Method for vectorizing line-structured engineering drawings based on window features extraction
Xiangyang Wang, Xinggang Lin, Youshou Wu · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1993
This paper presents a method for vectorizing line-structured engineering drawings based on window features extraction. A line-structured engineering drawing is composed of straight lines and curves (they may have different widths) as well as their ends, corners, and crosses (we call them feature points). In the paper we use 2-dimension black-run-length to trace and separate different lines. We present feature point extracting criteria to detect feature point. When any feature point is detected a small rectangle window is opened around the feature point. After an adaptive window enlarge algorithm is applied, a proper size and position of the window which is named as Window Feature is obtained. In this way, we can see whether it is really a feature point (end, corner, cross) or just a noise. We define 40 window features and with these window features, we can process and vectorize all the complicated cross points in mechanical drawings. Finally we give some experimental samples about vectorizing mechanical drawings.