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RE: fanning the flames




Ken Robinson wrote:

...but I am really happy with my Quadra except for one slight
misunderstanding regarding using half the 444 o/p.....  Anyone else
using the 422 and not the 022 beware!  Luckily my Russell Square filters
the signal enough not to see the aliasing!  BTW anyone know of a genuine
filter to overcome this?  Buying the 444 booster box is a little
expensive.  I understand that Leach may make something...

Ken,

The 4:4:4 to 4:2:2 conversion can also be handled by a daVinci or Pandora
color corrector (big $), Digital Vision DVNR4x4 noise reducer (medium $), 
Sierra Design Labs Transcoder (small $), and most likely a variety of other 
products to be shown at NAB. (Miranda, Leitch, etc.) What color corrector
are you using?

Your reluctance to use that "4:2:2" half of the 4:4:4 signal without its 0:2:2 
compliment is well founded. You can never properly decimate (under-sample) 
the chrominance data by discarding every other sample and then filtering 
downstream. The filtering must happen with ALL of the original chroma 
samples as it does in the products listed above. You might be able to hide 
most of the aliasing (and some color detail) with the downstream method, but 
then watch for more subtle color problems!

-Randy Reck

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