基于类似形原理从单幅轴测投影图识别平面立体  

On a New and Better Method of Recognizing Polyhedrons from an Axonometric Drawing

作　　者：张桂梅[1] 郭航[2] 高满屯[1] 沈允文[1] 

机构地区：[1]西北工业大学 [2]南昌大学宣传部,江西南昌330029

出　　处：《西北工业大学学报》2004年第5期586-590,共5页Journal of Northwestern Polytechnical University

基　　金：陕西省自然科学基金 (2 0 0 2 E2 2 4 );江西省自然科学基金 (0 3110 18)资助

摘　　要：根据仿射不变性提出在轴测投影下多边形的类似形定义 ;给出类似形的识别方法 ;据此提出一种基于类似形原理从单幅轴测投影图识别平面立体的新方法。定义的类似形能将具有不同特征的表面区别开 ,并将平面立体中的表面分类。匹配过程限制在类似形内进行 ,大大减少了搜索范围。用拓扑结构对类似形进行定性分析 ,对噪音不敏感 ,而用几何特征进行定量分析 ,则能反应平面立体形状的细微差别。该识别算法不仅能识别不同形状的平面立体目标 ,而且还可区分形状相同但大小、比例不同的平面立体目标。Existing methods for recognizing polyhedrons can, in our opinion, be improved. We propose a new concept——homograph——and then propose a new method for recognizing polyhedrons based on the principle of homograph. First, we define the new concept of homograph in terms of three topological characteristics and two geometrical characteristics. On the basis of this definition, we give a 12-step procedure for recognizing homographs. Second, we present a new algorithm for recognizing polyhedrons from an axonometric drawing based on principle of homograph. Homograph as defined by us can be employed to distinguish between surfaces with different characteristics and to classify the surfaces of polyhedron. As homograph′s categories are few in number and as it is only necessary to put the polygon to be recognized in one of these few categories, efficiency of recognition is greatly raised. We introduce the topological characteristics to analyze homograph qualitatively, therefore the algorithm is insensitive to noise; we employ geometrical characteristics to analyze homograph quantitatively, and thus the algorithm can show fine discrimination between polyhedrons. Thus, it can not only recognize polyhedrons of different shape but also distinguish between polyhedrons that are of the same shape but their sizes and proportions are different. Compared with other recognition algorithms, our algorithm has obtained obvious improvement. The effectiveness of the algorithm is demonstrated preliminarily by computer simulation.

关 键 词：类似形 轴测图 线图 识别 

分 类 号：TP391.41[自动化与计算机技术—计算机应用技术]