Invalid Linearize Curve


#1

Hello all

I am trying to create a .quad, but keep getting a message ‘Invalid linearize curve – not constantly increasing’ at the end of the …-out.txt file after running the QTR-Linearize-Quad.

I have tried this on both MacOS 10 and 11, with the same results. Other setup information:

Printed on Arches Platine with target Colorport/PiezoDN-129step-i1Pro.tif, scanned with a i1Pro rev e

Target image is attached

I have carefully reviewed the procedure from scanning the print to entering data into the CGAT Smoother, then out to a .txt and dropping onto the Linearizer. Looking through the forum has not rendered a solution. I suspect the problem is with the Target print itself, because so many of the highlight values are the same.

I have also attached the -out.txt file

I am probably making a very simple mistake somewhere. Thanks in advance for any help!

 

4900_032417-012_corrected-out.txt (11.6 KB)


#2

Hi Pardip~

I checked your “corrected-out” file, and see five measurements have the same value of 96.93, and two have the same value of 96.91- I think those values are causing the error.

Here is a corrected file for you to try, I hope it works well for you- please keep us posted!

Happy printing~ Dana

4900_032417-012_smooth.txt (4.92 KB)


#3

Dear Pradip. Dana’s corrected measurements should work. There is another way to go about it for reference for those who are on this list:

The process you are using seems to want to be limited before the linearization is done as the process seems to be needing a thinner negative in the highlights (it’s blowing out). The limitation process is documented in the PiezoDN chapter of the Deluxe manual. Essentially it consists of printing the 256 step “limit” target found in >Piezography>Images>PiezoDN and using it to make a special curve in photoshop. Using the input and output data from that curve, you manually adjust (limit) the PiezoDN curve you used to print the limit target. Then you linearize this manually adjusted “limited” curve.

If this is NOT piezodn, then you are most likely printing a K5 cool curve and your Green channel is either not printing with any ink or something else is wonky. The PiezoDN limiting / Dana’s measurement file will work in this case as well however. :wink:

best,
Walker


#4

Thanks for this Dana!

It worked!!

I just need to figure out why this happened. But that is for later.

You are brilliant.


#5

Thanks for this insight too, Walker. I should have said that I’m printing on PiezoDN K7, Epson 4900.

You are right about the neg blowing out. I am going to nose dive into the manual forthwith.

Thanks!
P