map the work

[Bart Cosyn]

Date: Thu, 26 Sep 1996 09:05:28 +0200 (MET DST)
From: Bart Cosyn <bcosyn at allserv.rug.ac.be>
To: Zorka Zegarra Rojas <zzegarra at condor.decom.uta.cl>
Subject: Re: map the work

Hi,


> GRASS User':
> 
> I' be that in GRASS4.1 can work with digitals maps geted from a digitalizer(i
.e.
> numonics) but... Can work with maps get across the a scanner ?

First some questions. With which program did you digitize?
What is the format?
Can you export your vectors to dxf?
If the answer to this last question is yes, you can use v.in.dxf it should
be somewhere in the src.contrib!

About scanners? I got a quite good experience by using scanned maps! In
grass there is a program called r.in.gif in src.contrib/r.gif which allows
to import gif images. You can also try to use r.in.tiff but there are some
bugs into that program. 
The problem with scanned maps is that you need to georeference it. For
that you need some points on your map which you can allocate exactly! (put
a mark on it!

For more info on georeferencing check the manual and check the commands
i.group,i.target,i.points,i.vpoints,i.rectify,i.rectify2

I have on the net a paper which tells how to use it for mapping images and
it explains how you can make the file POINTS yourself! and how to use it
with i.rectify!
Check for that
http://taoren.rug.ac.be/~bart/paper/node50.html

                        Bart
        ---------------------------------------------------     
        | ir. Bart Cosyn                                  |
        | VLIR-project Tunisia                            |
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        | University of Gent                              |
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