[mapserver-users] mapserver-users Digest, Vol 108, Issue 12

[lfilak]

On 2017-01-09 09:25, mapserver-users-request at lists.osgeo.org wrote:
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> Date: Mon, 9 Jan 2017 06:37:44 +0000
> From: "Schepers, Benjamin" <schepers at rvr-online.de>
> To: "'mapserver-users at lists.osgeo.org'"
> 	<mapserver-users at lists.osgeo.org>
> Subject: [mapserver-users] Oblique aerial images with mapserver?
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> 
> Hi list,
> 
> are there any suggestions or concepts out there to serve oblique
> aerial images with mapserver / opensource-software?
> The oblique images are not mosaicked and are just indirectly
> georeferenced. There do exist ground-footprints as shape with path to
> each file - comparable to a tileindex.
> 
> One way I thought of, could be mosaicking each direction (N-E-S-W) and
> add them as separate layers to the service... (I know the results look
> a bit strange and I also don't know such software for mosaicking -
> Google's/Bing's secret? Are there any open solutions for that?)
> Another idea could be to use a "special tileindex mode" for each
> direction, where just the most matching oblique will be rendered from
> footprint-tileindex.
> Would you suggest a real 3D-solution? How to serve that?
> 
> Any more hints are welcome :)
> ... and a happy new year!
> 
> Regards
> Ben

Ben,
For the oblique images, we use the ground footprint layer to populate a 
DB table with the four corners of each image and a calculated center for 
each shot. That table is used as a match against the center of the 
current map extent to locate the oblique that is the "closet" as a view 
starting point.
We then use Imagemagick for three different operations to merge the 
oblique and the map image. Rotate the current map image to match the 
orientation of the oblique image. Distort (-disort Perspective) to 
stretch the map image to match the perspective of the oblique. Composite 
to merge the map image and oblique into a single image.
The navigation is not fancy, there are pan arrows provided to allow the 
user to move to the next oblique to the N,S,E,W of the current oblique 
and a compass rose to allow the user to change the oblique perspective 
N,S,E,W. With the pan arrows and compass rotated to match whatever 
perspective is being viewed.
We have yet to investigate the methods used in Birds-eye to see how that 
works. We expect that the plugin provided by the oblique vendor is being 
used.
Hope that helps.

Lowell