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Author Topic: Printing Targets Without Colour Management  (Read 17358 times)
digitaldog
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« Reply #20 on: November 23, 2009, 11:25:54 AM »
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Quote from: SimonS
Adobe RGB (1998)


Shouldn’t matter. As long as both color space selections are the same (and you can’t use the “Working Space: whatever color space”). You have to specifically pick the profiles.
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Andrew Rodney
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Desmond
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« Reply #21 on: November 23, 2009, 11:42:29 PM »
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I agree that if the asigned profile, working space and output profile are the same there shall be no change in RGB value in the null conversion. But the working space play a part in the middle, if gamut of the working space is some how different from the asigned/ output profile, some clipping will occur near the mismatch.
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Desmond
eronald
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« Reply #22 on: November 24, 2009, 01:40:09 AM »
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Quote from: Desmond
I agree that if the asigned profile, working space and output profile are the same there shall be no change in RGB value in the null conversion. But the working space play a part in the middle, if gamut of the working space is some how different from the asigned/ output profile, some clipping will occur near the mismatch.

AFAIK Photoshop doesn't really have an internal working space ***while Lightroom does***, for RGB it just continues to work in whatever RGB space is being assigned to the file or whatever space you convert to when you load the file. It also assigns the default working space space to new files. The terminology of this stuff is confusing but then "current computational referential for colors"  might make immediate sense to someone with science training but not mean much to an artist.

Lightroom does have some default space; I think it's Prophoto RGB with linear gamma, but I cannot be bothered to go and check.

I'm sure Andrew will come in and correct me if necessary - btw he's written a very nice book about this stuff, although it may need a new edition.

Edmund

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Doyle Yoder
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« Reply #23 on: November 24, 2009, 06:20:04 AM »
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Quote from: Desmond
I agree that if the asigned profile, working space and output profile are the same there shall be no change in RGB value in the null conversion. But the working space play a part in the middle, if gamut of the working space is some how different from the asigned/ output profile, some clipping will occur near the mismatch.

All this assumes that ColorSync is not getting involved and applying a profile in the driver. Given what we all know about drivers not working correctly and defaulting to ColorSync instead on No Colormanagement that is a pretty big assumption.

Doyle

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Desmond
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« Reply #24 on: November 24, 2009, 07:35:25 AM »
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Quote from: eronald
AFAIK Photoshop doesn't really have an internal working space ***while Lightroom does***, for RGB it just continues to work in whatever RGB space is being assigned to the file or whatever space you convert to when you load the file. It also assigns the default working space space to new files. The terminology of this stuff is confusing but then "current computational referential for colors"  might make immediate sense to someone with science training but not mean much to an artist.

Lightroom does have some default space; I think it's Prophoto RGB with linear gamma, but I cannot be bothered to go and check.

I'm sure Andrew will come in and correct me if necessary - btw he's written a very nice book about this stuff, although it may need a new edition.

Edmund

Thanks Edmund, thats why I love this Forum, there is a lot to be learnt.


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Desmond
Ernst Dinkla
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« Reply #25 on: November 25, 2009, 03:09:59 AM »
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Quote from: eronald
AFAIK Photoshop doesn't really have an internal working space ***
Edmund


That doesn't say Photoshop isn't interpreting untagged files differently. In the past I have tried to check RGB number changes to see the influence of RGB-device printer profiles on images but I was never able to block Photoshop's CM in that process.  Picture Window Pro, Qimage, both with CM switched off and applications without CM showed identical numbers, PS didn't.



met vriendelijke groeten, Ernst Dinkla

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« Last Edit: November 25, 2009, 03:10:22 AM by Ernst Dinkla » Logged
eronald
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« Reply #26 on: November 25, 2009, 03:23:01 AM »
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Ernst,

 Describe your experiment more fully, please.

Edmund

Quote from: Ernst Dinkla
That doesn't say Photoshop isn't interpreting untagged files differently. In the past I have tried to check RGB number changes to see the influence of RGB-device printer profiles on images but I was never able to block Photoshop's CM in that process.  Picture Window Pro, Qimage, both with CM switched off and applications without CM showed identical numbers, PS didn't.



met vriendelijke groeten, Ernst Dinkla

Dinkla Gallery Canvas Wrap Actions for Photoshop
http://www.pigment-print.com/dinklacanvaswraps/index.html
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Ernst Dinkla
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« Reply #27 on: November 25, 2009, 06:15:46 AM »
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Quote from: eronald
Ernst,

 Describe your experiment more fully, please.

Edmund


There were problems with QTR B&W profiles used in Qimage, both the RGB and B&W versions. To check what the conversions did on the images I used Print to File of Qimage with said profiles and checked the changes in several programs with CM off. In several ways: untagged, both assigned with the same color space the unprocessed image had, etc. I couldn't get identical numbers from Photoshop while they matched in the other programs with CM off. That was Photoshop CS in Windows. I was told then that it is difficult to check values in Photoshop as CM is never really off.

http://helgaas.com/photo/DigitalBlackandWh...05/02/0488.html


met vriendelijke groeten, Ernst Dinkla

Dinkla Gallery Canvas Wrap Actions for Photoshop
http://www.pigment-print.com/dinklacanvaswraps/index.html
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eronald
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« Reply #28 on: November 25, 2009, 07:56:33 AM »
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Ernst,

 All of this is too complex for me - I don't have CS anymore - don't use Windows etc.

 What one can test is writing RGB values programatically into a tiff, and then checking the values displayed in various pieces of software, or picking a single color point and dumping it out numerically after the file has been spooled out and back in. There is, I think a raw format in PS which should allow anyone to do this by hand and inspect the values, although there is something funny about the coding of values , but it's documented.  I have software to do this somewhere, and did it a lot.

 I think you can find images with known values on Bruce Lindbloom's site.

Edmund

Quote from: Ernst Dinkla
There were problems with QTR B&W profiles used in Qimage, both the RGB and B&W versions. To check what the conversions did on the images I used Print to File of Qimage with said profiles and checked the changes in several programs with CM off. In several ways: untagged, both assigned with the same color space the unprocessed image had, etc. I couldn't get identical numbers from Photoshop while they matched in the other programs with CM off. That was Photoshop CS in Windows. I was told then that it is difficult to check values in Photoshop as CM is never really off.

http://helgaas.com/photo/DigitalBlackandWh...05/02/0488.html


met vriendelijke groeten, Ernst Dinkla

Dinkla Gallery Canvas Wrap Actions for Photoshop
http://www.pigment-print.com/dinklacanvaswraps/index.html
« Last Edit: November 25, 2009, 07:58:29 AM by eronald » Logged
digitaldog
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« Reply #29 on: November 25, 2009, 08:11:22 AM »
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Quote from: Ernst Dinkla
That doesn't say Photoshop isn't interpreting untagged files differently.

Photoshop has always interpreted untagged documents as being in the working space for each color model in the color settings, at least for previews. The print path is a separate issue.
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Andrew Rodney
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eronald
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« Reply #30 on: November 25, 2009, 08:20:18 AM »
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Quote from: digitaldog
Photoshop has always interpreted untagged documents as being in the working space for each color model in the color settings, at least for previews. The print path is a separate issue.

Who cares about the preview of an untagged image anyway? It's totally meaningless. I would assume that Ernst knows enough to pull up the Info panel,  and inspect the RGB values.  I would certainly hope that these are raw data

I used to do everything with my own software, generating synthetic images, so I never checked.

Edmund
« Last Edit: November 25, 2009, 08:25:32 AM by eronald » Logged
eronald
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« Reply #31 on: November 25, 2009, 08:25:47 AM »
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Quote from: digitaldog
Photoshop has always interpreted untagged documents as being in the working space for each color model in the color settings, at least for previews. The print path is a separate issue.

Who cares about the preview of an untagged image anyway? It's totally meaningless. I would assume that Ernst knows enough to pull up the Info panel,  and inspect the RGB values.

Edmund
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digitaldog
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« Reply #32 on: November 25, 2009, 08:29:40 AM »
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Quote from: eronald
Who cares about the preview of an untagged image anyway? It's totally meaningless. =

Anyone who’s ever been provided an untagged document should care. Its RGB or CMYK mystery meat. The only way to begin color managing it is making a big guess and that’s all based on the preview. Its also the assumption of the numbers as far as Photoshop is concerned so if you’re doing any conversions, its kind of important. But other than that, its totally meaningless.
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Andrew Rodney
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eronald
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« Reply #33 on: November 25, 2009, 08:54:20 AM »
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Quote from: digitaldog
Anyone who’s ever been provided an untagged document should care. Its RGB or CMYK mystery meat. The only way to begin color managing it is making a big guess and that’s all based on the preview. Its also the assumption of the numbers as far as Photoshop is concerned so if you’re doing any conversions, its kind of important. But other than that, its totally meaningless.


Yeah, well if it's untagged, as far as I'm concerned, it's meaningless. Pull up the "assign" profile list, assign something to it, that looks halfway ok, now it has some meaning.

I can understand that the Photoshop authors wanted their software to have a default behavior with untagged imagery, but this has got us into the situation where people now expect *their* defaults to be significant on other machines, in other countries etc.

The idea that untagged is something other than meaningless, that one can and should make some  assumption about it, is also what has landed us in such a mess with web imagery. Of course, the fact that one company wanted the world to assume that there was only one web browser may have helped that along

But I'm preaching to the choir, am I not?
No one else is listening but us chickens

Edmund
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digitaldog
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« Reply #34 on: November 25, 2009, 09:17:50 AM »
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Quote from: eronald
Yeah, well if it's untagged, as far as I'm concerned, it's meaningless. Pull up the "assign" profile list, assign something to it, that looks halfway ok, now it has some meaning.

Must be nice not to have to live in a real world where people send you untagged documents....

Yes, pull up the Assign list and start guessing. End result, no more untagged doc.

Quote
I can understand that the Photoshop authors wanted their software to have a default behavior with untagged imagery, but this has got us into the situation where people now expect *their* defaults to be significant on other machines, in other countries etc.

No, the user has to take some responsibly for setting the color settings so Photoshop can make a guess to the untagged data. In one environment (say a web designer), it makes sense to select sRGB as this assumption, for others, nothing could be worse. So Adobe allows someone who understands how the application operates to not only direct the assumption for all untagged data, it can also warn you which is kind of useful.

Its real, real easy: Tag files good. Untagged files, bad. Now how do we go about fixing the bad situation?

Quote
The idea that untagged is something other than meaningless, that one can and should make some  assumption about it, is also what has landed us in such a mess with web imagery. Of course, the fact that one company wanted the world to assume that there was only one web browser may have helped that along

Until untagged documents never appear again, which isn’t likely, we need a mechanism for defining the scale of the numbers. So the statement “Who cares about the preview of an untagged image anyway? It's totally meaningless.“ is kind of silly don’t you think?

Quote
But I'm preaching to the choir, am I not?
No one else is listening but us chickens

I wouldn’t make such an assumption considering the audience.
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Andrew Rodney
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« Reply #35 on: November 25, 2009, 03:12:21 PM »
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Quote from: eronald
Yeah, well if it's untagged, as far as I'm concerned, it's meaningless. Pull up the "assign" profile list, assign something to it, that looks halfway ok, now it has some meaning.

As it relates to RGB and gamma encoded greyscale files, agreed. But, intentionally untagging CMYK files for delivery to prepress and printers is, actually a much safer (albeit backwards) procedure...

If you send a CMYK file with no profile, the odds are REAL GOOD the printer won't do a thing with it and just print it. However, if the printer gets a CMYK image with a profile, only one course of action will result in the proper results assuming that the printer has a press profile and knows how to use it–convert to profile using a CMYK>CMYK transform. But the odds of a printer knowing what they are doing is so low that this is prolly the LEAST likely option they would use...

That's the problem with at least the American graphic arts industry...almost nobody knows what they are doing...

:~(

Tag RGB and greyscale for sure...be VERY careful tagging CMYK files.
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eronald
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« Reply #36 on: November 26, 2009, 02:52:13 PM »
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I once handed in some RGB imagery to a fashion magazine. Tagged by the appropriate profiles. Later they told me: Your pictures are horrible, the colors are dreadful, you don't know how to work the models (AD was on set), the lighting is bad, we'll never work with you again, but tell us: Who did you steal those wonderful colorful portofolio pictures from, the ones you showed us to get the job?

Edmund



Quote from: Schewe
As it relates to RGB and gamma encoded greyscale files, agreed. But, intentionally untagging CMYK files for delivery to prepress and printers is, actually a much safer (albeit backwards) procedure...

If you send a CMYK file with no profile, the odds are REAL GOOD the printer won't do a thing with it and just print it. However, if the printer gets a CMYK image with a profile, only one course of action will result in the proper results assuming that the printer has a press profile and knows how to use it–convert to profile using a CMYK>CMYK transform. But the odds of a printer knowing what they are doing is so low that this is prolly the LEAST likely option they would use...

That's the problem with at least the American graphic arts industry...almost nobody knows what they are doing...

:~(

Tag RGB and greyscale for sure...be VERY careful tagging CMYK files.
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DonCone
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« Reply #37 on: December 06, 2009, 12:59:53 PM »
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Quote from: SimonS
Printing Targets Without Colour Management

The Eric Chan Workaround With Canon Printers – A Report


I have now found some time to test Eric Chan’s devious(!) workaround for printing colour profiling test targets without colour management.

My system configuration is Mac OSX 10.4.11 (Tiger), Photoshop CS4, Canon printers Pro9000 and iP4500 (with latest drivers).

I have used a print from Photoshop CS2 without Colour Management as a benchmark.

I am sorry to report that Eric’s workaround does not work in the above set-up.  The resulting target patches are too light.  I tried substituting the ProPhoto RGB Colour Space for Adobe RGB and the patches are printed lighter still, which is contrary to the suggestion that changing the colour space will make no difference to the printed output (something which I find hard to credit).  Previewing the workaround prints in CS4 displays clipping of some patches which would appear to suggest that colour management is indeed taking place.

The results of my testing can be seen in the attached file.

There are scans of four tests:
Photoshop CS2 – No Colour Management (benchmark)
Photoshop CS4 – No Colour Management
Photoshop CS4 – Eric Chan Workaround
Photoshop CS4 – Eric Chan Workaround (ProPhoto RGB)

I am really sorry Eric …

I recall that a similar suggestion was made to me by Tom Attix of Adobe, but using the Generic RGB colour space.  Sadly this did not work either.

There are here enough variables to start endless speculations and I suspect a blizzard of postings will follow !

I have to say that I am not convinced that the printer drivers are contributing to the problem, but this is my opinion based on supposition only.

Given that Mark Dubovoy checked the targets he printed (using the workaround) against his reference targets (printed earlier without using CS4 and Snow Leopard), and that they were near enough identical, this would seem to suggest that there is something different about the way Mac OSX 10.6 (Snow Leopard) handles colour management compared to OSX 10.4 (Tiger).  As for Leopard (10.5), I can’t say.
Perhaps Mark could verify  this ?

In the meantime my personal, and strong, recommendation is not to rely on targets printed from CS4 to profile output devices such as printers; but to use an earlier version of Photoshop and Mac OS – one which is known from previous experience to produce accurate targets.


Simon for the past few days I have been chasing the Leopard/Snow Lwopard/CS4 and Epson printer profiling problem too. With Snow Leopard, Epson Pro3800 with v6.11, and CS4 I tried Eric's workaround and although it was an improvement the profile was not accurate. However, I did find a way to print from CS4 and maintain the integrity of the target file. It was really very simple. Although you are not using Snow Leopard, this may work for you in CS4 too.

Printing targets for Eye-One Match I open the original 72dpi untagged file in CS4. I set CS4 to not color manage the file. I hit Print and in the Adobe print dialog select "Printer Manages Color" instead of "No Color Management". In the Epson driver I select "No color management" and my normal printer settings and paper type.

This results in a perfect target print that matches previous targets from Tiger and earlier versions of CS. With color management turned off in the Adobe dialog Colorsync takes over if "No Color Management" is selected but it does not when "Printer Manages Color" is enabled.

Perhaps this may offer a clue to others that are having the problem.

Don


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« Reply #38 on: December 06, 2009, 02:26:54 PM »
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Quote from: DonCone
With color management turned off in the Adobe dialog Colorsync takes over if "No Color Management" is selected but it does not when "Printer Manages Color" is enabled.


Actually, I don't think this is true...ColorSync in Leopard (and SL) is ALWAYS engaged regardless of the app/driver settings...your results only apply in the case where the paper you are making a target for has both an Epson media settings _AND_ and installed ICC profile for the paper. Even the No Color Management settings in the driver calls ColorSync and the media settings dictates the "default" profile for ColorSync. Which can STILL cause "issues" if you are trying to profile 3rd party papers...
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Doyle Yoder
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« Reply #39 on: December 06, 2009, 04:54:48 PM »
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Quote from: DonCone
Simon for the past few days I have been chasing the Leopard/Snow Lwopard/CS4 and Epson printer profiling problem too. With Snow Leopard, Epson Pro3800 with v6.11, and CS4 I tried Eric's workaround and although it was an improvement the profile was not accurate. However, I did find a way to print from CS4 and maintain the integrity of the target file. It was really very simple. Although you are not using Snow Leopard, this may work for you in CS4 too.

Printing targets for Eye-One Match I open the original 72dpi untagged file in CS4. I set CS4 to not color manage the file. I hit Print and in the Adobe print dialog select "Printer Manages Color" instead of "No Color Management". In the Epson driver I select "No color management" and my normal printer settings and paper type.

This results in a perfect target print that matches previous targets from Tiger and earlier versions of CS. With color management turned off in the Adobe dialog Colorsync takes over if "No Color Management" is selected but it does not when "Printer Manages Color" is enabled.

Perhaps this may offer a clue to others that are having the problem.

Don

That is exactly how it is supposed to work when "Printer Manages Color" is selected, you should have all controls available to you in the driver. Where Epson has messed up is when the "No Color Management" call is given from PS the driver should react the same way as when the "PS Manages Color" call is given. Defaults to ColorSync in Color Matching and then turns off CM in the driver.

Doyle
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