From: canon.co.uk!laukee (David Lau-Kee)
Subject: Re: Japanese stereo TV/computer terminals
Date: Wed, 19 Jun 91 08:58:15 GMT
Organization: Canon Research Europe, Guildford, UK



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