Toward Automatic Extraction Of Cartographic Features

Toward Automatic Extraction of Cartographic Features

The problem of automatically extracting map symbology from source imagery is studied. It is concluded that a great deal of geographic knowledge used by humans, who currently perform this extraction function, must be made available to machines before the function can be automated. Several geographic knowledge sources are discussed and an attempt is made to define paradigms under which knowledge can be encoded and used in the computer. An automatic cartographic feature extraction system (ACES) is sketched which represents a best framework for continuing development on this difficult problem given current achievements. A systems approach is taken with first consideration given to desired outputs and available inputs. It is concluded that input/output technology is far in advance of technology available for interpretation of the data. Emphasis is placed on the use of knowledge by ACES during automatic interpretation of imagery. Many types of knowledge typically used by humans appear difficult to engineer into automatic processes. Use of positional knowledge encoded in a geographic data base (GDB) is selected as the most promising avenue. Proposals are given for future research work in that direction. (Author).

Geographic Information Systems (GIS) and Mapping

Geographical Information Systems and Computer Cartography

A concise text presenting the fundamental concepts in Geographical Information Systems (GIS), emphasising an understanding of techniques in management, analysis and graphic display of spatial information. Divided into five parts - the first part reviews the development and application of GIS, followed by a summary of the characteristics and representation of geographical information. It concludes with an overview of the functions provided by typical GIS systems. Part Two introduces co-ordinate systems and map projections, describes methods for digitising map data and gives an overview of remote sensing. Part Three deals with data storage and database management, as well as specialised techniques for accessing spatial data. Spatial modelling and analytical techniques for decision making form the subject of Part Four, while the final part is concerned with graphical representation, emphasising issues of graphics technology, cartographic design and map generalisation.