Abstract: The closed graph information plays an important role in processing graphics.The time effectiveness of recognition for large-scale closed graph in 2D influences the efficiency of the computer aided design.The paper studies the general process of recognition and provides the overall strategy,under which a counterclockwise and clockwise recognition method for single closed graph based on main point is put forward.With the number rules,scanning rules and bintree rules,the efficiency of recognizing large-scale closed graph in 2D in this method is increased.The effectiveness of the method has been proved by the practical application.

Key words: graphics recognition, closed graph in 2D, processing of graphics

摘要： 封闭图形信息在图形处理中有着重要的意义，对大规模二维封闭图形识别的时效问题影响着计算机辅助设计的效率。研究了二维封闭图形识别的一般过程，给出了二维封闭图形识别的总体策略，在该总体策略的指导下，提出一种基于主体点的逆（顺）时针搜索法来识别单个封闭图形，并辅以编号规则、扫描规则、二叉规则等规则提高了大规模二维封闭图形识别的效率。实际应用表明了该方法的有效性。

关键词: 图形识别, 二维封闭图形, 图形处理