6 
The user, by moving the cursor in one window can see 
the homologous point visualised in the other. 
The algorithm used is that of point based warping which is 
used not for realising a true warping operation but only to 
find the corresponding position of the identified point. 
S. Marco 
Rialto Arsenale 
S.Marta I Accademia | S.Margherita) S.Polo | S.Giorgio | P.Roma | S.Elena 
l_d 
fig 9 2W user's interface. The crosses in the middle of the windows show the homologous points 
& 
s|&|&| mJ fJ _j 
crosAo 
2104:1425 
2104:1880 
2188-1636/1869 
' central 
fig 10 2W operator's interface: it allows to collect control points, to calculate coordinates in the new reference system and therefore to 
obtain the correspondence 
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