What is a HDR display - Gary explains

HDR Displays: Understanding the Technology Behind High Dynamic Range

Hello there, my name is Gary Sims from Android Authority. Today, we're going to talk about something that I think many of you are familiar with, but might not necessarily understand - HDR displays. You know how when you hear the word HDR, you think about that special mode in your camera that allows you to take better photos, brings out the colors more vividly, and finds the details in the shadows? Well, actually, HDR is not only for capturing images; it's also for displaying images.

The question before us today is what is a HDR display and how does it work. So, let me explain. HDR stands for High Dynamic Range, and the idea is that it gives you a display that gives you more vibrant colors, greater brightness, and greater contrast, therefore giving you just a better picture on your smartphone. Now, there are different competing standards and ideas about exactly what HDR means and whether a display qualifies to be called an HDR display.

Really, there are three important ingredients when it comes to HDR displays. The first is the brightness - the display has to be able to offer a high level of brightness. And that's because actually, you want to have a good level of contrast. Contrast is the difference between the brightest pixel on the screen and the darkest pixel on the screen. So, obviously, the brighter you can get the screen, and the blacker you can get the blacks, then the greater the contrast. Brightness and contrast together give that kind of sharpness that you want in a display.

Once you have a bright display with good contrast, the next thing you need is some vivid colors. Colors are just made on our smartphone displays using a combination of red, green, and blue RGB - each one of those colors has eight bits of information, so that's 256 types of red, 256 types of green, and 256 types of blue. When you combine them together, you get an overall of just over 16 million colors. Now, the human eye can see more than 16 million colors.

The HDR is recommending the use of a new color space called Rec 2020 - it defines an area that takes in about 76% of the visible spectrum. To get that level of color, we need to move beyond eight-bit encoding of the colors into ten bits or twelve bits. When you're in ten-bit encoding of color, there are now a thousand types of red, a thousand types of green, and one thousand types of blue - combined together, you get over a billion different types of color.

To get the most from an HDR display, you need to watch HDR content. If a movie or TV series you're watching is actually encoded using eight-bit color channels, then you can't invent those extra two bits to give you that extra color. You can't create something from nothing, so to actually have full HDR, you need to watch media that's actually been recorded and encoded in ten-bit color or even twelve-bit color.

Now, some video formats don't support ten-bit color channels - MPEG 2 and the format used on Blu-ray don't support ten-bit color. But, there are newer codecs like H.265 and there are profiles for H.264 which means you can have ten-bit color media. So, if you've got ten-bit color media, you've got the brightness, you've got the contrast - then you can truly say that you're watching HDR content on your HDR display.

If you enjoyed this video, please do give it a thumbs up! A quick shout-out to my colleague Robert Triggs who wrote the HDR article that you'll find along with this video over at Android Authority.com. Please don't forget to subscribe to Android Authority's YouTube channel; hitting that Bell icon so you get a notification every time we publish a new video. And last but not least, do go over to androidauthority.com because we are your source for all things Android.