🚀 go-pugleaf

In article <OIY0JFR@math.fu-berlin.de> landgraf@hrz-serv7.hrz.uni-kassel.de  
(Landgraf Thomas  FB16   ) writes:
> Hi,
> does anyone know how I can extract the CMYK intensities of a 
> PS picture. One idea was to set something like a transfer function.
> So it'll be possible to extract the other colors, but there is no
> such function in PostScript Level 1 -- is thete one in Level 2 ?

If you're not worried about image and colorimage calls,
you can just redefine setcmykcolor (and the other
related commands) to just do what you want.  Note that this
is not always a great idea because the color seps might not
be useful.  You'll want to muck with the halftone screen as
well. 

The basic idea is that you do something like:

/setcmykcolor
{
	pop pop pop setgray
} def

To do a cyan separation (and similar things for the other
primaries) and then you muck the screen to be whatever you
need.  setrgbcolor can be rigged similarly: 

/setrgbcolor
{
	realsetrgbcolor currentcmykcolor setcmykcolor
} def

I do something similar here for two-color jobs to strip
out one or the other color.  It works, but trapping,
registration, and other factors can be a bear depending
on your application.

(image and colorimage calls should probably be handled
external to PostScript for those reasons.) 

ab