QTR-Quadtone RIP

Hi folks,

I just tried using QTR-Linearize-Data for the first time and found that for linearizing digital negatives it works, but not quite as Roy described it here, unless I misunderstood something. I read the part quoted below to mean the input data in the text file for digital negs should be from black to white. 

QTR-Linearize-Data will not take numbers from black to white; whether Den or LAB, it gives the error message "The Lab values are not in order. Cannot be linearized." 

However, when a text file with numbers from white to black is dropped onto QTR-Linearize-Data, it produces both a standard white to black LINEARIZE= string, AND an inverted one, black to white, for digital negatives.

LINEARIZE="88.18 83.49 75.44 69.33 66.12 63.64 61.83 60.05 57.75 55.53 51.78 48.73 45.82 42.59 38.68 34.25 30.54 27.43 24.22 22.41 20.68"

For Digital Negative:
LINEARIZE="20.68 22.41 24.22 27.43 30.54 34.25 38.68 42.59 45.82 48.73 51.78 55.53 57.75 60.05 61.83 63.64 66.12 69.33 75.44 83.49 88.18"


This may not be news to anyone but me, but I thought I should mention it just in case. I've never used QTR-Linearize-Data before, though I use QTR-Linearize-Quad frequently with PiezoDN.

One question though: Can both GRAY_CURVE and LINEARIZE be used in the same QTR Curve? I know at least one person who does that with digital negatives, and successfully I think, but I've never seen it discussed or written about anywhere.

Cheers,
Keith

Keith Schreiber
jkschreiber.com


> On Sep 13, 2016, at 11:02 PM, Roy Harrington roy@... [QuadtoneRIP] <QuadtoneRIP@yahoogroups.com> wrote:
> 
> For ordinary printing the
> values must be from White to Black, but for digital negatives use Black to White.
> LINEARIZE will create a correction curve such that the new curve set will produce
> a step with linear Lab values -- i.e. it linearizes for Lab values.