[mapserver-users] Oblique aerial images with mapserver?

[lfilak]

> Hi Lowell,
> 
> thank you for your response.
> 
> < 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.
> OK so far... could be done in a lot of ways.
> 
> <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 principle I do understand, but how is that implemented in a web
> application? I know ImageMagick as a commandline-utility; via CGI or
> PHP-plugin?
> 
> <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.
> Nearly same question as above, how is that done in a web application?
> Native mapswerver/mapscript-application? My optimum approach would
> have been to achieve a generic WMS with five layers (Ortho, N, E, S,
> W), where of them gets exclusively used in an application, say
> OL3/Leaflet/Mapbender...
> 
> 
> Ben

Ben,
We use PerlMagick for the image manipulation but there are plenty of 
ways to access the ImageMagick tools.
The trouble with creating a WMS service of the oblique is that the image 
needs to be warped to fit into the orthogonal map view or the map needs 
to be warped to fit into the oblique view. What we experienced, is that 
warping the cadastral data to the oblique has the best end result. 
Otherwise, you loose the clarity in the oblique and it is slow.
Perhaps if a projection string for each tile was generated and saved in 
the DB table, the projection could be used for the layer when rendering 
a map image instead of the basic image type of re-projection being done 
via ImageMagick.?

Lowell