Hi Sandy
I don't do digital negatives but this is the concept that I think should work.
I look at the QTR driver level all to be in the "negative" space -- i.e. fed negative values and print negative values.
As I think you get it, the Linearize is based on reading the "positive" output from whatever alt process you print with.
This is known by QTR driver curve generator because of the reverse order of L-values. The correction curve is
flipped and backwards because of being in "negative" space.
I see the ICC profile level entirely in positive space -- applied to the positive image based on the output of the positive print.
With all the steps: inversion, neg QTR driver printing, pos alt print -- looked at as one big black box.
On the Mac with Print-Tool this is simplified:
Print-Tool does these in order: applies print profile, negative/flip, QTR driver prints neg.
On a PC you need to do these manually in Photoshop and then QTRgui.
(making the ICC do the invert is a tempting idea but you still need the flip, and I'd be worried about the
inverted ICC messing up some CMS workflows)
Roy
On Tue, Feb 10, 2015 at 8:22 AM, sanking@... [QuadtoneRIP] <QuadtoneRIP@yahoogroups.com> wrote:
Any ideas on how to use Roy's QTR-Create ICC to print digital negatives? I have been using QTR-Linearize-Data, which allows one to invert the Linearize/Lab values to apply to digital negatives, and then installing the .txt file. Is there any way to invert the L values in the ICC profile?
Sandy