Interpretation of telephone system manhole drawings

The authors present efficient methodologies for interpreting manhole drawings of a telephone company for information extraction. They have developed a skew correction algorithm for deskewing scanned images, a new rule-based text/graphics separation algorithm for separating annotations in the drawings, and a graphics interpretation system which includes model-based arrow head detection, splice detection, and recognition of interconnections of cables and stubs. The final result from the interpretation system is a table which includes an ordered list of all cables and their interconnections which are contained in a manhole. Experimental results are used throughout to describe the algorithms