On Sep 20, 2010, at 10:42 AM, Micha Silver wrote:
> On 09/20/2010 06:35 PM, Hermann Peifer wrote: >> On 20/09/2010 18:09, Adam Dershowitz, Ph.D., P.E. wrote: >>> I have a large ortho image, that is in MrSID format (A full county at high >>> res). The file is ~3.5 gig. It covers a much larger area then I need. So >>> I set my region to the size that I do need, and then imported. The import >>> took something like 10 hrs. And, I now see that in my PERMANENT folder I >>> have 3 files that are each 15 gig (one red, one blue, one green), >>> The map was imported, but if I zoom to the size of the current map, it >>> seems that the whole map was imported, not just the area inside the current >>> region. >>> >>> I thought that imports are cropped to the current region? Am I mistaken >>> about this? Is there some setting to cause this to happen? >>> >>> I did the import with r.in.gdal. I am using the binary release of 6.4 on a >>> Mac. >>> The reasons that I care are 1) This map, for a small area of interest, it >>> taking up 45 gig on my hard drive. 2) Because the map is so large, it >>> takes a while for the display to update when I make any changes. >>> >>> Any guidance? > If you used r.in.gdal, then I guess your gdal has MrSID support. So you > should be able to use the gdal_translate utility with the -projwin flag to > clip out the area you need, and create a new tif. Something like: > gdal_translate -projwin ulX ulY lrX lrY original.sid clipped.tif >> >> >> > Raster import and export >> > >> > The module r.in.gdal offers a common interface for... >> > The full map is always imported. >> >> see http://grass.osgeo.org/grass64/manuals/html64_user/rasterintro.html Thanks. I ended up just using r.composite on the maps that I had imported. That did the crop to the current region that I had expected. Then I deleted the 45 gig of maps that I didn't need, but already had. The gdal_translate looks like a great solution for next time, before I do the huge import. Again, thanks to all. --Adam_______________________________________________ grass-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-user
