Re: How to publish CMYK EPS on the web?

[gerhard <ggrubbish@web.de>]

Hello Piotr,

Am Freitag 21 Januar 2005 18:22 schrieb Piotr Kopszak:
> 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. 

1st: There is no "right" conversion. It depends on what You want to get.
So, what version of Photoshop, do You use to convert the image? Do You 
have cms activated in PS? What kind of icc profiles do You use for 
conversion (RGB and CMYK profiles are important.) What is Your working 
colorspace?
http://www.eci.org/eci/en/044_working_colour_spaces.php

If You can determine the used icc profiles for the conversion in PS, 
then You can try to process the files the same way in imagemagick using 
lcms. I did this using gs8.11 (8.5 APFL gs is recommended) by using the 
jpg driver of gs and jpegicc to apply the appropiate icc profile to the 
JPEG I got by gs, like David Purton mentioned.
http://www.littlecms.com/newutils.htm#jpegicc  

> 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.

This depends on the used icc profiles. If You'll use the same profiles 
in PS You will get the same amount of Black in the saved RGB jpg.

Kind regards

Gerhard Gaußling