X Windows Based Map Display Utility
Senior Project: 1991-1992
Michael Eamon, James Newpower, Chris Tivel and Vincent Vogel
Graphics Information, Inc. (GII) provides graphical information systems and
data to many of the top oil and gas companies in the US. The current GII
software product supports vector display of mapping information, providing
energy explorationist's with graphical "point and shoot capabilities at wells,
leases and other geographical objects. Once selected, information for the well
or lease is displayed.
The goal of this project was to incorporate image/photographic display into the
product. This provides display of scanned USGS 7.5 minute topographic maps,
aerial photographs, and satellite photographs, as well as engineering drawings
of spatial information such as property ownership maps. There are two
difficulties with this approach. The first is that the image coordinate systems
are typically non-rectangular, but are usually skewed due to the angle from
which the image was produced. An algorithm had to be produced to stretch or
shrink the image appropriately so that it could be displayed in an exact
geodetic coordinate system. This allows the existing GII vector displays to be
"overlaid" on the images. The second difficulty is that the map is actually
made up of many different images which, when pieced together, form the complete
map. The software had to provide the abstraction to the user of a single
complete map over which the user could pan, zoom, and rotate. The software was
written in C, using the X Window System and Motif user interface toolkit.
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