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Re: Converting Between R'G'B' and 4:2:2



Hi all!

I have just read through this document, and it is quite interesting,
however it I feel that is bases some of the bold statements such as
conversion to YCbCr will cause an unrecoverable loss of 75% of the RGB code
words, are on the assumption that the YCbCr Component Digital used in
current post production facilities is only 8 bit.

8 Bit went out years ago, and is generally no longer used because of the
very reason that computer graphics looked very contoured, as they have no
noise so don't contain any natural dither like live images from say a
telecine. For this reason the standard was raised to 10 bit to cover this a
long time ago.

10 Bit YCbCr is a lot better at accurately matching RGB quantising levels,
and generally does a great job because you get quite accurate match of the
RGB levels and the full RGB level range can be contained in the YCbCr
gamut.


Regards,

Grant Petty.
Digital Voodoo.



>> MERGING COMPUTING WITH STUDIO VIDEO:
>> CONVERTING BETWEEN R'G'B' AND 4:2:2
>>
>> [The entire paper is available in Acrobat PDF format, 130705 bytes.]
>>
>>  <ftp://www2.discreet.com/dl2/whitepaper/discreet_poynton_rgb_422.pdf>





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