"Device CMYK" vs "Indexed Device CMYK", Acrobat Object Inspector

[BlueCat55]

Hello! I'm new-ish at using Acrobat, and have a question about some terminology/colour workflow.

I'm trying to determine whether an image in my PDF contains an embedded ICC profile. When I open the Print Production >> Output Preview for my PDF, take a look at the Object Inspector, and click on the image in question, the data entry for Colour Space reads "Device CMYK". Does this mean that the image has no embedded CMYK profile, and that, assuming I don't assign anything else to it, it's existing colour numbers would end up just being plotted in the destination profile of the printer?

Conversely, I have a different PDF with an image whose Colour Space data reads "Indexed Device CMYK"- does this indicate an embedded profile?

Thanks!

[Dov Isaacs · Accepted solution]

If the Object Inspector says DeviceCMYK, then the object is not directly color managed. If the file is a PDF/X file, there may be an Output Intent ICC profile which is used to indicate what type of CMYK color that DeviceCMYK actually is. (You can determine whether a file is a PDF/X file or at least pretends to be one by opening the left hand pane in Acrobat Pro and if there is an icon that looks like a miniature PDF icon with an exclamation point on its lower right corner, open that up and see what Conformance the file claims to be. It would tell you what actual CMYK color space DeviceCMYK will be interpreted as.)

Indexed DeviceCMYK for any image is the same as DeviceCMYK except that the image has no more than 256 distinct CMYK colors therein. The indexing is a shortcut that can dramatically cut the amount of space the image requires for storage in a PDF file.

          - Dov

[BlueCat55]

Thank you!

I didn't realize CMYK data could be treated that way (indexed)- that clears things up significantly.