在工程图纸矢量化处理中着眼于图形的宏观特征，提出了一种整体识别方法，该方法中，引入节点区域的概念，通过节点区域与图段的连接关系确定图形的拓扑结构，并由节点区域分离分割图段，图段的跟踪识别以图段轮廓的方向码序列为引导实现。整体识别算法矢量化速度快，有较强的抗噪声能力。

By introducing the conceptofnode region, the global recognition approach focuses on the integral characters of the graphics in vectorization process of scanned image of engineering drawing. It depends on the connection between node region and segmentin acquiring the topologic structure of the graphics. And node regions can be used to separate the segments. The segment is recognized via tracing the chain code of its contour. The global recognition algorithm has such advantages as high speed, noise resistance.