Re: [photo-3d] "Wobble stereo", "one-eyed stereo", VISIDEP

["Allan Griffin" <agriffin@xxxxxxxxxx>]

Abram,
                     ONE EYED STEREO
 Last night on TV I saw a demo of GREAT one eyed stereo.  It went into
detail to show that, if one used all the other depth cues EXCEPT STEREOPSIS,
the bulk of people would think they were looking at 3D.  Used were 1.
Perspective, 2. Colour change with distance etc., but then, the item which
took my eye was the 'perfect' use of MOTION PARALLAX.

Granted, there was no off-the-screen-stereo.  However, the motion parallax
together with all the rest of the depth dues we get in every-day life,
created a most convincing sensation that we were watching two-eyed 3D.  The
only limiting factor was the fact that the demo was limited to a certain
set-up where the L to R motion was continuous.  The computer generated
subject matter was such that there was a large number of items of similar
known size extending from screen level right back to infinity, each with its
own individual degree of motion-parallax.  It certainly was excellent ONE
EYED STEREO"

Allan Griffin
                                   *********************
Subject: [photo-3d] "Wobble stereo", "one-eyed stereo", VISIDEP

Abram Klooswyk, you wrote:

> Threads on this list often are like a Geysir burst: unexpected
> start, quick rise and suddenly over. So was the thread on
> wobble stereo which lasted for hardly a week last June.
> Although (too?)late, I have done some additional reading and
> should like to present some details for future reference.
>
> On 15 Jun 2000 I wrote: "Images of two TV cameras were shown
> in rapid succession, but not so quick as a flickering, I guess
> some 5 frames per second. If memory serves there even was a
> patent application for it."
> I could have found the answer in the Photo-3D archives.
>
> Ray '3-D' Zone wrote on 30 Aug 1998 to the list (in part):
> >>In 1982 a professor of media arts at the University of South
> Carolina named Porter McLaurin along with his colleague Edwin
> R. Jones, a physicist, showed videotape footage of their
> autostereoscopic TV process they called "Visidep" on ABC with
> a nationally syndicated television program named "That's
> Incredible." Despite several marketing attempts, no widespread
> commercial application of Visidep ever took place.
> It is yet another unique example of the attempt to find the
> "Holy Grail" of 3-D:  a simple and universal autostereoscopic
> system.<<
>
> The quest for the Holy Grail assumes that it _exist_ :-).
> Or is it more like the Alchemists' making of gold?
>
> Further back there was a Photo-3D thread on "one-eyed stereo"
> and Visidep in 1996. Tony Alderson also has written on
> Visidep.
>
> The TV broadcast was on aug 10, 1982 on ABC en CNN.
> John Dennis (then already editor!) wrote on it in "Stereo
> World", March/April 1983.  "VISIDEP" stands for "Visual Image
> Depth Enhancement Process".
>
> A patent search (www.patents.ibm.com) resulted in:
> Edwin R Jones Jr., A Porter McLaurin en LeConte Cathey filed
> a patent application on July 16, 1981, issued on jan 31, 1984,
> United States Patent 4,429,328, "Three-dimensional display
> methods using vertically aligned points of origin."
> Full text at:
> http://www.patents.ibm.com/details?&pn=US04429328__&s_all=1
>
> Later two other related patents were issued: 4,528,587 on
> July 9, 1985 and 4,924,853 on May 15, 1990.
> The inventors also have written: "VISIDEP (TM): visual image
> depth enhancement by parallax induction", SPIE Vol 457
> Advances in Display Technology IV, 16-19, 1984.
>
> >From the text of the first US patent, 4,429,328:
> >>a method for producing a three-dimensional illusion of a
> subject is provided which comprises the step of sequentially
> displaying on a viewing surface images of the subject as
> viewed alternatively first from one point of origin and then,
> time displaced, from another point of origin at a rate within
> a range of 4 to 30 changes between points of origin per
> second, with the points of origin being vertically displaced
> from one another. Preferably the above-mentioned range is
> between 6 and 15 changes per second, and most perferably about
> 8 changes per second. <<
>
> So my guess "5 frames per second" was not far off.
> This seems also some answer to Ron Beck (13 Jun 2000):
> >I wonder if there's an "optimum" wobble speed.  Would a
> >faster wobble speed give better depth perception?
> >Would a slower speed negate the 3D appearance?
>
> An obvious question for us stereoscopists is: What vertical
> "stereo" base? The inventors wrote:
> "Most preferably, the points of origin are vertically aligned
> with respect to one another and the points of origin are
> displaced from another a distance less than the standard 65 mm
> interocular distance of human eyes. The points of origin are
> perferably displaced from one another at a distance on the
> order of 10 to 15 mm."
>
> Video and TV where used for the demonstrations, but the
> patent description also says:
> "A still further aspect of the invention contemplates a method
> using two slide projectors for producing three-dimensional
> illusions from slides. (...) alternately displaying the slides
> at a rate within a range of 4 to 30 changes per second between
> the first and second slides. Perferably the rate of change is
> between 6 and 15 changes per second, and most perferably about
> 8 changes per second. It is also perferable that the first
> slide be displayed from a first projector and the second slide
> be displayed from a second projector, with the step of
> displaying being achieved by alternately activating light
> sources of the first and second projectors."
> (BTW: 'perferable' and '-bly' is the original spelling.)
>
> Vertical alignment of two projectors is not so unusual for us,
> and "alternately activating light sources" can easily be done
> by covering the lenses alternately. In fact, you can see this
> very often being done _before_ stereo slide shows, when the
> projection is tested! I indeed often see the wobble effect on
> those occasions. Moreover, you can see a similar effect, but
> horizontal, when you cover your eyes alternately with your
> hand _during_ stereoslide projection. Many of us have done
> this to test _which_ image is out of focus :-).
>
> Sergio Baldissara on 14 Jun 2000 referred to this "obsolete 3d
> standard for TV: VISIDEP!" , which he found on a site devoted
> to "Dead Media", however the link he quoted (to islandnet)
> also is dead... The active link is:
> http://www.wps.com/dead-media/notes/23/233.html
> Dead medium: VISIDEP 3-D Television.
>
> The first VISIDEP patent expired in 1996: "Expired due to
> failure to pay maintenance fee".
> It was not the Holy Grail after all...
>
> Abram Klooswyk
>
>
>
>