[cups.development] Color management in a cups raster driver

[Laser, Curtis]

I am working on a CUPS driver for a color printer. The driver accepts  
cupsRaster data (as created by cgpdfToRaster on Mac OS X). I have been  
pouring over the CUPS documentation and have been left with some  
questions.

There are two cups custom ppd keywords  to help with ICC profiles. The  
first is cupsColorProfile which is deprecated. The other is  
cupsICCProfile. These options provide for a single ICC profile to take  
the color from source space to device space. Traditionally we have  
used two tables, one goes from RGB to a device independent colorspace  
and the second goes from that space to CMYK. I can combine these  
profiles I suppose but it increases the number of profiles I must ship  
with the driver due to the number of combinations. Is there any way to  
specify a chain of profiles?

However, all of this may be moot because there is a note in the spec  
that says none of the raster filters currently support ICC profiles.  
Is this still true today, even with the filters in Mac OS X 10.6?

Are any specific actions taken by the printing system based on the  
value of pseudo-setpagedevice key OutputType (other than setting it in  
the raster header), or is that defined simply so the driver can use it?

Are any specific actions taken by the printing system based on the  
value of pseudo-setpagedevice key cupsRenderingIntent (other than  
setting it in the raster header), or is that defined simply so the  
driver can use it?

And though it has nothing to do with color, I would also like to know  
if any actions are taken by the print system based on the value of the  
pseudo-setpagedevice key OutputFaceUp (other than setting it in the  
raster header), and more generally what its purpose is.

Thanks for your help.

Curtis Laser