Newsgroups: sci.image.processing
From: paul@pcserv.demon.co.uk (Paul Carpenter)
Path: cantaloupe.srv.cs.cmu.edu!das-news2.harvard.edu!news2.near.net!news.mathworks.com!newshost.marcam.com!usc!cs.utexas.edu!swrinde!pipex!peernews.demon.co.uk!pcserv.demon.co.uk!paul
Subject: Re: Conversion of non-interlaced NTSC video to interlaced VGA/SVGA
References: <feferman.64.2F48D7EB@pond.com> <3ic87d$fbq@fbi-news.informatik.uni-dortmund.de>
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Date: Tue, 21 Feb 1995 12:20:19 +0000
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klaus@euklid.informatik.uni-dortmund.de "Alexander Klaus LS7" writes:
-Dear Ben,
-
-any Framegrabber for example that is able to input NTSC signals does.

Several _framegrabbers_ that have been DESIGNED in the last 2-3 years support,
transfer via the VESA interconnect to VGA. The very cheap ones tend not to
support this.

-Then you can display your "real-time"-video under e.g. Windows or OS half
-in a windows and scale it for your needs. You can even select the resolution,
-but be aware, scaling doesn't improve image quality, it's just larger pixels.
-But in high resolution you can display the whole image in a smaller box.

NOT all provide scaling some provide clipping, double scan, or windowing without
scaling.

-Most boards do support real-time scaling.

NO

-This way you have your VGA card and the video on the same monitor even 
-without switching.

CAN do if the right grabber is chosen.

-You don't even need PCI or VLB boards (if you are stuck on a PC like me)
-as most grabber card support the VGA Feature Connector which directly 
-moves graphic data on the VGA card. Thus the image needs not to crawl 
-via ISA bus.

Most board manufacturers of framegrabbers are moving away from VESA Feature
connector, especially as AFAIR the max resolution it was designed and speced
for was 800x600 NI 60Hz. Majority are moving to PCI bus and bus transfers of 
image, so scaling becomes an issue again.

-- 
Paul - "Any people you should meet are the products of a deranged imagination"
