[cairo] cmyk support in Inkscape/Cairo

[Jon A. Cruz]

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)