MSW@mplvax.sri.com (Mark S. Williams) (09/07/89)
There appears to be some interest, although not as much as I would have
hoped. One person who emailed me said that they remembered seeing the TV
demo that I mentioned - the one where a frisbee was thrown. Another
person was told about this technique by a friend a couple of years ago,
and together they have been looking for more info about it ever since.
So, it seems to me that what we are talking about is not just a
"marginal" effect, but one that is really worth looking into.
Excerpts from US Patent #4,429,328 Class 358/88 Jan 31 1984
"Three Dimensional Display Methods Using
Vertically Aligned Points of Origin"
Abstract
Developement of a three-dimensional illusion through sequential
displaying on a viewing surface of 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 the points of origin per second. The effect of the illusion is
maximized by having the points of origin vertically aligned with respect
to one another and having the points of origin displaced from one
another a distance less than normal interoccular distance.
Background of the Invention
(2) Description of the Prior Art:
Stereoscopic films are known. Such films may comprise a double row
of left and right images, or a single row of alternate left and right
images which have been photographed from horizontally aligned left and
right points of origin. Prior art three-dimensional systems typically
operate upon the principle that left and right eye images must remain
separated in order to create a stereoscopic effect. These "binocular"
systems therefore employ red and green colored glasses, mechanical
viewers, or polarized filters in order to assure that only left eye
images reach the left eye and the right eye images reach the right eye.
Although results from such systems can be spectacular, the need for
extraneous viewing equipment has led to the commercial demise of all
such systems. Furthermore, none of these system is capable of displaying
a three-dimensional illusion using simply a standard 24 frame per second
movie projector or using a standard home television receiver.
The history of prior art three-dimensional systems occasionally
includes mention of a "monoccular" or "cyclopian" system, in which
alternately left and right images were rapidly displayed in an effort to
create a three-dimensional illusion through "fusion" of the two images.
Complicated multi-film projectors were utilized to implement such
systems, left and right images were taken simultaneously on a single
film strip to facilitate registration, and speeds of 48 frames per
second were tried, but none of these systems achieved significant
commercial success and none were deemed capable of displaying a three-
dimensional illusion using sinply a standard 24 frame per second movie
projector or using a standard home television camera. Moreover, even at
a reduced rate of display wherein the stereoscopic effect is increased,
the inventors have determined that the appearance of jumping between
successive images renders an unsatisfactory result.
Each of the prior art systems known to the inventors is believed to
have failed primarily because the system was complicated. To succeed, a
three-dimensional system must be simple. The system must be capable of
use with a standard 24 frame per second projector and/or must be capable
of use for a standard home television receiver - without any
modification.
(objects of invention excluded)
Summary of the Invention
To achieve the forgoing objects, and in accordance with the
purposes of the invention as embodied and broadly described herein, 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 vertically displaced from
one another. Preferably, the above mentioned range is between 6 and 15
changes per second, and most preferably about 8 changes per second.
............
Most preferably, the points of origin are vertically aligned with
respect with one another and the points of origin are displaced from one
another a distance less than the standard 65 mm interoccular distance
of the human eyes. The points of origin are preferably displaced from
one another at a distance on the order of 10 to 15 mm.
End of excerpt.
To answer one query - the search was done with the inventor(s) nameon an
online patent database available via Dialog Information Services in Palo
Alto. The process was rapid, and I don't believe it cost over three
dollars. (maybe 2 dollars)
This method could be used by:
a) those with 3D modeling programs who could create images
viewed from the two vertically displaced points of origin.
b) those with a TV camera and digitizer/frame grabber who
could capture single still shots viewed from the two
vertically displaced (10 - 15 mm) points of origin.
c) those who care to read the detailed patent description of
the hardware used to capture the required images via TV
camera at a frame rate of 24 frames per second (or whatever).
I think that 3D modeling programs could automate the use of this
technique so that you would only have to actually create one image and
it would generate the second view.
Of course, commercial use of the technique requires arrangements to be
made with the patent holder - who would probably be glad to hear from
anyone (when was the last time you saw this used?) and would probably
not charge too much for a license to amiga software developers
considering the size of the market.
Mark Williams
Of course, for commercial use one must make arrangements with the patent
holder - who probably would