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Re: Converting Between R'G'B' and 4:2:2 (The Impossibly Blu e Sky)





Randy K. Reck wrote:

>         If you dismiss those impossible colors as heresy, then you may not
> be interested in the discussion of phosphor limitations. For example, why is
> it that the ATSC did not address the fact that NTSC red is actually
> reddish-orange in Kelley's color-designation regions on the CIE chromaticity
> diagram.

NTSC red (chromaticities) is not typically used either in monitors or home
receivers, nor is it reddish-orange.  Green is the most deficient primary of
the video system.

> (and to my eyes) Since film dyes can occupy a larger area on the
> diagram, wouldn't this be a perfect time (infancy of DTV) to make up some of
> the difference,

I totally agree. It would be nice to AT LEAST utilize the originally attempted
NTSC chromaticities from the 1950's.

> or is spatial and temporal resolution everything?

Not everything, but the visual differences in resolution change (especially from
standard NTSC to Hi-def) are much more perceptible than differences of color.

> Since we are stuck with tristimulus values to convey perceptual colors, let us not
> forget those truly lost colors: tristimulus values outside of the NTSC
> phosphor triangle.

I think about them all the time. :>)

Those truly lost colors of film would not even be completely recovered by any
"tri" color system since the color of film does not conform to just a 3 point color triangle.


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