Novice: Contours from GIF
bonk at nic.fns.uniba.sk
Thu Sep 18 03:25:32 EDT 1997
On Thu, 18 Sep 1997, James Cameron wrote:
> I've scanned most carefully a portion of a topographic map, ensuring
> that each pixel matches my resolution of five metres. So my GIF file is
> 600 x 800 pixels, 3km by 4km.
> I've been able to import it using r.in.gif and then adjust it's location
> using r.support. Displaying it actually worked too, with d.rast.
> 1) how do I make the display show only one portion of the area and
> magnify it to show the original level of detail? Or better?
> -try to do this: run d.zoom and make a borders of your desired area /by
mouse/, then run d.erase. Again run d.rast with your gif map , the
region you will see is that you done by d.zoom. Previuos region you can
call back by g.region /option 4 "set the current region by raster map"/
-try to run d.display it's GUI in GRASS /most like the like d.zoom/
> 2) how do I now digitise the GIF to produce a vector map of the
> contours? And a site map of some of the features?
> -have no experiences
> James Cameron (cameron at stl.dec.com)
> Digital Equipment Corporation (Australia) Pty. Ltd. A.C.N. 000 446 800
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