of river curves’ topological structure could be ensured.