OT: b/w printing of color pdf

Christoph Litauer litauer at uni-koblenz.de
Mon Jan 28 01:42:20 PST 2008


Helge Blischke schrieb:
> Christoph Litauer wrote:
>> Hi,
>>
>> some of our students recently noticed a problem, not exactly related to
>> cups. But I hope some of the ppd and postscript experts (Michael?) would
>> be able to give me some help.
>>
>> I have some color postscript printers (e.g. HP CLJ 4700 or HP CLJ 4550)
>> driven by cups. ppds are from linuxprinting.org. Sometimes students want
>> to print a colored pdf document black-white (greyscale) on these
>> printers but the printer always prints color. Printing other documents
>> (Microsoft word, Firefox, etc.) result in greyscale output. I should
>> mention the students print the documents using Acrobat Reader 6.x under
>> Windows XP. They switch from color to greyscale in the printers property
>> dialog box (Paper/Quality).
>> The windows driver has been added with cupsaddsmb using e.g. the ppd
>> file on
>> http://openprinting.org/foomatic-db/db/source/PPD/HP/HP_Color_LaserJet_4700.ppd
>>
>> But I noticed the same effect using the pdf converter of Robert Sander.
>>
>> Searching the web brought me to
>> http://www.adobeforums.com/webx/.3bc46aff but no solution.
>>
>> Comparing color vs. b/w print of the same document leads to the
>> following diffs:
>>
>> 8763c8763
>> < /E1 /ColorSpace findRes cs 0.24706 0.12157 0.0 sc
>> ---
>>
>>> /E2 /ColorSpace findRes cs 0.24706 0.12157 0.0 sc
>>
>> 8786c8786
>> < /E1 /ColorSpace findRes cs 1.0 0.62353 0.62353 sc
>> ---
>>
>>> /E2 /ColorSpace findRes cs 1.0 0.62353 0.62353 sc
>>
>> 8792c8792
>> < /E1 /ColorSpace findRes cs 0.81176 0.054902 0.18824 sc
>> ---
>>
>>> /E2 /ColorSpace findRes cs 0.81176 0.054902 0.18824 sc
>>
>> 8930c8930
>> < /E1 /ColorSpace findRes cs 0.80784 0.86275 0.99608 sc
>> ---
>>
>>> /E2 /ColorSpace findRes cs 0.80784 0.86275 0.99608 sc
>>
>>
>> and so on.
>>
>> Any help is greatly appreciated. I can provide some print-outputs (PS)
>> if needed.
>>
> 
> I'd suggest to set up a b/w queue for the same physical printer
> and set its default color model to gray (see. the following lines
> from the PPD you use):
> ---snip---
> *% =================================
> *% Print Color as Gray
> *% Chose NOT to use standard *ColorModel keyword because color on or off
> is simpler
> *% =================================
> *OpenUI *ColorModel/Print Color as Gray:  PickOne
> *OrderDependency: 20 AnySetup *ColorModel
> *DefaultColorModel: CMYK
> *ColorModel Gray/On: "<</ProcessColorModel /DeviceGray>> setpagedevice"
> *ColorModel CMYK/Off: "<</ProcessColorModel /DeviceCMYK>> setpagedevice"
> *?ColorModel: "
>   save
>     currentpagedevice /ProcessColorModel get
>     /DeviceGray eq {(Gray)}{(CMYK)}ifelse = flush
>   restore
> "
> *End
> *CloseUI: *ColorModel
> ---snip---

Helge,

thanks for your suggestion. I already found this possibility for
greyscale printing in the extended printer options, but for our students
this is far too complicated. Setting up an extra greyscale printer model
would be a solution ... but setting this up for every color printer
increases the number of our public printers very much ...
I want to understand what the greyscale/color checkbox in the
Paper/Quality dialogue is for. Why doesn't it change the ColorModel? Why
am I able to print greyscale with every application except acrobat
reader? Doesn't acroread use the same driver and ppd as the other
applications?

-- 
Regards
Christoph
________________________________________________________________________
Christoph Litauer                  litauer at uni-koblenz.de
Uni Koblenz, Computing Center,     http://www.uni-koblenz.de/~litauer
Postfach 201602, 56016 Koblenz     Fon: +49 261 287-1311, Fax: -100 1311
PGP-Fingerprint: F39C E314 2650 650D 8092 9514 3A56 FBD8 79E3 27B2




More information about the cups mailing list