Quote:
Does someone have actual experience using ImageMagick as a CMYK conversion tool?
Not for some time, either for IM or separate+ or anything else. The best way is still to start and finish in CMYK, which generally means PS. Now blessed with an extremely talented, conscientious, local printer who can produce posters, cards etc, far better than I can

Quote:
I can do the conversion easily, but it is quite complicated to evaluate how good the conversion from RGB is. I can compare with Photoshop's CMYK conversion, but to really see if it's working, I would need a real offset print, which is too much for testing.
That is the problem, monitor need to be calibrated, even then soft proofing is variable at best, there is no substitute for a print. Best advice
Get a proof print before ordering 1000 copiesQuote:
Is there anyone who works in Linux and uses ImageMagick or some other open source tools for CMYK conversion? Experiences? Tips for evaluating?
I can only point to a couple of possibilities.
CMYKtool
http://www.blackfiveimaging.co.uk/ You will have to compile it yourself, but that is not difficult.
looks like this
http://i.imgur.com/TkxsLHZ.jpgKrita, look in your linux repo. My version in PClinuxOS (KDE 4.13.3 Krita 2.8.6) is a bit flaky when it comes to large images but usually works
looks like this.
http://i.imgur.com/yxli08F.jpgThen there is Scribus, which I do not use so I cannot comment.
@ gjg The really basic syntax for IM is
convert <rgb_file.ext> -colorspace cmyk -profile <icc_file.icc> <cmyk_file.ext>
edit:
Quote:
C'mon people, there *has* to be some of you who make prints
The only prints I get these days tend to be photographic panoramas,
RGB 300 ppi, so can be larg-ish. Laser printing on photographic paper, no need to convert to CMYK