Is an 8K User Interface Necessary?
When we read on 9TO5Google that Android TV 12 is finally supporting 4K User Interface (UI) rendering, we sighed a sigh of relief at the 8K Monitor. Indeed, this Google announcement means that the TV UI will eventually leverage four times the screen real-estate as it can when rendered in HD. This jump in resolution represents an exciting steppingstone towards an actual 8K-rendered UI in the future. But what does it take to create an 8K UI – and is one needed? To find out, we reached out to Pascal-Hippolyte Besson, CEO of DOTSCREEN, a French company that has been building TV UIs for a decade.
First, is there any benefit from higher resolution UIs? The UI is the first thing a consumer sees when they turn on their TV, so making a good impression with crystal clear images and graphics seems like a good idea – especially when unboxing a new TV or upgrading a set-top box.
An 8K UI will require more processing power, especially with higher refresh rates (typically used when displaying live sports). But how can this be accomplished?
Besson explained that the UI is not handled within a specific UI layer from the TV’s graphics processing perspective. Upscaling of the UI is done as part of the regular video processing pipeline. This limitation is a shame because the upscale could be more efficient if it knew it was working on only UI elements. In other words, upscaling even simple UI overlays is as work-intensive as upscaling a complex video stream. Video upscaling technology has progressed in leaps and bounds over the last decade, but it remains dependent on significant processing power. Besson went further, noting that “a pristine 8K video can also be severely degraded in some cases when a UI element is superimposed on it.”
Despite TVs not being able to treat the UI within a specific processing layer, we noted in passing that Android 12 has improved support for background blur. This welcome enhancement will enable crisp images to be seen behind UI elements without making it harder to decipher the text displayed by the UI. This improved blur should enhance the visual separation of layers within the UI, enabling TV experience designers to be more ambitious to exploit more screen real estate.
But what’s the visible artifact of UI upscaling issues in the world of high-end, high-resolution TVs? As Stephen Reeder pointed out a few years ago, in an ekioh blog: video upscaling can “mean that any text and graphics in the video stream, such as football scores, are visually sharper and clearer than the TV’s own menus and app UIs.” The image below from the ekioh site illustrates his idea (I artificially re-pixelated the inserted menu slightly to illustrate the point more forcefully):
4K TVs have been providing a four-fold upscale to HD-rendered UIs for almost the last decade. We can expect UI rendering in 4K to become and remain the norm for several years to come. UI rendering in 4K instead of HD will enable the 8K ecosystem to live with a 4x upscaled UI and avoid a less sustainable 16x upscale.
Besson further noted that Google’s announcement came when Microsoft announced a 4K UI for the Xbox, pointing to an emerging trend in higher resolution UIs.
Besson doesn’t see upscaling text as particularly urgent for the big screen experience as resolution doesn’t improve text that much from over 6 feet away. However, when pressed further, he said that “a symbol with an oblique line will always look better at higher resolution, so the text could still feel crisper. The fluidity of the user experience and the overall realism are improved when text and video are natively of similar resolution. Our UI developers are always trying to remove as much text as possible, except for elements such as news tickers.”
When asked about the relevance of refresh rates, he brushed the issue aside as there is not much movement within UI elements, except perhaps some minor animations.
However, screen size is more impactful for UI design, even more so than the number of pixels. A large screen can be separated into multiple screens. When watching sports on Canal+’s myCanal multiscreen app, all the extra real estate on an 8K screen could be utilized, for example, for statistics overlayed by the UI onto a match showing in just one quarter of the screen.
Similarly, watching Netflix, CNN and keeping an eye on social media while playing a console game on the same 8K screen could justify a UI rendered at higher resolutions. Some of the latest 8K TVs already have features to make this sort of use case a reality today, even if your provider’s UI doesn’t yet support it. Samsung 8K TVs, for example, offer a « Multiview » capability allowing four 4K windows to be displayed on the screen simultaneously, each showing content from four different sources.
Besson finished our brief chat, pointing out that “a UI rendered in 8K will require a powerful CPU and more bandwidth as vignettes will be much larger. With a 16 X jump from HD, the UI could even become a data-intensive app.”
The takeaway from this discussion is that as screen sizes grow and the use case for multiple windows of content increases, the need for a higher resolution UI increases. But TV makers may want to consider architecture changes that can allow a better pipeline to optimize the UI without compromising the video quality.