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EVALUATION OF THE EFFECTIVENESS OF VARIOUS ENHANCEMENT 
AND IMAGE MANIPULATION TECHNIQUES * 
by 
N.K. Vyas* 
and 
D.S. Kamat* 
ABSTRACT 
Various kinds of image enhancement and manipulation 
techniques are available which, in general try to improve 
the image interpretability. However, there is no standard 
method that can tell as to which technique is best suited 
to bring out particular features in a particular image, 
with optimum clarity. 
  
This is partly because each image has its own unique 
Spatial distribution of intensity or brightness and partly 
because there is no quantitatives measurement available 
which can tell the effectiveness of an enhancement procedure 
in a particular situation. 
  
In this paper, the contrast of features and the homoge- 
neity of textures are taken as of fundamental importance to 
thé interpretation process and an analysis is made as to how 
the gray level co-occurence matrix will be influenced by any 
image manipulation procedure. The contrast and the homogeneity 
for both the original and the modified matrices are calculated 
and represented in two dimensional feature space having the 
homogeneity as one axis and the contrast as the other, 
- ED ED cnp GD GD an ED ED SID u D D ED DE ED DD ED DEE ED DD ED ED ED DC ED ED ED ED SD HE aD OD AD DD U xD eue US CUP = GD = WD nm ce cm 
Space Applications Centre, (ISRO) Ahmedabad-380053 INDIA 
+ Paper to be grosentsd at ISPRS Commission VII Symposium 
to be held at Toulouse (France) during 13-17th Sep.,1982 
in the session on Methodology for Enhancement. 
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