[GRASSLIST:2895] Re: unwanted map borders

[Glynn Clements]

Kirk R. Wythers wrote:

> Which command cuts off "clips" unwanted map borders? I have a series of 
> scanned and rectified images (essentially tiles) that I intend to use 
> r.patch to combine into a single large map. However, there are borders 
> around each that needs to be removed before r.patch is applied.

To crop to a rectangular region, use g.region (or d.zoom) to change
the region, then r.resample to create a new map from the portion of
the map inside the current region.

To crop to a non-rectangular region, create a raster map which defines
the region of interest, set it as a mask (with r.mask, or by naming
the map "MASK"), then use r.resample.

-- 
Glynn Clements <glynn.clements at virgin.net>