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Dead medium: VISIDEP 3-D Television
From: SeJ@aol.com (Stefan Jones)
Source(s): POPULAR MECHANICS "Technology Update," March 1983, Page 129

(((Stefan Jones remarks: Science nerds all over the nation are this week donning cardboard glasses with red and green celluloid lenses... the awful cost of viewing 3-D Mars landscapes captured by the Pathfinder's binocular camera system.

(((Although cheap and relatively effective, the inelegance of the red-green 3-D system has goaded generations of cinema and television technicians to build a better mousetrap. I know of at least two other cinematic 3-D systems == one that used a polarized screen and polarized lenses, and another that used glasses with mechanical shutters. This entry describes a system that does not require glasses or even a special TV. My comments in triple parentheses. Stefan Jones)))

"3-D TV is here

"Scientists generally believe that our ability to perceive depth is the result of our binocular vision. Now, challenging this concept, three University of Southern Carolina scientists have developed a technique that makes 3-D television, movies and slides a reality for everyone == even those with poor vision or vision in only one eye.

"No special glasses, cameras, projectors or television sets are needed. And unlike traditional 3-D, the Visual Image Depth Enhancement Process (VISIDEP) produces images which have realistic depth and fullness, rather than exaggerated images which seem to leap outward.

"Drs. Edwin Jones, LeConte Cathey and Porter McLaurin, experts in optics, electronics and media production, respectively, developed their novel approach by observing how a visually impaired person perceives depth. 'We discovered that a one-eyed person perceives depth by moving his head and comparing a sequence of visual 'frames' from different angles,' Dr. Cathey told PM. This concept was once considered impossible by physiologists.

"VISIDEP simulates the optics of a one-eyed person by using conventional video equipment, plus a special encoding device which produces a time-sequence display of images captured from two different points of view on a single channel.

((( The "shuttered glasses" 3-D technique also uses alternating frames; the shutters alternately black out the right and left lenses, limiting vision in a particular eye to the appropriate frames. VISIDEP seems to rely on the human eye's ability to fuse rapidly presented images... although how this produces a 3-D effect is not explained.)))

"Variations on the technique allow the South Carolina team to create 3-D images from slides, motion pictures, and computers.

(((The article at this point includes a photographic stereo pair depicting the three researchers. The caption implies ("You can simulate the new 3-D effect...") that it is produced by the VISIDEP effect, but it seems to simply be a high-quality stereo pair.)))

((( Description of the "red - green" 3-D technique, and its drawbacks, deleted.)))

"VISIDEP has none of these restrictions. Once encoded, the image may be reproduced by any single conventional video camera [sic], movie, or slide projector. ((( I believe the author meant to write 'video monitor.' ))) The depth moves into the screen rather than out toward the audience, making the image more lifelike.

"Since VISIDEP can be applied to images generated by virtually any means == including X-rays, sonar, infrared or visible light, as well as from fiber optics == potential applications range from undersea and satellite transmission ((( ?!!? -- SEJ ))) to medical and computer sciences.

"Once particularly exciting application involves VISIDEP's ability to produce three-dimensional computer- aided design and manufacturing [sic]. With VISIDEP it's possible to display these images in three dimensions.

"For nontechnical applications, the most immediate use of VISIDEP probably will be for televising commercials and sports events.

"VISIDEP may also have an effect on some long- standing theories of perception.

"As Jones stresses, 'Our development will force people to take another look at standard theories of how people perceive depth, and, thus, how all of us learn.'"

((( Whither VISIDEP? Like the dinosaurs, or the strange critters of the Cambrian epoch, the system may have failed to catch on through no fault of its own. Lost research grants, patent problems, a lack of investors, or inept marketing could have scuttled the system at any of the stages necessary to make a clever idea into a product. Of course, the system may have simply failed to impress == or even worse, caused headaches and eye strain, like so many other 3-D systems.)))

((( To forestall the inevitable questions: Those with a color printer == and a pair of red-green glasses hidden in a desk drawer == may obtain Mars landscape images from http://mars.compuserve.com, under "latest images." In addition to supplying marvellous glimpses at the landscape of another world, they are a tribute to a durable medium which has resisted the numerous attempts to replace it.)))

Stefan Jones (SeJ@aol.com)