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Old 6th January 2010, 15:45   #41  |  Link
MfA
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Join Date: Mar 2002
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Quote:
Originally Posted by 2Bdecided View Post
It's rare for interlaced signals to be filtered to half the vertical resolution, so suggesting you'll get 540 vs 720 isn't realistic.
As I said, the bandwidth is usually reduced to around 70% ... so the effective resolution is about 70%.

That's just when things aren't moving though. When things move at a multiple of 1 pel per field in the vertical direction even the best deinterlacers being used at the moment are not going to be able to make something sharp out of the result ... the object becomes identical (ignoring the shift) in both fields, all the image data for half the lines in every frame is simply gone, interpolation will have to do. So in that case the effective resolution becomes 50% ... but it's aliased, so it's actually a little worse than 50%.

Which is why you really don't want to do high movement video with interlacing (sports mostly, since action movies are of course shot with flicker cam, making interlacing moot).

Last edited by MfA; 6th January 2010 at 22:56.
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