一种顾及空间关系约束的线化简算法

摘要

Line element simplification has always been a hot research topic in the field of cartography generalization and expression.However, more existing line simplification algorithms aimed at single line rather than spatial relationship between linear elements.At the same time, there are some problems with classical algorithm, such as blunt performance(D-P algorithm), missing local extreme point and curve intersection(L-O algorithm).So, this paper puts forward a line simplification algorithm taking account of spatial relations between two lines.Line global simplification method(LGSM), vector displacement, area displacement and so on are proposed.Experiments are carried out on three kinds of line elements,such as contour lines, rivers and roads.The experiments' results show that the proposed algorithm can maintain the overall shape of the curve better and reduce the complexity of the curve effectively, the shape is more smooth and has a high position accuracy.%线要素化简在制图表达与综合领域一直是研究的热点和难点之一.然而,经典化简算法多针对单独线要素进行处理,缺乏对该线要素与周边线要素之间整体空间关系的考虑,并且,存在计算结果生硬(D-P算法)、局部极值点缺失,特别是在曲度较大之处出现相交异常(L-O算法)等问题.为此,本文提出一种顾及空间关系约束的线化简算法,建立线要素全局化简方法(LGSM)和矢量位移、面积位移等5类评价指标.采用等高线、河流和道路3类线要素实际数据进行了试验,充分检验了本文算法的优越性,其处理结果符合开方根模型规律,降低了曲线复杂度,在保证全局空间关系不变条件下,不仅更好地保持了曲线整体形状特征,而且光滑美观、精度高.