P3D Re: boris starosta's site

[Larry Berlin <lberlin@xxxxxxxxx>]

>Date: Thu, 4 Dec 1997
>Michael Kersenbrock writes:
>...............
>
>> Consider that for ORTHO pictures with a stereo camera, the ideal subject
>> distance is around 7 to 15 feet. That represents a finite range of
>
>Can a picture be "ORTHO" without definition of the viewing environment?

****  Ortho is specifically the accurate image reconstruction based upon
normal interocular spacing. It therefore exists only at a single geometry
based upon that single fixed stereo base. It would also be dependent upon
viewing technique, because it involves reconstruction of the original
situation through the viewing process. Therefore strict Ortho reconstruction
is a very narrow definition which only exists under ideal circumstances.
Since I freeview most of the time, Ortho is seldom applicable. Yet, there
are stereo images that appear to be the equivalent of an ortho view since
the subject being viewed appears with seemingly normal depth relationships
per scale, despite the fact that it's a small image on the monitor. I don't
think that ortho equivalence is considered to be Ortho however.

>
>Recall my suggestion about the "exercise" of walking-around-a-room in 
>front of a projected image and seeing how "distortion" varies
>significantly (more in some images than others) as one moves
>around the room.  It really "works".  I've done it (club did too
>a few weeks later).

*****  The amount and direction of distortion observed as you move around
the room and watch a stereo image depends on the position of the image
content relative to the stereo window. The entire image reconstruction
pivots about that point of equality which is the plane of coincidence or the
stereo window. That which is in front of the window moves in the same
direction that you do. That which is behind the window moves in the opposite
direction. The further from the window, the more relative movement.

>
>.............
>My personal experience is very different from this.  Looking at a 2D 
>photo of a distant view, or looking out of an airplane window at all
>the "small" houses, my brain interprets the situation as "big things
>far away".  When I look at a hyper image view of the same, my
>brain interprets "small versions of usually big things at some 
>distance".  VERY VERY different to my brain's way of processing 
>things.  
>

****  So do you think it's something that needs to be spelled out for the
viewer in each case?

Larry Berlin

Email: lberlin@xxxxxxxxx
http://www.sonic.net/~lberlin/
http://3dzine.simplenet.com/


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