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



Grant Petty <grant.petty at digitalvoodoo.net> writes to TIG,

> ... 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.

The statement stands, no matter how many bits are used. (If 8 bits
are used, 75% of the codewords are lost. If 10 bits are used, 75% of the
codewords are lost.)

> ... 10 Bit YCbCr is a lot better at accurately matching RGB quantising levels

When 10-bit R'G'B' is converted to Y'CBCR, then converted back to R'G'B', 
only 25% of the original colors are still there.

C.

C.

-- 
Charles Poynton 
<mailto:poynton at poynton.com> [Mac Eudora, MIME, BinHex, uu, qpv]
<http://www.inforamp.net/~poynton/>

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