Linearization


#1

My first attempt of linearization has failed, and did not get any response so far

Using PC Windows 7 64 bit

Trying to follow the instructions and run linearization.

  1. Can’t find 21steps-Eye1.tif for x-rite EyeOne ( Jon Cone in his Linearization instruction advised to contact “you” if we need this file. So. Contacting. The one Step-21-gray.tif file that is found in
    my Eye-One folder of your QuadTone RIP is not working so well.

2.Can’t find 21steps.txt ( is it the same format for Widnows??)
3.In EyeOne Profiler measure reference chart is empty, can’t select anything. with Dana we just assumed, that the 21steps or 51steps are coming with EyeOne.

My actions till now: used proofofpiezography-21 file (from which i cropped out 21 step section) ,printed, scanned it with Eye One -I tried to create 1 row and 21 column file ,Eye One I-1 gave me some kind of .qidf format.
That format scan is not opening as described in Linearization instruction by Jon Cone.

I have searched all forum… Please help.
Regards
Nune


#2

The Piezography linearization workflow [I]​has not been published yet[/I]. So I’m not sure what you are actually trying to do and what instructions you are following. If you are trying to follow the QTR instructions than you haven’t read past the first sentence of almost any Piezography instructions that says [I]ignore [/I][I]the QTR default manual![/I]

The 21step linearization_checker Excel file found at piezography.com and this forum is only for checking and not linearizing.

Now, one can print the 21step file in quadtonerip, read in the L* values with their spectrophotometer of choice (this means they need to know how to use their spectro) and use the QTR-Linearize-Quad tool provided in the QTR “Curve Creator” installation to linearize a quad. This does a not-very-good job.

The documentation for that workflow does not exist in a published form and we are going to publish our workflow and a set of tools as a Piezography Professional add-on tool-pack to our soon to release Piezography Community Edition curve archive and manual.

//

QIDF is the PC version of the QuadtoneRIP “descriptor file” and is something un-related to .quads or linearization of .quads. Normally, until the QTR-Linearize-Quad droplet was created very recently, one can’t just linearize a piezography .quad. We’ve done that here at IJM as a service for a decade with a very complicated and high-quality tool relying on algorithms that we license. With Roy’s QTR linearize quad droplet we are providing a solution for DIY linearization (soon!).

It’s very important to do acursory look or google search at the various discussions and documentation regarding linearizing .quads before assuming that there is a published workflow, etc…

This is upcoming and the tools to create Piezography-level linearizations [I]with the QTR-Linearize-Quad tool[/I] will be sold for a nominal fee.

best,
Walker


#3

[QUOTE=walkerblackwell;11630] This does a not-very-good job.

[/QUOTE]

Is this the official IJM position today? Dana said that it did a pretty good job in the past (http://www.inkjetmall.com/tech/showthread.php?2090-Carbon-Printer-no-longer-Matches-Selenium-Printer&p=9930&viewfull=1#post9930) , and so did you if I recall correctly. My experience is that it does a good job of linearisation. Perhaps we need a definition of what ‘not-very-good’ means, and how something can go from great to not-very-good.

I can’t speak for Nune but I would be seriously miffed with your response.


#4

First, I apologize. I really was not part of the conversion that Nune had with Dana nor was I hired when the previous conversation took place online.

//

I guess. I can explain my recent experience a bit more with the 21step vs 51 vs 129. (This is in-fact why it’s created a delay in releasing the workflow and why it’s under active final development.)

21 steps [I]will[/I] linearizer the quad to a reasonable degree. However it will not hit any jags that are closer than 12 Luminance points (most jags) and in some cases it will actually make them worse. I’ve been noticing this limitation lately. For day to day printing one would probably be just fine with 21steps however there is a possibility that doing 21step over and over will actually degrade the .quad over time. (Possibility, not that it would definitely happen.)

There is another reason not to do 21steps directly with the QTR tool and that reason is due to how the QTR linearization tool interpolates gaps. It does not do a the correct spline (like photoshop curves) but instead multiplies the movement of the curve between datapoints that are non-linear. 51 and 129 steps correct for this. our 21step scanner tool that we will be publishing (and an eventual 31 step tool) will do a pre-interpolation with a better spline formula to take a small number of data points and make 129 data points that can then be fed into roy’s linearizer to produce more accurate results.

//

What I recommend is 51 steps as the initial linearization and then 129 steps as the final linearization. (again, all to be discussed in the deluxe manual and pro tools)

So yes, it is the official position of InkjetMall that 21 steps of raw L data is not enough. What one person says in-person (and in passing) at a workshop is not the law of the land going forward. 21 steps is enough if you have a smooth linearized .quad that just needs tweaking (in our case we are starting on .quads at cone editions that were calibrated for our printers at 256 steps) but not if you are starting with a printer that may be out of spec or with a very old .quad. We want to ensure that when people are calibrating with a workflow that we publish that it’s not half-baked and that it can encompass real-world situations. So if I come out right now and tell everyone to calibrate at 21 steps I’m going to get a ton of responses from people in the future that says it doesn’t work (due to the limitations listed above). Rough publish date for the new tools is after next week’s piezodn workshop.

I did not mean to offend.
-Walker


#5

Thanks Walker.


#6

[QUOTE=walkerblackwell;11634]21 steps is enough if you have a smooth linearized .quad that just needs tweaking (in our case we are starting on .quads at cone editions that were calibrated for our printers at 256 steps) …[/QUOTE]

In our experience, this is by far the norm, and exceptions are rare, at least starting with IJM supplied curves. I for one would not expect to use the droplet repeatedly on the same curve and get good results, I only use one iteration and very, very rarely two.

If the release is imminent, as you said in another thread, then there’s little point speculating about what’s going to be in it. But I’m a little confused. I think I’ve read most of the comment about it, and initially it just seemed to be an error correction tool to use in conjunction with the droplet, but in the latest newsletter IJM says:

And now - we have a workshop release version of the Piezography Profiler app. This may be the best reason to attend a Piezography workshop. You will learn how to perfectly linearize your Piezography system as well as [U]create your own custom curves for non-supported papers[/U]. Master you own domain!

The underlined part of the quote implies that it’s more, and will allow us to create our own custom curves, a capacity I’d certainly be prepared to purchase. We will see soon enough.

I realise that you’ve put a lot of work into this new package, and clearly you want to talk it up compared to the droplet. But simply to say that the 21x4 + droplet does “not a very good job” as a general statement flies in the face of many users’ experiences, and particularly these ones. By all means promote the virtues of what you’re producing, but simply denigrating the ingenious tools that Mr Harrington has produced lowers the tone of the forum. Especially as his droplet seems have pushed IJM into allowing users to self-support to a much greater extent, something that can only promote the uptake of Piezography.


#7

I don’t get to edit all of the emails that fly out. I certainly would have edited that one (sigh).

Our soon-to-be-published tools RELY on Roy’s linearizer. It [I]is[/I] an (unique) error correction tool in conjunction with the droplet along with a custom tuning tool and a few more tools [I]and specific targets and specific documentation[/I]. Absolutely zero denigration there. Our workflow just starts at 51 steps and goes to 129 steps because of some observed and measured irregularities in the 21step lin process when dealing with very out-of-lin curves (say printing the HPR curve on uncoated Kozo for example) when compared to our internal profiler. Again, we are looking to achieve basic parity with our internal profiler. That is the goal. The solution we are providing will be very close to that. As close as we can get with the QTR-Linearize-Quad droplet. Our internal profiler will probably still have the edge when dealing with master curves but Roy’s profiler is iterative. We can’t distribute our internal profiler because it relies on complex external math libraries that we license.

//

We are all huge fans of Roy’s tools here. We just want to make them great for Piezo customers so that’s what we’re doing.

-Walker


#8

Thank you for that clarification. Creating a custom curve starts with printing a target with the master curve. Will be be able to start with the master curve with this new tool? (I suspect not, perhaps for a number of reasons, but partly because it’s going to be hard to set the black limit without the full profiler.)


#9

The suggestion (written about in the upcoming release) will be to use the nearest (correctly-limited) curve for you given paper. (As stated above, it’s an iterative-capable process.)

We will be releasing new master K6 and K7 curves for x900 series printers (and the P-series whenever QTR dithers are upgraded) in the future that will be built around a newer Piezography HD photo black inkset that does not require such aggressive limiting while achieving darker dMax. (our current WN1 Opaque Photo Black ink will always remain for digital negatives and legacy printers and curves.)

We have also added iterative capability to our internal profiling suite at IJM. As of the writing of this post, we have updated our Custom Curve service target and instructions at shop.inkjetmall.com to enable the service-linearization of [I]any[/I] piezograph curve, not just master curves. Our internal profiler also has the ability to limit to desired densities and to do 256 steps (something the QTR droplet does not do).

regards
Walker


#10

I caught cold and was not able to follow, meanwhile the discussion went into very advanced areas. And non answers my question, which was pretty simple.
I am trying to CHECK linearization. And for once, I am one of these people, who reads the instructions . Jon cone published together with the excel file “Linearization Check Measuring Instructions” which is part of the download. Walker, please check it yourself in the downdload to relate to my question. And what i am doing - just simply trying to do my first linearization check, which i cannot complete since i can’t find the right file. Quoting Jon Cone’s instuctions "3. Click the type of test chart to measure menu: Select
“Open” and find the file 21steps.txt (supplied in our
Piezography Custom Profiling download kit) " I just cannot find that txt file or whatever the equivalent format is for windows. As well as this file " 21steps-Eye1.tif for x-rite EyeOne " . which Jone Cone in the same instructions says that can be provided.
Trying droplet and correcting the linearization is my next step, which looks very unreachable , since I can’t pass through the first. Please let us bury the hatchet and again, please help:) SOS! I am not as dumb as it seems, just got stuck in the very beginning.
Nune


#11

I’m sorry that the discussion went into areas that you didn’t answer your question and that you didn’t understand.

You use W7-64 and have an i1. I use these too, so I will try and help. I have the same .zip download from IJM as you do, but the PDF is from 2009. While the principles of checking linearisation haven’t changed, some of the software used has changed.

Back in 2009 many people used the Measure Tool to do the measurement. As you are using i1Profiler, I take it that you have a newer i1 (V2), rather than the older i1 (V1). To use i1Profiler, you need the reference file in CMYK rather than greyscale (I don’t know why, but it seems you do). You can get the files from Richard Boutwell’s blog: http://www.bwmastery.com/blog/2014/i1-profiler-and-qtr-stepwedges . Note that this post has an update and he recommends using a different workflow without a reference file. I don’t recommend following his advice, as it is too different to what you will read elsewhere. I recommend you stay with his 2014 approach.

If you want to use the TIFFs and reference files that come with QTR, then you need to download a demo version of Profilemaker 5.0.10, which allows you to use the Measure Tool, even in demo mode. I’m fairly sure that this is what IJM assumed people were using when that 2009 documentation was written. (The Measure Tool no longer works on a Mac, but it still does on Windows, so it still is an option for you if you wish to use it.) i1Profiler can do much the same thing, so long as you use a different reference file.

I hope this helps and is clear.


#12

The linearization checker can be downloaded here: http://www.piezography.com/PiezoPress/blog/piezography-k7-inks-and-curves/checking-your-linearization/

I’m currently updating it and the instructions that are downloaded with the Linearization Service at shop.inkjetmall.com due to confusing language.

Also included in the upcoming Piezography Community Release will be 21 step checking workflows for ColorPort and i1Profiler.

stay tuned,
best,
Walker


#13

Thanks, Brian
I will try both, see which one works better for me
Nune


#14

Thanks, Walker.
The link is where I initially downloaded the instructions. I will check the update.
Nune


#15

Here is a “beta” of the updated linearization checker. http://piezography.com/PIEZOGRAPHY_LINEARIZATION_CHECKER.zip

This will soon be included in a revamped Piezography.com website that will include a “Piezography Community Edition” curve, target, and image archive. The 21step targets will work with i1Pro, Spyder, ColorMunki, and other spectrophotometers.

regards,
Walker


#16

Update.
Apparently my i1Pro had some kind of bogus, it would not have let me save measured date… so that was the beginning of my confusion.
Brian, I did check the Richard Boutwell’s blog,helped me to figure out couple of mistakes I had. I used his new method idea- instead of copy-pasting a target file,somewhere in the program directory ( which was not entirely clear), just choose number of raw and columns in Eye One Measure chart.
Walker, I did download the new checker. Awesome. Clear language.I linearized my too dark EpExF curve using 21 step.And as you predicted, it is not perfect, but it is a very good place to start.Just small detail- would be good to mention for a beginner, that to linearize a .quad ,one need to simultaneously drug the new .txt file together! with the .quad in question into the QTR-Linearize-Quad.exe
Thank you guys
Regards
Nune


#17

Our linearization workflow and documentation will be fully spelled out when we publish the Piezography Professional Edition set of curves and tools soon.

regards,
glad it all worked out,
Walker


#18

[QUOTE=Nune;11747]Just small detail- would be good to mention for a beginner, that to linearize a .quad ,one need to simultaneously drug the new .txt file together! with the .quad in question into the QTR-Linearize-Quad.exe[/QUOTE]

Because we were only discussing checking linearisation rather than relinearisation, I didn’t want to get ahead of things, and so I didn’t mention this blog post on the subject. Whether the approach described remains relevant once the new IJM kit is eventually released is not clear, but as things stand today, this works well enough for me.