Algorithm for Engineering Drawing Recognition Through Extracting Implicit Graph Information

The implicit graph information should be taken into consideration for engineering drawing recognition to imitate human behavior in reading engineering drawings. A new algorithm is presented to extract the whole line from sparse segments and get the implicit graph information. Intersection points are determined via the whole line, and the line type is worked out from analyzing its constituent elements and spacing. Finally, the topological relation among lines is adjusted according to the general knowledge of engineering drawing.