anyone has some experience editing icc profiles

[Donateli]

Hi I was wondering if anyone has some experience editing icc profiles or knows of a good piece of free software for doing edits in, We run prinergy, I created an icc in photoshop to do under color removal and would like to be able to isolate some colours, and not have them reseperate we are Running to GRACol specs and are G7 certified if that's of any help.
Thanks

 

[leonardr]

Hi I was wondering if anyone has some experience editing icc profiles or knows of a good piece of free software for doing edits in, We run prinergy, I created an icc in photoshop to do under color removal and would like to be able to isolate some colours, and not have them reseperate we are Running to GRACol specs and are G7 certified if that's of any help.
Thanks

Your only option for free would be the SampleICC source code from the ICC. That allows you to convert from the binary ICC format to an XML representation. Yo ucan then edit the XML version and convert it back.

Of course, this assumes intimacy with the ICC format and color.

 

[Stephen Marsh]

Firstly, I think that you may need to go into more details of what you are trying to achieve and what you are currently doing.

As you have Prinergy, do you have ColorFlow Pro or just the basic ColorFlow that comes with Prinergy? With ColorFlow Pro you would be able to create a true GRACoL profile from measurement data and create and or edit the profile.


Stephen Marsh

 

[Donateli]

We only have the basic version of color flow, my problem is that when I apply the icc profile in prinergy and the file is re-separated, the solid cyan yellow and magenta, have trace amounts of the other colours in them, I was hoping to be able to tell the icc profile to leave these colours alone

 

[Magnus]

We only have the basic version of color flow, my problem is that when I apply the icc profile in prinergy and the file is re-separated, the solid cyan yellow and magenta, have trace amounts of the other colours in them, I was hoping to be able to tell the icc profile to leave these colours alone

Sounds like you should be looking for a Device Link solution. ColorWiki - Device Link Profile

 

[Stephen Marsh]

Yes, indeed Magnus, ColorFlow Pro can also create device links, in addition to device profiles and press curves.

I am not sure that a legacy Photoshop CMYK setup is the best option, if one is targeting GRACoL (at least the legacy Photoshop setup is flexible and user configurable when one has no other software).

Donateli, why do you have to re-separate in the first place? What is wrong with the CMYK input - is it not targeted at GRACoL when supplied to you? Is it something to do with the black generation? As you have found, there are trade-offs, whatever you gain by re-separating with the legacy Photoshop setting you are also having issues with primary solids, secondary solid overprints etc. It would not surprise me if you are getting very different output colour compared to the input from this conversion (independent of black generation, which in theory should not change the colour when done correctly).

You mention that you use the legacy Photoshop table to perform UCR... What don't you like about the input data, what benefits are you receiving when re-separating with the legacy Photoshop UCR setting saved as an ICC profile? Could you do the same or better with a different device profile than one generated by the legacy Photoshop settings?


Stephen Marsh

 

[rich apollo]

1) If you want to maintain the purity of the solids you'll need a device link profile. Some color engines will allow you to specify that solids should remain pure, but I think that kind of steps around some ICC rules. Editing a profile won't do it.

2) Don't use Photoshop to "edit" profiles. You're not editing the profile - you're building an entirely new profile utilizing an outdated color engine (unless things have changed a lot).

Check your RIP to see if it will allow you maintain the purity of the solids. If this is for colorbars, you may be able to specify in the RIP that colorbars bypass the color transforms.