工程图扫描输入与智能识别技术的研究

【作者】 王晓丽；

【导师】 胡青泥；

【作者基本信息】 大连理工大学 ， 机械设计与理论， 2000， 硕士

【摘要】 工程图纸的自动输入与识别是当今CAD/CAM领域的研究热点。本文在研究了目前有代表性的扫描图纸识别输入系统和识别算法的基础上，设计并实现了一个工程图扫描输入与智能识别系统。主要研究内容包括图线识别和智能校正；图文分离；尺寸标注和剖面线识别；及系统与AutoCAD的接口。 针对交点处理和线型识别问题，本文提出了一种基于图线和行程段特征分析、由行程段直接拾取整条图线的工程图识别算法。本算法根据整条图线的信息和图线识别标记动态确定交点；通过分析线素、间隔等的规律自适应确定线型。建立图线拓扑关系图，并在该图中对识别结果进行基于知识的智能校正。 本文还提出了一种新的图文分离算法，针对工程图中的文字符号笔划密集、大小相当、一般标注在空白区域的特点，用膨胀——腐蚀算法强化文字特征，利用滑动窗口等方法搜索字符，自动过滤掉独立字符区域，对于粘连字符和与图线相交的字符，通过有效地字符分割和识别获得相应信息。 提出了一种识别和理解工程图尺寸标注的算法和剖面线识别算法。并利用新一代面向对象的AutoCAD开发环境ObjectARX设计了系统与AutoCAD的接口。 经过实践，以上算法取得了较理想的效果。更多还原

【Abstract】 The EDLRS(Engineering Drawing Inputting and Recognizing System)which automatically converts image drawings into graphics drawings is an important problem solved urgently in the research field of CAD/CAM nowadays. In this paper, on the bases of analyzing typical EDIRS and recognizing algorithm, a new system for interpretation of images of paper-based line drawings was designed. On the bases of analyzing feature run and character of line, a new approach to extract the whole line by tracing black blocks was proposed. The line intersection was decided by vector calculating according to information of the whole line and the mark of line station. The line elements and intervals were analyzed to get line types. It was adequate to generate a topological graph of the drawing in the course of recognizing with line segments and their interconnections. In this graph, the result was adjusted according to relative knowledge. Since a typical engineering drawing contains both strings and graphics; an algorithm has been developed to locate and separate text string of various font size, style, and orientation. This algorithm based on three features: concentrated strokes, shape and size, and isolation. Expansion and erosion algorithm is first used to strengthen those features, and other algorithms like sliding frame algorithm are used to find the locations of characters based on the characteristic features. Then, it is easy to delete them with the known size and shape. - Dimension, hatching and filling patterns were also identified. Furthermore, a communication program between the system and AutoCAD was designed, which takes advantage of ARX (AutoCAD Runtime eXtension) developing environment. The results demonstrate the effective of these methods.更多还原