Digitization of Old Maps and Possible On-line Tools for Their Use

Abstract

Oldmaps are one of themost important historical sources.Today’smodern methods of digitization for on-line access allow much more than just making copies of old maps for viewing. Is it possible to fully exploit the potential of old maps as cartographic works with all of their specific properties. The various tools and services for digitized old maps are shown in this chapter. Thanks to georeferencing of this digitized images of old maps followed by layering associated with opacity can be effectively compared the contents of the different maps between themselves. For these purposes are important on-line tools for georeferencing of raster images of old maps. Important are also on-line tools for display of georeferenced maps in 3D view on digital terrain model. On-line tools of new generation can do also automatized processing of georeferenced raster images of digitized old maps. These are e.g. searching for occurrences of map symbols, classification of digitized old maps, automatized extracting of texts etc. In addition to the above, this chapter also deals with the requirements for proper digitization of old maps. Reported are mainly requirements for the preservation cartographic properties of old maps. Special attention is paid to the preservation of positional accuracy of drawing on old maps during their digitization.