On Fri, 2008-09-26 at 16:58 -0300, Felipe Sanches wrote:

what is the current status of cmyk support in inkscape? what about cmyk in cairo?

There's nothing in cairo currently, though the topic comes up every once in a while.

Any suggestions about what should be preferably done?

Would it be better to focus on cairo cmyk development?

Which cmyk features are needed and currently not implemented?

For cairo, it's really a matter of users with actual needs telling us what they need, (that could be inkscape developers, for example). And then, together, we'll try to come up with the most "cairo-like" way of exposing the functionality.

At that point, we'd have an API specified and if someone wanted to hire someone to implement it, then that might be feasible.

-Carl

On Sep 26, 2008, at 12:58 PM, Felipe Sanches wrote:

what is the current status of cmyk support in inkscape? what about cmyk in cairo?

I have a friend working on brazillian government and they seem to be interested in paying some brazillian developers to put some effort on cmyk support in inkscape

Any suggestions about what should be preferably done?

Would it be better to focus on cairo cmyk development?

Which cmyk features are needed and currently not implemented?

Currently the "CMYK" color picker really just does RGB, so that's to be avoided.

The "CMS" color picker will actually store CMYK values using ICC profiles. But there is no UI to add an ICC profile to make that tab turn on. Once there is, however, it works.

Working in CMYK with target soft-proofing should work if profiles are present in the system and in the file.

Export to PDF from Inkscape is using Cairo, which only has RGB APIs. However even if Cairo did full CMYK, we still would have to tune much of our rendering code to create proper CMYK values to feed it.

Another alternative is Scribus. For version 1.3.6 they plan to support a lot more color management, and to import SVG files with color managed info, including our proper CMYK SVG files.

At the moment I would say it is a toss-up which project (cairo or scribus) would present the first short term solution for full printing/production of CMYK. In the long term it would be best to have both.

In fact, I've been getting a few notes together to do a blog entry about this very issue, so look for a few more details hopefully by the end of the weekend. (Oh, and my quick guess on where the current slow points are is that the cairo folks are mainly waiting on Inkscape to specify some API needs, and that scribus folks have enough info from Inkscape people, and need to be able to fit things into their timing and workload)