hlab@milton.u.washington.edu (Human Int. Technology Lab) (06/18/91)
From BUSINESS WEEK, June 24, 1991:
THREE DIMENSIONS, NO FUNNY GLASSES
Watching 3-D movies wasn't always fun. For years,
you had to don glasses with red and green lenses that
promised crude images and a cross between a popcorn
hangover and a migraine. Lately, companies such as Imax
Systems Corp. in Toronto have refined this approach with
liquid-crystal goggles. But Imax's short films are costly
to produce, and they've been relegated to science museums
and exhibitions.
Now, Nippon Telegraph & Telephone Corp. is
developing 3-D liquid-crystal displays (LCDs) that don't
require special glasses. Like earlier systems, NTT's
prototype simultaneously transmits separate images,
recorded at slightly different angles, to each eye. But
instead of using colors or shutters to keep the sets of
images discrete, the system employs an outer screen,
known as a lenticular lens, which fits over a 15-inch
color LCD panel. This lens is lined with hundreds of
vertical ridges that divide and direct the twin images
to the eyes.
Others have tried lenticular lenses. But in
earlier versions, a slight sideways movement could mix
the signals and shatter the effect. NTT's display has
two infrared sensors that track a viewer's head position
and adjust for these movements. NTT hopes to produce
its screens for computer terminals and video phones but
says commercial systems are still two years away.
(Edited by Robert Buderi)brucec@phoebus.labs.tek.com (Bruce Cohen) (06/19/91)
In article <1991Jun18.161206.19250@milton.u.washington.edu> hlab@milton. u.washington.edu (Human Int. Technology Lab) writes: > NTT's display has > two infrared sensors that track a viewer's head position > and adjust for these movements. NTT hopes to produce > its screens for computer terminals and video phones but > says commercial systems are still two years away. > > (Edited by Robert Buderi) Fascinating! Some questions come to mind: 1) How bad is the view of a screen for one person when the screen is tracking another person? Is this inherently a solo device? 2) Could the position data also be sent to the computer building the image so both horizontal and vertical motion parallax can be computed? The image could be regenerated for the different eye-positions, giving the illusion of looking at nearby objects through a window as the viewer moves. 3) How intrusive is the target for the tracking device (correct me if my assumption is wrong, but I would guess from your description that the viewer has to wear some sort of optical target which the sensors detect)? -- ------------------------------------------------------------------------ Speaker-to-managers, aka Bruce Cohen, Computer Research Lab email: brucec@rl.labs.tek.com Tektronix Laboratories, Tektronix, Inc. phone: (503)627-5241 M/S 50-662, P.O. Box 500, Beaverton, OR 97077 [MODERATOR'S NOTE: Anyone at NTT have the answers? -- Bob Jacobson]
hlab@milton.ogi.edu (06/19/91)
brucec@phoebus.labs.tek.com (Bruce Cohen) writes: >In article <1991Jun18.161206.19250@milton.u.washington.edu> hlab@milton. >u.washington.edu (Human Int. Technology Lab) writes: >> NTT's display has >> two infrared sensors that track a viewer's head position >> and adjust for these movements. NTT hopes to produce >> its screens for computer terminals and video phones but >> says commercial systems are still two years away. >> >> (Edited by Robert Buderi) >Fascinating! Some questions come to mind: >1) How bad is the view of a screen for one person when the screen is > tracking another person? Is this inherently a solo device? >2) Could the position data also be sent to the computer building the > image so both horizontal and vertical motion parallax can be > computed? The image could be regenerated for the different > eye-positions, giving the illusion of looking at nearby objects > through a window as the viewer moves. >3) How intrusive is the target for the tracking device (correct me if my > assumption is wrong, but I would guess from your description that the > viewer has to wear some sort of optical target which the sensors detect)? I tried the system over a year ago when I visited NTT. What is reported above may differ, but... What I saw was a solo device. I seem to remember that the images came straight off a video tape. The system was set up to give stereo images from 3 positions: face on, from the left and from the right. The jumps between the positions were quite noticeable. As for the optical target for the track- ing device... hmmm... I don't recall wearing anything. (This is backed up by a vague memory of the image switching getting confused when two people moved around the sensed area.) The aspect ratio of the screen was unusual; something to do with the way the video frames were stored. I remember being surprised by the quality of the 3D effect. It felt slightly odd not to have to "dress up" to watch a stereo image. All in all, what I saw was very impressive. [I was also impressed with the helpfulness and openness of the NTT researchers.] ------------- David Lau-Kee, Canon Research Centre Europe, 17/20 Frederick Sanger Rd, Surrey Research Park, Guildford, Surrey, GU25YD, UK. laukee@canon.co.uk, laukee@canon.uucp, ..!mcsun!ukc!uos-ee!canon!laukee Tel: +44 (0) 483 574325 Fax: +44 (0) 483 574360
jdb9608@ultb.isc.rit.edu (J.D. Beutel) (06/20/91)
I've never heard of the NTT display before, but I have actually used a very similar display from Dimension Technologies here in Rochester. (I'm not affiliated with them in any way.) Their first commercial product is on a monochrome LCD, and has the drawback of about a one second update speed (yes, a whole second). They've been working on their next project for the government---a color LCD with a reasonable refresh rate, which they expect to release within a year. Their current screen is PC compatible (with its own display cards, I think), and their next screen will have cards for some graphics workstations additionally (Sparc's, I think). This technology struck me as exciting (especially for something like television in the near future), but not applicable to most VR applications. Video phones give a 360 degree field of view, whereas video screens provide just a sliver of that. Furthermore, I don't see how this technology can be applied to video phones because as long as you're going to have a private screen stuck to your face, two little ones are as good as one big one (or better because they're close to your eyes). brucec@phoebus.labs.tek.com (Bruce Cohen) writes: >hlab@milton.u.washington.edu (Human Int. Technology Lab) writes: > >> NTT's display has >> two infrared sensors that track a viewer's head position >> and adjust for these movements. NTT hopes to produce >> its screens for computer terminals and video phones but >> says commercial systems are still two years away. >> >> (Edited by Robert Buderi) > >Fascinating! Some questions come to mind: > >1) How bad is the view of a screen for one person when the screen is > tracking another person? Is this inherently a solo device? The DTI screen has no tracking device. The users must sit within a certain range of viewing distences from the screen. There are overlapping diamonds of correct viewing perspectives, which the viewers must find for themselves by moving their heads (a little L/R key makes it easy when you close one eye and see if the other is seeing the correct letter). Sitting directly in front of the screen gives the best perspective. Several people can use the same perspective vertically (e.g., someone can stand behind you and look over your head). Additionally, there are several good zones to either side. The 3D perspective from the side is slightly distorted because you see the same thing you would see sitting in front, but if there really was a 3D object then you'd see not exactly the same thing. Overall, the side views are not bad. The NTT device may have the same properties. If so, and it tracks one person in the right zone, then all the other people will have to move, so it sounds like more of a solo device than it could be without the tracking device. (But then, it should have some switch for turning off the tracking for multiple viewing.) >2) [Use position tracker for motion parallax simulation?] You have a fascinating idea there. >3) How intrusive is the target for the tracking device (correct me if my > assumption is wrong, but I would guess from your description that the > viewer has to wear some sort of optical target which the sensors detect)? I don't know about the NTT device. The DTI does no tracking, and of course nobody needs to wear glasses to look at it, so it's less intrusive than most 3D view systems. Even with a target it would probably be less intrusive than electric glasses. Both of the salespeople who did the demo had a distant stare, however, which made me worry that the way one must relax one's eyes to look at the screen may have some long-term effects. A clever gentleman at the demo suggested that one use for a 3D system could be detection of movement in satellite photos. If a satellite takes a picture of the same place on different orbits, and the pictures are shown to left and right eyes respectively, then anything that changes position between orbits will stand out (literally). This would be especially useful for complex pictures, as long as nothing moves so far that we stop perceiving it as the same object. There was a similar discussion in this newsgroup a while ago about how we can write programs to translate positional differences into three-dimensional data for translating orbital photos of other planets into VR models. Of course, our brains do it already. I have seen some papers on neural networks simulating the hypercolumns and other structures of the visual cortex, which may be the way to get computers to see in three dimensions and/or extract that extra data. I can provide a reference if anyone's interested. But, I haven't seen anything that can actually do it, besides the wet grey stuff. -- -- J. David Beutel 11011011 jdb9608@cs.rit.edu "I am, therefore I am."
ron@uunet.UU.NET (Ron Peterson) (06/20/91)
In article <1991Jun18.161206.19250@milton.u.washington.edu> hlab@milton.u.washin gton.edu (Human Int. Technology Lab) writes: >From BUSINESS WEEK, June 24, 1991: > THREE DIMENSIONS, NO FUNNY GLASSES > NTT's display has > two infrared sensors that track a viewer's head position > and adjust for these movements. Any indication of how the tracking is accomplished? Does the viewer have to wear an emitter or perhaps paste an IR reflective sticker on their forehead? Or does it just look for reflections from the face? (And how would that work with black people and other colors? In the IR band is everyone white/reflective?) Sounds like it won't work with two people also. ron@vicorp.com or uunet!vicorp!ron