22 Replies Latest reply on May 28, 2009 1:34 PM by Christian Davideck

    problems with gammut mapping

    Christian Davideck Level 1

      Hi folks.

       

      My brother and I are trouble-shooting a colour management issue, but just don't get to the bottom of it. Any help would be greatly appreciated.

       

      It seems as if Windows has troubles setting the monitor profile, or at least communicating this information to Photoshop. The problem is, that in some scenarios, Photoshop does NOT do the gammut mapping [working color space => monitor color space]. We have tested this on two machines.

       

      The strange thins is, that on the MacBookPro (dual boot), Photoshop CS4 does the gammut mapping on Os X, but not on Win XP ... although the hardware is obviously identical.

       

      On the Dell notebook (Win XP), things are equally strange, as the only way to have Photoshop (CS3 in this case) do the gammut mapping is to have an external monitor attached in dual-monitor-mode. No gammut mapping takes place, when internal or external display is used exclusively.

       

      To sum it up:

       

       

       

      MacBook   Pro (dual boot)

      Os X + internal display

      yes

      Win XP + internal display

      no

      ..

       

       

      Dell Inspiron notebook

      dual monitor set-up

      yes

      only external monitor

      no

      only internal monitor

      no

       

       

      We used the "color" control panel applet (wincolor.exe) and ("control panel >> Display properties >> settings >> advanced >> color management") to set the monitor profile.

       

      Have you ever observed/heard similar things ?

      Do you have any explanation ?

       

      Thanks so much !!

        • 1. Re: problems with gammut mapping
          Lou Dina Level 3

          Christian,

           

          I run WinXP and I have NEVER had a problem getting my monitor to work properly or convert colors, especially within Photoshop.  It's automatic.  Just calibrate and profile, and allow your software's gamma loader to load the profile.....Done.  I'd be sure you don't have conflicting gamma loaders trying to load different things (Adobe gamma loader, etc).  Make sure only the gamma loader that works with your monitor profiling software is active.

           

          I suspect you are your own worst enemy....you seem intent on messing with applets, changing defaults, renaming profiles, etc.  Disable all that stuff and just let the monitor profiling software do its thing.  It works fine.  You just need to establish appropriate monitor parameters in the monitor profiling software.  I won't take the time to try replicating your problem.  Windows XP works great with color management, one monitor, two monitors, etc.  Vista has had some issues, but I believe there are fixes for that (I don't run Vista, so I am not up to speed).

           

          If you have two monitors on a Win XP system, you may need to download XRite's DisplayProfile.exe, which allows you to load different monitor profiles for each monitor.  I believe it only works with Gretag profiles that contain the proper tags (EyeOne Match, ProfileMaker, i1Display).

           

          Lou

          • 2. Re: problems with gammut mapping
            Christian Davideck Level 1

            Many thanks for your reply, Lou! And also thank you for the X-rite tip.

             

            You suggest, that there is more than 1 program writing conflictingly to the LUT. This is definitely not the case, because:

             

            1) I load the profile manually via the color item in Windows XP's control panel. (If I don't load the profile, no other software does anything automatically, so no conflicts).

             

            2) the "write-on-LUT" part works fine. Instead, as I pointed out in the OP, it's the gammut mapping [working color space => monitor color space], which doesn't occur under certain circumstances (as posted in the OP). This part has to be done by each program individually. I have other programs which let me specify the monitor profile manually, and they execute the gammut mapping correctly in ALL scenarios, mentioned above.

             

            Photoshop doesn't let the user set the monitor profile but is talking to the OS to get this information. But this talk doesn't take place in the scenarios described in the OP, and in these cases Photoshop won't do the gammut mapping.

             

            It's easy to test. Set the attached ICC profile as your monitor profile. It creates massive hue shifts. Photoshop should now display all images in completely absurd colors.

             

            However, in some scenarios, Photoshop fails to comply (see OP).

             

             

            (PS: As for you saying "messing around": The "color" applet is part of Windows control panel and Microsofts recommend way of setting the monitor profile. Hardly messing. And the other thread you are refering to is merely theoretic in nature.)

            • 3. Re: problems with gammut mapping
              Christian Davideck Level 1

              Lou Dina wrote:

               

              just let the monitor profiling software do its thing.  It works fine.

               

              The monitor profiling software has absolutely nothing to do with the gammut mapping, which has to be done by the photo editor (i.e. Photoshop), and that's the problem this thread is about.

              • 4. Re: problems with gammut mapping
                Lou Dina Level 3

                Christian,

                 

                It seems to me you are confused....either that, or I don't understand your question.

                 

                You don't need to adjust things in Control Panel, Display properties, etc...set them to default and leave them there.  (of course, you will set your display to the desired resolution, color quality, etc)  Your monitor profiling software should install a "gamma loader" that loads your profile and adusts the LUTs in your video card during your calibration and profiling process.  This loader is usually put into your Startup directory when the software is loaded.  If it is not there, your VLUT and monitor profile are probably not being loaded automatically.  Maybe that is the problem. If your loader is not in your startup directory, try reinstalling the monitor calibration software.

                 

                Calibration affects how ALL programs display, since it adjusts your video card's LUTs (if your LUT loader is doing its job).  You just want to be sure ONLY ONE loader is operating.  You normally don't need to manually load your monitor profile, and you shouldn't.  Yes, some programs (Qimage, etc) ask what your monitor profile is so they can render images correctly, but that is program specific.

                 

                Photoshop doesn't need to specify the monitor profile.  It looks to your OS default and uses that.  Again, your LUT loader will calibrate, generate a profile, upload curves to your VLUT, and set your profile as the default in Windows.

                 

                I have calibrated and profiled a LOT of windows XP systems and have never had a problem.  I'm not sure what you are doing wrong, but I'd try the above.  It's easy...don't complicate it.  The hardest part is determining what settings to use when you calibrate your monitor (white point, gamma, luminance, etc).

                 

                Lou

                • 5. Re: problems with gammut mapping
                  Christian Davideck Level 1

                  Lou, many thanks for your long post and the effort that this represents! That's very kind of you.

                   

                  As a regular poster in the color management section, I think you have sound knowledge.

                  But there are two different things: (1) Writing stuff to the graphics card's LUT and (2) gammut mapping.

                  Your entire post is about (1), but my problem is about (2).

                   

                  If you can, please set your monitor profile to colorspin.icm (or rename it to colorspin.icc depending on your OS) and activate it as your monitor profile. It's attached above. This just takes 10 seconds. Photoshop should now display every normal looking image in absurd colors (see below). If it does NOT, then PS fails to do the gammut mapping. This is what happens for me in some scenarios as posted in my OP.

                   

                  it-looks-like-this-when-gammut-mapping-is-working.jpg

                  • 6. Re: problems with gammut mapping
                    Lou Dina Level 3

                    Christian,

                     

                    Your primary problem is having a picture of George Bush in your image, which is really messing up the colors.  Just look what he did to the US?  (OK...lampooning over).

                     

                    What in the world is Colorspin?  It certainly isn't a monitor profile.  I looked at the profile in ColorThink Pro, and while it has the same exact white point, black point, and RGB primaries as sRGB, it is a 1.8 gamma matrix profile, as opposed to a 2.2 gamma (sRGB).  But, that would only affect the lightness.

                     

                    However.... and this is the big problem......the red, green and blue primaries are swapped.  Instead of the colorants being in their normal Red/Green/Blue order, they are in Green/Blue/Red order.  I am assuming the author of this "editing space" was doing some "fun" stuff with this profile, and the name "ColorSpin" suggests he is wildly shuffling colors for dramatic effects.  It is a non-standard, "oddball" working space, and should not be used for any normal work.  The profile defines Red with Green primaries, the Green with blue primaries, and the Blue with Red primaries.  I assigned ColorSpin to an existing sRGB file.  Since the primaries are in a different order, here is what happened (and SHOULD have happend):

                     

                    Reds turned Green

                    Greens turned Blue

                    Blues turned Yellow

                    Cyan turned Magenta

                    Magenta turned Yellow

                    Yellow turned Cyan

                     

                    This isn't a failure of color management or Photoshop's ability to implement it....it is a raging success!  It is working exactly as it should. The problem is this weird profile.

                     

                    As I suggested previously, set things back to default, make sure your gamma loader is in your startup folder, and then calibrate and profile your monitor normally.  If your profiling software is working properly, everything will be loaded in the right places and you will get accurate monitor previews (based on your target white point, gamma and luminance).

                     

                    Put ColorSpin into the trash bin (unless you want it for wild, weird effects.....or for use with George Bush).

                     

                    Lou

                    • 7. Re: problems with gammut mapping
                      Christian Davideck Level 1

                      Lou, as you are a color expert, I thought I didn't have to explain all this. The colorspin.icc profile is doing (as I already said) some massive hue shifts (hence the name colorspin).

                       

                      Normally Photoshop does this gammut mapping : working color sapce => monitor color space (created by your hardware calibration device). This gammut mapping can be very subtle, so in order to see, if it really works, you do - for testing purposes only - use an "extreme" profile, for example colorspin.icc. So the gammut mapping that MUST occur is: working color space => colorspin color space

                       

                      So if Photoshop does the gammut mapping like it should, every normal looking picture that you open (blue sky, red tomatoes, etc.) should be displayed in completely absurd colors. That's the expected outcome, Lou. Not a problem! Otherwise gammut mapping is broken.

                       

                      So did you try, Lou. Do you get the absurd colors in Photoshop or not ?

                      • 8. Re: problems with gammut mapping
                        Lou Dina Level 3

                        Christian,

                         

                        I set Colorspin as my default profile, as you requested, and everything works fine on my system.  Yes, colors go weird and remapping takes place.  I've never had the need to use Colorspin or look for anything like it, since I have never had a problem getting my monitor (or anyone else's on a WinXP system) to display or remap properly.  Sorry, I glossed over some of your posts and missed the intent of what you were trying to do.

                         

                        I am using Photoshop CS2 on a WinXP Pro, SP3 system.  I have two monitors hooked up to a Matrox Parhelia video card.  Perhaps your hardware is the issue, or perhaps it is a CS3 or CS4 issue, though I haven't heard of this problem myself.

                         

                        Lou

                        1 person found this helpful
                        • 9. Re: problems with gammut mapping
                          Christian Davideck Level 1

                          OK, no worries Lou. Good to see, that we are on the same page, now 

                           

                          So if I understand you correctly, you see those weird colors in Photoshop now? In that case, your gammut mapping works fine, and you don't have any problems with your color management.

                          As I said in my OP, I have some scenarios where it works, but others where it does not ;( ...

                           

                          Thanks for taking the time to try this out, Lou.

                          • 10. Re: problems with gammut mapping
                            Lou Dina Level 3

                            Good luck.  Report back if you figure out what the problem is.  Perhaps others will have the same problem and they may find the solution here.

                             

                            Lou

                            • 11. Re: problems with gammut mapping
                              Christian Davideck Level 1

                              Lou Dina wrote:

                               

                              Yes, colors go weird and remapping takes place.

                               

                              In Photoshop ? Or were you talking about another app ?

                              • 12. Re: problems with gammut mapping
                                Lou Dina Level 3

                                In Photoshop.

                                • 13. Re: problems with gammut mapping
                                  Christian Davideck Level 1

                                  Lou Dina wrote:

                                   

                                  Good luck.  Report back if you figure out what the problem is.  Perhaps others will have the same problem and they may find the solution here.

                                   

                                  Lou

                                   

                                  Thanks for looking into this issue, Lou. Yes, if I figure out what the problem is, I'll post an update here. I guess most of the color experts are working on Macintosh, but maybe there is a Windows guy around, who knows the answer.

                                  • 14. Re: problems with gammut mapping
                                    Christian Davideck Level 1

                                    Lou Dina wrote:

                                     

                                    I am using Photoshop CS2 on a WinXP Pro, SP3 system.  I have two monitors hooked up to a Matrox Parhelia video card.

                                     

                                    Lou, there might be the problem. From my OP you can see that everything works fine for me in dual-monitor-setup. The bug occurs when I deactivate either one of my two displays.

                                     

                                    Lou, if you have 1 minute, I'd be enormously appreciative if you could rerun the test, with only 1 monitor (the other monitor must be deactivated, simply switching it off is obviously not enough). Thanks a lot.

                                    • 15. Re: problems with gammut mapping
                                      Lou Dina Level 3

                                      Christian,

                                       

                                      I shut down my computer, unplugged my 2nd monitor, rebooted, and set ColorSpin.icc as my default windows monitor profile (Display Properties/Advanced/Color Management).

                                       

                                      Then I opened a test target file with an embedded sRGB profile.  As I would expect, the files' colors were all topsy turvy (reds displayed as blue, greens displayed as red, etc).  I then Assigned the Colorspin profile, all colors are displayed properly (reds were red, greens were green, etc).

                                       

                                      So, it doesn't matter whether I have one monitor or two connected to my computer.  Photoshop is displaying and remapping colors properly on my system.

                                       

                                      On this computer, I'm running Windows XP Home Edition, 5.1.2600 Service Pack 3, Build 2600.

                                       

                                      If you are running the same O/S, then it has to be something else....your version of Photoshop (I'm using CS2), a hardware or video card problem, a corrupted file, software conflict, competing LUT loaders, incorrect policy settings in Photoshop, or something like that.  Try pointing Scott Martin to this thread....perhaps he has seen this before and has a solution.  The fact that it is happening on two different computers may help to narrow it down......probably isn't a hardware issue, now that I think of it.

                                       

                                      Lou

                                      1 person found this helpful
                                      • 16. Re: problems with gammut mapping
                                        Christian Davideck Level 1

                                        Thanks so much for taking the time to try it again Lou.  I owe you

                                        something ...

                                         

                                        Sorry for having you go through this in vain, as your system is running

                                        completely fine. As my deactivating the second monitor made the bug

                                        occur, I thought it might be the same on your system.

                                         

                                        Scott Martin has seen this before ? Okay, I'll try to contact him, let's

                                        see.

                                         

                                        Thanks so much for all your assistance and private messages.

                                        If I find the cause for the problem, I'll post back here.

                                         

                                        Cheers.

                                        • 17. Re: problems with gammut mapping
                                          Christian Davideck Level 1

                                          Lou, one last thing ...

                                           

                                          Prof. Gernot Hoffmann wrote me with a very good idea. Photoshop tells the user what monitor profile it thinks is currently active here:

                                          edit >> color settings >> RGB >> now scroll all the way up to MonitorRGB and see the profile mentioned there.

                                           

                                          Now load a different monitor profile. Go back to Photoshop's color settings and verify if "MonitorRGB" has been updated accordingly.

                                           

                                          For me it doesn't !

                                          I have to restart Photoshop in order to get the currently active monitor profile in the drop-down-list as "MonitorRGB". But normally it *should* be updated instantly.

                                           

                                          Does it work on your system ?

                                          • 18. Re: problems with gammut mapping
                                            Lou Dina Level 3

                                            Christian,

                                             

                                            I loaded the ColorSpin profile in place of my standard monitor profile as my default Windows display profile (Display Properties/Settings/Advanced/Color Management) while Photoshop remained open.  Then, from within PS I looked at the monitor profile in the Color Settings RGB dropdown box and it continued to show the profile that was set as the OS default when PS was originally launched.  Yes, rebooting PS updates this dialog box to show the new default profile, in this case, Colorspin.

                                             

                                            However, even without rebooting Photoshop, my color management is working perfectly and reflects the use of the new Windows default profile.  I can keep loading different profiles using Windows Display Properties, and Photoshop sees the new profile immediately, displaying colors accordingly.  Colorspin whacks the colors as one would expect.

                                             

                                            Yes...Photoshop's color settings drop down box still shows the original monitor profile until PS is restarted.  Adobe should probably change the default monitor display in Color Settings so it updates without rebooting, but at least on my system, PS recognizes and uses the new profile immediately.  When PS initially boots, it looks at all the profiles, plugins, etc, so it probably loads that info in that drop down box and does not update it again until the program is restarted.

                                             

                                            What monitor profiling software are you using?  Many monitor profiles contain a "vcgt" tag, which stores the calibration data, white point, gamma, etc,  that gets downloaded to the VLUT.  I know the monitor profiles I create with ProfileMaker and EyeOne Match contain this tag, but some other programs do not write this tag to the profile when it is created.  Without this tag, the calibration info may NOT be loaded in Windows, whereas I am pretty certain OSX sees it and adjusts automatically.  This is the reason a LUT loader is provided with many profling software packages, so the calibration data is properly loaded into the LUT.  To test this, download the free DisplayProfile.exe file from XRite and launch it.  It will list your available display profiles.  The ones with (*) directly after the profile name have the required vcgt tag, and if you click on one of those profiles, it will download the required data to your VLUT and you should see an immediate change in your monitor.  The profiles without the vcgt tag will not download calibration data to the VLUT using DisplayProfile and in all liklihood, your monitor display will not change at all. I know I am back to calibration and not remapping, but perhaps PS needs this to detect the new profile and use it?  Give it a try.

                                             

                                            Lou

                                            • 19. Re: problems with gammut mapping
                                              Level 7

                                              Photoshop queries the OS for the display profiles if the OS says they have changed, or when you switch from another app back to Photoshop.

                                              If you leave a dialog up while switching apps, Photoshop may not get the chance to update the menu name, but the display profile information should be updated.

                                               

                                              Now, we have seen some cases where Windows failed to recognize that a display profile had been changed - but I thought they fixed that a long time ago (XPSP1?).

                                              • 20. Re: problems with gammut mapping
                                                Christian Davideck Level 1

                                                Thanks for checking, Lou. I will reply in detail tomorrow to your PMs and postings.

                                                 

                                                But see, after all it must have turned out to be a bit interesting for you as well ? At least I hope, it wasn't a unidirectional exchange.

                                                (considering the colorspin-approach and considering that the monitor profile in PS's color settings isn't updated, etc.)

                                                • 21. Re: problems with gammut mapping
                                                  Christian Davideck Level 1

                                                  Chris Cox wrote:

                                                   

                                                  Photoshop queries the OS for the display profiles if the OS says they have changed, or when you switch from another app back to Photoshop.

                                                  If you leave a dialog up while switching apps, Photoshop may not get the chance to update the menu name, but the display profile information should be updated.

                                                   

                                                  Now, we have seen some cases where Windows failed to recognize that a display profile had been changed - but I thought they fixed that a long time ago (XPSP1?).

                                                   

                                                  Have you really tried it out under Windows XP Chris ?

                                                   

                                                  Lou Dina (XP SP3 + CS2), Prof Gernot Hoffmann (I think) on XP + CS2, and myself (XP SP2 + CS3) are all experiencing the same issue. You change your monitor profile (and afterwards close all windows so that no "dialog is still up" as you said). Switch back to Photoshop. MonitorRGB is not updated in the PS colorsettings drop-down-list.

                                                   

                                                  Try for yourself on Windows XP.

                                                  • 22. Re: problems with gammut mapping
                                                    Christian Davideck Level 1

                                                    I agree that this is actually a completely independent second issue. I will file a bug report for this, too.