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GRAY_CURVE vs K_CURVE and other Individual ink curves

2014-03-26 by Alan Vlach

I've been running some tests on regulating the inks for digital negatives. I am trying to develop a method for easily determining the minimum ink to print paper white. I am using two gray parts: K and LK with Y following K and C following LK. I would like to specify curves that independently affect the K values and the LK values. I started with this profile:

and I get this quad file:


If I use a GRAY_CURVE= that sets the values at "0;0 100;50", I get this quad file:


Notice that the ink limits only change for K and Y, and quite significantly given that I only specified a 50% reduction. I would like to be able to test changing both sets of ink limits proportionately - K and Y as well as LK and C.


If I substitute CURVE_K="0;0 100;50" and CURVE_LK="0;0 100;50" for the GRAY_CURVE, I get the same Quad file as the Test-nocurve:


There is no change in the ink limits, no change whatsoever. Printing results for a stepwedge are the same as if I hadn't specified either of the curve values.
Any ideas on why CURVE_K and CURVE_LK don't do anything?

I've also tried using the linearize command, but haven't had any success there. I get errors if I include the above specification. I can't find any detailed info about the linearize command.

Thanks

Alan




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