[cups.development] filter: grayscale or color

[Jan Engelhardt]

On Nov 18 2006 08:22, Michael Sweet wrote:
>Jan Engelhardt wrote:
>> 
>> is there a way for a filter to find out whether the end result that is 
>> going to be sent to the backend will be grayscale or color?
>> ...
>
>The Adobe ColorModel option and ColorDevice attribute can be used,
>however Foomatic drivers don't follow the standard and use other
>other option names.

I am sure they follow, at least the one I randomly picked,
2500c-pcl3.ppd.gz:

  *FoomaticRIPOptionSetting ColorMode=CMY: " -sColorModel=CMY"
  *FoomaticRIPOptionSetting ColorMode=CMY+K: " -sColorModel=CMY+K"
  *FoomaticRIPOptionSetting ColorMode=CMYK: " -sColorModel=CMYK"
  *FoomaticRIPOptionSetting ColorMode=Gray: " -sColorModel=Gray"
  ...
  *DefaultColorMode: Gray

The difference to the same instance with another default color is

16:20 ichi:/etc/cups/ppd # diff -dpru nullgray.ppd nullcmypk.ppd 
--- nullgray.ppd        2006-11-18 13:27:29.457045175 +0100
+++ nullcmypk.ppd       2006-11-18 13:27:36.677045176 +0100
@@ -204,7 +204,7 @@ USE -sDEVICE=pcl3%A%Z -sOutputFile=- -"
 *OpenUI *ColorMode/Color Mode: PickOne
 *FoomaticRIPOption ColorMode: enum CmdLine A
 *OrderDependency: 110 AnySetup *ColorMode
-*DefaultColorMode: Gray
+*DefaultColorMode: CMY+K
 *ColorMode CMY/CMY: "%% FoomaticRIPOptionSetting: ColorMode=CMY"
 *FoomaticRIPOptionSetting ColorMode=CMY: " -sColorModel=CMY"
 *ColorMode CMY+K/CMY+K: "%% FoomaticRIPOptionSetting: ColorMode=CMY+K"

Which is where I would set my grep on.

>You're probably better off defining a list of options and choices that
>override the default color mode of a printer

This is just an accounting filter, not a modifying filter. In its 
simplest form, it is just a pipe to the next filter.

>, e.g. default to the
>ColorDevice true/false value and then update the color state based on
>option selections.

	-`J'
--