Recognition and Integration of Dimension Sets in Vectorized Engineering Drawings

摘要

The benefits of the existing CAD systems are not available to a large number of engineering drawings which were created manually on paper using conventional drafting methods. An automated system which will scan and convert these drawings into CAD files recognizable by the existing CAD systems is very desirable. An important element in the conversion process is the automatic recognition and understanding of dimensional information which is used to denote the exact size and location of the various entities present in the geometry described in the drawing. This paper discusses a system which has been developed to recognize the dimension sets from the vectorized image of the drawing and obtain the logical relationship between the dimension sets and the geometry. The recognized dimension sets are also integrated with the geometry of the object using a variational geometry approach to rectify the errors which are introduced during preprocessing. The drawing obtained after processing consists of an accurate vectorized representation of the geometry in terms of the basic geometric entities and a vectorized representation of the dimension sets which can be used in an dimension-driven CAD system.