改良型PVTによる地図図面からの鉄道線路網の自動抽出

抄録

Recently desk top publishing, in which editing and printing of manuscripts are performed by computers, has been vastly progressed. Because of this fact, CAD (Computer Aided Design) and automatic input of drawings are becoming important themes in the field of publishing. In CAD, figures and tables are made by a computer, and in automatic input of drawings, already drawn figures are transformed into data suitable to CAD. In the present paper, an automatic extraction method of railroads is proposed as one of the automatic input techniques for maps, which is in demand nowadays. Railroads, including JR lines and private companies' lines, are automatically extracted from 1/25, 000 scaled maps by this method. In this paper, Parallel Vector Tracer (PVT) which was already proposed by the authors in order to analyze structure of line drawings is improved. This improved method has two added functions, 1) it continues to trace the current line element even if a cross point is found ahead, 2) it sets efficient start points for the tracing of the railroads. In this paper, the original PVT, the improved PVT and experimental results are described.