Abstract: The representation and recognition for graphical objects plays an important role in engineering drawings.The paper presents a method about representation and recognition for graphical objects based on the topological，which can obtain the vectors for all the graphical objects by vectorization.Then the topological relations between the graphical objects are defined by the zone of influence for vectors，which can provide some information for interpretation the engineering drawings.Finally an application，recognition for mini arcs，is also presented as case in point.The algorithm is also be evaluated by the experiments using benchmark data and real drawings.The experiments indicate that the algorithm is fast and effective.

Key words: vectorization, graphic recognition, topological representation, mini arc

摘要： 工程图纸识别中，图形对象的表示方法是研究的重点和难点。在矢量化的基础上提出了一种基于拓扑结构的图形对象表示与识别方法，该方法通过矢量化获得各个图形对象的矢量基元，通过建立矢量基元的影响区域确定各矢量基元的拓扑邻接关系图，进而确定图形对象之间的位置关系，为进一步理解识别工程图纸提供了基本的信息。然后介绍了一个应用实例：圆弧角的识别。在实验中，分别用标准数据和真实图纸进行了测试，实验结果显示该算法具有较高的识别精度和识别效率。

关键词: 矢量化, 图形识别, 拓扑表示, 圆弧角