Towards the end of last year, the Video Electronics Standards Association (VESA) announced an open HDR standard with three levels of certification—DisplayHDR 400, DisplayHDR 600, and DisplayHDR 1000. Now it's rolling out a new software testing tool to help verify certain parameters on monitors that bear one of those badges.
The initial tool is aimed at "professional and lab-level users" who want to test and evaluate their HDR displays. It uses a command line interface rather than a spiffy GUI that users might find more user friendly, and works with off-the-shelf calibration colorimeter tools.
One of the biggest parts of the DisplayHDR standard is peak luminance measured in nits. The corresponding number in each of the three tiers refers to the peak nit rating, so for example monitors bearing the DisplayHDR 400 badge must be capable of hitting 400 nits. Only one monitor so far is DisplayHDR 1000 certified, that being the recently introduced Philips 436M6VBPAB, a 43-inch 4K monitor with a 60Hz refresh rate.
Brightness is not the only determining factor, however, as there are other requirements that VESA lays out. The way the tool works is it projects various display patterns onto the screen, which are then interpreted by the colorimeter. Here are the parameters that the testing tool takes into account:
- Three peak luminance tests (small spot/high luminance, brief period full-screen flash luminance, and optimized use in bright environments).
- Two contrast measurement tests (native panel contrast and local dimming).
- Color testing of the BT.709 and DCI-P3 color gamuts.
- Bit-depth requirement test (stipulates minimum bit depth, confirmed via a simple visual test).
- HDR response performance test (analyzes the speed at which the backlight can respond to changes in luminance levels, a key parameter for gaming and rapid action in movies).
The tool appears to be a free download in the Microsoft Store. VESA says it plans to release a consumer version that ditches the command link interface for a GUI later this year. The next release will also include a list of colorimeters that VESA recommends using.