[cairo] RFC the idea of n-plane color support

[Jim Gettys]

On Wed, 2004-11-03 at 11:59 -0500, Carl Worth wrote:
> On Sun, 31 Oct 2004 11:05:44 +0100 (CET), Kai-Uwe Behrmann wrote:
> > How passes an ICC profile through Cairo to an final PDF output or to glitz
> > for monitor correction? Physical devices are allways different.
> > As Microsoft plans to overcome GDI, they will go steps further to
> > support 8/16-bit (sRGB,scRGB,CMYK,n-color) colorspaces in WCS.
> 
> The concept in cairo is that the user input color is all specified in
> sRGB. Currently implemented backends are 8-bit per channel, but the API
> is floating-point so future 16-bit or floating-point backends are
> possible.
> 
> Since cairo provides only an sRGB API, it just assumes that the monitor
> is already calibrated to sRGB. So the calibration issue is external to
> cairo.
> 

Note that this implies (correctly) that there is a project that isn't
currently really happening: which is to deal with all of the color
issues end to end, so that input devices are properly calibrated,
(e.g. cameras, scanners), your monitor is properly calibrated, and that
the printing backends are as well.

So people who want to tackle that problem would be a welcome.

There may be a starting point in the LittleCMS project to help...
				- Jim Gettys