Linearization issues with importing LAB #'s in QTR-Linearization-Quad

PiezoDN Digital Negatives
1

Hello,

I am following the steps to linearize my process with PiezoDN and have been stalled by this problem:

When combining the LAB numbers derived by printing out a 129 step tablet using the 79-99-PiezoDN-Pd-AC-ILM.quad and that quad profile in QTR-Linearize-Quad.app (step 8 in the PiezoDN manual) I get the following message: Invalid linearize curve – not constantly increasing. Here are the Lab numbers I arrived at using ColorPort and the i1 Pro II profiler–on the left hand side, and the Quad profile attempt on the right hand side, see excel attachment:

Any help would be appreciated!
kane stewart

Attachments:
  1. LABnumbers_Quadproflieattempt.xlsx

LABnumbers_Quadproflieattempt.xlsx (43.6 KB)

2

Ok. I see.

I took the first three columns of this excel (L,A,B) and pasted them into the CGATS_SMOOTHER tool.

Then I copied the data from that smoother tool’s second sheet (CGATS) into a new workbook and saved that workbook as a tab delimited file.

This step is REQUIRED before linearizing. This corrects for the reversals in every darkroom printed swatch. (see attached screenshot and “smoothed” txt file.). FYI, your densities are very dark. You may find that you need to do this linearization process again (iteratively) on this first linearized .quad to get the final .quad perfectly linear.

 

3

Hi,

That worked, I am not sure why it didn’t work for me originally, I followed all the steps including the one you just outlined–except I may have not used the Excel version of the smoother tool, but may have used the numbers one instead…

Went through the rest of the procedures and made a quad curve that I see loads up in the Print Tool. I will make the negative later and then print it to see where things are at.

Thanks for your help!

kane

4

For Numbers, you need to copy/paste into a new txt file as numbers will not allow saving of Tab Delimited txt. I will update the instructions.

-Walker

5

Those columns are the first sheet of the Numbers tool saved as excel.

There’s a lot of math under the surface.

 

best,

Walker

6

Hmmmmm. You know I did that weeks ago when I was unable to open the Excel Smoother tool. I didn’t see those columns then and I don’t see them now. But after I posted last night I made another linearization with the QTR-Linearize-Quad droplet and noticed that all of that appears in the temporary -out.txt file that it creates.

I know there is a lot going on below the surface! :smiley:

~ Keith

PS - I have notifications turned on for this forum but I have yet to actually get one. What’s up with that? Do I have to also check the box on every message?

7

debugging the notifications . . . it will be a few days.