A few year ago, Ultra High Definition (UHD) was just an idea and today it’s on the verge of widespread adoption, says Sean McCarthy Ph.D., Fellow at ARRIS.
Equipment is emerging, content is in development and consumers are expectant. The stage is set for another TV evolution.
UHD changes the game by offering more pixels and therefore more detail for bigger screens. Add in High Dynamic Range (HDR) and there's an even more impressive array of colors, contrast and depth.
Many service providers are already making their future intentions clear. With UHD TVs already commonplace in retail stores, an appetite for content is building. With this in mind, the likes of Sky, Virgin Media, NOS, DirectTV and BeIN have all announced or launched UHD services. Some 78% of video service providers say they will have launched 4K UHD content by 2018, according to an SNL Kagan Irdeto report.
HDR is part of the wider UHD growth trajectory. And although it's still an emerging technology, some providers are already rolling out compliant set-tops. HDR TV shipments are only going to increase and OTT players are already raising the bar in terms of content. Netflix and Vudu are among those leading the field.
There are actually different forms of HDR in existence that deliver content to customers in slightly different ways. They all transfer linear light from the picture captured by the source camera. It’s then delivered to the TV display through a process of compression, encoding, decoding and rendering. But because this can be done in different ways, there are concerns of a format war. The truth is that because of the emergence of streaming media, the differing HDR transfer functions can coexist because there are advantages for each.
For example, the Perceptual Quantizer (PQ) formats - HDR10, Dolby Vision and Technicolor Philips - are ideal for controlled environments. This includes non-live studios and cinematic content where post production can enhance the picture. The Hybrid Log Gamma (HLG) format, however, is at its best in live studios and outdoor events.
The good news is that the International Telecommunications Union (ITU) has announced a standard that allows us to convert between the two. We can now gain the advantages of both. And the flexibility for studios, operators and consumer electronics manufacturers will benefit the industry.
With all the content providers, formats and equipment companies how exactly do you measure UHD quality? It's a question that still doesn't have a comprehensive answer but it's one that researchers are looking into. The UHD Alliance has galvanized the major TV players such as Sony and Panasonic and this will help inform consumers. But the best academic means of measuring quality is still up for debate.
Various tools such as peak signal-to-noise ratio (PSNR) and the structural similarity (SSIM) index already exist. But the tools that work well with SD and HD formats don't always capture the nuances of HDR. Studies are looking at new metrics and they're making progress but the goal should be simplicity. They should aim to develop UHD HDR video quality metrics that are easy to calculate and provide information that companies can act on.
What UHD is really about
UHD isn't about impressing consumers with bulging spec sheets. The reason the technology will gain ground is because it enables creatives to tell better stories. And for the viewer, it's about offering them a better experience that's even more compelling than HD. With that comes a fantastic opportunity for providers to offer a premium service.
As technology providers, we're helping to get the infrastructure in place that will enable the growth of UHD and the evolution of home entertainment.