[cairo] Spot colors (and CMYK)

[ecir hana]

On Thu, Feb 18, 2010 at 8:36 AM, Kai-Uwe Behrmann <ku.b at gmx.de> wrote:
>
> Yes, it is needed. But not directly by blending RGB over Cmyk. I would not
> know how to directly do this.
> The app must decide, which space is prefered for blending and then after
> colour conversion of on element the blending can be done in one common color
> space.

Can't you use the space of destination surface per default? That way
there would be no need of setting the blending space.

> I would choose Cmyk as blending space and convert Rgb to that and put all
> the resulting Cmyk with the ICC profile into PDF.
> For screen simulation Cmyk would have to be converted to monitor RGB.

So if I want to draw CMYK image over RGB surface, I should first
convert the surface to the space of image, blend, and then convert the
whole result back to RGB. Right? (I really like the idea of blending
in CMYK, btw.)