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Brehon
Participant
June 12, 2018
질문

I receive PDF files everyday, and some have greyscale images that show up as cmyk. if I import the pdf into indesign, it appears as greyscale! Why is this happening, and how can I fix it?

  • June 12, 2018
  • 2 답변들
  • 1034 조회

I receive PDF files everyday, and some have greyscale images that show up as cmyk.  if I import the pdf into indesign, it appears as greyscale!  Why is this happening, and how can I fix it?

이 주제는 답변이 닫혔습니다.

2 답변

Abambo
Community Expert
Community Expert
June 13, 2018

What makes you tink the greyscale is cmyk?

ABAMBO | Hard- and Software Engineer | Photographer
Brehon
Brehon작성자
Participant
June 13, 2018

Yes I use the Seration preview, but even then if I send it to the RIP, it rips as cmyk.  If I import it into Indesign, it shows in the separation preview as grey!  So I export it as a new PDF, and it rips fine.  The object inspecter in Acrobat confirms that it's grey, but still it appears as cmyk in the preview.

Stephen Marsh
Community Expert
Community Expert
June 13, 2018

It’s all about colour management.

The object’s source ICC profile is Dot Gain 20%. The Output Preview window has a Simulation ICC Profile of U.S. Web Coated. So the “preview” is a colour managed conversion from ICC grayscale to ICC CMYK.

Depending on workflow and or RIP settings, the grayscale object may or may not be converted to CMYK, it depends.

If you removed the grayscale source profile, then the object should preview as K only with no CMY.

If you changed the simulation profile from CMYK to Dot Gain 20%, then the image that was previewing as CMYK would now preview as K only… However other elements on the page may now show converted, not actual values!

Countless users have been “misled” by their lack of understanding of how this tool works.

Stephen Marsh
Community Expert
Community Expert
June 13, 2018

Brehon, what makes you believe that the grayscale images are CMYK? Are you using Output Preview and the “Separations” feature? If so you should try the “Object Inspector” and or Preflight instead.