Re: Re[2]: color video?

Richard Cogger (R.Cogger@cornell.edu)
Tue, 20 Sep 1994 11:00:02 -0400

For the record, we do plan to implement color, but other things have had a
higher priority. From talking to folks who have done it for desktop
conferencing, it can be a little fussy: for example, you need to add hue
and saturation controls, etc. I agree with Michel Carleer that color is
potentially a "good deal" in terms of increase in effective information for
not much increase in bw. I also agree with others that grayscale may be
sufficient or preferable in many cases. Accordingly, I expect we will
implement it so that individuals can choose to send color or not and so
that receivers can choose whether to receive it-- the reflector will be
able to chop off the color info if a particular receiver doesn't want to
spend receive bw on it. This selective "pruning" of parts of certain video
streams will also be available to reduce resolution or frame-rate so that
each receiver can get a custom feed, oriented to using bw available on
their path from the reflector to best meet their preferences and needs.
(Currently, a receiver can close a window and thereby get rid of an entire
video stream.) -Dick

At 8:20 AM 9/20/94, Bob Junke wrote:
>On Tue, 20 Sep 1994, M. Carleer wrote:
>
>> Dear all,
>>
>> I personally think color is very important: Our eye/brain system is trained
>> since birth to interpret color. In understanding what is going on at the
>> other end of a CUSeeMe transmission, the color is of great help, especially
>> when the spatial resolution of the picture is not great (CUSeeMe: 160x120
>> pixels). On the other hand, to increase resolution of the picture by a
>> useful amount, you have to more or less double the linear resolution, which
>> means transmit 4 times more info per picture. Compare this to the
>> transmission of color where, because of the characteristics of the eye, you
>> need only to transmit around 6 percent more info, and you get the same
>> perceived increase in understanding of the picture. Because transmission of
>> color imposes such a small burden on the jerkiness of video, and because it
>> so much improves the comfort of viewing, I think it should be included as
>> fast as possible in CUSeeMe. If you are not certain of the latter ascertion,
>> try just to look at a small (16x120 pels) picture in color side to side with
>> it's B/W version, and you will clearly see that it is far easier to read the
>> color one, even if you are not interested by the actual color of the shirt
>> of the person facing you!
>>
>
>Yes, color is prettier to look at, but in an environment of productivity,
>it isn't always necessary or desired. In keeping with network
>efficiency, 16 shades of gray does the job beautifully. If something
>must be delivered in color, save it as a compressed still, and use FTP
>while at the same time conducting your conference in gray.
>
>Just my humble opinion,
>Bob
>
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