Abstract:

In order to solve the difficulties of the similarity assessment between the shoe last to be carved and the workpiece last, the similarity assessment algorithm of periphery polygons based on closed free curves was proposed.First,the envelope rectangles set was obtained by equiangular rotation the initial envelope rectangle, and the periphery polygon was constructed by calculating the intersection points between the corresponding edges of the envelope rectangles set. The topological relations between the polygons to compare were calculated according to the edge linkage, global feature and local feature of the polygon. The similarity degree between two polygons was calculated by weighted mean method and the shoe lasts were grouped. As an example, the similarity assessment and group algorithm were discussed for the multi-type shoe lasts derived from the same casual shoes. The results show that this classification can group the multi-type shoe lasts, and can search the similar products in the shoe lasts library rapidly.

Key words: shoe last carving;closed curve;grouping algorithm;periphery polygon

摘要：

针对鞋楦刻制时待刻鞋楦与坯料鞋楦之间的相似性识别较困难的问题，提出了基于封闭自由曲线的外包多边形相似识别方法。首先利用等角度旋转方法求得封闭曲线的包络矩形集，利用矩形集对应边的交点得到曲线的外包多边形。然后根据多边形各边的连接方式和多边形特征得到待比较多边形构成元素之间的拓扑关系，利用加权平均方法求得两多边形之间的相似度并对鞋楦分组。以某休闲鞋的衍生类型为例，阐述多类型鞋楦相似识别和分组方法。结果表明，利用该分类方法可以较快捷地把多类型鞋楦分组，为快捷地在库中找到与之相似的已知鞋楦提供依据。

关键词: 鞋楦刻制；封闭曲线；分组算法；包络多边形