anbul 2004 
| different 
ion, hue, 
angement 
1996); 
order; 
:k, blink, 
y (Kraak 
  
riables 
International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part B2. Istanbul 2004 
Blur gives symbols a fuzzy appearance and can for instance be 
applied to visualise uncertainty, while focus will introduce 
blinking symbols to attract attention. Transparency can be seen 
as a kind of fogginess, by which part of map content is 
obscured or faded in favour of other information. Apart from 
the browsing, another particular interesting feature of web- 
based environment is the plug-in function. With this function, 
virtual reality technique could be integrated into web-based 
visualisation, via JAVA, JAVA-Script and/or VRML. 
4. CONSIDERATIONS OF THE USE OF COLOURS ON 
WEB MAPS FOR NAVIGATION PURPOSE 
In the set of primary visual variables, three of them are colour, 
ie. hue, saturation and intensity. Traditionally, blue is used for 
hydrographic features, green for vegetations, grey for 
settlements and red for transportation networks. Table 4 lists 
the use of colour in traditional maps, as well as some cultural 
meanings. 
However, the use of colours for navigation maps displayed on 
screen may need a change. For example, Spiker et al (1986) 
has made a recommendation on screen maps for aeronautical 
navigation based on his empirical study (Figure 4). This is just 
a starting point and more study on this issue is very desirable. 
Table3 The use of colour in traditional maps 
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
Colour Colour Cartographic features Meanings in western Meanings in Chinese culture 
Names symbols culture 
Bi Hydrographic features Advisory, status Sky 
ue 
à Mountain 
Cyan 
Vegetation Go ahead, good, on, Water 
Green 5 e 
friendly, safe 
Yellow Medium height, Caution, warning, standby Sexual, noble 
cos dryness/bareness 
Higher lands 22 22 
Brown 
Red Important features (e.g. Danger, stop, off, Happy, fortunate, good 
e roads) excitement, unsafe 
Ice/cold lands tired unhappy, lack of 
White ; 
  
  
  
  
Table 4 Recommended colour use for screen topographic maps for aeronautical purpose (Spiker et al., 1986) 
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
Colour Colour Recommendation for features on topographic maps for aeronautical purpose 
Names symbols 
Open water 
Blue 
: Streams 
Cyan 
: Railway lines, obstacles 
Green 
Cultural features, bridges 
Yellow 
Cities, aeronautical data 
Magenta 
Contour lines 
Black 
: Roads 
Pink 
Enemy point symbols and tactical overlay 
Red 
: Friendly point symbols and tactical overlay 
While 
G Bare terrain surface (non forested terrain) (16 shades) 
rey 
  
  
Un