originals very often contain features of most varying 
qualities. The planimetric representation of our basic map 
at the scale 1:5,000 is an example of such a scanning 
original. Here we find road signatures, building signatures, 
water areas, divers land-use-areas, topographic and trigo 
nometric single symbols, etc. 
A full-automatic extraction of certain object categories 
from a binary image meets with many difficulties and tests 
which can be compared have not been very sucessfull so far. 
Some available software or some proposals in published 
papers do use the line width or the line length or the 
node-characteristic of signatures for the classification 
of the object-qua1ity. These techniques are sometimes 
usefull for the classification of characters or single 
cartographic symbols, but not for the extraction of building 
or street signatures. 
At the scale 1:5,000 many objects are represented with 
their natural or simplified contours, not in form of a 
single uniform symbol. Furthermore we have the problem that in 
our basic map several topographic objects are contoured 
with lines of the same line width. So the line width indi 
cates no feature quality. 
TESTS ON THE RECOGNITION OF AREA PERIPHERIES 
AND AREA QUALITIES 
At the time we are engaged in investigations of the practi 
cability of a certain solution (Lichtner 1981) for the 
planimetric representation. For this solution we need a 
colour-scanner which are used in the reproduction and 
printing industry and an image»processing system. Both are 
available on the market and with these equipments it is 
possible to get feature-se1ected representations or image 
matrices of the planimetry map original. 
In the following the procedure chosen for this operation is 
shortly outlined (see fig.l). First the planimetric re 
presentation is copied onto a medium which can be drawn on 
folt-tip-pen or another pen of special making. Then in this 
copy of the planimetry all areas enclosed by peripheries 
are manually encoded with a colour dot line or point 
related to the quality of the represented object. For the 
road net usually only one single colour dot is sufficient. 
Building signatures - because of their hachures are made up 
of severals single areas enclosed by peripheries - are not 
encoded with colour dots. That's the class of uncoloured 
areas. The manual colour-encoding of all these small areas 
would be very time-consuming and susceptible to mistakes. 
The vacant part of a real estate with a building is encoded 
with a colour-dot.