Knowledge-Based Recognition of Utility Map Sub-Diagrams

An integrated map of all utility services in a locale would facilitate better management of the road infrastructure and the utilities themselves. To meet this goal, there exists a need to integrate raster scans of paper maps into GIS by capturing the semantic relationships between the objects in the drawings. In this context, commercially available vectorisation algorithms do not produce a sufficiently rich object representation. We present a structural object recognition system that successfully isolates sectional sub- diagrams in maps of underground utilities. This is built upon a vectorisation system based on a constrained Delau-nay triangulation of pen strokes.