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REPRESENTING TOPOLOGIC PROPERTIES IN RASTER DATA STRUCTURES
J. R. Muller and R. P. O'Connor
Synectics Corporation
310 E. Chestnut Street
Rome, NY 13440
BIOGRAPHICAL SKETCH
James R. Muller received an M.S. degree in Urban Planning from the
University of Washington, Seattle, WA in 1979 and a B.S. in Geography
from the State University of New York, Oneonta, NY in 1975. He is
currently serving as project director of the Interactive Raster Data
Structures (IRDS) study sponsored by the Rome Air Development Center
(RADC). Previous experience includes automated cartography, remote
sensing, and geographic information systems.
R. Patrick O'Connor is a graduate of Syracuse University with a B.S.
degree in Mathematics. He is currently serving as principal investi-
gator of the IRDS study. Mr O'Connor has been involved in automated
cartography and interactive systems since 1972. Additional experience
includes systems programming and implementation of real-time radar
and data acquisition systems.
ABSTRACT
A major obstacle to satisfying the need for digital cartographic data
has been the high cost and long lead time associated with data capture
of cartographic source material. Dramatic improvements in the rate of
data capture and in the processing of cartographic data are promised
by the emergence of raster technology within the digital mapping arena.
A major deterrent to the acceptance of raster data has been the in
ability to interact with cartographic entities as features and
segments. This interaction can be improved by a raster data structure
which expresses basic topologic properties. This paper defines the
topologic properties of raster data, presents an encoding scheme for
representing neighborhood connectivity, and examines techniques for
interpreting other properties from the data. Finally, an example
illustrates the enhancement of cartographic editing through this
procedure.
INTRODUCTION
Synectics Corporation is currently performing a research and develop
ment effort for the Rome Air Development Center (RADC) entitled
"Interactive Raster Data Structures (IRDS)". The purpose of this
study is to survey and investigate data structures and techniques