of "near-line" data storage. Floptical disk systems are 
now providing read-write storage for 21 MB of data on 3- 
1/2" diskette. 
2.1.4 Display Technology. In order for geographic 
information to be useful, it must be converted from its 
digital form to a visible product. The visible form that is 
most easily interpretable for the human user is that of a 
graphic product. Advances in display technology have 
brought the graphic display from a 256 X 256 pixel 
display capable of displaying pseudo-color images to a 
1024 X 1024 pixel, "true color" and stereo display, with 
2K X 2K or 4K X 4K displays becoming feasible. 
2.1.5 Decreased Cost. What is interesting to note is 
that, with the exception of the extreme cutting edge of 
the advances mentioned above, this technology is 
commonly available in off-the-shelf systems. In addition, 
each advance in technology is accompanied by a 
corresponding decrease in cost. With each passing year, 
we can process more megabytes faster and cheaper. 
2.2 Software Advances 
2.2.1 Programming. In former years, most of the 
software for processing geographic data or images was 
written in FORTRAN or assembly language. Currently, 
this software is programmed in C or C++. This has 
meant, generally, an increase in both processing speed (in 
addition to hardware speed increases) and cross-platform 
portability. This is particularly important from the 
systems point of view since it allows programs 
developed, for example, on a workstation to be ported to 
the PC environment and vice versa. 
This portability is also being enhanced by the general 
shift to the use of UNIX operating systems for program 
development and operation. While it was once considered 
impractical to run UNIX on a PC, this is no longer the 
case due to the advances in computing power. The recent 
introduction of Windows NT will bring further potential 
for cross-platform portability. 
Efforts are also beginning to define a set of standards for 
geoinformation processing functions which can be 
implemented in a programming toolkit. This toolkit 
approach would be similar to those used by many of the 
windowing environments such as the X-11 toolkit 
(Faust, et al., 1991b). 
2.2.2 Interface. Another important advance in 
geographic information processing has been the move 
towards the graphical user interface (GUI). Early systems 
required the use, first, of batch processing (essentially no 
user interface) and, then, a command line approach often 
requiring the memorization of cryptic commands and 
complex syntax. Today's software, for the most part, 
makes extensive use of a graphical user environment 
using windows, icons and buttons. In many cases, the 
interface is built using a set of standard interface tools 
such as those available in X-Windows, MS-Windows or 
the MacOS. This means that the 'look and feel' of the 
378 
system is familiar to the user making learning and using 
the software easier. 
Current trends indicate that, in the future, which interface 
a user prefers will have less impact on which software 
they use. Products and tools are being developed which 
will allow software developed for one interface to run 
under another. Examples include Suns WABI (for 
Windows software) and a recent agreement to port 
Apple's GUI to other platforms. 
2.2.3 Integration. Where once there was a clear 
division between the various systems and software used 
for geographic information processing, we are seeing the 
boundaries becoming more and more blurred. In the past, 
dedicated image processing systems were used to extract 
information from satellite images and photogrammetric 
systems to do the same from aerial photos. These data 
might be transferred to a GIS for analysis or to a separate 
cartographic system for map output. This is no longer 
necessarily the case. 
Even a cursory look at the literature will show that 
systems are being developed and marketed that combine 
the features originally available from a dedicated system. 
Image processing systems, such as those from Erdas or 
Intergraph, offer the capability to perform some 
geographic analysis and orthophoto production (formerly 
the realm of photogrammetry). On the other hand, 
geographic information systems, such as Arc/Info or 
ILWIS, offer image processing capabilities and hardcopy 
output, as do digital photogrammetric systems, such as 
those from Intergraph, Vexel, or Zeiss. 
- Many vendors are offering solutions to the "integration" 
of digital image processing and GIS. The definition of 
integration seems to be somewhat variable and the 
solutions range from the ability overlay vector GIS data 
on an image backdrop to the combination of "image 
processing, complete raster GIS modelling, and powerful 
topologic vector digitizing and editing" (Treadwell, 
1991). 
3. GEO[INFOR]MATICS - AN EVOLVING 
DISCIPLINE? 
Recently, Advanced Imaging presented a survey of 
vendors that offer products for the acquisition, 
processing, display, storage and output of digital 
imagery. Its list contained about 1100 addresses, most of 
them from the United States (Advanced Imaging, 1993). 
While the majority of these specialized in areas such as 
desk top publishing or medical imaging, many of their 
products could be linked to photogrammetric, remote 
sensing or GIS applications. Surveys on GIS and remote 
sensing software that also demonstrate the integration of 
spatial data handling technologies were published by 
Parker (Parker, 1989) and Sader and Winne (Sader and 
Winne, 1991) and Ehlers (Ehlers, 1992). 
  
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