Good Morning,

I'm interested to know if anyone has used i.points in Grass to register 
SPOT , LANDSAT(MSS) or LAndSAT TM data. I have a couple of questions. 

1) In the documentation on i.points it talks about having a map layer and the 
   image you want to register. Then by looking at the "map" you can plot 
   points on the image , minimum 3 , and register it that way. My question 
   is does grass then take these points and extrapolate values over the 
   whole image ? 

   And if so surely the accuracy of this will depend on the user knowing 
   where on the image the referenced points are by looking at "map" layer. 
   From the resolution of the images I have pulled into GRASS I can't see 
   that this is going to be an accurate way of doing things , even with the 
   "zoom" feature - Any other ways of doing it ?

2) Once the image is registered in needs to be rectified , correct ? . Shouldn't   this happen first ? 

3) One final thing can I pull the image directly into a cell directory and 
   then run r.support on it ? or does i.tape.tm etc do something to the 
   image ? If so how do I get around this as my data is on CDROM ?

4) Sorry one more thing , when specifying a region I take it that it doesn't 
   matter what the region is before registration occurs ?

Any comments would be most helpful .

Thank you 

Jeremy 



