2-3-2 
OFFICE COMPONENT 
MOBILE COMPONENT 
Figure 1: The system architecture 
This also provides us the recording of GPS 
data from a standard receiver. Though it 
doesn't support real time differential 
correction, a separate research has been 
undertaken to include the function. This will 
not be discussed here. 
The other major component of the system is 
Digital Video (DV). Specifically DV has 
been chosen against the analog to overcome 
the loss in quality of the image during the 
transformation from analog system to digital 
format for processing the images. 
Figure 2: The ROMDAS Hardware Interface 
The coordinates received from the GPS 
receiver is overlaid on to the digital video 
for referencing the image to get the real time 
positioning. 
The other essential component of the system 
is the capture card to downlink the video 
image with the computer through standard 
IEEE-1394 (iLink) connection. This enables 
us a perfect coordination between the 
devices and reduces the loss. 
3 CONCEPT 
The basic concept of underlying extraction 
of road width using a digital image is the 
simple trigonometric function as shown in 
figure 3. Since the focal length of the 
camera used for operation and the height it 
is mounted are know prior the vehicle run on 
road. This enables us to estimate the scan 
line in the image at nadir. Applying an 
appropriate would give us the width of the