Point Object Extraction From Scanned Topographic Maps

Abstract

The fundamental research problem this thesis addresses is how to extract point objects automatically from scanned topographic maps. Map objects include natural objects such as rivers and lakes as well as artificial objects like roads and mines. Some objects have spatial extent (such as a lake or a road), whereas others are conceptualized as point objects defined by a single coordinate location. This research is a case study that focuses on the extraction of mine symbols from USGS topographic maps. All of the mine symbols of interest here are point objects. Of course, topographic maps contain many other point objects, as well as linear and areal objects. They also include textual information, which in some databases is also considered an object class. Like other objects, extracting point objects faces the challenge of object intersection and scanning artifacts.