17 Replies Latest reply on May 13, 2013 9:35 AM by MarkJan77

    ICC profiles - few issues

    MarkJan77 Level 1

      Dears, I've been trying to understand color managment issues and there are still some gaps difficult to fill so far. Thanks in advance for a little support in answering following questions (OS: Win7 64bit, Dell Vostro 3560, testing CS6 ext.) :

      1.   I am aware that screen of my notebook is not able to generate corectly the whole sRGB space. My question is : if I calibrate the screan by Spyder or other device and if I open in Photoshop a picture showing the whole sRGB gamut is it possible to use "color warning" function in CS6 to display which collors will not be generated by my screen?  Is the procedure described in http://damiensymonds.blogspot.com/2010/04/check-your-monitors-gamut.html correct? If not - how to make the settings to do that?

       

      2. How I can find in Photoshop my actual ICC screen profile (it is notebook)? I found in C:\Windows\System32\spool\drivers\color the profile called "CalibratedDisplayProfile-1.icc" which is probably the standard screen profile of my notebook but I cannot find that name in Photoshop list of profiles.

       

      3. I understand the need for ICC profiles of hardwere like screens, printers, scanners, etc. which enable translation of information about collors but what is the meaning of ICC profile of a picture itself? What is editing (or working) collor space?

       

      4. When you save a picture you can choose an option to embed a profile. Why this is necessary? Is it a profile of a target printer or screen on which the picture is going to be watched?

       

      Thanks for any ideas!

      Marek

        • 1. Re: ICC profiles - few issues
          D Fosse Adobe Community Professional & MVP

          First of all: No screen matches sRGB precisely, and it doesn't have to as long as you have a monitor profile that describes it accurately. This profile is used to translate the document color space into the monitor color space. That's how color appears "correctly" on-screen, not because the screen matches sRGB or anything else.

           

          And that pretty much sums up what color management is all about: A source profile is converted into a destination profile, maintaining color intent as far as possible. One single profile doesn't do much, except that it defines the color and gives the RGB numbers specific meaning. It does this by way of what is known as the Profile Connection Space, which is usually nothing more esoteric than good old Lab.

           

          The point is that within the profile, every color is defined against a certain Lab value. In another profile, that very same color, with the very same Lab values, will have different RGB numbers (because it's a different color space). And that's how one profile is converted into another. To be more specific: the RGB numbers in your document are converted from the embedded profile, say, sRGB, into the monitor profile made by the calibrator.

           

          Here's the important thing: Do not confuse the two. They serve different purposes in the color management chain, and they are both necessary. One single profile does not constitute color management. An icc profile is just a description of a color space, and as the file goes from one color space to another, the profiles facilitate the translation.

           

          There are several reasons why we use standardized color spaces for documents (sRGB, Adobe RGB, ProPhoto). They are synthetic, ideal spaces, not tied to the quirks and irregularities of input/output devices. They mean the same everywhere. And they can have much larger gamuts - can contain much more saturated colors - than any device currently can. That gives editing headroom, and is future-proof.

           

          In Windows, you find the display profile in Control Panel > Color Management > Devices. But there's no need to go there, the calibrator sets eveything up automatically. But if you need to override it for some reason, you can do it there. However, it needs to be repeated: The display profile has nothing to do with the document itself. It is used by color managed applications to display the image, nothing else.

           

          ---

           

          I'm not a native English speaker, so I suppose this could be explained clearer than I can. In any case, color management isn't nearly as complicated as many people would have you think. Just keep the basic formula in the back of your head: source > destination, each with its profile.

          • 2. Re: ICC profiles - few issues
            MarkJan77 Level 1

            Thank you 21 for your help!!!

             

            It's clear to me what you wrote except one thing -  which profile I shoud assign (embed) with my image - sRGB, AdobeRGB or other? Is there any sence to embed to an image profile of a target printer ???

             

            Also if you know the answer for my questions nr.1 & 2 above I will be very pleased to read your comment.

             

            One more question about soft proofing and profiles: I open a file which shows 3 examples of sRGB gamut with embeded sRGB profile (bellow). I set AdobeRGB (1998) profile as target for the soft proofing.Then I choose gamut worning tool and I see a few grey areas which suggest that my target equipment with its profile (AdobeRGB) will not be able to "reproduce" corectly parts of the sRGB color space. But AdobeRGB is larger than sRGB so why this occurs (look at the last picture bellow)?

             

            grangers.jpg

            Why some gamut warnings appear when soft-proofing sRGB image into AdobeRGB profile as target?:

            Clipboard01.jpg

            Thx again! Marek

            • 3. Re: ICC profiles - few issues
              D Fosse Adobe Community Professional & MVP

              MarkJan77 wrote:


              Is there any sence to embed to an image profile of a target printer ???

              No, absolutely not, that was my main point, and let me emphasize it here. A printer profile is a device profile, just like the monitor profile. It is the "destination" in the formula above. The source is the document profile, sRGB, Adobe RGB etc. The printer profile characterizes the specific printer/ink/paper combination used when printing, and it should not be associated with the document itself.

               

              • Again: Document profile > monitor profile for display. This is performed by the application on the fly as the file is sent to the display.
              • Document profile > printer profile for print. You pick the printer profile in the print dialog. With a different printer or different paper, you pick a different profile.
              • In both cases, the embedded document profile is the same and unaffected.

               

              As for your question #1 it is largely academic. The difference in gamut will not be significant. But I suppose the procedure described is correct as far as it goes.

               

              If you have an sRGB document and soft proof to Adobe RGB, and you get out-of-gamut warning, then something's wrong. Could be the soft proofing itself is buggy. SRGB is contained completely within Adobe RGB.

               

              Which one to use depends on the purpose. SRGB is often recommended as "fail-safe" for the inexperienced, and for web use it is the de facto standard. This is precisely because most monitors are natively very close to sRGB. So in the absence of any color management an sRGB file will display more or less correctly regardless. But it's a very narrow space and there are printable colors that  cannot be contained within sRGB.

               

              Oh, and in Photoshop you find the monitor profile listed in Color Settings, under the drop-down options for working RGB space. It'll be listed as Monitor RGB <profile name>. But don't pick it - leave it alone. Working space should be one of the standard ones.

              • 4. Re: ICC profiles - few issues
                MarkJan77 Level 1

                twenty_one wrote:

                 

                MarkJan77 wrote:


                Is there any sence to embed to an image profile of a target printer ???

                No, absolutely not, that was my main point, and let me emphasize it here. A printer profile is a device profile, just like the monitor profile. It is the "destination" in the formula above. The source is the document profile, sRGB, Adobe RGB etc. The printer profile characterizes the specific printer/ink/paper combination used when printing, and it should not be associated with the document itself.

                 

                 

                Now I really got it !!! Thank you a lot for your time! You saved me a lots of nervs Someone told me some time ago about embeding printer or screen profiles into a file and I couldn't understand how it works. Now I understood that the person didn't know what was taking about...

                 

                Is it possible that an image file has no ICC profile embeded ? How to deal with that? How to check simply the profil of an image (windows explorer doesn't show such information in file properties)?

                 

                Have you got any idea why I cannot see many of my ICC profiles in the Photoshop profile-window although they are installed and visible in my operating system? For example I see in my operating system the file "CalibratedDisplayProfile-1.icc" which represents actual profile of my screen but I don't find such name in Photoshop so I cannot choose it for proofing.

                 

                And the last question: when calibrating a screen is it better to choose white point for 5000K or 6500K (editing images for printing)?

                • 5. Re: ICC profiles - few issues
                  D Fosse Adobe Community Professional & MVP

                  MarkJan77 wrote:

                   

                  Is it possible that an image file has no ICC profile embeded ? How to deal with that?

                  Oh yes, that happens. This is where the working space in Photoshop comes in, because in that case the working space is assigned to the file. But you can assign any profile you like (that looks like it should be the right one). You'll normally get a dialog asking what you want to do.

                   

                  And the last question: when calibrating a screen is it better to choose white point for 5000K or 6500K (editing images for printing)?

                  That's open to taste. Simply put, you choose the white point that gives you the best match to printed output (which can vary according to a lot of factors). It doesn't have to be either, you can choose anything in between.

                   

                  Personally I have my monitors at 6100K. 6500 seems a bit cool, and 5000 makes me feel like I'm looking at the image in candlelight.

                   

                  Why you don't see the display profile in Photoshop I don't know. But generally there's little reason to proof to monitor RGB. Actually what that does is to effectively turn display color management off (source profile is identical to destination profile, so no conversion occurs. That is in fact the definition of no color management. The RGB numbers in the file are just sent directly through to the display without any correction for it).

                  • 6. Re: ICC profiles - few issues
                    MarkJan77 Level 1

                    I've just found that there is something missing in the above logic. I think it is possible to convert an image to a profile of particular printer (Edit->Convert to profile...) in order to work on actual collors possible to generate by this printer. Isn't it ???? I know people who do like that. So it means that printer profile is embeded to such file. So how it is ?

                    • 7. Re: ICC profiles - few issues
                      D Fosse Adobe Community Professional & MVP

                      That's what proofing to printer profile is for. Not converting.

                      • 8. Re: ICC profiles - few issues
                        MarkJan77 Level 1

                        twenty_one wrote:

                         

                        That's what proofing to printer profile is for. Not converting.

                        Ok. you proof to see the final result on your screen. But then you send the file to a printing company. If you convert the file profile into specific printer profile space you have chance to choose different method of conversion and decide which looks the best. If you don't do it then you lose this oportunity, no? (that was at least explanation of my colleague who is profesional graphic designer - now I reminded myself).

                         

                        How to check simply if / what profile is embeded to an image file?

                        • 9. Re: ICC profiles - few issues
                          John Danek Level 4

                          Let me see if I can help...

                           

                          2. How I can find in Photoshop my actual ICC screen profile (it is notebook)? I found in C:\Windows\System32\spool\drivers\color the profile called "CalibratedDisplayProfile-1.icc" which is probably the standard screen profile of my notebook but I cannot find that name in Photoshop list of profiles.

                           

                          -Photoshop uses the OS for display performance and, since the .icc profile is established in the OS; that's where it ends.

                           

                          3. I understand the need for ICC profiles of hardwere like screens, printers, scanners, etc. which enable translation of information about collors but what is the meaning of ICC profile of a picture itself? What isediting (or working) collor space?

                           

                          -Photoshop and every other adobe app has color settings.  Adobe developed another app called Bridge where you can sync all of your color settings ( if you want to ).  If you have a picture that does not have an profile tagged to it, it could be referred to as "RAW" or has no profile ( yet ).  Photoshop's working color space for RGB could be any of the RGB profiles, which one depends on the type of work you do and where the file ultimately ends up being printed.  Certain industry standards are or have been in place now for quite a few years.

                           

                          If you'd like more information, try Adobe's Print Publishing Guide.  They have written a nice reference guide that could help you better understand preliminary file prep and final output parameters.

                          • 10. Re: ICC profiles - few issues
                            MarkJan77 Level 1

                            Thank you John!

                            John Danek wrote:

                             

                            -Photoshop uses the OS for display performance and, since the .icc profile is established in the OS; that's where it ends.

                             

                            Ok. But this applays always - no matter if you use notebook or standard PC I gues?. So if you have an external profiled monitor you can normaly easily find its profile in Photoshop. Why I cannot find the profile of my screen in the Photoshop list? Maybe the name of profile is different than name of file but I don't know how to check it.

                             

                            If you have a picture that does not have an profile tagged to it, it could be referred to as "RAW" or has no profile ( yet ).

                             

                            So maybe that is why sRGB space was created? Maybe all "standard images" (if not contain embeded profile) are considered by Photoshop as sRGB?

                            • 11. Re: ICC profiles - few issues
                              MarkJan77 Level 1

                              John Danek wrote:

                               

                               

                              If you'd like more information, try Adobe's Print Publishing Guide.  They have written a nice reference guide that could help you better understand preliminary file prep and final output parameters.

                              That was very good idea!!! I've downloaded the book and see that it is very interesting! Thnaks John! Marek 

                              • 12. Re: ICC profiles - few issues
                                D Fosse Adobe Community Professional & MVP

                                Sorry, had to sleep...

                                 

                                Just want to clarify one thing: The display profile is not something you, as a user, ever need to concern yourself with (with a few specialized exceptions). All you need to do is make sure it's there and valid. The rest is handled by the OS and applications (insofar as they are color managed and will actually use it).

                                 

                                If it's listed in Photoshop Color Settings as Monitor RGB <profile name>, that's it. End of story, nothing more you need to do. Proofing to monitor RGB is unnecessary, all it shows you is how the image looks without any color management at all. And under no circumstances should it be used as document profile or working space. That point needs to be hammered in for the benefit of anyone reading this, because it's a very common misconception.

                                 

                                And one more thing: I suppose some confusion could arise because the term "convert" is used for all normal color management operations. Mechanically, they're all the same. But there is an operational distinction in that some conversions are done by the user, as when converting a document from one color space to another. Others are automatically performed by applications, like when the document RGB values are converted into the monitor profile for display. For this reason, some like to call this a "color transform" to avoid giving the impression that this is something the user should do to the file itself. However, I like to use the same term because it's basically the same thing that is happening.

                                 

                                So, to sum up: You need two profiles to have color management. Where the file is coming from (document RGB), and where the file is going to (monitor, printer etc).

                                • 13. Re: ICC profiles - few issues
                                  MarkJan77 Level 1

                                  twenty_one wrote:

                                   

                                  Just want to clarify one thing: The display profile is not something you, as a user, ever need to concern yourself with (with a few specialized exceptions). All you need to do is make sure it's there and valid. The rest is handled by the OS and applications (insofar as they are color managed and will actually use it).

                                   

                                  Yes, that is  clear.

                                   

                                  If it's listed in Photoshop Color Settings as Monitor RGB <profile name>, that's it. End of story, nothing more you need to do.

                                   

                                  The issue that disturbs me is only that  I do not know how to recognize the name of ICC profile of my screen in the list of profiles of Adobe Photoshop. For example when I installed a profile of minilab Frontier I see the icc file in my OS: C:\Windows\System32\spool\drivers\color as well as I see this profile in Photoshop list for example when I want to choose a profile for proofing or profile conversion. I know that when you calibrate a monitor and you save the current icc profile it is also visible in Photoshop profiles list. So my only question is why I am not finding the profile of my screen "CalibratedDisplayProfile-1.icc" if its visible in C:\Windows\System32\spool\drivers\color ???

                                   

                                  Proofing to monitor RGB is unnecessary, all it shows you is how the image looks without any color management at all.

                                   

                                  Well, to be honest the above is not very clear to me because:

                                  a) I heard that if you work on a wide-gamut monitor you can proof to other monitor for example to emulate how your client (who owns worse sRGB screen) will perceive your work

                                  b) I would like to see which colors from sRGB space will not be corectly shown on my monitor according to the excercise described in http://damiensymonds.blogspot.com/2010/04/check-your-monitors-gamut.ht ml

                                   

                                  And under no circumstances should it be used as document profile or working space. That point needs to be hammered in for the benefit of anyone reading this, because it's a very common misconception.

                                  Ok about moniotr' profile. But do you agree that converting to a profile of a minilab (which becomes embeded to the original image) can be used in order to make sure that your work will be corectly printed?

                                   

                                  And one more thing: I suppose some confusion could arise because the term "convert" is used for all normal color management operations. Mechanically, they're all the same. But there is an operational distinction in that some conversions are done by the user, as when converting a document from one color space to another. Others are automatically performed by applications, like when the document RGB values are converted into the monitor profile for display. For this reason, some like to call this a "color transform" to avoid giving the impression that this is something the user should do to the file itself. However, I like to use the same term because it's basically the same thing that is happening.

                                   

                                  So, to sum up: You need two profiles to have color management. Where the file is coming from (document RGB), and where the file is going to (monitor, printer etc).

                                  So how to explain the following fact: I took an image with embeded sRGB IEC61966-2.1 profile (the image which I presented in my post from May 11, 2013 1:49 PM). I converted the image profile by EDIT->CONVERT TO PROFILE and I choose a RGB profile of a minilab. Collors reduced as in proofing test. Now when I open the file I see that the source profile (the embeded profile) is the profile of chosen minilab. So the initilal sRGB IEC61966-2.1 image profile disappeared.

                                  • 14. Re: ICC profiles - few issues
                                    D Fosse Adobe Community Professional & MVP

                                    Look at it this way: proofing temporarily either assigns that profile to the original file, or converts to it (depending on whether you have "preserve numbers" checked).

                                     

                                    Either way: If your file is in monitor RGB, and you send that to the display, which by definition is monitor RGB, that means the RGB numbers in the file are sent unchanged to the display. The two profiles are identical, so no change. They just go right through, just like they would in a non color managed environment. The net result is the same.

                                     

                                    Normally the file RGB numbers would go through a conversion to the monitor profile on their way to the display. That's color management.

                                     

                                    Now, if you proof to someone else's monitor profile, that's different.

                                    • 15. Re: ICC profiles - few issues
                                      MarkJan77 Level 1

                                      If your file is in monitor RGB, and you send that to the display, which by definition is monitor RGB, that means the RGB numbers in the file are sent unchanged to the display. The two profiles are identical, so no change. They just go right through, just like they would in a non color managed environment. The net result is the same.

                                       

                                      Normally the file RGB numbers would go through a conversion to the monitor profile on their way to the display. That's color management.

                                       

                                      Now, if you proof to someone else's monitor profile, that's different.

                                       

                                      Now I am little lost for which issue the above statement should be answer for.

                                      Of course if profiles of an image and a monitor are the same then no conversion takes place.

                                      But this is not my concern. When I wrote  "I would like to see which colors from sRGB space will not be corectly shown on my monitor according to the excercise described in http://damiensymonds.blogspot.com/2010/04/check-your-monitors-gamut.ht ml" I meant to see gamut wornings on sRGB image due to the fact that my monitor is not able to generate some sRGB colors. So I believe (but I might be wrong) that if I proof the image to my monitor then I will not see different colors but I will be able to see gamut worning because the picture color space (sRGB) is wider than my moniotr color space.

                                      • 16. Re: ICC profiles - few issues
                                        D Fosse Adobe Community Professional & MVP

                                        MarkJan77 wrote:

                                         

                                        I would like to see which colors from sRGB space will not be corectly shown on my monitor

                                        OK. But I maintain that this is a largely academic exercise with little real information, given the close proximity of a standard gamut display and sRGB. It would be different with standard gamut vs wide gamut.

                                         

                                        Here's a more or less typical plot of an average standard gamut display:

                                        gamut.png

                                        As you can see the issue isn't so much gamut size; it's geometry. The three primaries aren't in the same places. Without a monitor profile to compensate for that, you'd get slight hue shifts in saturated colors: a blue sky would turn cyanish, for instance. Nothing dramatic, but enough to throw the colors a little off.

                                         

                                        So what you should see if you could soft-proof to the gamut differences (if soft proofing is accurate enough, which I doubt), is just those narrow wedges. It's pretty insignificant. There's much bigger fish to fry in this.

                                        • 17. Re: ICC profiles - few issues
                                          MarkJan77 Level 1

                                          Thank you 21! I don't expect huge amount of gamut wornings on my screen. However I use plain office notebook and it may happen that its color space will be far from sRGB. But as I mentioned at the very beginning - I cannot recognize (find) its ICC profile in Photoshop profiles list and that is my primary problem...