[GRASS-user] question on georectification

[Harri Kiiskinen]

ma, 2006-07-24 kello 19:58 +0200, Wolfgang kirjoitti:
> Hi,
> 
> I've scanned some maps but as my scanner is not big enough I had to scan 
> each quarter on its own. I've imported these scans into a xy-location. 
> Can I use i.group to group these 4 scans together and then i.points to 
> get directly the full map? Or do I have to project the scans 
> individually and to combine them after rectification?

I did the latter and the results were not too good; even though using 10
to 12 control points, the overlapping parts did not sit together too
well. And you have to create a separate location for each scan (logical
though not intuitively apparent).
	Were I to do it now, I probably would start by combining the scans
together with a program like Hugin (http://hugin.sourceforge.net/). It
has performed well in joining partial scans of large drawings for me,
and the tutorials do have a nice example of just this kind.

Greetins,

Harri K.

-- 
Harri Kiiskinen <harkiisk at utu.fi>