The Study On The System Of Automatic Input And Recognition Of Engineering Drawings

On the basis of referring widely to the material about engineering drawings input and recognition at home and abroad, this paper implements an experimental system for automatically inputting and recognizing engineering drawings. The system transfers the scan digitized image of engineering drawings to the DXF graphics file format in CAD system. The methods for preprocessing and vectorizing the scan image are described in the paper. The preprocessing steps include drawing scanning, binary image transforming, line thinning and cure tracing. The vectorizing steps include straight-line fitting and conic fitting. Some algorithms for raster-to-vector conversion, which are capable of recognizing and fitting straight line segments and circular arcs are discussed, The performance of the system is evaluated with several test drawings and the results are presented. The system is capable of processing BMP~. TIFFS PCX graphics-file formats and has a good extension.