On Wed, Dec 7, 2011 at 10:41 AM, Andres Kuusk <[email protected]> wrote: > > > Hi! > > 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 map > > - r.info reports the correct new region and the correct size of the small > map > > - 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 > file. > > 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.
Memory has nothing to do with the error "ERROR: Error writing segment file", this is an error while writing to disk (not enough disk space?). i.rectify has a separate option controlling memory usage, default is 300MB; this does not affect disk space requirements. As Moritz suggested, try r.region to shift a raster map: g.region rast=my_map -p # shift 5m to north and 5m to east, g.region understands n=n+5 etc g.region n=n+5 s=s+5 e=e+5 w=w+5 -p r.region map=my_map -c Markus M > > Thanks for suggestions! > > Andres Kuusk > Tartu Observatory, Estonia > _______________________________________________ > grass-user mailing list > [email protected] > http://lists.osgeo.org/mailman/listinfo/grass-user _______________________________________________ grass-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-user
