Re: How to publish CMYK EPS on the web?

[Piotr Kopszak <kopszak@mnw.art.pl>]

On Fri, Jan 21, 2005 at 10:08:13PM +1030, David Purton wrote:
> On Thu, Jan 20, 2005 at 08:48:59PM +0100, Joerg Rossdeutscher wrote:
> > Am Donnerstag, den 20.01.2005, 09:32 +1030 schrieb David Purton:
> > > On Wed, Jan 19, 2005 at 08:45:33PM +0100, Joerg Rossdeutscher wrote:
> > 
[...] 
> > And exactly that one is used by ImageMagick.
> > 
> > > Although, you with some stuffing around, you might be able to use
> > > gs7.07, I *highly* recommend you use gs8.50, unfortunately not available
> > > yet as a deb, so you will need to grab source.
> > > 
> > > gs8.50 has a tiff32nc device that will give you a CMYK tiff from your
> > > eps, e.g:
> > > 
> > >         gs -sDEVICE=tiff32nc -sOutputFile=cmyk_image.tif cmyk.eps
> > 
> > ImageMagick just delegates postscript to ghostscript. If you use IM, you
> > use GS. Just easier.
> 
> ImageMagick appears to use the pnmraw device from gs which is an RGB
> format, so the actual conversion to RGB is done using gs. If you attempt
> to specify an import cmyk profile to convert, you will get an lcms error.
> 
> You could also try:
> 
>         $ GS_OPTIONS=-dUseCIEColor convert my.eps my.jpg
> 
> But, IMHO it does not give as good results as using profiles.
> 
> 
> Boy, colour management is a pain :( So much to learn and understand and
> it still seems like black magic if you end up with anything like a good
> preview on screen. *sigh*
> 
> cheers
> 
> dc
> 
> 
> -- 
> David Purton
> dcpurton@chariot.net.au
>  
> For the eyes of the LORD range throughout the earth to
> strengthen those whose hearts are fully committed to him.
>                                  2 Chronicles 16:9a

I think that, although from a "metaphysical" point of view there might be
nothing like a right conversion, I would be entirely happy with
obtaining the same effect as when I save the eps as rgb jpg in
Photoshop. Obviuosly Image Magick fails miserably in that regard. In
my case it does not even produce any output at all. I was using
approach similar to David's and the colors are almost right except for
the enormous amount of black in the black channel. Probably
Ghostscript does not allow any tweaking of the amount of black it
generates in the output. Please correct me if I'm wrong. 

Piotr

-- 
   Piotr Kopszak, Ph.D.          
   Polish Art Gallery, National Museum in Warsaw    
   ----------------------------->    http://kopszak.mnw.art.pl/
   http://www.magnatune.com/artists/altri_stromenti