[argyllcms] Re: Gamut mapping problems in 1.1.0

  • From: Idea Digital Imaging <qcore@xxxxxxxxxxxxxxxx>
  • To: argyllcms@xxxxxxxxxxxxx
  • Date: Fri, 13 Nov 2009 17:44:03 +0000

On 12 Nov 2009, at 19:22, Klaus Karcher wrote:

What they saw is the image in the RGB working space clipped to the display gamut. It strongly depends on

- the gamut of the photographer's monitor
- the viewing conditions in the studio (often very dark)
- the state of adaptation of the viewers
- the quality of the display profile

So the question is always: did they see what we see? Is e.g. the oversaturated red we see intentionally or did they see a clipped version? Is the clipping /we/ see intentionally? Did they desaturate the greens intentionally or enforced by the gamut limits of the equipment (I don't want to consider the Photoshop skills of the photographer as another possible limiting factor for the moment ;-)

This is why I have a problem with Kodak ProPhoto RGB being used routinely as an editing space - where the question includes "how much of the image editing couldn't they see?"

The next input are the creative ideas of the advertising agency involved. Our struggle consists in brining together the parts and ideas an to merge them to something thats actually printable -- often for a variety of different media like sheetfed and web offset, various flavors of gravure printing, digital large-format printing on all kinds of substrates and -- far the worst -- Newspaper.

Ha ha, I've been working on newsprint separations this morning. I love this quote from the IFRA web site:

"Agencies and ad suppliers can now supply all newspapers worldwide
(with the exception of the USA) with a single CMYK data set, separated
in accordance with ISOnewspaper26v4."

The US is an exception... now there's a surprise!

Although it's about time that we had ISOnewspaper26v5 -- 2004 is a long time ago in colour management.

The great thing about newsprint is that it doesn't matter what technique you use to do the separation, or how different the variations look on screen, they all look as bad as each other when you proof them -- especially on the 57gsm GMG FOGRA paper :-)

A consistent, decent gamut mapping combined with the chance to "copy" the separation behavior of a given profile is the key to improve this unfortunate situation substantially IMHO. And Argyll is on a very good way to provide both.


So: congratulations, Graeme -- the upcoming release will be a great leap forward once again :-)

Yes, it is a very impressive suite of tools -- a big thank you for making them available to us.

Martin Orpen
Idea Digital Imaging Ltd

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