10-bit and HDR

Umang Goel · April 17, 2016

I understood the difference between 8-bit and 10-bit displays but how does High Dynamic Range come into equation?

Basically, what is an HDR display?

Are all HDR displays the 10-bit display?

Are all 10-bit diplays HDR?

Is HDR also possible in 8-bit?

And finally, which technology is better of the two, HDR or 10-bit (if they are different) ?

Allshevski · April 17, 2016

HDR is often mentioned when advertising new OLED displays, it basically allows for even higher than "infinite" contrast present in older OLEDs (basically more of the color palette)

You can think of it as better contrast between the slightest light a display can emit and the 100% light.

No, not every HDR display is 10 bit as they are often found in TVs where you will not see any particular benefit.

No, not all (basically most of) 10 bit displays are HDR, they just can display more of substeps in colors. But they are often high quality and have really high contrast.

Yes, it is possible in 8 bit.

Both have their pros and cons. 10 bit is rather used in production stage of content, where designers need to have extra information in images and videos. Although you could work with 10 bit files on an 8 bit display. HDR alone gives you more vibrant, true colors while 10 bit means smoother transitions to black etc.

Glenwing · April 17, 2016

56 minutes ago, Umang Goel said:

I understood the difference between 8-bit and 10-bit displays but how does High Dynamic Range come into equation?

Basically, what is an HDR display?

Are all HDR displays the 10-bit display?

Are all 10-bit diplays HDR?

Is HDR also possible in 8-bit?

And finally, which technology is better of the two, HDR or 10-bit (if they are different) ?

It is difficult to say what HDR is because so far no companies will actually say specifically what it is. They just give vague descriptions that it's some kind of thing that magically makes everything look better, and everyone is goes crazy over that.... I'm skeptical, personally. But we'll see.

From what I've gathered from the limited information available, HDR is mostly just a bunch of features that already exist, just repackaged under the brand "HDR" to make a second crack at standardizing it, since it didn't go so well the first time around. For example, 10-bit color was added to the HDMI specification a long time ago, but it was pretty much ignored, TVs and content alike have pretty much ignored it. Similarly, wide-gamut color spaces like AdobeRGB have been possible for a long time, but no one has made a push to transition mainstream content to them, everything is still just on sRGB. So, now this term "HDR" has been created, where if you implement all these features that have been around for a long time but no one adopted, then you can be sold as "HDR".

HDR is basically just a feature package which includes 10-bit color and a wide-gamut color space (DCI P3), so yes 10-bit color is a requirement for the "HDR" label, and it also sets some requirements for contrast and peak brightness. There's also some newer encoding standards that were introduced to take the higher brightness and contrast into account, since current formats were only designed with around 80-100 cd/m² in mind, and the HDR spec calls for over 1,000. The encoding is really the only unique thing "HDR" has introduced, the rest is just features that can already exist on their own. The contrast requirements basically disqualify any kind of LCD technologies from qualifying as "HDR" but I'm sure they will still sell some LCDs with that label... only OLED displays can actually meet the full "HDR" requirements though.

The whole thing is a bit superfluous IMO, and I don't really see why everyone is getting so excited, but we'll see when it actually starts appearing on the market.