Hello Grassusers
We have some aerial photographs of an area.
We do not know the coordinates of each photo to put it
in the location in GRASS but we know the coordinates of a few points
which are easily identified on the photos.
How we can geo rectify the photos? (already converted to rasters) and
put them in the correct order to produde the whole area of interest??
Thank you in advance for your help
Giorgos Zacharioudakis
School of Earth Sciences
University of Birmingham
Edgbaston B15 2TT
Birmingham
UK
Tel 0044 121 4146146
Fax 0044 121 4143971
e-mail:giorgos@ers.bham.ac.uk
This should be very easy to do. You only got to know how i.points or
i.vpoints work. When you use i.points (after running i.group to get a
list of the images to rectify and i.target to tell where the rectified
image must be putted) a file POINTS is made in
$GISDBASE/$LOCATION_NAME/$MAPSET/group/name_ofthegroup.
This file has an easy format (5 colums y:x:y_rectified:x_rectified:?)
In which column 5 contains 0(=exclude) or 1 (=include). In fact you can
edit this file and enter the 3d and 4th column. 1 and 2 of the original
image can be found using d.where!
To got more information try to run i.points on a test photo and check the
format of the files! I refer to
http://taoren.rug.ac.be/~bart/paper/node50.html
to get more info!
Bart
---------------------------------------------------
| ir. Bart Cosyn |
| VLIR-project Tunisia |
| Laboratory for Hydrology and Water Management |
| University of Gent |
| Coupure 653, B-9000 Gent |
| Belgium |
| Tel: +/32/9/2646137 |
| Fax: +/32/9/2646236 |
| E-mail: Bart.Cosyn@rug.ac.be |
| URL: http://taoren.rug.ac.be/ |
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On Wed, 24 Jul 1996, G. Zacharioudakis wrote:
Hello Grassusers
We have some aerial photographs of an area.
We do not know the coordinates of each photo to put it
in the location in GRASS but we know the coordinates of a few points
which are easily identified on the photos.
How we can geo rectify the photos? (already converted to rasters) and
put them in the correct order to produde the whole area of interest??
Thank you in advance for your help
Giorgos Zacharioudakis
School of Earth Sciences
University of Birmingham
Edgbaston B15 2TT
Birmingham
UK
Tel 0044 121 4146146
Fax 0044 121 4143971
e-mail:giorgos@ers.bham.ac.uk