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RE: "True", "True" (H)DTV....and the relation to 720/60P Display Systems



0.7 is a reasonable in theory (some would claim as low as 0.6), but if
you concatenate
the transfer functions of the entire DTV system (lens, optical
antialiasing filter, CCD
line pairing, 3:1:1 recording gear with internal DCT compression, any
signal processing
in post, ATSC encoder, MPEG itself in the transmission channel, and then
the actual
interlaced display device you get substantially less delivered vertical
resolution in the
case of interlace than the 1080 being promised by the mystic
numerologists (much less
than the 756 lines that a Kell of 0.7 would lead one to believe).

> -----Original Message-----
> From:	Phil Bennett [SMTP:phil at trillian.org]
> Sent:	Friday, October 10, 1997 10:10 AM
> To:	multiple recipients of
> Subject:	Re: "True", "True" (H)DTV....and the relation to 720/60P
> Display Syst ems
> 
> >Now for your video camera material ie. News, Game Shows, Sports
> >your 1280x720p buys you a 720 vertical spatial resolution for your
> 60fps
> >frame rate compared with the 540 vertical spatial resolution of
> >1920x1080i at 60fps.You've got a 74.25Mhz production bandwith slice
> it
> >any way you see fit. 
> >
> >Howard Lukk
> >I.V.C.
> Sorry Howard but this isn't quite true. The interlaced resolution is
> higher
> than 540 lines. You may want to take a look for info on Kell Factor
> which
> gives the perceived resolution. A value of 0.7 is normally used. This
> is the
> whole reason for using interlace in the first place. Dig out a copy of
> "Transmission and Display of Pictorial Infomation" by D.E. Pearson.
> This has
> is a great  fundamentals book on spatio-temporal resolution and and
> colorimetry for imaging. Plus Don was my PhD supervisor in the 70's
> before I
> baled out and got into the grubby business of Television.
> 
> Phil Bennett (X-Abekas)
> 
> ---
>   HDTV discussion thread is at
> http://www.alegria.com/telecine/hdtv.txt
>          Thanks to Bill Topazio for support of the TIG in 1997
>       TIG subscriber count is 868 on Fri Oct 10 10:10:03 PDT 1997
>      mailinglist digest available.... unsubscribe via a message to
>         'telecine-request at alegria.com' with Subject: unsubscribe

---
  HDTV discussion thread is at http://www.alegria.com/telecine/hdtv.txt
         Thanks to Bill Topazio for support of the TIG in 1997
      TIG subscriber count is 868 on Fri Oct 10 14:15:24 PDT 1997
     mailinglist digest available.... unsubscribe via a message to
        'telecine-request at alegria.com' with Subject: unsubscribe