The Society for Information Display LA Chapter held its 14th annual One-Day Conference on February 3, 2017 at the Costa Mesa Country Club in Costa Mesa, California. At the conference, Gerard Catapano gave a presentation entitled “HDR, Today into Tomorrow.”
Catapano, formerly Associate Director of Electronics Testing at Consumer Reports and now Director of Quality Assurance at Samsung’s QA Lab in Pine Brook, New Jersey, introduced high dynamic range (HDR) as “the latest and most innovative technology that helps film studios deliver a better expression of details in shadows and highlights to the consumer.” He presented the Consumer Technology Association’s definition of an HDR-compatible display as one that has at least these four attributes:
- Includes at least one interface that supports HDR signaling as defined in CEA-861-F, as extended by CEA-861.3.
- Receives and processes static HDR metadata compliant with CEA-861.3 for uncompressed video.
- Receives and process HDR10 Media Profile from IP, HDMI, or other video delivery sources. Other media profiles may be supported in addition.
- Applies an appropriate electro-optical transfer function (EOTF) before rendering the image.
The HDR definition has been endorsed by a variety of organizations, include the Blu-ray Disc Association, MPEG, the UHD Alliance, and the ITU. Although HDR is currently a premium feature, Catapano predicted that it will become a basic feature of TVs over all screen sizes and display technologies.
Samsung TV is supporting only the HDR10 media profile because it is an open standard that does not require licensing fees and, as a result, permits customization within the profile. Since use of at least HDR10 is required by the CTA definition of an HDR-compatible display, it will be supported by all major manufacturers. Although Catapano didn’t say so, some of Samsung’s competitors also include Dolby Vision, and in its new “Wallpaper” OLED TV, LG also includes hybrid log-gamma (HLG) HDR for a total of three HDR profiles.
Catapano noted that at NAB 2016, the major encoder manufacturers were offering 4K HDR as an option, and the major mastering and editing tool sets were implementing it.
Dynamic Metadata?
I apologize for the delay, but here’s where I finally get to the content promised in this column’s title. The CTA definition only requires HDR sets to support static HDR metadata: metadata that is constant throughout the entire film or video. But much more can be done with dynamic HDR metadata, which changes scene by scene. SMPTE ST.2094-40 provides for dynamic metadata for tone mapping.
Tone mapping is a key technology in HDR TVs, Catapano said. It is a color-volume transform that renders incoming HDR content for a display having a dynamic range that is smaller than that for which the contents were coded. With static metadata, the only way to compress the scene with the greatest color volume so it fits into the set’s color volume is to over-compress the much larger number of less demanding scenes.
With dynamic metadata, each scene can be optimally compressed, with that result that many scenes will not require color-volume compression at all. Catapano observed that Samsung HDR TVs for the 2017 model year “are ready for ST.2094-40.”
In the Q&A, Catapano answered a question by saying that HDR works best with movie mode, which he recommends for general viewing, at least with Samsung TVs.
Now, when you go into Costco or Fry’s to buy your next TV set, you can ask the sales associate whether the set supports SMPTE ST.2094-40. I look forward to hearing how that conversation goes.
Ken Werner is Principal of Nutmeg Consultants, specializing in the display industry, manufacturing, technology, and applications, including mobile devices and television. He consults for attorneys, investment analysts, and companies re-positioning themselves within the display industry or using displays in their products. You can reach him at [email protected].
