P3D Re: Aerial 3d !

["Dr. George A. Themelis" <DrT-3d@xxxxxxxxxxxxxxxxxxxxxxxxxxx>]

John Gaasland writes:
  
>Met a person in the building I work in today. He works in the
>photogrametry section with 3d-photos taken from planes. 

One of our subscribers (not sure if he is still around) is Prof.
Mugnier, head of the Photogrammetric Laboratory of the U. of New
Orleans... He was kind enough to let me borrow a few of these
aerial photographs to copy in slide film for my presentations.

>There is a
>single camera on the plane that takes a progression of  photos while
>flying along freeways and other highway consturction projects. 

Usually, a 60% overlap is used, which means the 60% of the image is
common in the pair (the rest is non stereoscopic information).  The
purpose of photogrammetry is to make measurements and exaggeration
of the height of topographic features will make measurements easier.

>The transparencies are scanned into a computer...

Some of the pictures I received were prints, others transparencies.
Talking about LARGE format!

>Imagine that, working  as a professional 3d viewer!

Prof. Mugnier admitted that he had no inclination to use stereo 
photography for entertainment as most of us do.

Other people who use stereo imaging in their regular jobs include
researchers working with stereo microscopes or Scanning Electron
Microscopes used to take stereo pairs.  We do a lot of that in my
work place.

George Themelis


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