5 Replies Latest reply on Jan 24, 2010 9:35 PM by p_d_f

    How to control Display Rendering Intent in PS CS3 & XP?

    Dave505

      Does anyone know a way to control the display rendering intent in Photoshop CS3 runing on XP?

       

      The consensus seems to be that Relative Colormetric is always used.  If I am using a large working space such as ProPhotoRGB, I would like to be able to switch between Perceptual and Relative Colormetric.

       

      Here is some info I think may be relevant:

       

      http://www.color.org/advantagesv4.pdf says one of the advantages of v4 over v2 is to "permit profiles containing multiple rendering intents to be specified for input and display devices as they currently are for output profiles".

       

      Using http://www.color.org/version4ready.xalter I see that my system is not v4 compatible, but Photoshop CS3 does correctly render images with v4 profiles on my computer.

       

      When I look at the profile that came with my monitor, using ICC_Inspector from http://www.color.org/profileinspector.xalter,  I see it is ICC version 2, and the rendering intent is listed as Perceptual.

       

      If use Monitor_RGB as my working space, and do edit > convert_to_profile, converting from ProPhotoRGB to MonitorRGB:

        • Using engine:Microsoft_ICM, I get different result for Perceptual vs Relative_Colormetric.
        • Using engine:Adobe(ACE), I get the same results for all intents, and they all look very close to Microsoft_ICM Perceptual.

      However the original image in the ProPhotoRGB space is apparently rendered to my display space using Relative Colormetric because it looks like the image produce using convert_to_profile: Microsoft_ICM Relative Colormetric.

       

      Thanks.

        • 1. Re: How to control Display Rendering Intent in PS CS3 & XP?
          Printer_Rick Level 4

          Photoshop rendering intents are for file conversions, and soft proofing CMYK. I don't think Photoshop can change the display rendering intent embedded in an ICC profile, which is usually Perceptual. Maybe someone else can shed light on this.

           

          I do know monitor color should never be used for a file conversion. There are a couple ways monitor color may be utilized in Photoshop under View: Proof Setup. First, you could choose Monitor RGB – the colors that shift indicate the colors in the file that are beyond your monitor. Second, you could select View: Proof Setup: Custom: by Device to Simulate select the monitor profile. Then select View: Gamut Warning. Again this indicates what is beyond the scope of your display.

           

          I should emphasize that doing this is just a means of finding out what colors exists in the file that you are unable to see because of the limitations of your monitor.

           

          Always calibrate and profile your monitor so it provides the most accurate soft proof.

           

          Regarding CMYK. To accurately soft proof CMYK in RGB, View: Proof Setup. Device to Simulate, select the CMYK profile recommended or supplied by your print vendor. Rendering Intent, select the intent you normally use at the final conversion stage. Display options select "Simulate Paper Color".

           

          When you do this, Photoshop is first honoring the file conversion to CMYK that has not yet taken place. Then for the final soft proof, the CMYK is converted to the monitor space using Absolute Colorimetric. If the CMYK profile was created properly, the Lab values of the CMYK black point and paper white will be displayed accurately. The conversions of course don't really occur, it happens behind the scenes.

           

          Again, I'm not really sure about the rendering intents of the ICC profiles themselves. The standard RGB and CMYK profiles all utilize a perceptual intent. My assumption is this intent has to be for display purposes, and is unrelated to file conversions (???). A monitor is never able to show all the colors that can exist in another color space, even a CMYK color space. So a perceptual rendering would attempt to preserve the relationships between all the colors as seen on the monitor.

           

          If you use InDesign for document layout, it's usually best to leave the images RGB. Place them in InDesign. The conversion to CMYK can take place at the export to PDF stage. If your printer uses a late binding workflow it can even occur beyond the export stage (one of the reasons why the new PDF/X-4 standard was introduced).

          1 person found this helpful
          • 2. Re: How to control Display Rendering Intent in PS CS3 & XP?
            Dave505 Level 1

            Thanks Rick.

             

            Let me clarify the intent of my question:

             

            When I am working in Photoshop, with a large working space such as ProPhotoRGB, I want to be able to choose/switch the rendering intent used to map the colors from the working space to my display.  The consensus seems to be that Relative Colormetric is always used.

             

            I have always used RGB working spaces.  I often start with photos and my final product is much more likely to be displayed on a computer then printed.  I wonder if Photoshop maps CMYK working spaces to the display using the relative colormetric rendering intent (as it does RGB working spaces).

             

            The Proof_Setup w/ Gamut Warning is a very useful tool for understanding the difference between the display space and the working space.

             

            I found an intersting discussion at: http://lists.apple.com/archives/colorsync-users/2005/Jan/msg00129.html, which discusses some of the problems Photoshop has converting between spaces.  They mentioned a banding phenomena which I observed when I used the perceptual rendering intent for ProPhotoRGB -> MonitorRGB.  They talk about 2 types of profiles: LUT and matrix.  It was a difficult discussion for me to understand, but the impression I came away with is: for some conversions in Photoshop, a LUT profile works better, for some a matrix profile works better.  I guess the matrix is smoother, and the LUT is more accurate.  So I bought i1Display2 which will build both types of profiles and supports ICC V2 and V4.  I could not find any indication that Spyder3Elite can build both LUT and matrix profiles.

            • 3. Re: How to control Display Rendering Intent in PS CS3 & XP?
              Printer_Rick Level 4

              Let me think about this.

               

              Looking at my monitor profile with the Color Sync Utility (I’m on a mac), the rendering of the profile is Perceptual.

               

              With Photoshop, I open a saturated Pro Photo image. View: Proof Setup: Custom. Device to Simulate, Monitor Profile.

               

              This is supposed to show me a file conversion to my monitor color space. I see no change in color (as long as preserve numbers is disabled). It makes sense, because the conversion is something that happens anyway. I can never truly see a Pro Photo image. It must be translated to my monitor profile before I see anything.

               

              I can change the rendering and black comp all day long and it does not affect the color I see. I have to assume that what I see is actually a Perceptual rendering, not Relative Colorimetric,  because Perceptual is the intent embedded in the Monitor ICC profile.

               

              CMYK is a little different. With the same image open, View:  Proof Setup: Custom. US Web Coated SWOP v2. Relative Colorimetric, Black Point checked. Simulate Paper White.

               

              Now duplicate the image. Convert to Profile: US Web Coated. Relative Colorimetric, black point enabled. Now View: Proof Setup: Custom. Device to Simulate, monitor profile. Absolute Colorimetric.

               

              Comparing the two images, the color is a dead on match.

               

              In the second image (already converted to CMYK), if I change the rendering and black comp, the color shifts dramatically. This behavior is different from what I saw earlier, soft proofing Pro Photo to monitor, where the rendering and black point settings did not change the image color.

               

              So at this point I have to conclude that Photoshop can control the display rendering for a CMYK image. But with RGB, it’s locked in somehow. I would imagine it defaults to Perceptual, not Relative Colorimetric. Can you open your monitor profile and check the rendering?

               

              I have a utility that actually allows me to change the intent of an ICC. I went ahead and did that to the monitor profile and saved a copy, with Relative as intent. Using this in Proof Setup (with Pro Photo image) also yields no change. Makes sense, because the color gamut of the new copy is identical, and Photoshop is rendering a file conversion.

               

              To get the Relative Colorimetric display requires changing the system profile to the new profile. Unfortunately when I do this, the screen color goes absolutely bonkers. All color are super saturated and I can hardly make out anything. I have no idea what that means.

               

              I apologize for rambling on, I’m probably not much help. Thanks for the link and I will look into this matter more when time allows.

               

              • 4. Re: How to control Display Rendering Intent in PS CS3 & XP?
                Dave505 Level 1

                Printer_Rick wrote:

                 

                 

                With Photoshop, I open a saturated Pro Photo image. View: Proof Setup: Custom. Device to Simulate, Monitor Profile.

                 

                I can change the rendering and black comp all day long and it does not affect the color I see.

                When I use the Adobe(ACE) color engine changing the rendering intent in the Proof Setup makes no difference for me either.  However, if I use the Microsoft_ICM color engine (which is set in Edit > Color_Settings > Conversion_Options), then I get different renderings for the ProPhotoRGB to the color space defined by my monitor profile.  The rendering with Proof Colors NOT selected, and the renderings produced with Proof Colors and the Adobe(ACE) color engine with all intents, look very similar to the Proof Colors with the Microsoft_ICM color engine and the Relative Colormetric rendering intent.  The rendering intent in my monitor profile is Perceptual, and the rendering intent in  Edit > Color_Settings > Conversion_Options is Perceptual, so I don't think these have any effect on the rendering with or without Proof Colors selected.

                 

                I could not find a CKYM color space which was wider than my monitor color space, however I did have a RGB printer color space that is significantly wider in the cyan region.  I converted my ProPhotoRGB image to the printer color space using the perceptual rendering intent.  Using the printer profile as the working space I got the same result I did above with the ProPhotoRGB working space: The rendering with Proof Colors NOT selected, and the renderings produced with Proof Colors and the Adobe(ACE) color engine with all intents, look very similar to the Proof Colors with the Microsoft_ICM color engine and the Relative Colormetric rendering intent.

                • 5. Re: How to control Display Rendering Intent in PS CS3 & XP?
                  p_d_f Level 2

                  "I want to be able to choose/switch the rendering intent used to map the colors from the working space to my display.  The consensus seems to be that Relative Colormetric is always used."

                   

                  The RGB working spaces always use Relative no matter what you specify and even if you have Perceptual listed as the default intent. That's why there's that little advanced feature in Color Settings called "Desaturate Monitor by _ _ percent" That's an advanced feature that will try and simulate a Perceptual rendering to the screen from your larger and monitor rgb space. Unfortunately deploying that also throws off the overall monitor rendition, but it will show you on screen differences you could never see before.