Automated acquisition of geographic information from scanned maps for GIS using frames and semantic networks

Data acquisition is the bottleneck for the introduction of geographic information systems (GIS). This paper presents a system for automatic extraction of semantic information from land register maps. The system uses explicit knowledge of the map, which is given by the legend of the map, the drawing rules, and the objects functionality. The knowledge is represented by frames and semantic networks. The system uses four levels of representation and processing: 1. raster image, 2. image graph of lines and junctions, 3. graphics and text objects, and 4. semantic objects of the map. The interpretation of the map is performed by instantation of the concept nodes of the semantic network. Results are presented for extraction of legal information (parcels and boundary stones) and topographic information (buildings, roads, sidewalks, farmland) from land register maps of scale 1:1000 and 1:5000