采用斜拉式弯曲划分的曲线化简方法

线要素化简一直是自动制图综合中的重要研究内容。分析已有线化简算法在线弯曲形态保持和单调弧段划分时只考虑一侧等不足，提出线要素的斜拉式弯曲划分和化简新方法。该方法对线要素采用斜剖方式划分弧段，兼顾线要素两侧的弯曲形态；识别出每个划分的单调弧段是U型弧段还是V型弧段，是大弧段还是小弧段，从而分别对其进行不同的处理；在处理过程中，每化简完一个单调弧段，重新对线要素进行弧段划分，然后再次对每个单调弧段进行化简，以此类推，因此该算法是一种动态化简过程。实例显示，本算法在线要素特征点保持、u型弧段和V型弧段保持、大弯曲的保持、整体形态保持等方面非常有效，且化简率非常高，充分证明本算法的科学性和优越性。

Simplifying Line with Oblique Dividing Curve Method

It has been found that line simplification is one of the most important aspects in automated cartographic generalization.Most of current line simplification algorithms only consider one curved section of line the shape of which during curve dividing and generalization,is not enough to preserve the whole shape of line.This paper puts forward a new approach of line simplifying termed as "oblique dividing curve" method.The approach divides curves into monotone arcs with oblique section and pays attention to curve shapes on both sides of line;At first,it identifies whether each monotone arc is U-type or V-type arc,big or small arc,and then generalize different type of arcs with different details;during the course of generalization,if one arc is simplified,the approach will re-divide the whole line into new arcs,and simplify them one by one again,or the next arc will be simplified.The rest may be deduced by analogy.Thus the algorithm is a dynamic simplifying process.Example shows that the algorithm is more excellent in the aspects of holding line feature,U-type and V-type arcs,big curvature,whole shape and so on,and undergoes a high simplifying rate,which fully proves its scientificalness and advantage.