6 Replies Latest reply on Mar 17, 2008 2:50 PM by (Mike_Ornellas)

    Determining the embedded profile in a pdf

      There's probably an easy method that has escaped me, but is there an easy way to tell what profile(s) are used in a PDF? Preferably without using Acrobat or a preflighting software? We regularly receive PDFs from unknown sources for use in various projects and need to know what profile was used so we can be consistent. I know Acrobat can do the job in it's preflight menu but it seems like such a waste to buy a copy for everyone just to do that function. Unfortunately, the sips command in terminal doesn't do PDFs. Thanks to anyone who can assist!
        • 1. Re: Determining the embedded profile in a pdf
          John Danek Level 4
          Try opening the PDF using Illustrator and/or Photoshop. The application may ask what profile to use and list what is embedded as a choice.
          • 2. Re: Determining the embedded profile in a pdf
            This doc contains on p.6 six images in six different
            color spaces, with embedded profiles:
            http://www.fho-emden.de/~hoffmann/colpdf27022008.pdf

            Adobe Acrobat Professional 7 was used to identify
            the profiles. This failed essentially for Gray,
            and it failed as well (less understandable) for
            Euroscale Coated v2.

            For any test it's necessary to download the PDF.
            (without profiles the size would be only 327 kB,
            but with embedded profiles it sums up to 2.69 MB).
            Then analyze by the newest version of Acrobat.
            My guess: even with newer versions, the Gray profile
            will be not be identified correctly.

            Best regards --Gernot Hoffmann
            • 3. Re: Determining the embedded profile in a pdf
              Tim Lookingbill Level 1
              Gernot,

              Thanks for posting that pdf.

              It inadvertantly illustrates the dynamic range compression going from RGB to CMYK and its affect on saturation and why the feature encoded within PS's tools that increases saturation when darkening an image is useful in overcoming this DR compression especially with Soft Proofing on.

              IOW, if the original RGB image started out as desaturated and flat as the CMYK preview is it would've been even more desaturated when actually converting to CMYK without including saturation/density edits.

              Now I understand a little more why Thomas Knoll called this a desireable feature within PS. It's basically a way to overcome DR limitations of output devices and still allow the image to pop.

              Please excuse this off topic observation. The reason for the inclusion of this feature was something I suspected long ago but could never see it for myself because I've never printed to the limited DR of offset presses.
              • 4. Re: Determining the embedded profile in a pdf
                Tim,

                thanks for the feedback. Of course I didn't
                choose the images as excellent examples for
                color reproduction. Nothing in the CMYK and
                Gray versions is optimized - just converted.

                Best regards --Gernot Hoffmann
                • 5. Re: Determining the embedded profile in a pdf
                  Tim Lookingbill Level 1
                  You're welcome, Gernot.

                  I wasn't addressing the fidelity of your images, just a pattern I've been noticing. I've seen this on some wide format inkjets and minilabs I've printed to. Saturation levels get slightly reduced no matter how well you Soft Proof for this. I guess this is due to the limitations mentioned about CM technology and why you can't always get a perfect match.

                  I've suspected either RIP's are doing something internally to show a more flattened less contrasty linear appearance on the final print or the "Simulate Paper Color" and "ink Black" really does have something hardwired to preview for this.

                  However, I see quite a few grayramps off presses that flatten shadow detail and darken spectral region highlites these settings don't quite accurately preview. I don't know by looking at the print if it's from the limited dynamic range of the press or printer or the RIP software unnecessarily changing tonal distribution characteristics to compensate.
                  • 6. Re: Determining the embedded profile in a pdf
                    Level 1
                    http://www.eci.org/eci/en/044_working_colour_spaces.php