MacLeech
The one and only
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join:2001-07-14
SoCal
| reply to cbyrd
Re: Digital Cable not getting some channels
said by cbyrd  :
I figured as much. While on the subject, what causes the artifacting I'm seeing, especially in dark scenes?
My guess is that the artifacting is most likely a side effect of the compression method used to digitize the original analog signal. I get similar effects if I digitize the analog signal my video camera puts out and I pick too high of a compression rate. Its kinda of like what happens when you pick a higher compression when you save a JPEG pic.
The software or equipment used in the compression selects a larger range of similar colors (either because of a lower sampling rate or a smaller range of possible final colors) the higher the compression rate you pick. So instead of getting smooth gradients in subtly shaded areas, you get a stepping type effect where one black area is next to a dark grey area with little blending in between.
But then again I'm not a headend tech nor do I have direct experience working with the equipment that does the A/D conversion in the headends so that's just my guess from personal experience, conversations I've had with headend techs, and the assorted papers I've read on the subject.
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