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Color management issues w/network clients

Posted: Sun Aug 23, 2009 9:43 pm
by mk9
Just downloaded and installed TP to try to provide high quality network print services for a home network. Color printers were previously served from a dedicated XP machine, but only other XP machines could print over the network, and we are moving to Macs.

TP runs on a 64-bit Ubuntu 8.04 server. Two printers: Canon i860, Canon PIXMA Pro9000. Printers are connected to Ubuntu server through USB.

Clients are XP machines and Macs with Leopard. Would also like to print from the Ubuntu server (command line is OK) but not a high priority.

I run Adobe Lightroom and am careful about color management. Have had custom ICC profiles made for both printers and use those in Lightroom and disable color correction in the XP printer driver. Using all XP-to-XP printing over the network, results are beautiful.

The problem: how do I set up all the pieces to achieve the same results but with TP on Ubuntu driving the printers? I have tried many combinations and results have varied from dull, lifeless colors (but the right amount of ink) to massive pools of ink on the paper.

In any case, TP on Ubuntu immediately recognized the printers and set them up -- getting data to the printers has never been a problem. The color management is the issue.

I don't know if I should disable color correction in TP? In Lightroom? Should I use an ICC profile in TP? Can I set this up so that TP does the ICC based correction for all clients? How would that be done?

Sorry for all the questions at once. I have read the manual and it sounds straightforward but appears to be oriented to a user on the Linux system printing to a printer on the same Linux system. When XP or Mac OS is involved as a client over the network and using a managed color workflow, does it get much more complex?

Posted: Mon Aug 24, 2009 9:08 am
by zedonet
Hello mk9,

in your network setup, you should deactivate any printer color management on the clients and let TurboPrint do the color correction. Please note that color profiles that were created for a Windows printer driver cannot be used with TurboPrint as profiles are driver specific and only work with exactly the driver they were created for. If color output is not accurate enough for your needs you can create a special color profile for the TurboPrint driver and install it on the printer server.

Select the appropriate color space in TurboPrint on the printer server, e.g. RGB. Then make sure that all applications send their images in RGB color space.

Printing should also work directly from the Ubuntu server.

Posted: Wed Aug 26, 2009 6:39 am
by mk9
Zedonet, thank you -- the setup is simple, after all.

Please note that color profiles that were created for a Windows printer driver cannot be used with TurboPrint as profiles are driver specific and only work with exactly the driver they were created for.

My impression from the company that produced my current profiles (ICC) are that they can be used on Macs also (which I have not yet tried), which might mean they are universal. Is that not so? I did try to read them into TP, which accepted them and the windows says the profile's status is "complete" and Color data is from an "ICC-File" -- but on reading this profile in, there was an error on the console that the ID String is missing.

Of course I would rather not have to redo a profile if I don't have to.

Posted: Wed Aug 26, 2009 8:30 am
by zedonet
Of course you "can" use profiles that were created for a different driver with TurboPrint, however they will not produce the expected results.
Color profiles have rules how to correct colors when printing. However the necessary correction is not the same for different drivers as they already produce a different output without any correction.

Posted: Fri Jan 29, 2010 3:06 am
by mk9
It has been some time since this thread. I ordered a custom profile and installed it successfully, and disabled clients' color management. The results have never been satisfactory and I am not sure why.

In any case, I have custom profiles made for the clients a few years ago that were very accurate and performed well. I would like to ask two questions:

1) How and where do color spaces enter into the printing flow? I use Lightroom 2 which works in (I believe) 16-bit ProPhoto RGB, and do not see a setting for color space anywhere in the work flow except for exporting the image to an external use (JPEG or external editing) -- specifically not for printing. So the final color space conversion for printing is done where?

2) How can I set up TP to do *no* color modifications at all? No profiling, no color space conversion, etc.? If I want to do color management in the client app (Lightroom), then I want TP to only manage the queue and send the data to the printer, nothing else. TP has a plethora of options which I do not know how they might interact or affect color. Can this be done -- make TP completely color-neutral?

I have spent quite some time educating myself on color management but there is still a lot that goes on under the hood in each app or driver. If there are better ways to approach this problem, I'm willing to try but I know that I have excellent profiles for my clients(when I was running all XP-based flow; now my setup includes Macs and I must drive the printer from a Linux server therefore the need for TP). I just have not been able to get good performance from the TP custom profile. I can do some amount of diagnosis but really don't want to spend a lot more time on this, given that I have a solution that *should* work (client custom profiles, TP in simple pass-through mode).

I'm using TP Pro 2.13-2, Ubuntu 8.04, Canon Pro9000 on USB, Mac Snow Leopard (same issues occur under Leopard and from XP clients too).

Thanks for any help!!!

Posted: Fri Jan 29, 2010 10:26 am
by zedonet

we must first check which drivers you are using on the client computers - please excuse that I haven't thought of this before:

If you are using Canon's manufacturer driver on your Mac or Windows computer, the print job will be converted to printer command language on the client and the Linux computer will just pass through everything without any modification. In this case you won't have to set up anything on your Linux computer and you can use the manufacturer's ICC profile in Lightroom.

It is also possible to set up a print queue on the Mac that uses the TurboPrint driver - see the following post for setting up a print queue on the Mac: ... =2066#2066

Before configuring your mac, please try if color reproduction on your Linux machine is correct - e.g. print an image fom GIMP using the GIMP-TurboPrint print plugin and choose our profile in the media type selector.

If results are good, you should get the same colors when printing from a Mac.

Note that there is no simple way to set up the Windows computer that it actually uses the TurboPrint driver.

Posted: Sat Jan 30, 2010 12:41 am
by mk9
Regarding drivers used on the clients, I first set up the queue through TP and CUPS administration on the Linux server which has the printer connected to it by USB.

Once the queue is set up on Linux, I set up printers on the clients in the normal way a network printer is set up. The client therefore does not know anything about whether TP is running the queue or not, or whether it does any further processing. On each client I specify the printer model (Canon Pro9000) and therefore I believe it uses the manufacturer's drivers. This is less clear on the Mac, because I believe only the PPD file from the driver package is used (Canon driver software doesn't support network printing, IIRC).

I have not tried copying the TP PPD file from Linux's /etc/cups/ppd directory to the Mac as outlined in the referenced post, but I looked under /etc/cups/ppd on the Mac client and the Pro9000 PPD file that is there is, in fact, a TP version of the PPD file, but with a few differences from what is under the Linux server's /etc/cups/ppd, including the setting of *DefaultzedoColorspace, for example.

I am really quite mystified how to put all this together. There is a "Media Type" setting in the Mac print dialog box that includes the TP Profile name. How does this setting interact with the TP driver/profile/etc. on the server?

And then how do I get (hopefully) identical print results from the Windows clients?

It is all very confusing. You see why I am thinking to completely remove all color functionality from TP and just have it manage the queue, and let the clients do all the color management. Although it may not be optimal, it appears to be much easier to get right.