6 Replies Latest reply: Jul 16, 2009 10:27 PM by Gernot Hoffmann RSS

    Hidden output intent in PDFs by InDesign CS2

    Gernot Hoffmann Community Member

      I'm producing PDFs by InDesign CS2 via Export. The ingredients

      are manually programmed EPS pages, where all colors are defined

      by CIELab, besides a few graphic elements in device CMYK.

      The doc contains only vector graphics.

      The export happens with

      - No Color Conversion

      - Don't embed profiles

      Acrobat Professional 8 says: the PDF doesn't have an Output Intent.

       

      The manufacturer of my RIP says: as detected by Jaws, the PDF

      contains the Rendering Intent Relative Colorimetric (RelCol),

      and this one is used for the conversion of Lab to CMYK.

      If I change in the global settings (as synchronized by Bridge)

      or locally in InDesign the Rendering Intent to AbsCol, then AbsCol

      is used for the conversion, which is measurable in the print.

       

      I don't know how to detect and to change in Acrobat Professional 8

      the hidden Rendering Intent. Any solution ? Was the problem

      solved in Acrobat 9 ?  The PDF below contains RelCol.

       

      http://www.fho-emden.de/~hoffmann/munsell15052009.pdf

       

      Best regards --Gernot Hoffmann

        • 1. Re: Hidden output intent in PDFs by InDesign CS2
          rob day Community Member

          It sounds like the warning is referring to the Output Intent which is required by a PDFX standard, not a color conversion rendering intent.

           

          The PDFX standard requires there to be an output intent (the intended destination) rather than a document color profile. The idea is to prevent unwanted or accidental color conversions at output. So, in the case of PDF/X1-a everything is forced into CMYK or spot on export and no profiles are included—just the output intent. In that case the document CMYK values are always output. If there's no Output Intent included the PDF would not be PDFX compliant.

          • 2. Re: Hidden output intent in PDFs by InDesign CS2
            Gernot Hoffmann Community Member

            Rob,

             

            thanks for your reply, but it isn't really related to my question.

            A good occasion for a further clarification:

             

            a) I'm printing often PDFs by large format RIP which contain

               CMYK graphics and RGB images. In such a case a global

               Output Intent would be quite useless.

               I can define Profiles and RIs (Rendering Intents) for

               -RGB vector

               -RGB raster

               -CMYK vector

               -CMYK raster

               -Gray vector

               -Gray raster

               but nothing for Lab !

            b) I'm familiar with PDF/X. For offset I'm using PDF/X-1a with

               exactly one CMYK profile for the conversion and the respective

               Output Intent.

               Attention: the Output Intent doesn't affect the print (print-ready

               PDF/X-1a).

            c) the RI for Lab is derived from the 'hidden RI' , which is a result

               of the color settings in InDesign. This hidden RI affects the

               print result.

            d) In Acrobat 8 I cannot detect the RI nor can I change it.

                Truly hidden.

             

            Best regards --Gernot Hoffmann

            • 3. Re: Hidden output intent in PDFs by InDesign CS2
              rob day Community Member

              I'm just pointing out that there's a difference between the terms rendering intent and output intent and from your first post it sounds like Acrobat is complaining about a missing Output Intent (set in the export Output tab) not rendering intent

              • 4. Re: Hidden output intent in PDFs by InDesign CS2
                Gernot Hoffmann Community Member

                No, there is no complaint or warning by Acrobat.

                A PDF can exist happily without an Output Intent.

                 

                Output Intent for a PDF: a profile which is valid for all ingredients

                of the PDF. Useful mainly for PDF/X-1a.

                 

                Rendering Intent: a choice of RelCol, AbsCol, Perceptual

                or Saturation (always meaningless nowadays) for the application

                of a somewhere else defined profile.

                 

                Concerning my inquiry: the PDF doesn't have an Output Intent,

                but it contains a HIDDEN  Rendering Intent.

                Such a feature is - as far as I know - nowhere explained by

                Adobe docs.

                 

                Best regards --Gernot Hoffmann

                • 5. Re: Hidden output intent in PDFs by InDesign CS2
                  Jeffrey_Smith Community Member

                  The Preflight functionality of Acrobat 9 is much more comprehensive and improved from Acrobat 8. There is a fixup profile that will change the existing rendering intent to whatever you like (RelCol, AbsCol, Sat, or Per). You can apply this to all objects or certain types: (image, text, vector).  As well as fixup profiles, there are check profiles to examine document for the various rendering intents.

                  • 6. Re: Hidden output intent in PDFs by InDesign CS2
                    Gernot Hoffmann Community Member

                    Thanks, very helpful and probably correct.

                     

                    But if the Rendering Intents can be defined or re-defined by Acrobat

                    then this will cause new problems if these settings are in conflict

                    with similar settings in the RIP.

                    So far, I'm defining everything in the RIP - except for Lab, where the

                    rendering is based on the hidden intent.

                    I'm already in contact with the RIP manufacturer. The solution, IMO:

                    1. Add choices for the RIs of Lab data, vector and raster.

                    2. Use always 'RIP RI overrides PDF RI'.

                     

                    Best regards --Gernot Hoffmann