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QTR-Quadtone RIP

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Re: QTR-Linearize-Quad -and- 51-step charts -- not working

2015-10-14 by brian_downunda@...

I agree with Paul. I once made a 51x3 image and reference file to average out the variations he speaks of and still use a strip reader. It worked for me, but I think that it resulted in spurious precision. The linearisation plot showed a lot of bumps and wiggles, and this is the sort of thing that can cause the supplementary QTR programs to fail. The 21x4 works for me.


---In QuadtoneRIP@yahoogroups.com, <roark.paul@...> wrote :

In general, I think that sometimes the smaller incremental changes of a 51 step test strip interact poorly with the random variations in the paper and the inaccuracies of the rather inexpensive instruments we use to measure the test patches. With a well made profile to start with, a 21-step is usually enough and probably less prone to errors or unwanted artifacts in the final. It's also a way easier target to read and deal with.



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