In message <Pine.LNX.3.91.961010164344.14668B-100000@ces.iisc.ernet.in> writes
:
Help! I don't know if this is an obvious question, but I have been
searching the Grass manual and can't find an answer - I have large raster
images and want to extract smaller ones from them for the purpose of
supervised classification. How do I do this? I have the coords of the
smaller images I want. Defining smaller regions doesn't help, since
i.class doesn't take a region name, it simply loads the entire image !
Please help.... I don't want to export to IDRISI, then extract, and then
reimport, as that would take rtoo much time.
Thanks a lot
Harini
After defining a smaller region, run r.mapcalc with the command:
newfname = original_raster_fname
This will create a new file containing just the smaller raster image, since
mapcalc only works on the active region.
Michael Hanratty Phone: (612) 627-4590
Dept. of Civil Engineering (612) 626-0024
University of Minnesota Fax: (612) 627-4609
St. Anthony Falls Laboratory
Mississippi River at 3rd Ave SE
Minneapolis, MN 55414