inbul 2004
ti-temporal
toring in
ng, 22(16),
fodulation:
Improving
e Sensing,
aker, J. R.
1. Remote
Integration:
grammetric
Sensing &
Sons, Inc,
ogg, D. H.
[he Use of
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Geographic
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COMPARING DIFFERENT SATELLITE IMAGE CLASSIFICATION METHODS:
AN APPLICATION IN AYVALIK DISTRICT,WESTERN TURKEY.
Aykut AKGÜN*"', A.Hüsnü ERONAT? and Necdet TÜRK"- (aykut.akgun(deu.edu.tr)
" Dokuz Eylul University, Department of Geological Engineering, Building-A, IZMIR
b > . > ; S . Ai. : er ;
Dokuz Eylul University, Institute of Marine Sciences and Technologies, IZMIR
KEYWORDS: Classification, GIS, Image, Satellite, Landsat
ABSTRACT
The different satellite image classification methods were compared using the satellite images of the Ayvalik district located
- ^^ . . 2 . . m . . . .
on the western coast of Turkey covering approximately 560 km”. For this purpose, landuse classification of the Investigation
area was made by different supervised image classification procedures and the results were compared with one another.
Landsat 7 ETM+ satellite image, IDRISI Klimanjaro image processing and the GIS package were used in this study. Of the
classified images, the maximum likelihood method is found to be more applicable and reliable for the satellite image
classification purposes. While the minimum distance method has given more reliable results than the linear discriminant
procedures, the parellelpiped method is found to give the least reliable results compared to the other methods.
1. INTRODUCTION
Image classification is an important part of the remote sensing,
image analysis and patern recognation. In some instances, the
classification itself may be the object of the analysis. For
example, classification of landuse from remotely sensed data
produces a map like image as the final product of the analysis
(Campbell 2002). The image classification therefore forms an
important tool for examination of the digital images.
The term classifier refers loosely to a computer program that
implements a specific procedure for image classification
(Campbell 2002). The analyst must select a classification
method that will best accomplish a specific task. At present, it
is not possible to state which classifier is best for all situation as
the characteristic of each image and the circumstances for each
study vary so greatly. Therefore, it is essential that each analyst
understand the alternative strategies for image classification so
that he or she may be prepared to select the most appropriate
classifier for the task in hand.
At present, there are different image classification procedures
used for different purposes by various researchers (Butera
1983, Ernst and Hoffer 1979, Lo and Watson 1998,
Ozesmi&Bauer 2002, Dean&Smith 2003, Pal&Mather 2003,
Liu et al 2002) . These techniques are distinguished in two main
Ways as supervised and unsupervised classifications.
Additionally, supervised classification has different sub-
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classification methods which are named as parellelpiped ,
maximum likelihood, minimum distances and Fisher classifier
methods.These methods are named as Hard Classifier.
In this study, the Ayvalik district located on the western coast
of Turkey (Figure 1) was selected as a study area covering
approximately 560 km? for comparing the
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Figure 1. Location map of the study area