A strategy for on-line interpretation of sketched engineering drawings

This paper describes a strategy for online interpretation of sketched engineering drawings. It represents the design for The Designer's Apprentice-a pen-based system for producing detailed mechanical engineering drawings on a realistic electronic drawing board. The paper examines the problems of interpreting scanned drawings and assesses how such problems affect online systems. It is therefore relevant to online and offline systems. The strategy is enhanced by making an early distinction between annotation and the object outline. This discrimination shapes the subsequent processing: the object outline is subjected to node connecting, face-finding and beautification whereas annotation is classified according to the BS308 engineering standard.