Re: UCR vs GCR


Ruud uit het Instituut
 

Dan Margulis wrote

We also fall victim to a terminology trap here--there's no real agreement
on what constitutes a "UCR" sep, other than that it's a subset of "GCR".

You're right. IMO the terminology went wrong when vendors started to make
their own definitions. I worked with the old Magnascanners from Crosfield.
There I could choose between UCR and PCR or a combination of those two.
UCR = Under Color Removal
PCR = Poly Color Removal
The difference between those two was that UCR was only active in the
neutrals and PCR in the colors.
But PCR was in fact the same as the german definition 'unbunt' on the Hell
scanners or the American GCA (Gray Component Addition) and it's opponent
GCR.

So UCR and GCR both mean the same and are active in the neutrals (the L axis
in Lab).
PCR, unbunt and GCA are also the same and use the combination of all three
axis in Lab.

Excuse my English, I seem to have a Dutch accent.

Ruud de Korte

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