[OSM-talk] Three-dimensional aerial imagery

[Richard Bullock]

>I saw this news story about how three-dimensional aerial photos, viewed 
>with
>special glasses, make it easier to pick out structures on the ground.
>
><http://www.bbc.co.uk/news/magazine-13359064>
>
>I wonder if any such 3-d imagery is available today?  It would seem to 
>involve
>having two cameras a set distance apart.  If OSM ever charters a plane 
>again, as
>was done for Stratford-upon-Avon, England, a few years back, it might be 
>worth
>taking two cameras instead of one.  In the meantime I guess we'll wait for 
>the
>3-d display Windows Phone to come out, with accompanying Bing Maps 3D.

Stereoscopic images used to be very common and were, as far as I was aware, 
usually used to draw up contour lines for OS maps in the UK.

You can see some examples here and on the next few pages
http://rst.gsfc.nasa.gov/Sect11/Sect11_3.html

They're a bit like "magic eye" images - and a lot of people should be able 
to see them without special glasses.

Basically, you put two images side by side, taken from slightly different 
angles. Look in the centre of the two images and "defocus" to a point beyond 
the page. Eventually you should see the image in full relief.