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Author Topic: Rendering intents when printer manages colour ???  (Read 19538 times)

Rhossydd

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Rendering intents when printer manages colour ???
« on: April 23, 2009, 04:23:57 am »

Can someone explain why there is still a rendering intents option available when selecting “Printer manages color” when printing from CS4 ?

I would have expected it to just pass the data straight to the printer unaltered. How can it apply a perceptual rendering intent if it doesn’t know what profile the printer driver will use ? or does it just add some sort of tag to the unaltered image data to get the printer to use the required rendering intent ?

Further what difference is there between ‘no color management’ and ‘printer manages colors’ ?

TIA
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madmanchan

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Rendering intents when printer manages colour ???
« Reply #1 on: April 23, 2009, 03:42:38 pm »

Quote from: Rhossydd
Can someone explain why there is still a rendering intents option available when selecting “Printer manages color” when printing from CS4 ?

I would have expected it to just pass the data straight to the printer unaltered. How can it apply a perceptual rendering intent if it doesn’t know what profile the printer driver will use ?

The Rendering Intent option has no effect in this case. (Ideally it would be disabled to make it clearer.)

Quote
or does it just add some sort of tag to the unaltered image data to get the printer to use the required rendering intent ?

Further what difference is there between ‘no color management’ and ‘printer manages colors’ ?

The tagging is the difference. When you use Printer Manages Colors, PS tags the document with the document color space and then passes the image data off unmodified to the OS for the OS to perform the required output-specific color transformation. When you use No Color Management then neither PS nor the OS should be applying any color transformation whatsoever to the image data. (The underlying mechanisms by which NCM operates is OS-dependent and unfortunately has been a source of frustration for Mac users recently due to miscommunications / misunderstandings among the new OS X print API and some printer driver implementations. Ask any Leopard CS4 user who has tried to print Epson ABW images with No Color Management on Leopard.)
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Eric Chan

Rhossydd

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Rendering intents when printer manages colour ???
« Reply #2 on: April 23, 2009, 04:01:48 pm »

Brilliant, thanks for such a helpful and comprehensive answer Eric.
Quote from: madmanchan
(The underlying mechanisms by which NCM operates is OS-dependent and unfortunately has been a source of frustration for Mac users recently due to miscommunications / misunderstandings among the new OS X print API and some printer driver implementations. Ask any Leopard CS4 user who has tried to print Epson ABW images with No Color Management on Leopard.)
Yes, I'm trying to support a Mac user who seems to be having terrible trouble with this at the moment, and people say Macs are simple.....
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Mark D Segal

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Rendering intents when printer manages colour ???
« Reply #3 on: April 23, 2009, 04:10:30 pm »

On a more general note, I'm wondering whether problems of un-sticky driver settings experienced with Epson drivers for some current professional printer models and Mac OSs have finally been resolved.
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Mark D Segal (formerly MarkDS)
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Damo77

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Rendering intents when printer manages colour ???
« Reply #4 on: April 23, 2009, 06:25:35 pm »

Quote from: madmanchan
The Rendering Intent option has no effect in this case. (Ideally it would be disabled to make it clearer.)
Agree 100%.  In the same manner, it would be great if unavailable rendering intents were grayed out in "Convert to profile".
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Damien

Wayne Fox

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Rendering intents when printer manages colour ???
« Reply #5 on: April 23, 2009, 09:32:10 pm »

Quote from: MarkDS
On a more general note, I'm wondering whether problems of un-sticky driver settings experienced with Epson drivers for some current professional printer models and Mac OSs have finally been resolved.

For the most part yes.  In addition, all of the relevant settings are displayed in 1 single dialog box now if Photoshop is managing colors.
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Mark D Segal

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Rendering intents when printer manages colour ???
« Reply #6 on: April 23, 2009, 09:33:27 pm »

What part remains unresolved?
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Mark D Segal (formerly MarkDS)
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Wayne Fox

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Rendering intents when printer manages colour ???
« Reply #7 on: April 23, 2009, 09:37:06 pm »

Quote from: Rhossydd
Brilliant, thanks for such a helpful and comprehensive answer Eric.

Yes, I'm trying to support a Mac user who seems to be having terrible trouble with this at the moment, and people say Macs are simple.....

What are the problems?  Why are you trying to let the printer manage color instead of Photoshop?  Most of the issues can be resolved pretty easily if we knew what the challenges are.
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Schewe

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Rendering intents when printer manages colour ???
« Reply #8 on: April 24, 2009, 12:41:55 am »

Quote from: Wayne Fox
What are the problems?  Why are you trying to let the printer manage color instead of Photoshop?


This is a specific issue relating to Epson's ABW mode...with the most recent drivers (at least the 79/9900) sending a print using "No Color Management" barfs (meaning the image doesn't actually spool–just goes in to the ether) so you need to use a different approach. You can either send it 'Printer Manages Color' and try to fight the gamma game or send it Adobe RGB (which the driver is expecting) and then also 'manage color' using the Advanced B&W mode in the driver. It's one of the rare cases of intentional double color management being desirable...
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Rhossydd

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Rendering intents when printer manages colour ???
« Reply #9 on: April 24, 2009, 05:28:51 am »

Quote from: Wayne Fox
What are the problems?
Print output changes between 'no color management' and 'printer manages color' in CS4, which as Eric says shouldn't be the case.

Discovered when a customer has tried to print out profiling targets for a Canon Pro 9000 on Mac OS 10.4.11 and the resultant prints were way too dark although all the settings were correct.

Slowly going through all the possibilities to find out what's going(gone) wrong, but even though the customer is technically competent diagnosing OS/driver failures is never going to be easy.
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Mark D Segal

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Rendering intents when printer manages colour ???
« Reply #10 on: April 24, 2009, 07:47:33 am »

Quote from: Wayne Fox
What are the problems?  Why are you trying to let the printer manage color instead of Photoshop?  Most of the issues can be resolved pretty easily if we knew what the challenges are.

Wayne: I mentioned what the problem is. You said it was partly resolved, so I asked what part isn't resolved.

Who ever said *I* let the printer manage colour - I never do.

Yes I agree, it's usually easier to solve problems when you know what they are - trite, isn't it; but beleve it or not sometimes that just doesn't happen.

Jeff, yes what you're addressing is the specific issue at play - I was expanding content a bit to glean intelligence about any resolution of the broader issue related to avoiding the need for recycling through driver settings when combining Epson drivers (various versions) with Mac OSX - i.o.w - one of those rare occasions where one would hope for Windows-like functionality on the Mac. It's an old story - I'm wondering whether it's finally dealt with.
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Mark D Segal (formerly MarkDS)
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madmanchan

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Rendering intents when printer manages colour ???
« Reply #11 on: April 24, 2009, 08:36:30 am »

Hi Mark, with a fully-compliant Leopard driver, I am not aware of any outstanding issues when printing on Mac Leopard in terms of color management. The steps are the same as when printing from Windows, except for the physical appearance of the dialog boxes. That is, I don't believe there is anything that Apple needs to address/fix at this time.

One of the issues that has come up is due to Apple's printing interfaces for developers, which have evolved over time (and thus apps like LR, Photoshop, etc. as well as printer drivers need to evolve, too). When I say "interfaces" here I'm talking about under-the-hood programming interfaces which are transparent to the end user -- except for the results when something goes bad. The old interfaces were well tested on the driver front since folks used them for years. On the Mac side, folks didn't start using the new interfaces till CS4. And that's where some of the trouble started, because even though CS4 was doing the right thing (and we double-checked with Apple to be sure that we didn't goof), some of the drivers have minor glitches when using the new interfaces and those are now being encountered. One might ask, "well if the old interfaces worked why change anything?" Because all the new technology on the OS side depends on migrating to the new interfaces. For example, Mac folks want 64-bit Photoshop, right? Can't do that using the old printer interfaces.
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Eric Chan

Simon J.A. Simpson

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Rendering intents when printer manages colour ???
« Reply #12 on: April 28, 2009, 05:23:10 am »

The Customer Speaks

I am the customer referred to by Rhossydd.  I believe it would be helpful to share the results of my tests with everyone as they have far reaching and important implications.

Firstly though, a big thank you to Rhossydd – for his help and forbearance, and the honourable and generous way he has dealt with the issues that have arisen.

Over the last four days (and over fifty prints) I have undertaken extensive and meticulous tests to identify the cause of the problem; namely that targets for profiling, printed with ‘no colour management’, were printing far too dark and with what appeared to be a colour cast.

I have conclusively eliminated the printer, the printer drivers, the Mac OS, corrupted preference files, corrupted user accounts, incorrect Photoshop settings, incorrect printer driver settings, the ‘sticky settings issue, and user error as possible causes of the problem.

I can say with 95% certainty that my tests, conducted using Mac OSX 10.4.11, have proved the following:
1.   That, printing to a Canon Pro9000 or iP4500, Photoshop CS4 does not print accurate targets suitable for producing profiles.  This applies to both the No Colour Management (NCM) and the Printer Manages Colour (PMC) settings.
2.   Photoshop CS and CS2 are not effected.
I did not test CS3.
Furthermore, colour managed prints (using the same accurate profile made in CS2), printed in CS2 and CS4, show subtle differences.  This may not be an issue except in the most critical applications.

It is likely that the problem will not be confined to the two Canon printers above since many other Canon printers share the same driver architecture.

Reading posts and discussions on other websites would seem to indicate that this problem is also manifest with some Epson printers and may also effect Mac OSX 10.5.

I have to conclude, therefore, that Photoshop CS4 cannot be replied upon to print targets sufficiently accurate to produce reliable profiles for a colour managed workflow.

The fact that this is only just being reported can be attributed to four factors.
1.   That many CS4 users are continuing to use profiles made under older versions of Photoshop and have yet to make new profiles using CS4.
2.   Some users may not immediately notice a problem, or may ascribe it to other causes.
3.   Some users may take the line of least resistance and use a previous version of Photoshop to work around the problem.
4.   Some users are still using the older versions of Photoshop not effected.
If Eric Chan is correct, and Adobe changed the APIs in Photoshop CS4, this begs question of whether Adobe sufficiently tested CS4 before release ?
If Adobe did not test their software, and therefore failed to identify this critical problem, this would suggest negligence on Adobe’s part.  If Adobe identified the problem but then did not inform users that a potentially serious colour management issue existed this would suggest wilful or gross negligence.

With all due respect to Eric Chan it is not good enough to say that Adobe simply followed the ‘conventional’ path and ‘followed the rules’ regarding API implementation.  The experience of end users does not correspond to a “minor glitch” and, in my case, has been extremely costly in terms of time (over five days in all), lost revenues, and materials.

In UK law providers of goods and services (and this includes software) have to supply them as “fit for purpose”.  Clearly, in terms of colour management, CS4 is not fit for purpose.  Neither can Adobe hide behind its labyrinthine licensing terms since any exclusions would be ruled unlawful under the UK’s ‘Unfair Contract Terms’ Act.

My strong and unequivocal recommendation is that representatives from Adobe, Apple, and the printer manufacturers meet together – with the utmost urgency – and provide a rapid and complete solution.  It is simply not good enough to pass this ‘over the wall’ saying “it’s not our problem”.  It is.  All of yours.  Please solve it.  And quickly.
Clearly identify the problem, make it and your solution public; and publicise it widely and thoroughly.

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madmanchan

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Rendering intents when printer manages colour ???
« Reply #13 on: April 28, 2009, 08:25:52 am »

SimonS, unfortunately you may have misunderstood my post. There is not much that Adobe can do if a printer driver is not behaving correctly. This is an issue you'll have to take up with Canon and hope they provide a driver update.

There was a similar issue not that long ago with some of the Canon large format printers on Leopard and some users spent a long time explaining why they were absolutely convinced Adobe was at fault, and some Adobe staff (myself included) spent a long time explaining why it was a driver issue ... which was ultimately resolved when Canon released a driver update.
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Eric Chan

Ryan Grayley

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Rendering intents when printer manages colour ???
« Reply #14 on: April 28, 2009, 08:41:59 am »

Quote from: SimonS
I have to conclude, therefore, that Photoshop CS4 cannot be replied upon to print targets sufficiently accurate to produce reliable profiles for a colour managed workflow.

I agree with your conclusion.

I came to the same conclusion a few months ago when trying to create profiles for my Epson 7900.

http://luminous-landscape.com/forum/index....410&hl=7900

I now use Photoshop CS1 for profiling my Epson printers.
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Ryan Grayley BA IEng MIET ARPS
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digitaldog

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Rendering intents when printer manages colour ???
« Reply #15 on: April 28, 2009, 09:23:30 am »

Quote from: madmanchan
Hi Mark, with a fully-compliant Leopard driver, I am not aware of any outstanding issues when printing on Mac Leopard in terms of color management.

The problem is finding them! And of course, the app has to be compliant too.

Printer Manages Color on paper works and I suppose there are examples where it does, but most of the time, it doesn't where application manage colors more often does. It would be useful if someone (Apple? What am I thinking, a printer manufacturer) listed app's and drivers that really did work with PMC.

As for rendering intent, I suspect the default intent built into the profile is what's used here. There can't be no rendering intent of course.  

As for targets, you simply have to use a No Color Management option in the app. That's why we are very fortunate that Photoshop continues to provide that option. I've seen no issues nor have those who've sent me targets, doing so in CS4. And I've had no issues using profiles built in older versions either. That said, the large majority of those are printing targets from Epson drivers although I've done Canon printers as well and again, no issues. Since the targets are printed by others and sent to me, I can't comment on what settings, OS or other factors were used.
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Mark D Segal

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Rendering intents when printer manages colour ???
« Reply #16 on: April 28, 2009, 10:07:21 am »

Quote from: madmanchan
Hi Mark, with a fully-compliant Leopard driver, I am not aware of any outstanding issues when printing on Mac Leopard in terms of color management. The steps are the same as when printing from Windows, except for the physical appearance of the dialog boxes. That is, I don't believe there is anything that Apple needs to address/fix at this time.

One of the issues that has come up is due to Apple's printing interfaces for developers, which have evolved over time (and thus apps like LR, Photoshop, etc. as well as printer drivers need to evolve, too). When I say "interfaces" here I'm talking about under-the-hood programming interfaces which are transparent to the end user -- except for the results when something goes bad. The old interfaces were well tested on the driver front since folks used them for years. On the Mac side, folks didn't start using the new interfaces till CS4. And that's where some of the trouble started, because even though CS4 was doing the right thing (and we double-checked with Apple to be sure that we didn't goof), some of the drivers have minor glitches when using the new interfaces and those are now being encountered. One might ask, "well if the old interfaces worked why change anything?" Because all the new technology on the OS side depends on migrating to the new interfaces. For example, Mac folks want 64-bit Photoshop, right? Can't do that using the old printer interfaces.

Thanks Eric - somehow this message did not hit my inbox and I am just seeing it from another post now. This is re-assuring news and removes one more reason for not migrating to Mac one of these days, as my XP box becomes dated by more demanding versions of PS.

Mark
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Mark D Segal (formerly MarkDS)
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Simon J.A. Simpson

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Rendering intents when printer manages colour ???
« Reply #17 on: April 28, 2009, 11:21:41 am »

Hi Eric.

I do not believe I misunderstood your post.

You did say that Adobe had changed the APIs did you not ?

OK.  So how did Adobe make sure that the printer manufacturers were aware of this; and that they were aware that the changes could seriously effect the ability to create a colour managed workflow ?

Did not Adobe test CS4 with different printers (or, at the very least, with a selection of professional printers) and identify this problem ?  Having identified this problem did they make the manufacturers aware of this ?  Did they post warnings on the internet and with the installation software so that users would be aware of the pitfalls ?

And there you go again, handing the problem 'over the wall'*.
May I respectfully suggest that it would be more constructive to engage in dialogue with Apple and the printer manufacturers and focus on providing a solution.

* With equal respect may I suggest Adobe takes a look at pages 78 though 83 of the excellent book 'Four Days With Dr. Deming' (how cooperation improves standards).  See this URL:  http://deming.org/
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Wayne Fox

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Rendering intents when printer manages colour ???
« Reply #18 on: April 28, 2009, 08:25:16 pm »

Quote from: MarkDS
What part remains unresolved?


It is more of a case that it works almost all of the time, but occasionally doesn't.  The settings appear to be stored based on paper type and size, so adding a new custom size sometimes reverts to default settings.  It appears sometimes a paper size gets corrupted and further settings don't stick.

 The fact that all of the relevant settings show up in the same dialog box makes it pretty painless when it doesn't stick ... easy to see and fix.  No shuffling through multiple dialog boxes, no accidently leaving printing color management accidently on.
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Wayne Fox

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Rendering intents when printer manages colour ???
« Reply #19 on: April 28, 2009, 08:30:11 pm »

Quote from: MarkDS
Wayne: I mentioned what the problem is. You said it was partly resolved, so I asked what part isn't resolved.

Who ever said *I* let the printer manage colour - I never do.

Yes I agree, it's usually easier to solve problems when you know what they are - trite, isn't it; but beleve it or not sometimes that just doesn't happen.

None of my comments you are quoting referenced you ... they were directed to the OP.  I didn't say anything regarding what you were doing with the printer managing colors and wasn't asking what your problems were.

The original post really didn't reference what the problem was.  The OP responded and clarified it, and as it turns out the problem is something that has been analyzed extensively and well discussed here as Ryan pointed out.
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