P3D Re: 2D to 3D (Using Batteries)

[GBMars <GBMars@xxxxxxx>]

John N. Dukes wrote:
>Let's say we have continuing video FIFO (first in first out) frame storage
>of, who knows, maybe 10 or twenty video frames with the ability to assign
>left and right images to any slot along it. (Forgot to say, we need
>switched glasses in this system.) I'd guess that some quite simple image
>processing algorithms could determine if the picture is moving left or
>right as the frames get dumped into storage, and the left and right images
>could be selected with the appropriate delay. (The images, so selected,
>would be displayed alternately as the glasses are simultaneously switched.)

>In a sense this is an automatically optimized Pulfrich-like system which
>derives its two viewpoints using delay during scene motion. But it wouldn't
>depend on the Rolling Stones always turning counterclockwise (remember?),
>and both eyes would see the same intensity.

It's been done.  Actually, I sent a post on this to P3D some months ago.  I
saw a demonstration of a system using a personal computer with video capture
and overlay capability and LCS goggles.  Video from any NTSC source could
be brought in and digitized.  A primitive motion analysis then determined the 
predominant direction of motion a delayed left or right display accordingly.
By
adding a slight (fixed) shift so that the window doesn't coincide with the
surface
of the screen the effect will impress many people.

Personally, I thought it looked awful.  For one thing, there was a disruptive
discontinuity when the direction of motion changed.  But an important lesson
is that a great deal of depth perception is "made up" in the brain rather than
the
result of processing actual disparities between left and right.  Often it is
sufficient
to remove the reality of a flat image (by introducing a shift between left and
right)
to get the imagination going (using 2D depth cues) and, viola!, you see depth.

Similarly, I believe that the "cardboard cutout" effect which non-3D-nuts
often
experience when shown stereo images happens because the brain is accustomed
to a "real world" which looks slightly different from a stereo image, so it
interprets
the image as being slightly "unreal", the cardboard cutout interpretation
being a
common prior experience for many people.

Greg M.


------------------------------