iswer simple 
| like line 
[E] " 
Bjarka-saby 
i. The data 
was also used 
iysieal Geog- 
my of Fore- 
. developed 
, The prog- 
between 
ng Programmes 
^ogrammes: 
isat computer 
ferent data 
or two 
using only 
n also read 
cillary re- 
rinter. 
on about the 
e mean and 
ands, cova- 
ncy and 
the line-prin- 
ocessinge 
n=cements 
cement. 
" transforma- 
cement is 
EPDCS system 
irst two 
one to show 
  
the most informative portion of the scale. On the other hand it is 
better than the second one to express pixels of which the brightness 
levels are far away from the most informative portion. 
With this programme package, the user can also select different 
scales for every brightness level, based on the printed histogramme. 
Hence, the user can print out. the pixels of specified brightness 
levels, showing the other pixels as blank. Density slicing is an- 
other type of contrast enhancement technique in the system.identi- 
ficution of objects in the multilevel density slicing pictwe is 
better than the original picture. 
Another EPDCS programme used for an image enhancement is com- 
binations of images, like additive, subtractive and ratio images. 
At last EPICS programme can make edge enhancement by filter. 
4, Training area extraction, calculation and display. 
The computer analysis of remotely sensed data is often con- 
sidered to consist of two parts: feature extraction and classifica- 
tion. The first process concerns the problem of selecting parts of 
the observed area so that classes are efficently described. These 
areas have to be extracted and analyzed so that they can be used as 
training areas. This part of programmes are used for this. They 
can perform the following tasks: 
A. Training area extraction. The programme can deal with up to 
30 training areas at the same time by means of three diffe- 
rent methods: 
1/ Line and column number of training area. 
2/ Data from bounderies which have been digitized and 
transformed. 
The digitization of training area boundaries is also 
performed by this programme. lt possible to digitize 
the exact boundary of training areas. The data must be 
entered along the boundary in an anticlockwise direc- 
tion. If you enter Less than four points of one trai- 
ning area, its boundaries must be construeted of str- 
aight lines (cf figure). 
Figure,Entering of boundary DATA of training areas. Note the 
anticlockwise direction.