[GRASS-user] color anomalies after orthorectification

[Stefan Kiefer]

Hi,
I tried to orthorectify aerial photographs.  That worked fine by now, 
until i got scans wich appear to be darker as before. At least this is 
the first observation I made. The effect occured with that scans is, 
that after rectification some of the dark areas become white (or rather 
null, querying that cells result in -0.722622310236638).
Has anyone had similar experiences when rectifying aerial photographs. 
And hopefully a hint how to avoid this damages. I suspect that the 
orthorectified images become double precision whereas the imported scans 
are integer...

best regards

Stefan