[GRASS-user] How to shift a raster map?

Andres Kuusk andres at aai.ee
Wed Dec 7 04:41:53 EST 2011


I have a high-res satellite image which has a positioning error about 5 m.
A previous GRASS version had a simple shift of coordinates however in the
GRASS-7 I cannot find such a tool.

A workaround is to use i.rectify. It seems to me that there could be a 
more simple possibility for such a simple operation.

The image is large and i.rectify returns ERROR: Error writing segment 
file. I get this error even after splitting the image and trying to 
rectify a small piece of the large image. The procedures I did were:

- defined a small region

- with r.resample made a copy of the small region of the original large 

- r.info reports the correct new region and the correct size of the small 

- i.rectify of the new small map reported in the output window the 
previous large region and I got the same error: Error writing segment

I could to run i.rectify on another PC which has a bit more memory (4G, my 
PC can use 3.2G, both are Linux), but anyway, to shift a raster should be 
more simple.

Thanks for suggestions!

Andres Kuusk
Tartu Observatory, Estonia

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