Path: utzoo!utgpu!attcan!uunet!cbmvax!jesup
From: jesup@cbmvax.UUCP (Randell Jesup)
Newsgroups: comp.sys.amiga
Subject: Re: FlickerFixers
Message-ID: <4451@cbmvax.UUCP>
Date: 9 Aug 88 06:19:39 GMT
References: <3269@crash.cts.com> <8473@swan.ulowell.edu> <7977@cup.portal.com>
Reply-To: jesup@cbmvax.UUCP (Randell Jesup)
Organization: Commodore Technology, West Chester, PA
Lines: 32

In article <7977@cup.portal.com> Chad_The-Walrus_Netzer@cup.portal.com writes:
>In a previous article,  blunders... er, writes:
>)haitex@pnet01.cts.com (Wade Bickel) wrote:
>)>But I really don't like the way objects in motion split

>	I'm sory to say that this is WRONG, Bob.  What the Flicker Fixer does
>is buffer the last frame, and then displays that frame one more time, so that
>the scan lines that would have faded by 1/30th of a second, are shown again.
>The magical result is no flicker.  This make static images look GREAT
>(ESPECIALLY on a Zenith Flat Screen Monitor, by the way).  However, since that
>last frame is displayed once more, if the current frame is significantly
>different from the last frame, you will see "lines" left over where the object
>was.  A simple way to demonstrate this is to move the mouse pointer
>semi-rapidly on the screen.  You will clearly see those left over lines...  It
>is not caused by the monitor, or in the way your eye/brain interprets the
>interlace (as you state), but is a result of something which otherwise would
>have faded being re-displayed...

	Sort of.  FF takes video that consists of SF1,LF1,SF2,LF2,...
(short field/long field), and displays it as (SF1/LF1),(SF2/LF1),(SF2/LF2),
(SF3/LF2), etc.  The reason objects break up when moving more than 1 pixel
per field (1/60sec) is that between sf1 and lf1 the object has moved.  Normally
your vision integrates this as a solid object moving, even though you only
see every other line at any 1 time.  When they are displayed at the same time
(and therefor same luminance) it is obvious that every other line is offset.
This is why digital TV people who do scan-doubling do interpolation to make
this less obvious (I think).

	It's still nice to have de-interlaced video.

-- 
Randell Jesup, Commodore Engineering {uunet|rutgers|allegra}!cbmvax!jesup