Excellent question from +Aden J Purcell:

Apparently the display on the G4 follows the DCI color space instead of sRGB. Do you know if this is a good thing? I thought movies were mastered in sRGB, not DCI? And even if LG has accurately calibrated the G4 to DCI, could they have messed up the gamma? Or is a 2.2 gamma part of DCI meaning LG can't mess with it otherwise they can't market their device as DCI compliant?

Like +Samsung Mobile has done before, marketing their Super AMOLED devices as color accurate according to the Adobe RGB standard to appeal to photographers, +LG Electronics described the LG G4 display as following another standard they call "DCI"

First of all, DCI acronym stands for "Digital Cinema Initiatives, LLC" and not the name of a color standard.
Assuming they are talking about DCI-P3 color gamut, it's the gamut part of one of the color encoding formats for professional cinema projection.

– white point coordinates x: 0. 314, y: 0.351 vs sRGB x:0.3127 y: 0.3290
– gamma 2.6 vs sRGB around 2.2 average
– pretty wide gamut, color primaries color hues not being the same as sRGB: green has less yellow, red has less orange,

A comparison of sRGB and DCI-P3 color gamuts by +Jeff Yurek's blog:
Additionally, the white point is not even the same.

Today, Android applications lack color management abilities which would allow to convert one color encoding to another and display content as intended on various displays seamlessly.

+LG Electronics throws in the "DCI" name to impress reporters and customers with the intent to convince them of the benefits in color accuracy and true-to-life color reproduction of their new display.

However, when checking what they're mentioning stands for, it is clear that displaying today's content, which color are encoded using sRGB (Rec.709 gamut and around 2.2 gamma) on a "DCI-P3" display (wide gamut and gamma 2.6) would lead to particularly inaccurate color rendering.
Colors would not be rendered with the right hue, look too intense (over-saturated look), and annoyingly too dark due to the gamma 2.6, which increases saturation even more.

In conclusion, +LG Electronics is proud of their new wide-gamut display but please don't be fooled by the marketing mumbo-jumbo employed.
It doesn't correspond to any professional standard or any standard altogether, it will distort colors instead of rendering them faithfully, and this is mostly a response to Samsung, just as bogus Adobe RGB accuracy claims.

Source: DCI-P3:

#supercurioBlog #LG #critic #marketing #color #display


Source post on Google+

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François Simond

Mobile engineer & analyst specialized in, display, camera color calibration, audio tuning

11 thoughts on “Excellent question from +Aden J Purcell:”

  1. +François Simond​ thank you so much for this 🙂 I'm a little disappointed though.

    So when I watch movies on the G4, will it look more "cinematic" in any way? Or just oversaturated?

    I know that all consumer content including movies are encoded in sRBG, so is it only the film reel that studios give to theaters that's mastered in DCI to match the projectors? Is there any content at all that we can watch on the G4 to take advantage of the DCI-certified display?

  2. +Aden J Purcell none of the +YouTube videos, Netflix or Google Play movies are encoded in DCI standards

    Here's a recap:
    – DCI-P3 is a standard for professional projectors. It doesn't mean every projector is capable of rendering that but it's a target.
    – DCI content is encoded in linear XYZ 16-bit or gamma-encoded (gamma 2.6) XYZ 12-bit.

    During projection, each frame has to be converted mathematically from XYZ colorspace (that can represent every visible color) to the color space of the projector, according to its specification and calibration.
    This is what allows to have a consistent experience.

    +YouTube videos, Netflix or Play Store movies are encoded in RGB instead, and the simple RGB values can be displayed as-is without any conversion on panels with a transfer function of around gamma 2.2, a gamut close to Rec.709 and a white point of D65.

    DCI content (in XYZ, a theoretical mathematical representation of colors) functions completely differently than regular RGB content we have now.

    A display calibrated to emulate DCI-P3 standard for projectors will not give a cinematic look or any benefit.

    Each "real" color is encoded according to a mathematical formula (what we call colorspace) into numbers.
    Showing sRGB content on a DCI-P3 display correspond to decoding those values with the wrong formula.

    However don't forget that LG here just used DCI as a buzzword.
    They have a wide gamut display: okay, it has a great contrast ratio for a LCD: cool.
    How they use the DCI word doesn't correspond to anything real or meaningful tho.
    Even if the panel color primaries indeed somewhat matches with those of the DCI-P3 standard, there's no DCI-P3 RGB content available and won't be.
    Instead, Ultra HDTV specifications define Rec.2020 gamut with BT.1886 transfer curve.

  3. +Aden J Purcell DCI-P3 white point coordinates correspond to a CCT of 6302K.
    Because y is 0.351 instead of 0.3290, as you can report on https://dotcolordotcom.files.wordpress.com/2012/12/pantone_2013_dot_color.png, it also means there's more green in the white point, and people are pretty sensible to the intensity of green.
    However the intensity of green is mostly absent in the color temperature calculation (that's meant to tell you if things are cool or warm 😉

  4. I don't even watch phone / device announcements at all. I can't listening to OEM PR nonsense. Sadly so many reviewers just repeat the crap in their press kits afterwards anyway

    For example somewhere today I seen or heard that lg was working super close with Qualcomm for two years with the 808…. Yeah ok….

  5. +Brian Z yes it was really strange to see Qualcomm on stage continuing with damage control on the 810.
    LG probably got a sweet deal for the 808 for that which will allow them to be more price-competitive.
    We shall see if this CPU+GPU combo will be good enough to drive smoothly the Quad HD display with Lollipop.

  6. Don't hold your breath for a flagship device from a big OEM to compete on price.

    Also what your average tech head doesn't even realize is just how cheap the SoCs are in these devices. The amount they save from one sku to another one that's one step down isn't even worth changing the retail price to be honest.

  7. I say nope.

    These SoCs / skus aren't made for a specific OEM / customers. The closest you get to that is when a entire market like China wants to play to core count game.

    SoC providers do their bring up / BSP. OEMs take it from there. They will work together after that to iron out any issues. Do the camera stuff that relies heavily on the underlying SoC platform.

    Which even now should be easier for the OEM's to implement due to camera2 api. Before stock android provided basically shit. So now in order to do a full manual mode they don't have do all that crap on their own at a lower level. Just have proper api 2 hw support along with the software and do it via api.

    I'm no camera expert. Not am I expert by any means on the new api. But this should be the general jist of it.

    François has extensive knowledge and experience on this subject though. If I derped it up he can straighten it out!

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