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Color management in Photoshop
It's time to get down to business ! We will now study how to use all the menus dedicated to color management in Photoshop. In the end, there are not so many of them and, with a little practice and keyboard shortcuts, they are easy to integrate into your workflow.
In the second part of this Photoshop tutorial (previous page) I first wanted to show the different menus and windows available to the photographer to know where he stands in managing the colors of his images - color information in Photoshop.
Now, in this tutorial about color management in Photoshop, it is time to study the different color management rules during a work sequence on a photograph by distinguishing the management of ICC profiles when opening photos - so the choice of the famous photo working space - then during processing in Photoshop and until the preparation for printing work.
Colour management when opening a file : choosing your working space
When opening a new image in Photoshop correctly configured - color preferences - Be careful, I'm not talking about a RAW file because I'm talking about it specifically on this page - it will read the colorimetric profile - ICC profile - of this one or notice its absence to know how it should display it (Photoshop sees many RGB values in the photo but until the ICC profile has been assigned, it does not know by which colors L*a*b* display them). Depending on what it detects, Photoshop opens a different menu, a menu that seems very strange the first time (But what is it asking me??). There are three possible scenarios :
- Either the image does not have an ICC profile. It therefore does not know where the image comes from and does not know how to display its colours correctly.
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Or it has one, but different from the working space.
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Or the image has the same built-in profile as the working space in which case it is displayed directly, without going through a menu. So there's nothing more to add !
No ICC profile (tag #)
This case is less common today because our photos are all tagged as digital camera outputs in sRGB or Adobe RGB. However, this can happen with images from the Internet, your scanner or some software such as panoramic assembly software, some of which remove the ICC profile from images during the assembly process. The window that appears is then this one : |
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Illustration of the differences in display that can be observed simply by changing the profile at the opening. The photo came from a digital camera and was developed in sRGB but I did not incorporate the ICC profile when recording it. Now here is an example of its appearance when opening in Photoshop if the working space is different - here ProPhoto - and I choose - "Do not modify..." -
The red colors in particular are particularly saturated because the RGB values of the image are displayed in ProPhoto RGB, my working space, and whose gamut is much wider.
And here is the open picture with its ICC profile ! I now assign it another profile, the one I know or imagine, when I see what I do, that is, the sRGB...
Everything is back in order and the colours regain their natural saturation...
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2 - "Assign working RGB" - This is the right solution if you know that the ICC profile of your photo is the same as your Photoshop working space. This was not the case here. This is the only case where you can choose it.
3 - Assigning a profile / conversion in the working space : this will often be the preferred menu if you know where the image comes from, for example from your scanner. You must then scroll through the list of ICC profiles to select the appropriate ICC profile.
Another example: for example, you have developed your RAW files in a color space and your assembly software has deleted it; simply select from the list the ICC profile of these BEFORE assembly. The display of your panorama will be correct.
Last example : let's say this time that your image comes from the Internet. It was probably recorded in sRGB but for reasons of file size - a real problem on the Web at one time ! - and more probably today because the button "embed ICC profile" has not been checked - is not tagged with this ICC profile. The profile is therefore missing. That said, it has been transformed - converted - in this space. You can easily choose: assign ICC profile sRGB and convert in the working space or leave as such.
The photo has an ICC profile similar to the working space (No tag)
If your photo contains an ICC profile that is the same as your working space then the image opens directly !
The photo contains an ICC profile which is different from the working space (Tag *)
If your photo contains an ICC profile but different from your working space then the following menu opens :
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1 - Use the embedded profile : it is nowadays the most commonly used. You have chosen your working space on your camera if you work in JPG, in your demo software if you work in RAW. You will continue to use it. No need for conversion since your working space is neutral.
Either it is larger than your working space and you have every interest in continuing to work in a large gamut so as not to risk losing colors as a result of a hasty conversion or it is smaller and you know that you will not "gain" colors by converting into a larger space !
2 - Convert the document colors to the working space : in general, this is appropriate when the image profile is larger than the working space and IF the profile is actually a color space and not a device profile like that of a scanner for example.
However, I don't like this menu too much because you can't choose the conversion mode since Photoshop will automatically use the default one chosen in the software preferences.
 Note ! When you do a conversion, you know that it can be done in two different ways, according to two different conversion modes : relative or perceptual, but there, you have no option to choose. So it is simply done according to the default mode chosen in Photoshop's color preferences. That's why I rarely choose this option.
3 - "Discard the embedded profile" : it is possible, perhaps for educational purposes !.
Manage colors while working in Photoshop
In the previous two paragraphs, we saw that the photographer who opens a new image in Photoshop could be presented with different scenarios. When the image did not have an embedded profile and if we do not know where the photo came from, we saw that it was better to wait until the image was open and therefore visible on the screen to assign it a profile by seeing what is actually happening. I therefore advised you to tick: "Do not assign a profile". Let's see how to assign a profile now. I don't come back to the need to paste/tap a profile to an image - see ICC profiles -
Assign an ICC profile
As we saw on the previous page - Photoshop information and color menus -, after opening your photo which does not contain an ICC profile by the "Do not modify" menu, you must open the "Edit / Assign a profile" menu in order to assign it one while seeing what you are doing - on our calibrated monitor ! So first, check that the "overview" box is checked. Then click in the box : "Work RGB" or "Profile: ..." - by searching the list for a suitable ICC profile - and look at the image on the screen by checking / unchecking the "overview" box. When it is convenient for you, click on OK.
Through this menu, the ICC profile will be tagged/pasted to the image, like a Post-It. The original is kept but a small tag, ICC profile or color space, is pasted on it to be read by Photoshop, by the screen, or other to correctly display the colors. Until you find the right ICC profile, your image will be more or less contrasted, more or less saturated depending on whether the "normal" space of your photo is more or less large than the one you are trying to paste.
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Illustration of the differences in display that can be observed simply by forgetting to make a conversion between, here, a large space and the famous sRGB.
The colors are normally saturated on this photo whose ICC profile is the ProPhoto RGB. I want to place it on the Internet and without an ICC profile...
...but I "forgot" to convert it into an sRGB and incorporate its ICC profile! The colors are desaturated, blacks absent, etc. A simple conversion would have allowed me to keep the same colors, even if the RGB values would have been modified.
The same would apply if you forget to convert your photo before printing it even if this conversion is done directly in a special Photoshop Print menu and not through the Edit / Convert to Profile menu.
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 To open this menu, you must pull down the Edit / Convert to Profile menu in Photoshop. As we saw on the previous page, we see the Source profile and we can of course choose the destination profile from a long drop-down list. Once chosen, you must choose the Relative or Perceptual conversion mode. By ticking the "Preview" button alternately, you can get a good idea of the ideal conversion mode. However, this will depend a lot on your screen and the nature of your photos. The higher the quality of your screen - wide gamut, display accuracy, calibration - the easier it will be to see the effects of conversion on your image... if of course it contains fairly saturated colors. We often forget it but if you photograph pastel colors, it will be almost impossible to see the difference, no matter what the gamut of your screen !
If we have just mentioned one of the cases where it is necessary to convert using this menu to prepare the photos before they are put online, there is a second very frequent case : printing. There are two possible scenarios :
Now, it is important to know how to choose the color space of your photos, much more than that of Photoshop between the small but so practical sRGB, the largest Adobe RGB or the very large ProPhoto or what color management rules adopted to put your photos online 
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 Once you have enabled color management in photoshop, you will use the various menus dedicated to controlling ICC profiles and color spaces.
To do this, you must be comfortable with the menus that open when you open a new photo and ask you what to do if a profile is missing or if the profile does not match the one in the working space.
If the profile is missing, I advise you to choose "Open without profile" and you will choose the right profile to assign directly in photoshop, while seeing what you are doing through the "Assign profile" menu.
If the profile does not match the working space, choose "Do not modify" and work in the color space of your photo unless it is a file from a scanner.
Take the time to learn how to assign a profile and convert an image. This is essential once you have calibrated your screen.
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