Video and Audio Center Blog



Friday, February 13, 2015

DOLBY VISION — EXTENDING THE VISION


Dolby is known for their audio technologies, but video — not so much. So when you hear “Dolby Vision” you’re not sure if that means some kind of new audio technology to use with video or maybe it’s the name of a TV set? Nope, all wrong. So to find out, we turned to Roland Vlaicu, VP, Consumer Imaging, Dolby Laboratories. He knows what Dolby Vision is all about and soon we will too.

What is Dolby Vision?


Roland Vlaicu: Dolby Vision is an end-to-end ecosystem solution that delivers a dramatically different visual experience—astonishing brightness, incomparable contrast, and captivating color—that brings entertainment to life before your eyes. It achieves this stunning image quality by leveraging breakthrough HDR and wide color gamut imaging technologies, both on-screen and in specially mastered content. As a result Dolby Vision enabled TVs deliver images with much greater brightness while also providing much deeper, more nuanced darks, while rendering a fuller palette of rich new colors never before seen on TV.

To deliver this experience, Dolby Vision augments the video fidelity of Ultra HD and HD video signals used in over-the-top online streaming, broadcast, and gaming applications by maintaining and reproducing the high dynamic range and wide color gamut of the original signal as created during the artistic post production process.

What is the challenge that Dolby Vision takes on?


Roland Vlaicu: One of the challenges in todays system comes as a natural result of the limitations of current TV and Blu-ray standards. The maximum brightness for a movie or game is 100 nits. But modern TVs often have 300 to 500 nits maximum brightness, so TV manufacturers stretch the brightness of the output. This often distorts the images from what the director created. And because each manufacturer stretches the output differently, every viewer will experience a movie, TV show, or game in a different and unpredictable way. Dolby Vision solves this problem. Content creators can now color-grade their content using prototype Dolby Vision reference monitors, which have dramatically higher dynamic range and wider color gamut, to ensure the highest-fidelity mastering. The Dolby Vision picture contains metadata about the system used to create the final version of the content. Because any Dolby Vision television has been carefully calibrated by the manufacturer and Dolby technicians, our technology can produce the best and most accurate possible representation of what the creator intended, even when talking about future Dolby Vision TV that will be able to take advantage of more and more elements captured in the Dolby Vision signal.

Can't such problems be fixed in post processing?


Roland Vlaicu: If the color and dynamic range is not in the original signal, then post processing can never recover them. Too much brightness/contrast cranking gives you washed-out images, because the colorist had to make tight choices during the grading session. Our demos clearly show the difference. Dolby Vision technology allows visual displays to accurately represent a wider set of colors that better match the millions of colors your eye can actually distinguish in real life. By increasing the brightness of the original signal and using a higher dynamic color and contrast range, Dolby Vision presents stunning true-to-life colors and a dramatically different viewing experience that other technologies just arent able to reproduce. Todays advanced cameras capture a tremendous amount of detail, and now you can actually see it.

What's different about a Dolby Vision-enabled TV?

Roland Vlaicu: Dolby Vision-enabled sets are different in that they utilize Dolbys licensed technology, they also use panels and backlighting technology that meets our specs and they also meet the necessary components from our deliverables list. In the case of LCD TVs, improved contrast performance is usually achieved through the use of local-dimming dual-modulation backlight technology. OLED TVs inherently have a better contrast performance which makes them a great target for Dolby Vision.

So content will be mastered at a much higher quality?

Roland Vlaicu: Yes, content will be mastered at a much higher quality level using our reference monitors for Dolby Vision. This currently includes a peak brightness of 4000nits and DCI-P3 color gamut although the system is designed to handle peak brightness up to 10000nits and ITU-R Rec.2020 color gamut. This makes Dolby Vision content future-proof. As Dolby Vision TVs evolve, the content will look better and better from one generation of TVs to the next without having to re-master the content. What this means for the post-production process is that facilities will continue to use their existing color-grading tools by adding a Dolby Vision plug-in that is available for most products. Also, the grading monitor will be replaced by a Dolby Vision reference display. This creates the Dolby Vision master which is delivered via a mezzanine file to distribution partners such as OTT providers or broadcast operators.

In final encoding, the Dolby Vision information is carried via existing H.264 (for HD) or HEVC (for UHD) codecs for playback on Dolby Vision TVs. Existing TVs will be able to display the same quality as today through built-in backward compatibility.

Is Dolby Vision restricted to any particular resolution or screen size?

Roland Vlaicu: At any resolution or screen size, Dolby Vision makes a dramatic difference.  Dolby Vision improves each and every pixel in the picture and consequently the technology is applicable to HD, 4K UHD, 8K and beyond.

U.S. consumer products with Dolby Vision are expected to be seen in the first half of 2015.


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