A Look At QD Vision's Color IQ And The Philips 276E6 Monitor: Quantum Dots for Wider Color Gamuts

Color Management

Readers may be wondering why I didn't run the Philips 276E6 through our sRGB test bench. The story behind that is a long one, and to tell it I need to first go over some aspects of how color management works, and how the 276E6 exposes a number of problems with color management on current computers.

Color management isn't discussed very often. In my view, there are three reasons behind this. The first is the fact that most consumers have been using displays that don't even meet the sRGB gamut for many years now, and so there wasn't much need to discuss color management in a display-related context. The second is the fact that Windows computer manufacturers have only really started bothering to calibrate their displays within the last two years or so, and prior to that time color management almost didn't matter because you were getting a severely inaccurate sub-sRGB display that wouldn't show anything accurately regardless of what gamut content was made for. The third reason is simply that color management should just work, and it should be invisible to the user. In some contexts, this is true, such as how an operating system manages color conversions between RGB and CMYK when printing. When it comes to displays, the issue can be much more complicated.

Before moving ahead it's important to make sure that the basics regarding color management are clear to anyone who hasn't encountered it before. Put simply, color management is the process of transforming image data between different standards for displaying color. As I mentioned above, an application of this that many people encounter every day without knowing it is the transformation of an image from an additive RGB color space, to a subtractive CMYK color space which printers use. Essentially every operating system handles this without issue, but the same cannot be said about managing different color standards for displays.

For the purposes of this article it's sufficient to just consider sRGB and Adobe RGB. sRGB is the current standard for all images and graphics displayed on the web, while Adobe RGB is a color space developed by Adobe which extends the green primary of the sRGB color space. Both of these standards define various characteristics about how color should be displayed, including the color gamut, gamma function, white point, luminance, and black level. The Adobe RGB gamut is significantly larger than the sRGB gamut in its reproduction of green and cyan shades, which is why monitors that support it are referred to as wide gamut displays.

Having a display with a different color gamut than that of the one used on the web can pose significant problems. It's up to the operating system, its frameworks and APIs, and the apps built on top of them to properly handle the mapping of content made for the sRGB color space to the monitor's wider color space. To help with this, displays should provide an ICC profile, which is a file that describes information about the monitor's color characteristics. With a proper ICC profile, the system's color management framework will know the specifics of the monitor's gamut, along with the gamma ramps to be loaded into the GPU's lookup table to provide corrections. It's worth going over the process of applying these in Windows and OS X.

Windows makes the task of setting an ICC profile quite confusing for the average user. To do so, one has to open the Windows Color Management settings, which is still part of the legacy control panel rather than being integrated into the new Settings application that has existed since Windows 8 launched. In the case of the Philips 276E6, you'd expect that you could simply select the default monitor profile, click "Use my display settings", and you'd have every application managing color properly.

Unfortunately, the process I described above won't change anything about your display's output. For starters, simply checking that box doesn't actually do anything regardless of what profile you've selected, despite the fact that it explicitly says the box enables the settings you've chosen. For whatever reason, you then need to click on the advanced tab, and then click on the button to change the system defaults. From there, you're then brought to what appears to be the screen you began on, but in this case you're managing the default settings for the system which will apply to all users. From here, you should check the box that enables the use of Windows display calibration, which will actually enable the settings you changed in the first window.

On OS X, the process involves going to the color tab of the display settings page and clicking on the profile you want to use. This instantly sets the profile across the OS. I tend to lean toward the OS X implementation as being the simpler one, as clicking on one thing is simpler than having to navigate a number of menus, toggle checkboxes with inaccurate descriptions, and eventually resort to finding a guide on Google such as this one to figure out how to load an ICC profile properly. In my experience the color management at the OS level in Windows is notoriously unreliable as well, with Direct3D applications being able to load whatever they want into the GPU's LUT if they run fullscreen, and the ICC's LUT often not loading again even after exiting, which requires trying to force it to load by toggling it on and off or just rebooting the entire computer.

Fortunately, there are a number of third party applications to handle the loading of ICC profiles on Windows, which have mainly been created to address the problems with the built in functionality. Users who profile their display with CalMAN will likely opt for SpectraCal's CalMAN Client 3 to manage profiles, and there are many free programs like Color Sustainer and CPKeeper which work reliably and often can reload on a timed basis which allows settings to be properly restored after being overwritten by the bad behavior of most game developers.