How much color gamut do displays really need? Part 3: Existing color gamut standards

Last week I looked at the three “P’s” of human color perception– physical, physiological and psychological– as a way to help define a color gamut for the ideal display. Based on real world examples from art and commerce, I concluded that the range of colors found in nature, as measured by Pointer, provided the best fit with our two design goals which were an accurate and exciting, immersive experience.

This week, I’d like to get a little more practical and take a look at existing color gamut standards to see what we might realistically be able to achieve today.

What fits best?

Color gamut of 4,000 surface colors found in nature as measured by Pointer in 1980 against the color gamut of the iPhone 5.

Color gamut of 4,000 surface colors found in nature as measured by Pointer in 1980 against the color gamut of the iPhone 5.

The first thing you’ll notice about Pointer’s gamut (pictured above again) is that it’s a pretty odd, squiggly shape. This means it is going to be difficult to cover efficiently with a three primary system that mixes just red, green and blue to create all the colors we see, like the LCD found in the iPhone. In order to cover Pointer’s with just those three colors, we’d need to make them extremely saturated. There are proposed standards that take this  approach, such as rec.2020, but since they are not practical to implement today from a technology standpoint I’ve decided to ignore them for this discussion.

For the near future, we’ll need to rely on just three colors to get the job done, so what can we do now? Let’s look at two popular wide color gamut standards: Adobe 1998 and DCI-P3:

Current wide color gamut standards Adobe RGB 1998, commonly used by pro photographers and designers, and DCI-P3, used in digital cinema, compared to Pointer's gamut in CIE 1976

Current wide color gamut standards Adobe RGB 1998, commonly used by pro photographers and designers, and DCI-P3, used in digital cinema, compared to Pointer’s gamut in CIE 1976

Let’s start with Adobe 1998. Many people are familiar with this color gamut since it is found as an option on many consumer cameras and it is popular among creative professionals. It certainly covers a significantly wider range of colors than the HDTV broadcast standard with a very deep green point. The rich cyans that we talked about in the movie “The Ring” would look great in Adobe 1998. But, we’re not getting any more of those exciting reds and oranges. In fact, Adobe’s red point is identical to the HDTV broadcast standard.

What about DCI-P3 then? Designed to match the color gamut of color film and used in cinemas all over the world, DCI-P3 has a very wide gamut. The reds are particularly deep and, of course, all of the colors from the movies we looked at are covered. Still, it’s missing a lot of the deep greens found in Adobe 1998 and only just fits the green Pantone color of the year. So DCI-P3 is not quite perfect either.

What about a hybrid, custom gamut? 

What if we combined the green from Adobe with the red from DCI-P3 and their shared blue point? We’d end up with pretty good, high 90’s percentage coverage of Pointer’s gamut, coverage of all of the existing HDTV broadcast content, full coverage of cinema content from Hollywood and a superior ecommerce experience with most of the colors from the natural world covered.

Hybrid color gamut standard that combines the green point from Adobe 1998 with the deep red of DCI-P3

Hybrid color gamut standard that combines the green point from Adobe 1998 with the deep red of DCI-P3

Looks pretty great and we can make displays now that cover this color gamut with today’s technology. But how would it work on the content side? Would we need to get together and agree on this new standard and then wait for years while it is slowly adopted by content creators and display makers?

Next week

Next week we’ll look at how content delivery might evolve to support gamuts like this without the need for major changes to broadcast standards.

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11 thoughts on “How much color gamut do displays really need? Part 3: Existing color gamut standards

  1. Pingback: How much color gamut do displays really need? P...

  2. This is an interesting idea which, based on the owner of this blog, I’m guessing is achievable with quantum dot film. Since full Rec. 2020 color space coverage will probably require laser projectors and/or OLEDs, this is a decent interim step.

    Personally, I’d prefer the green point to be a bit further out. When using the green point of AdobeRGB, your Hybrid Adobe-DCI color gamut will have 100% coverage of AdobeRGB but only ~99% of DCI-P3. By moving the green point out a bit, we could have 100% coverage of AdobeRGB and 100% coverage of DCI-P3 making the monitor perfect for all kinds of content creation.

  3. Pingback: How much color do displays really need? Part 4: Content Delivery | dot color

  4. Interesting article. Covering the entire Pointer’s gamut becomes a lot easier by the way when using a color system with more than three primary colors. Sharp already has HD-TVs with RYGB primaries on the market for a couple of years (Sharp Aquos Quattron models) and showed a 60.5″ TV with RYGCB on SID 2009 with over 99% coverage of the Pointer’s gamut (http://sharp-world.com/corporate/news/090529.html). There are also multiple papers around discussing displays with 6 primaries.

    Displays with perfectly monochromatic primaries should be just around the corner too. At least with red and blue/violet. Even some conventional TFT LCD’s with B+RG LED, GB-R LED or RGB LED backlighting already have nearly monochromatic red and blue primaries. The Samsung SyncMaster S27A850D S-PLS display for instance, with a red primary very close to 610 nm and blue also quite close to 462 nm. And there have already been OLED-like prototype displays based on lasers, resulting in monochromatic primaries.

    Combining those two would make it possible to display nearly every visible color, even the purely additive colors, that can only be produced by a light source and cannot be reflected off any surface. If you optimize for coverage of the entire CIE 1931 xy chromaticity diagram you can reach 73.84% with 3, 86.68% with 4, 92.54% with 5 and 95.49% with 6 primaries. If you optimize for CIE 1976 u’v’ you can reach even higher coverages.

    One question, do you have the Pointer’s gamut as raw data in CIE 1931 xy or CIE 1976 u’v’ coordinates in Excel, Matlab, CSV or TXT format? Because I would love to have those for making plots and calculations myself.

  5. Speaking of color gamut standards, how do you think about BT.1361 and xvYCC(IEC 61966-2-4)? The former one doesn’t seem to have products to support it, while there are some products claiming support the latter standard.

  6. Hi Jeff,
    I’m using color think Pro to analyse some images as compared with the Standard gamuts (sRGB, ProPhoto, Adobe 1998). Unfortunately, Color think Pro is missing DCI-P3 profile, and therefore I can’t compare my images with respect to the DCI-P3 in the Lab or xyY colorspace, I mean in 3D.
    Could you please point me to any source from where I can get DCI-P3 profile (.icc) or the characterization dataset that can be used to create DCI-P3 profile?
    thank you

    • Hi Shah,

      Unfortunately don’t have any .icc dataset for DCI-P3 either. I would also love to see something like this. Comparing these spaces in 3D is definitely the way to go. Please let me know if you come across something!

      • Here you go: https://db.tt/HB5sOqLm

        Not sure where I got it from, but I’m guessing it’s either the Adobe Creative Suite Master Collection or the X-Rite i1Publish Pro kit. By the way, you can find your profiles in “C:\Windows\System32\spool\drivers\color” (on Windows).

        If you want to make your own profile it’s a bit harder, because you have to convert the CIE 1931 xy primaries to XYZ primaries (easy so far) and then do a chromatic adaption to D50 (that’s the most common profile connection space illuminant), but I’m not sure what the starting point of that chromatic adaption should be (I’m guessing the DCI-P3 white point).

        Rx 0.680
        Ry 0.320
        Gx 0.265
        Gy 0.690
        Bx 0.150
        By 0.060
        Wx 0.314
        Wy 0.351

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