13 Replies Latest reply on Aug 6, 2008 9:45 AM by Larry Tseng

    grayscale help

      hi,

      i now iD dont support dot gain.
      so what you are don't when you place grayscale picture
      from pS to iD?

      because the picture it'S darkin more in ID

      any tip?
        • 1. Re: grayscale help
          Koki,

          your printer should recommend a printing process,
          for instance SWOP or ISOCoated. The printing
          process is on the one hand characterized by an ICC
          profile and on the other hand at the press estab-
          lished so, that the characterization is valid.

          Assumed, the recommendation is ISOCoated.
          Then don't use in Photoshop a simple DotGain or
          GrayGamma but derive for Gray a K-only ICC profile
          by loading ISOCoated. It's automatically called
          Black Ink ISO Coated.
          Then convert your images from RGB to Gray, based
          on this profile. You can leave them as Grayscales
          or paste the Grayscale into the K-channel of an
          empty CMYK doc.

          Now I'm coming to your actual question: how to
          handle such a Grayscale or K-only CMYK in InDesign:
          Your synchronized color settings are for instance
          RGB=sRGB, CMYK=ISO Coated, Gray=Black Ink ISO Coated
          and Spot=DotGain 20%.
          For the Gray images - even if the profile is embedded -
          don't expect correct brightness. InDesign (at least
          ID CS2) uses for the visualization a fixed Gray Profile,
          probably GrayGamma=2.2.
          It's not posssible to assign a Gray profile (opposed to
          RGB or CMYK). The same for 'convert to'.
          We have to live with a slightly wrong appearance of gray
          images. This doesn't matter, because image colors are
          normally not manipulated by InDesign.
          Export to PDF: uncompressed (or ZIP/LZW), downsample for
          300ppi if above 300ppi, with Unchanged Colors (which means
          unchanged color numbers).
          The PDF will contain CMYK and Gray data as originally
          defined by Photoshop.
          CMYK profiles should not be embedded, but a PDF/X-1a
          would contain an entry 'Rendering Intent = ISOCoated'.
          The joboption settings PDF/X-1a can be used, but
          compression should be None or ZIP/LZW instead of
          Automatic, (Automatic allows lossy JPEG).

          Now we can see the importance of a correct decision for
          the printing process. This has to be decided early.

          Best regards --Gernot Hoffmann
          • 2. Re: grayscale help
            but way iD (the last station for fill) don't do it
            so important thing1?

            it's not astrange?

            so the picture grayscale cnot been exactly like in pS,
            in asimple word?

            >>Export to PDF: uncompressed (or ZIP/LZW), downsample for
            300ppi if above 300ppi, with Unchanged Colors (which means
            unchanged color numbers).
            The PDF will contain CMYK and Gray data as originally
            defined by Photoshop

            ok. but whay not "high Qulity" in pdf, the to save number, no?
            thank
            • 3. Re: grayscale help
              Kokii,

              it's important to understand that ID's lack of
              color management (CS2) for the visual presentation
              of Grayscales doesn't affect the content of the

              PDF and the printing.
              Can somebody confirm that this visualizatio problem
              is still not solved in CS3 ?

              Correct joboptions are the key to good print results.
              There are plenty variations. My recommendation:
              Start with PDF/X-1a:2001 as source.

              Images:
              Color Images:-Bicubic Downsampling for 300ppi if above 300ppi
              --------------(I'm using 288ppi=4*72ppi for zoom tests 400%)
              --------------Compression ZIP or none
              Grayscales:---the same.
              --------------Compression ZIP or none
              Monochrome:---Bicubic Downsampling for 1200ppi if above 1200ppi
              --------------Compression CCITT (default)

              Colors:
              Settings file none
              Leave Color Unchanged (do not convert into CMYK)
              Preserve Rendering Intent or Relative Colorimetric with BPC

              Standards:
              Compliance standard PDF/X-1a:2001
              When not compliant: Cancel Job (or Continue, test later)
              Output Intent: ISOCoated (depending on your CMYK space)

              Save as destination PDF/X-1a:2001-kokii joboption file.

              The PDF can be tested by professional Acrobat for compliance.

              A new version of 'High Quality' could be based on the same
              settings and modifications. But H.Q. is based on Acrobat
              5.0(1.4) whereas PDF/X-1a:2001 uses the older version 4.0(1.3),
              which excludes layers (these are flattened automatically).

              There are good reasons for just these settings. The explanation
              would need some time (can be discussed step by step).
              For instance: no automatic RGB-CMYK conversions. If there should
              be RGB images, then this would be a mistake, which had to be
              corrected deliberately.

              Best regards --Gernot Hoffmann
              • 4. Re: grayscale help
                Level 1
                thank you Gemot Hoffmann!!!

                >> A new version of 'High Quality' could be based on the same
                settings and modifications. But H.Q. is based on Acrobat
                5.0(1.4) whereas PDF/X-1a:2001 uses the older version 4.0(1.3),
                which excludes layers (these are flattened automatically).<<

                but if the press wont 1.4, so i close to H.Q, yes?
                • 5. Re: grayscale help
                  Larry Tseng Level 1
                  Gernot,

                  >it's important to understand that ID's lack of color management (CS2) for the visual presentation of Grayscales doesn't affect the content of the PDF and the printing. Can somebody confirm that this visualizatio problem is still not solved in CS3 ?

                  IDCS3 behaves the same way as before: a placed grayscale image displays as if its source profile is gray gamma 2.2, and exports out as DeviceN black in a pdf.

                  I get the feeling that this is how it will be from here on out.

                  Regards,

                  Larry
                  • 6. Re: grayscale help
                    Kokii,

                    for the moment let me refer to two understandable
                    publications about PDF/X:
                    http://www.npes.org/standards/PDF-X-Application-Notes_V4-Sep06.pdf
                    (2006)
                    http://www.planetpdf.com/mainpage.asp?webpageid=1220
                    (2003)
                    The benefit of standards: the compliance of software for
                    RIPs, imagesetters and platesetters can be tested and guaran-
                    teed. It's impossible to update&upgrade with respect to all
                    PDF modifications by Adobe.

                    Larry,

                    DeviceN for a Grayscale would be correct if the Grayscale
                    represents a spot color. How does Preflight interpret a file
                    with CMYK and DeviceN black ? Four or five plates ?

                    Best regards --Gernot Hoffmann
                    • 7. Re: grayscale help
                      Larry Tseng Level 1
                      Hi Gernot,

                      CMYK + DeviceN black uses only 4 plates.

                      Interestingly, IDCS3 seems to export DeviceGray instead of DeviceN when No Color Conversion is specified (I have not tested all possible combinations). CMYK + DeviceGray also uses only 4 plates.

                      Regards,

                      Larry
                      • 8. Re: grayscale help
                        Level 1
                        Hi larry

                        >>IDCS3 behaves the same way as before: a placed grayscale image displays as if its source profile is gray gamma 2.2, and exports out as DeviceN black in a pdf.

                        i thast wont andersten something: if may monitor
                        it's 1.8 game gray - so the grayscale image in iD
                        it's still 2.2?

                        thank
                        • 9. Re: grayscale help
                          Larry Tseng Level 1
                          Hmmm, very interesting question Kokii, if I understand you correctly:

                          Since InDesign does not color-manage grayscales, does InDesign actually assign a gray gamma 2.2 profile to the grayscale image for purposes of color conversion for display, or does it just let the grayscale show up on the screen unmodified (other than setting R=G=B)?

                          I'm afraid I don't know the answer since my monitor is always calibrated to gamma 2.2, and I may have been fooled all along.

                          If you are running a gamma 1.8 monitor, perhaps you can tell us after doing this little test:

                          Assign Gray Gamma 2.2 to a set of gray patches (e.g., 10%-K, 20%-K, ..., 90%-K) in Photoshop. Display the patches on the monitor, do a screen grab, and save as TIFF. Then display the same grayscale image in InDesign, do a screen grab, and save as TIFF. Compare the RGB values of the two.

                          This should tell us whether InDesign assigns Gray Gamma 2.2 to grayscale images (if both sets of values are identical) or whether it just does nothing to them, in which case, the display would be affected by monitor gamma.

                          Regards,

                          Larry
                          • 10. Re: grayscale help
                            Larry Tseng Level 1
                            Okay, if anyone is still interested, it looks like InDesign does not color-manage grayscale images for display at all.

                            After calibrating my monitor to Gamma 1.0 and profiling it, InDesign (CS3) displays a 50%-K grayscale patch as RGB 128,128,128, whereas Photoshop (CS3) displays the same patch as RGB 56,56,56 if assigned a Gray Gamma 2.2 profile.

                            This behavior is consistent with InDesign's treatment of grayscales in other areas.

                            So to address Kokii's question, the display of grayscales is dependent on the gamma (and other characteristics of) the monitor.
                            • 11. Re: grayscale help
                              Level 1
                              thank!!!!!!

                              you the men, LARRY TSENG!!!!!!!
                              • 12. Re: grayscale help
                                I have a color 8-page booklet, needs to print out in multiples (it's a presentation handout).
                                Is there any way to somewhat cleanly transpose all the color to greyscale? All at once?
                                Thanks in advance, folks.
                                Steve Perkins
                                • 13. Re: grayscale help
                                  Larry Tseng Level 1
                                  Steve, if the booklet is a pdf, you can use Acrobat 8 Professional to convert the colors to grayscale.--Larry