5-2 Required Functions of GIS Software

In practical GIS applications, a lot of software are required for input, manipulation, processing, analysis and output of spatial data, both in vector and raster format.

The following functions are required for rather wide GIS applications (see Table 5.1)

Operating System (OS)
Unix for workstation, MS-DOS
WINDOWS for PC

Data Input
Map digitizing and editing for vector based GIS
Map/Photo scanning for raster based GIS
Color separation

Database Management
Relational database software
Database integrator for data exchange through network

Spatial Analysis
Vector Data Analysis
building topology
spatial query
buffering
mixing layers
overlay of layers
network analysis (route finding, tracing etc.)
Digital Terrain Model (DTM)
Overlays of layers
buffering
raster vector conversion
TIN
Grid based DEM
Drainage Analysis
Shading
Oblique Views of Bird’s Eye Views

Image Proceessing
Image Enhancement
Color Manipulation
Classification
Image Analysis/Measurement
Mathematical Morphology

Mapping System/Data Output
Map Projection
Graphic Representation
Cartographic Output
Vector raster conversion
Raster Data Analysis

Table 5.1 shows a comparison between two major GIS softwares ; MGE of Intergragh and ARC/INFO of ESRI.