Adobe RGB to sRGB conversion, why does the color change?

Question

When I convert my photos from Adobe RGB colorspace to sRGB for browsers, the color slightly changes and I’m bothered by it. I know that sRGB covers a smaller space of colors so I won’t get an exact same result after conversion, but I still wonder if there is a way to get better results.

Of course it’s not a problem in cases when I start with converting and do the retouch afterwards, but many cases I either don’t want to do anything with the photos or forget to change the colorspace. So I would like to know if it can be converted without any noticable change, or should I just get used to it?

I used (Photoshop CS5) “Edit -> Convert to Profile”, I tried both Relative and Absolute Colorimetric, I checked all the boxes at the bottom (“Use Dither” and such). I also tried without those boxes checked, but it resulted almost the same, only a bit worse.

I already read the answers for How do color spaces like sRGB and Adobe RGB overlap?, but changing to 16 bits/channel didn’t help either.

Answer 1

If everything is working correctly, the difference should be subtle and you shouldn't generally notice a big shift.

I have a suspicion:

You may be working on a monitor which is not capable of rendering the whole Adobe RGB gamut. In this case, out-of-gamut colors are clipped or approximated (perhaps poorly). When you convert to sRGB, the colors are mapped more correctly and can be actually rendered, and you get the shift. In other words, the sRGB version was "right" all along — you just weren't seeing it.

This is one reason I recommend that most people work in sRGB even though bigger color spaces sound better.

The other possibility, if you're working in a nicely color-calibrated setup, is that your image does have a lot of tones not represented in sRGB and losing them does happen to make a big difference in the scene. In that case, there's nothing you can really do, although if web and sRGB are a large portion of your display audience you may want to take the time to do sRGB-specific color work.

This is kind of web-browser specific, but take a look at Microsoft's color management test page, and in particular the "image test" link. In a properly-configured system, as you click between Adobe RGB, sRGB, and ProPhoto (click between the or thises), you'll see only very subtle changes. If your environment isn't set up correctly (in the browser test, including if you don't have proper browser support), the Adobe RGB and ProPhoto examples will look horribly washed out and wrong. (Viewing the page on my iPhone provides a great example of a browser with no proper color profile support.)

Answer 2

It is very likely that your monitor cannot support the full AdobeRGB gamut. The best way to convert an image from one color space to another with minimum changes in color reproduction is by following the below process:

1. Having set your workflow's color management to AdobeRGB (Photoshop, Lightroom, etc)
2. Having your monitor profile set in AdobeRGB as well (for premium monitors with good coverage of AdobeRGB color space)
3. Process the photo
4. Convert to sRGB
5. Change monitor profile to sRGB
6. Assign Profile to AdobeRGB (that's odd but I explain below why)
7. Convert again to sRGB

That process may look strange at first but it's the best method I found out -the hard way by myself after a lot of efforts!-. Explanation: When you convert from AdobeRGB to sRGB in Photoshop (or other software) the image may still look the same inside the program but you will have the wrong profile loaded in your monitor; if you change the profile of the monitor (to the converted one) is similar like assigning profile in photoshop so you will need to "offset" that shift with reverse "Assign Profile" (these are steps 5 & 6). If you do the above process you will have (almost) the same image: sRGB image with the monitor profile set in sRGB AND AdobeRGB image with the monitor profile set in AdobeRGB.

Answer 3

The above answers are incorrect. It is NOT because of the lack of a monitor that correctly displays AdobeRGB gamut. (I have two matched NEC monitors that are 98% aRGB.) I deal with this all the time both for my own website and having clients complain that my "images are too saturated".

The problem comes from an image that covers the full range of AdobeRGB (and worse, if you use ProPhoto, though that's a waste since no devices on earth can display that "theoretical" colorspace). Your colors are being compressed in sRGB. I have yet to find a suitable solution except to slightly desaturate (or reduce vibrancy) of the image and save as a copy. Some images don't suffer from the conversion in colorspaces, others -- usually skin tones and greens -- are much more affected. (I shoot fashion and so am always battling with it.) I usually use Lightroom to do my web/color conversions, so I can non-destructively apply the saturation change to my TIFFs.

A good way to check yourself is to drag a final sRGB JPEG into a browser like Chrome and see how it's rendered. If you work in windows, Windows Photos doesn't manage color, so you'll see sRGB when displayed, even if your image is AdobeRGB.

Answer 4

The color space is basically instructions on what a certain color in a tuple (like rgb) should be represented as in the real world. When you change color spaces you are changing what a certain color should be represented as, while the number representing the color never changes.