文章基本信息

标题：Semi Automatic Digitizing of Contours from 1:25000 Scaled Maps
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作者：C. Helvaci ; B. Bayram
期刊名称：ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences
印刷版ISSN：2194-9042
电子版ISSN：2194-9050
出版年度：2004
卷号：XXXV Part B3
页码：461-464
出版社：Copernicus Publications
摘要：It is an expensive and time consuming task to digitize 1:25000 scaled maps which are made in the past with analogue methods. The development in digital image processing depending on the development of hardware technology made this process less expensive and faster. This study is based on this reality. In this thesis a new algorithm which aims to decrease human work time by making the work carried out to digitize 1:25000 scaled maps easily and less time consuming was developed. The first step of the process is interactively rectification of the map. The grid network is used for rectification. Scanned maps at the scale of 1:25000 and the training area on this map which is given by the operator that is showing the elevation contour pixels are used as input data. The other elevation contour pixels are determined automatically. Elevation contours in vector format are created from the elevation contours in raster format. Produced vectors may contain errors depended on the topographic condition of the map area. Elevation contours with XY coordinates are generated after the manual editing. The Z values of these contours are given by the operator before the end of the process. Finally, produced data is saved in ASCII format which is supported by common CAD, GIS and engineering software. The output file contains X, Y, Z values delimited with comma (",").
关键词：Digitization; Extraction; Rectification; Algorithms; Raster; Vector