One of the handiest solutions for extracting 3D data
using SfM is this:
http://homes.cs.washington.edu/~ccwu/vsfm/
It includes georeferencing and can handle the coordinate
ranges that occur in geographical data. It is free
to use for non-commercial applications but unfortunately
not open source.
Anyhow, SfM works best when there is a large series
of images with a lot of overlap and small angular
displacement between consecutive images. Traditional aerial
imagery will not always give good results. There can also
be trouble with the simple camera model that some SfM
tools (including VSFM) use.
An open source solution that is optimised for remote
surveying applications is currently lacking, AFAIK.
Best,
Ben
On 09/10/2013 04:45 AM, Tim Bowden wrote:
On Mon, 2013-09-09 at 15:08 +0200, Markus Neteler wrote:
On Mon, Sep 9, 2013 at 10:59 AM, Tim Bowden <tim.bow...@mapforge.com.au> wrote:
Hi,
If all I've got is raw (ie, unrectified) aerial photography & sufficient
ground control points, what is the process for creating a DEM (assuming
it's possible with GRASS)? I've not been able to find any documentation
apart from orthorectification using an existing DEM.
You can find something in the Wiki
http://grasswiki.osgeo.org/wiki/Stereoscopic_analysis#GRASS_5
There is an old software "stereo" which seems to offer this, see links there.
It would be great to get this functionality into GRASS 7.
Markus
Thanks Markus,
For now this capability seems to be 'missing'. Once again I'm
left wishing I was a competent c/c++ programmer (wip...).
In any event, I suspect this approach has been mostly (?) superseded by
'Structure from Motion' type modelling which I'm also playing with- was
just hoping to be able to add 'traditional' photogrammetric modelling
to my toolkit and be able to do a comparison between the two).
Regards,
Tim Bowden
_______________________________________________
grass-user mailing list
grass-user@lists.osgeo.org
http://lists.osgeo.org/mailman/listinfo/grass-user
--
Dr. Benjamin Ducke, M.A.
{*} Geospatial Consultant
{*} GIS Developer
bendu...@fastmail.fm
_______________________________________________
grass-user mailing list
grass-user@lists.osgeo.org
http://lists.osgeo.org/mailman/listinfo/grass-user
