Apple and Colour Management – Just When You Thought It Was Safe To Go Out

[Simon J.A. Simpson]

In 2010 I bought a ColorMunki and have used it to successfully produce profiles for monitors and printers alike.  Until recently I was using Apple’s Tiger (OSX 10.4.11) on a G5.  I have two Canon printers, and A4 and A3 Pro.

Recently my G5 tower gave up and I acquired a new 27 inch iMac.  This, of course has Lion (OSX 10.7.2).  And this is when things started to become ‘interesting’.

For those who don’t know, the ColorMunki software produces its own targets (colour patches) and you print direct from the software.

The colour management path is quite different in the two operating systems.  The issue revolves around the setting in the printer dialogue under “Color Matching” (see screenshot below).

When printing from Photoshop, using ‘Photoshop Manages Colors’ the “Color Matching” option is greyed-out in the printer dialogue although the “ColorSync” radio button is selected (but greyed).
When printing using the ColorMunki software there is a choice of “ColorSync” or “Canon Color Matching”.  This is, of course, counter intuitive – we don’t actually want any colour matching.  Using “ColorSync” you can then choose from a list of profiles.  Leaving it on “Automatic” the driver seems to select a profile of the Canon paper type selected in the driver (it is listed underneath the menu – see screenshot below).

So what “Color Matching” should you select in the printer dialogue ?
In brief, there is conflicting advice – but advice which concurs with Eric Chan’s ‘null transform’ workaround.
On their website X-Rite ColorMunki advise using “ColorSync” and selecting the “Generic RGB” profile.
Datacolor/Spyder’s advice is more specific as to printers and operating systems.  The most up-to-date operating system they refer to is Snow Leopard 10.6.3 and they say to use the “sRGB” profile.

So I have conducted some tests.
I have printed targets selecting the following profiles under “Color Matching”:
1.   ColorSync – Generic RGB profile
2.   ColorSync – sRGB profile
3.   ColorSync – ProPhoto profile
I have also a target printed under Tiger to compare them with.

In addition I used the print dialogue to export a PDF of the target which I rasterised in Photoshop (CS5).  When importing it had as its “Mode” set as sRGB (whatever that means) and had an sRGB profile attached.  I discarded the profile and opened it as a ‘non colour managed’ document.  I saved it as a tiff and then printed it using Adobe’s  ‘Color Printer Utility’ (designed for printing targets without colour management).  For ease of reference I will call this test print the “PDF target”.

So, what did I find ?

Well all the targets are different.  We can disregard the ProPhoto target as that was wildly out (much too light).  The Generic RGB target was slightly darker than the other three so can we safely eliminate that one ?  That leaves the remaining three:
a.   sRGB target
b.   Tiger target
c.   PDF target

There are slight visual, and measurable, differences between all the three.  There are slight differences in hue and lightness.

So my question is this:
Which of the three targets will most closely replicate the conditions under which Photoshop prints ‘Photoshop Manages Colors’ so I can get accurate prints ?

[digitaldog]

When printing from Photoshop, using ‘Photoshop Manages Colors’ the “Color Matching” option is greyed-out in the printer dialogue although the “ColorSync” radio button is selected (but greyed).

Some software products are using a private (undocumented) SPI called kPMApplicationColorMatching which you see in Photoshop and Lightroom and the Adobe Color Print Utility. When you set Application Manages Color, the area of the driver that controls Colorsync will alter the radio buttons such they are grayed out. X-Rite’s i1Profiler has also implemented this SPI so I suspect at some point, we’ll see ColorMunki use it too.

[Doyle Yoder]

You need to be selecting Canon Color Matching and then set No Color Correction on in the driver when printing from ColorMunki.

Also to clarify your attachment shows the dialog you will get from an application that uses Apples old printing path or a setting of Printer Manages Color from application that uses Apples new printing path.

I would use the Print Dialog to output a tif for printing in Adobe’s  ‘Color Printer Utility’. I think I tested the PDF method one time and could not find a way to create a tif from it with some conversion happening. This I tested from a profiling application that had the ability to export tif and that was the only method I could find to get a match in PS.

The big question is how does your Canon driver support applications that use Apples new printing path? Does the driver need a special cases file like the Canon iPF drivers or not. Refer to this thread for information on that. http://www.luminous-landscape.com/forum/index.php?topic=58226.0

[Simon J.A. Simpson]

Rodney.

When Photoshop is using the kPMApplicationColorMatching SPI is it using the ‘null transform” method or is it switching colour management off ?

[Ellis Vener]

Just for clarification, although it may not change things, OS X Lion is now up to v 10.7.3  so Simon you may want to update . idon't know what if any changes were made between 10.7.2 and 10.7. 3 as I went straight from 10.6.8 to 10.7.3.

[digitaldog]

When Photoshop is using the kPMApplicationColorMatching SPI is it using the ‘null transform” method or is it switching colour management off ?

As far as I know, this simply sets this portion of the driver for the user correctly and doesn’t allow them to set it incorrectly.

[Simon J.A. Simpson]

So I guess we still don't know what is going on, under the hood so to speak, when ‘Photoshop Manages Color’ – what is happening when the the “kPMApplicationColorMatching” SPI is used.  Is it a “null transform’ or simply switching-off colour management in the Apple part of the path.  It would be useful to know so as which method to adopt when printing targets.

It is clear to me now that there are three things which can manage the colour in the printing path:
1:  The printing application
2:  The Apple OS
3:  The printer driver.

Hmmm …  Thinking aloud – eliminating what is going on in the Apple part of the path seems to be the problem.

[Doyle Yoder]

Hmmm …  Thinking aloud – eliminating what is going on in the Apple part of the path seems to be the problem.

There are plenty of printer drivers that do this ( eliminating what is going on in the Apple part of the path), so what does that say.

[Scott Martin]

I've been talking with Adobe's Printing engineer about all of this and what's in store for the future and indeed it's a mess. To make a long story short when "Printer Manages Colors" is specified Photoshop sends profiledRGB, ProfiledCMYK and ProfiledGray to the OS without conversion. The OS may change the colorspace if it's not in the correct color mode (like RGB for inkjets). So the Null transform trick is *the* way to profile both RGB and CMYK devices from PSCS5. Just make sure to choose RGB for printer drivers and CMYK for true Postscript printers. I've been implementing this procedure as I travel around the country profiling all kinds of devices and it's been working great for some time.

[digitaldog]

So the Null transform trick is *the* way to profile both RGB and CMYK devices from PSCS5.

What about just using Adobe’s Color Print Utility?

[Simon J.A. Simpson]

You need to be selecting Canon Color Matching and then set No Color Correction on in the driver when printing from ColorMunki.

There is no simple way (like a radio button or menu item) of turning ‘off’ colour management in the driver, or selecting ‘No Color Correction’.  

There are plenty of printer drivers that do this (eliminating what is going on in the Apple part of the path), so what does that say.

Actually, the printer driver cannot, by definition, eliminate what is going on in the Apple part of the path – in the same way that an application cannot. This is the problem, for all brands of printer and indeed all applications.  It says, therefore, this is an Apple created problem.


Onsight.
Thank you for your posting.  This gives me the confidence to stick with the ‘null transform’ method and selecting an sRGB profile.  I will try making and testing some profiles over the next few days and report back.

What about just using Adobe’s Color Print Utility?

This is what I was wondering.  But what is odd is that the ‘null transform’ and the Adobe Print Utility targets (see above) are slightly different, visually and measured, when I would expect them to be the same.  But the ‘settings’ for printing of the targets (application/Apple/printer) have to exactly replicate those for making accurate prints from the resulting profile.  Thus my question as to which method to use.  Perhaps Adobe or Apple could give us the answer since this is the crux of the matter ?

[Ethan_Hansen]

Going back to the original question on how to properly print profiling targets:

Simple answer: Use Windows. It just works. Oh wait ... wasn't that a slogan for something else?

On a Mac, your best bet is, as Andrew mentions above, to use Adobe's print utility. As far as I am aware, none of X-Rite's applications use kPMApplicationColorMatching. Without it, any print driver claiming a native color management mode using an ICC profile rather than sRGB or Adobe RGB will create a color transform on the way to the printer and corrupt your targets. A really wonderful aspect of Apple's mess is that the kPMApplicationColorMatching SPI allows, by design even, some objects to be managed by ColorSync while the remainder are not. What could be the practical use of that? Beats me.

If you use the ACPU for target printing be aware that it shrinks the target dimensions by about 3%. If you are using minimum patch dimensions, this can create chart reading problems or measurement inaccuracies depending on the instrument used. Scale the target size up slightly and you'll be fine.

[digitaldog]

As far as I am aware, none of X-Rite's applications use kPMApplicationColorMatching.

i1Profile is.

[Scott Martin]

What about just using Adobe’s Color Print Utility?

Although it works great for the inkjet-only masses, it's functionally is too limited for people like myself for these reasons:

1) Occasional issues with scaling.
2) Doesn't support CMYK or Grayscale.
3) The masses have Photoshop and don't have ACPU. In a remote profiling situation the hassle of downloading and using new software is just too much for some people.

[Scott Martin]

On a Mac, your best bet is, as Andrew mentions above, to use Adobe's print utility.

Why use the ACPU when you can use the Null transform trick? It's one method that works for all devices on all operating systems.

[Scott Martin]

Onsight. Thank you for your posting.  This gives me the confidence to stick with the ‘null transform’ method and selecting an sRGB profile.

Recommend assigning and printing with AdobeRGB (RelCol, no BPC) over sRGB. There are a lot of weird sRGB profiles out there. I'm using the old "U.S. Web Coated (SWOP) v2" profile to profile CMYK Postscript devices (think laser printers).

[Simon J.A. Simpson]

Recommend assigning and printing with AdobeRGB (RelCol, no BPC) over sRGB. There are a lot of weird sRGB profiles out there. I'm using the old "U.S. Web Coated (SWOP) v2" profile to profile CMYK Postscript devices (think laser printers).

Scott, I'm not quite sure we're on the same page here ?

Having tried this in previous testing (not quite as the OP above) I would not be confident that the Adobe RGB would work in a ‘null transform’.  Certainly there are visible differences between using sRGB (point taken about weird profiles), Generic RGB, and ProPhoto RGB (the last being dramatically different).  My understanding is that, in theory, the profile does not take part in the Apple part of the printing path, it merely tells the Apple part not to ‘colour mange’ the document (oh what tangled web has Apple woven !).

BTW – Andrew, sorry to have have called you Rodney (smiles apologetically).  My mistake.

[Scott Martin]

Simple answer: Use Windows. It just works. Oh wait ... wasn't that a slogan for something else?

Actually I'm told Microsoft is following Apple lead and will soon adopt the policy of converting images in the wrong color mode to the correct color mode as Apple's OS does now. Adobe tells me they are prepping for this and because they have no control over the OS they were forced to eliminate the "No Color Management" policy. Again, the null transform trick in CS5 behaves identically to CS3's "No Color Management" as long as it's done right.

[Doyle Yoder]

[quote author=SimonS link=topic=63451.msg511229#msg511229 date=1331400635
Actually, the printer driver cannot, by definition, eliminate what is going on in the Apple part of the path – in the same way that an application cannot. This is the problem, for all brands of printer and indeed all applications.  It says, therefore, this is an Apple created problem.

[/quote]

This is simple not the truth. There are many printer driver and application combinations that do not cause the OS to do any CM in the driver or the OS.

[Scott Martin]

Having tried this in previous testing (not quite as the OP above) I would not be confident that the Adobe RGB would work in a ‘null transform’. 

Yes, be confident that it will! It does. CS5 works great for the null transform trick via RGB, CMYK and Grayscale. Your results may vary on old versions of PS.

Certainly there are visible differences between using sRGB (point taken about weird profiles), Generic RGB, and ProPhoto RGB (the last being dramatically different).  

Doesn't matter. For RGB profiling targets, assign and print with AdobeRGB, RelCol, noBPC and you're good.

My understanding is that, in theory, the profile does not take part in the Apple part of the printing path....

In theory yes, in real world usage, some profiles have been known to screw this up.