Interactive recognition of graphic objects in engineering drawings

Abstract

In this paper, an interactive approach to recognition of graphic objects in engineering drawings is proposed. Interactively, the user provides an example of one type of graphic object by selecting it in an engineering drawing, and then the system learns its graphical knowledge and uses this learnt knowledge to recognize or search for other similar graphic objects. For improving the recognition accuracy of the system, we also propose a user feedback scheme based on multiple examples from both positive and negative aspects. We summarized four types of geometric constraints to represent the generic graphical knowledge of graphic objects. We also developed two algorithms for case-based graphical knowledge acquisition and knowledgebased graphics recognition, respectively. For the user feedback scheme, we adjust our original knowledge representation by associating a few types of tolerances to every piece of graphical knowledge and use different tolerances for recognizing different graphical objects. Experiments have shown that our proposed framework is both efficient and effective for recognizing various types of graphic objects in engineering drawings. copy; Springer-Verlag 2004.