[GRASS-user] question on georectification

[Wolfgang]

I wonder why the result should be bad! If the points for rectification 
are ok, then it should fit quite well. But today I had not the time to 
finish the first map, so tomorrow evening I can report my reports.

Wolfgang

Harri Kiiskinen schrieb:
> 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.
>