International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part B4. Istanbul 2004 
The KVR1000 photo with an effective pixel size of 2.2m (table 
1) has some advantages for mapping against the multispectral 
IKONOS image. As a typical analogue photo it is still 
influenced by the film grain, but nearly all individual buildings 
can be identified. Of course there is no discussion, the 
a required pixel size of 2m for a map scale 1:50000. The rule of 
5 pixels is not a fixed value; it is quite depending upon the 
contrast and colour information. For the interpretation this size 
may be required, but if we do have additional information like 
the location of an object on the road, by the size we may get the 
  
  
J M T 
    
  
  
IKONOS pansharpened 1m pixel size 
IKONOS pan reduced to 4m pixel size 
  
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a e 
  
  
Figure 4: comparison of different IKONOS image products in the area of Zonguldak 
  
  
  
  
  
panchromatic IKONOS image with 1m pixel size is quite better. 
The range of grey values shows also details in areas where we 
do not have a differentiation in the KVR1000 (see top of 
building in lower right corner of figure 3) and it shows quite 
more details (see the cars on the parking place in figure 3, lower 
centre). Of course the advantage of the colour can be combined 
with the high resolution of the panchromatic image by a 
pansharpening (figure 4). This still improves the interpretation. 
4. VISIBLE OBJECTS 
The smallest individual object which can be shown in a map has 
a size of 0.2mm caused by the printing technology but also the 
resolution of the human eye in a usual reading distance. For the 
identification of individual objects approximately 5 pixels are 
required under usual conditions. If individual objects shall be 
shown in a map, under this condition a pixel size of 0.2mm/5 = 
0.04mm is required in the map scale. This would correspond to 
information of the object (see figure 5). In addition in such a 
topographic map only under special conditions individual 
objects are presented. A topographic map in this scale range 
includes more vector elements like roads, railway lines and 
water courses. Vector elements can be identified with a much 
smaller width. In the extreme case the separation lines on roads 
can be seen even if they do have only a width of 0.2 pixels 
(figure 6). The required pixel size for mapping is also 
depending upon the contrast, spectral range and colour 
information, so in general the situation is quite more complex 
than just expressed by the pixel size in relation to the map scale. 
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