Why HDR matters more in VR and AR
High Dynamic Range (HDR) is a term that is used in relation to describing the increased area of variation in both color and brightness made possible by displays that support it. HDR comes in a confusing handful of standards, HDR10, Dolby Vision, Hybrid Log Gamma, Advanced HDR and most recently HDR10+. What matters is that all of theses standards are mapping colors across an increased 'color space'. In the image above the smaller 'HDTV' triangle represents the colors that can be displayed using the 'Rec. 709' color area standard that was developed in the mid-to-late 1990s, for Standard Dynamic Range displays. The larger 'UHDTV' triangle represents the 'Recommendation ITU-R BT.2020.' color area (Rec. 2020) that HDR televisions aspire to cover. Color But wait! The image you are looking at is not an HDR image, and the display you are reading this on may not be an HDR display, your computer/phone is probably not rendering to a HDR framebuffer (10 bits or 12 bits per RGB channel instead of 8), and your browser is probably not capable of displaying HDR content. So the colors you are seeing above are in reality all being mapped within the 'Rec. 709' standard color area, the smaller triangle. If you could see the image in HDR it would look much more vivid. But since you cannot, lets at least examine quantization in relation to the '8 bits per channel RGB frame buffer' that displays use. 8 bits yields 2^8 = 256 possible values per channel, which makes '256 reds * 256 greens * 256 blues' possible. This results in a total of 16,777,216 possible colors. That sounds like a lot! And yet actually it is only going to contain 256 possible grey-scale values (0, 0, 0 through to 255, 255, 255). If you look carefully at the image above on a large display, you'll...