Representation of Contours ad Regions for Efficient Computer Search

A novel computer-searchable representation
for the three basic pictorial features, contour 
maps, region coverage, and line structures, is described.
 The representation, which has practical storage 
requirements, provides a rapid mean of searching large
files for data associated with geometric position 
as well as with attribute value.  An application of this
representation to handling terrain information 
illustrates its utility.  The algebraic properties
of the data structure make it computationally easy 
to determine whether a point lies within a closed boundary;
compute the area contained by a closed boundary; 
generate the closed boundary representing the union or
intersection of two closed boundaries; and determine 
the neighboring boundaries to a point and the
minimum distances between them and the point.

CACM February, 1973

Merrill, R. D.

contour map representation, region boundary representation,
computer-search-able structure, graphic 
data retrieval, graphic language, two-dimensional
patterns, computer graphics, graphic display

3.21 3.23 3.79 6.35

CA730201 JB January 24, 1978  3:30 PM

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