QTR-Quadtone RIP

I read a 51-step test strip with an i1 , processed the LAB file with the QTR-Linearize-Data.app and pasted the appropriate output for digital negatives at the end of the ink descriptor file. This file failed to compile to a quad file when I used the Install command.

Using 51-step strips with LINEARIZE is possible, but the minor variations in densities that often result when measuring step wedges made with hand coated processes can cause the process to fail at one of two points. The first point is when we drop the the .txt file on the QTR-Linearize-Data app, and a command is returned that the values are out of order. However, even if that works, the install command may fail when we copy the LINEARIZE numbers to the profile and run the install command. The issue is that for LINEARIZE to work the LAB values must be consistently increasing or decreasing. In some cases the consistency is enough for the app to create the necessary numbers and work in the first step, but not with the precision needed for the install program in the second step.

It is possible to "fudge" the numbers, but that of course defeats the purpose.

Sandy

Aha - this explains it. So the digineg workflow would be to linearize in an ink descriptor using 21-step data, and then use 51-step data to fine-tune the resulting .quad file.

I linearize with 21 steps and results are very good.
After that, where would you insert/apply your 51 step data to fine tune?

Sidney

As it turned out, after reading Roy's post, I familiarized myself with the Data-Tool app, and used it to slurp up the 51-step readings from my CGATS file after I stripped off the header and footer information. I picked a smoothing level of 1, clicked the 'negative' check box, and then copied and pasted the calculated LInearize="" string to the end of my ink descriptor file. The file compiled into a .quad file without a problem.