On 31/10/11 11:34, Markus Metz wrote:
On Mon, Oct 31, 2011 at 11:22 AM, Moritz Lennert
<[email protected]> wrote:
On 31/10/11 10:08, Markus Metz wrote:
On Sat, Oct 29, 2011 at 11:25 AM, Moritz Lennert
<[email protected]> wrote:
On 27/10/11 21:10, Moritz Lennert wrote:
Hello,
Trying to use the georeferencing tool in 6.4.1, I have the following
question: is it possible to define a vector map as target map when
georeferencing a raster map ? I can't seem to find how to do this.
Just to be precise: I'm talking about the tool in the wxgui.
Am I the only one seeing this as a problem ? I can work around this by
transforming my vector map in a raster and then use the result as target
map. But I find this less than ideal. It should be possible to use vector
map as reference, not only raster maps.
I will file a bug report about this, but was just wondering whether I'm
missing something obvious.
Vector support in the georeferencing tool is poor. Ideally the tool
would have something like a layer manager where you can add as
reference maps any number and combination of raster and vector maps,
just like in the regular layer manager. Further more, the C module
v.rectify is still missing (I want to write it based on v.transfrom
and v.proj but did not get around yet to do it).
Ok, so currently I have to use the v.to.rast workaround, then. But does the
solution really have to be a whole layer manager ? Generally one does not
use many different layers as reference maps, so just having a choice between
vector and raster reference maps in the preparatory steps of the tool should
be enough IMHO.
OK. Then the option for reference maps could be one raster map and/or
one vector map (vector map always on top of raster map).
This sounds good to me.
v.rectify is still another issue. v.transform probably covers most of the
use cases anyway, or ?
Yes, apart from the case when source and target LOCATION_NAME are
different. This is handled by v.proj. Since GCPs are specific for a
given source / target location combination, a TARGET like for imagery
groups would also be needed.
I think that in many cases you can import the data directly into your
target location and run v.transform there. This is less the case for
raster data. But I agree that the possibility should be there for the
user to georeference vector data between two different locations.
Moritz
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