SPATIAL INFORMATION PROCESSING IN DIGITAL 
IMAGE ANALYSIS SYSTEMS 
Eugene E. Derenyi, Professor 
Rostam Yazdani, Research Associate 
University of New Rrunswick, Fredericton, N.R. 
Canada 
Commission II 
ARSTRACT 
The utility of digital image analysis systems extends beyond 
the processing of remotely sensed imagery data. It + can 
successfullv be used for overlaying and interrelating results 
of multidate classifications performed over the same geographic 
area, or to correlate information obtained from various remote 
sensing and/or non-remote 'sensing sources. The ‚concept of 
information processing in digital image analysis systems is 
introduced, the methodology is outlined and examples are 
presented. 
INTRODUCTION 
Digital image analysis systems are designed for interactive 
processing of imagery data, which is in raster or cell format. 
The two principal operations performed are image enhancement 
and image data classification. These activities are augmented 
by a number of support operations such as geometric and 
radiometric correction, statistics generation, image display 
and manipulation. : 
Image enhancement highlights features in an image to facilitate 
the. extraction. of ‘information hy‘ visual: interpretation’ or 
further digital processing. The output remains to be image 
data and does not serve as a direct input. to geographic 
information systems (GIS). 
Classification, on the other. hand, is |uftilised. for. the 
extraction of thematic information of the kind displayed on 
maps or stored in geographic information systems. Forest cover 
types, agricultural erop. types, soil. types. are | iust a: few 
examples. In. fact, the «most. common. way „of utilizing; the 
information. generated by this operation is. to display iti ns a 
graphical plot which can then serve as a thematic map or be 
overlaved on other mans for visual: correlation with other 
information, Fventually, the result of the classification may 
find its way to: a GIS through digitization of-theegraphical 
product, or by transforming the digital output from the image 
analysis. system into a. format. compatible with. they GIS in 
question. Haually the latter requires a raster to: vector 
conversion. 
Basically, «digital. image analysis. systems are utilized, for 
generating raw’ information lust. Like digitizing tables or 
stereo plotters are, which is then further. manipulated hy 
mapping, ‘visual ‘and digital overlay techniques, or numerical 
modelling to- provide the Rind of refined, integrated 
information that decision makers need. Upon careful 
examination of the capabilities of such systems it becomes