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Author Topic: What printers allow custom profiles w Photoshop Manages for B&W?  (Read 8011 times)

Alan Goldhammer

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Re: What printers allow custom profiles w Photoshop Manages for B&W?
« Reply #20 on: October 04, 2019, 04:22:24 pm »

I have coded and verified that this approach works for creating a profile that can be used for both printing and soft proofing B&W and it correctly soft proofs both tinted and untinted images. It works with both Argyll and I1Profiler. I am cleaning up the code and will post it to github in a day or two. The code is in pure C++ with no external libraries and can be compiled and run on iOS, Linux, and Windows systems. I will also post a link to a Windows executable as well as a Argyll profile that demonstrates soft proofing and printing based on my Pro1000 B&W mode.
Can you create an Argyll 'ti1' file for the synthetic data set that users can create patch sets for different papers?  I've tried adapting CGATs files in the past but I cannot get them to read properly.
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Doug Gray

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Re: What printers allow custom profiles w Photoshop Manages for B&W?
« Reply #21 on: October 05, 2019, 12:22:49 am »

Can you create an Argyll 'ti1' file for the synthetic data set that users can create patch sets for different papers?  I've tried adapting CGATs files in the past but I cannot get them to read properly.

I haven't looked much at ti1 files but they appear quite specific to Argyll. Also, Argyll doesn't support i1iSis spectro so it's not an attractive approach.

Also, if I adopted only using Argyll tools there would have to be extensive revisions to the io in my code.

Argyll does have a nice conversion utility that processes I1Profiler CGATs files into ti3 files which work quite well for making Argyll profiles.

Since I1Profiler, unlicensed, can be used to create/print charts and save CGATs files it's a good alternative.

I've attached a file containing 6 files including the final icm profile. It's got a large B&W patch set, 0 to 255 step 1 repeated 3 times and scrambled. Much more than needed. A 52 patch set works just fine but this lets me average patches and evaluate print consistency compared to printing with regular color mode.

Here's a rough workflow:

Run the program to create patch sets. 52 and 256 CGATs sets are created with an option to make N duplicates to reduce the impact of printed patch variation.

Load the cgats file "256BW3x.txt" into I1Profiler by dragging and dropping it into the patch set block. Select the instrument and chart type then print it using B&W settings and whatever tint is desired. Save the settings for easy printing later.

Scan the target then save the result as a CGATs file making sure LAB is one of the selected fields. Spectral data does not need to be saved.

Next run the program with the name of the CGATs measurement file. This creates two new CGATs files that have RGB and LAB data. They have the original name with "RGBLAB" and "RGBLAB_adj" appended. These contain the RGB and measured Lab data as well as appended synthesized data to make profiling software happy. The "RGBLAB" CGATs file has the a* and b* fields zeroed while the "RGBLAB_adj" includes the measured Lab data.

Profiles can then me made by dragging and dropping these file into the Measurement tab of I1Profiler or, for Argyll profiles, running the CGATs files through the short batch file included. Both work.

The program then runs with the names of the two profiles and the white point and A2B1 table is copied from the "RGBLAB_adj" made profile into the "RGBLAB" made profile. The RGBLAB made profile can then be installed and softproofing performed. It will show proper paper white and any tint in the print.

The same profile can be used to print using the usual process with Epson printers or the workaround described earlier for Canon.

The profile included is from MP101 Matte on the Canon Pro1000. Ignore the name, it's from testing. Since the paper has a fairly large amount of OBAs and measurements were made with M1, having a L* min of 18, it makes for a pretty good demonstration of softproofing showing the blue shift of the OBAs.
« Last Edit: October 05, 2019, 12:27:03 am by Doug Gray »
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Alan Goldhammer

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Re: What printers allow custom profiles w Photoshop Manages for B&W?
« Reply #22 on: October 05, 2019, 02:43:03 pm »

Doug,

Thanks for the extensive discussion.  I don't have i1 Profiler and the work arounds for me are just too many steps.  Perhaps Graeme will add something to Argyll that will give similar results to what you are getting and that might make things more interesting for me.  I'll play around with the QTR derived profiles on my Canon Pro1000 to see if those make a difference with the B/W print path. 

Alan
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Doug Gray

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Re: What printers allow custom profiles w Photoshop Manages for B&W?
« Reply #23 on: October 05, 2019, 06:59:47 pm »

Doug,

Thanks for the extensive discussion.  I don't have i1 Profiler and the work arounds for me are just too many steps.  Perhaps Graeme will add something to Argyll that will give similar results to what you are getting and that might make things more interesting for me.  I'll play around with the QTR derived profiles on my Canon Pro1000 to see if those make a difference with the B/W print path. 

Alan

Certainly would be good if Argyll had i1iSis support. Their support of spectros is exceptionally large otherwise.

As for QTR, it would be cool if they would add support for soft proofing that would show tint and paper white properly. It is doable and should result in very small but accurate profiles. Still, using them to print on Canon's requires the null trick. Works great but Canon should really not lock out custom profiles from the usual workflow which necessitates it.
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Doug Gray

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Re: What printers allow custom profiles w Photoshop Manages for B&W?
« Reply #24 on: October 07, 2019, 01:03:05 am »

Wow.

I never realized how consistent B&W (even with tints) prints. I've finished the code. It does a great job of soft proofing with a much lower dE00 than color prints of neutral images. It also does a great job printing using standard "color" management techniques letting Photoshop manage and selecting the B&W profile. The statistics on same and nearby patch variations are markedly smaller.

Prints match the soft proof exactly with the strongest tint I can select.

My guess is that the consistency of ABW is because there is much less use of CYM inks except for a small amount required for the tints if used.

Just packaging it up to post on github later tonight.

It would be nice if Canon's printers would let you select custom B&W profiles like Epsons do to avoid the null transform trick needed to print on the Canon.
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deanwork

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Re: What printers allow custom profiles w Photoshop Manages for B&W?
« Reply #25 on: October 23, 2019, 11:36:53 pm »

I’ve been doing this for 8 years using True Black And White from Bowhaus on the 8300/8400s. They also supported the 24 inch models. It does everything you are discussing.

 Grayscale workflow with easy color tinting if desired. Much simpler and intuitive than any of these qtr programs. You just print the patches and plug in the iI to yiur Mac ( Mac only). But for some screwed up reason they still haven’t released it for the new canons. 

I don’t have a new canon but I email them every six months anyway. And they always tell me it’s about to be released. Canon has always allowed them to do whatever they need to do in the past. It is a stand alone program not an adjunct of the canon driver or photoshop plugin.

My prints are dead neutral on all the papers and you save warm or cool profiles for specific papers. It’s fast and painless. I remake the curves which they call profiles, after head changes but probably isn’t necessary.

 I just don’t think enough people are demanding them to finish it up writing code for the new Canons - and they keep coming out with new ones, who knows. People want everything great like that to be free and it costs $200.00, where Studio Print is about two grand to do similar monochrome linearizations on all the printer platforms. You softproof the file right in the software window.


If interested everyone should email them. The interface is smart, clean, and non geeky simple. What canon should have written from the beginning.

http://bowhaus.com/trueblackandwhite/truebw.php4

John

Wow.

I never realized how consistent B&W (even with tints) prints. I've finished the code. It does a great job of soft proofing with a much lower dE00 than color prints of neutral images. It also does a great job printing using standard "color" management techniques letting Photoshop manage and selecting the B&W profile. The statistics on same and nearby patch variations are markedly smaller.

Prints match the soft proof exactly with the strongest tint I can select.

My guess is that the consistency of ABW is because there is much less use of CYM inks except for a small amount required for the tints if used.

Just packaging it up to post on github later tonight.

It would be nice if Canon's printers would let you select custom B&W profiles like Epsons do to avoid the null transform trick needed to print on the Canon.
« Last Edit: October 23, 2019, 11:41:35 pm by deanwork »
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Alan Goldhammer

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Re: What printers allow custom profiles w Photoshop Manages for B&W?
« Reply #26 on: October 24, 2019, 08:13:11 am »


If interested everyone should email them. The interface is smart, clean, and non geeky simple. What canon should have written from the beginning.

http://bowhaus.com/trueblackandwhite/truebw.php4

John
Only works on MacOS and Canon Pro-1000 is not supported so this doesn't help me at all.
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Doug Gray

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JRSmit

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Re: What printers allow custom profiles w Photoshop Manages for B&W?
« Reply #28 on: June 22, 2021, 12:06:03 pm »

Would like to see a neutral measurement of an ABW print. Thusfar i was not able to.
For my Printing i do my own  profiling, and with a focus on neutral aka grey behaviour. So each profile is tested with amongst others a grey ramp , linear  in L-ab color space with steps of 2% for L and a and b equal 0.
When printed ideally is should give straight lines from paper-white to black , normally i print relcol  plus bpc
of course the bpc will give a deviation. As you can see in attached screencopy of such a test.
Here the a and b values follow the ‘straight line’ quite well.
So , in what area would ABW give an improvement if I print a black-white image?
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digitaldog

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Re: What printers allow custom profiles w Photoshop Manages for B&W?
« Reply #29 on: June 22, 2021, 01:08:20 pm »

I have many dozen or prints (some printed by others like those who worked on the Epson Print Academy, many I've made) where the B&W prints appear totally neutral; under many kinds of lighting all output using Epson Advanced B&W mode, no profiles.

I can measure them but I don't see the point; they appear totally neutral. That's the actual color appearance.

Colorimetry and the dE testing and the creation of profiles is about (based on) color perception. It is not about color appearance. There's a significant difference. The reason why viewing a print is more valid than measuring it is because measurement is about comparing solid colors. Color appearance is about evaluating images and color in context which measurement devices can't provide. Colorimetry was never designed as a color appearance model. It was never designed to even be used as an interchange space between device dependent color models. It's not designed for imagery at all. Colorimetry based on solid  colors in very specific ambient and surround conditions.
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Doug Gray

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Re: What printers allow custom profiles w Photoshop Manages for B&W?
« Reply #30 on: June 22, 2021, 06:04:29 pm »

Would like to see a neutral measurement of an ABW print. Thusfar i was not able to.
For my Printing i do my own  profiling, and with a focus on neutral aka grey behaviour. So each profile is tested with amongst others a grey ramp , linear  in L-ab color space with steps of 2% for L and a and b equal 0.
When printed ideally is should give straight lines from paper-white to black , normally i print relcol  plus bpc
of course the bpc will give a deviation. As you can see in attached screencopy of such a test.
Here the a and b values follow the ‘straight line’ quite well.
So , in what area would ABW give an improvement if I print a black-white image?


ABW uses much less of the color inks. Just enough to sort of correct for small a,b shifts each of the neutral inks have. The result is smoother transitions across L*, a* and b*. For instance if you print L* = 50.0, 50.5, 51, 51.5, 52.... the patches printed using color have larger variations in L*,a* and b* compared to ABW. On my Epson 9800 those variations are about half what they are with color printing.  These tiny changes no profile can correct. They are intrinsic to the driver's inking algorithms.

Also, the 9800 driver's RGB response is much smoother in ABW which makes the profiles work very well, even smaller LUT profiles.

ABW profiles thus are more accurate than color profiles for these reasons. But do they matter? No, they don't. Unless you are doing something really weird.

An example of a semi-crazy thing is to print a nearly black image in color mode and ABW. Say by shifting the white point on an image from L*=100 to L*=40. Then, instead of illuminating it with 500 Lux, use 5,000 Lux. This will make the L*=40 area as bright as unprinted paper under 500 Lux. And you will then be able to just see areas of transition noise that become apparent in the color print while it's much smoother in the ABW print.

Obviously this isn't a normal condition so it would be the rare case where it would matter.  One possibility is in an exhibit where one is creating an image that seems to shine a bright beam of light from a small area of a print. By using ultra bright illuminating lights and carefully exhibiting the print in a very black matte frame and surround one can create a rather unique effect. ABW would do much better for this than standard color mode B&W printing.

The other thing that ABW profiles bring is consistency between printers and the ability to soft proof with accurate rendition of any tint that is actually there. Especially useful for something like Sepia prints.
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