A new global approach for the recognition of lines in scanned engineering drawings is proposed in this paper.This method can not only obtain the crucial points placed in line contour but also analyze and process these points.It shows good effects on cross areas without dealing with interaction areas after recognition. The algorithm detects widths of lines in scanned engineering drawings first

and then extracts trapezoid black blocks and converts the image of scanned engineering drawings into several trapezoid block adjacent graphs which are composed by the trapezoid black blocks based on the different line widths in drawing image

and then generate and recognizes lines based on the different graphs receptively.The results demonstrates the effectiveness of this method

especially at the interaction points.