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Sky digital picture quality/artefacting

Discussion in 'Sky Digital TV Forum' started by audiop, Dec 18, 2004.

  1. audiop

    audiop
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    Can anyone enlighten me on the problems associated with the sky digital picture, ie the lack of definition and slight blockiness or pixelation which seems most noticable on peoples skin.

    Is this assocated with a poor signal or is it normal? What can be done to improve the signal and or picture ? Would a larger than standard mini dish make a difference ?
     
  2. Nick_UK

    Nick_UK
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    When you're fitting six or eight digital TVchannels into the same space as one analogue channel, something has to be sacrificed. With digital TV, all the analogue picture information has to be converted into a string of numbers, and then converted back to an analogue signal again at the other end. The brightness of any given pixel has to be converted into a number, and if you use too few numbers, then the "grey scale" looks like a series of steps. It's this stepped brightness effect (caused by poor analogue>digital conversion) that gives the weird effects noticed on people's faces. There's nothing you can do to improve it. The bigger the screen, the more you notice it.
     
  3. bobcar

    bobcar
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    Thats not exactly true. Its not down to the analogue/digital conversion, thats the same whatever the bitrate. The problem is over compression of the digital data (entirely in the digital domain) to get the bitrate low enough to send a lot channels in a limited space. A compressed picture is re-built in a series of "steps", to low a bitrate and there are not enough "steps" to fully recreate the picture, especially if the picture is fast moving or complex.

    The end result is the same though, too many channels in one space means poor picture quality.
     
  4. audiop

    audiop
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    So is this ever likely to improve ?
     
  5. GGTVBD

    GGTVBD
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    Nope.

    A. Dork
     

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