Ticket #33 (closed defect: fixed)

Opened 14 years ago

Last modified 14 years ago

wrong computation of ink values in cmyk mode

Reported by: schreiberx Owned by: jerome
Priority: critical Milestone:
Component: pkpgcounter Version: development
Keywords: cmyk, black ink Cc: schreibm@…

Description

after bugfix
http://trac.pykota.com/changeset/280
i think that the black value is computated wrong because printing dark colors using the black ink, the value for the black ink is not subtracted from the cym colors. moreover, black is set to 0 for colored dark pixels.

Change History

Changed 14 years ago by jerome

Not sure if I understand well, since I'm not a color specialist and I didn't write the original algorithm. In any case we're working with what are basically only RGB pictures, for which CMY is the complement wrt (255, 255, 255). So black is computed (as gray level, i.e. where R == G == B, or C == Y == M) instead of being really present as with real CMYK files.
- Could you attach a simple file which exposes the problem ?
- Could you check in pkpgcounter's tests/ directory if the output of the following code is incorrect or correct as per your explanation :

for cspace in BW RGB CMY CMYK ; do
        echo "Colorspace : $cspace" ;
        pkpgcounter --colorspace $cspace colors.pdf ;
        echo ;
done

Thanks in advance.

Changed 14 years ago by jerome

  • status changed from new to accepted

I've received your test case privately, and I'll work on this ASAP.

Changed 14 years ago by jerome

  • status changed from accepted to closed
  • resolution set to fixed

(In [3447]) Fixes #33 by implementing Martin Schreiber's patch.

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