线状要素化简算法的分析与评估

线状要素是地图中量最大、形式最多样的要素,它们的化简在自动制图综合中非常重要。目前对线状要素化简的算法研究较多,但其化简质量却少有研究。针对化简算法的基本要求,提出了易于操作的评估化简算法质量的6个方面:面积差、弯曲度、最大拐角比率、化简变化趋势、化简结果一致性和自相交性。通过大量实验,比较了Douglas-Peucker等算法的化简效果,最后对化简中的自相交问题提出了相应的改正措施。

Quality Assessment of Linear Features Simplification Algorithms

Linear element is the largest various element in the map.Line simplifying is very important in auto-generalization. There are many simplifying methods most of which are practical and effective.Considering the principles of simplifying,six aspects have been proposed to estimate these methods which are area-difference,bend ratio,maximal-bendangle ratio,change-uptrend,result-coherence and self-intersection.The effect between Douglas-Peucker and Beam of Light has been compared by many experiments.At last,the corresponding step has been proposed to settle self-intersection.