A methodology for the interpretation of images of engineering drawings is presented. The approach is based on the combination of schemata describing prototypical drawing constructs with a library of low-level image analysis routines and a set of explicit control rules applied by an LR(1) parser. The resulting system (Anon) integrates bottom-up and top-down processing strategies within a single, flexible framework modeled on the human perceptual cycle. Anon's structure and operation are described and discussed, and examples of its interpretation of real mechanical drawings are shown.>

schema-driven image analysis system capable of producing high level interpretations of greyscale images of mechanical engineering drawings. The system has been extended to incorporate a drawing memory into which completed schema instances are placed and which may be accessed as an integral part of ANON's knowledge directed visual search. This memory provides a basis for the integration into a coherent whole of the piecewise interpretations previously supplied by the system. It leads to a richer description of drawing content, improves efficiency and allows ANON to deal with partially complete interpretations. The new system's structure and operation are discussed and examples shown of it's interpretation of real mechanical drawings. 1 ANON [1,2] is a knowledge directed image analysis system