Stimulating the human eye: Creating true-to-life displays
The human eye is the most dynamic, highest-resolution biological optical sensor in the world. It has biological sensors embedded in strategic physical locations with real-time adaptable sensitivity to impact us every second of our waking life. The more realistic we sense that escape with our eyes, the greater the stimulation of the eye sensor and the greater the enjoyment of the experience. The largest impact in creating true-to-life images over the past 20 years has been resolution. These changes have occurred in the home with television and computers as well as at the theater. We have all experienced the increasing trend in resolution improvements for both digital cinema converting from film to enjoyment in our home television. We have also moved from DVD standard resolution to HD (2k), and today to UHD (4k) and have seen demonstrations of soon to be available 8K systems. As amazing as the eye performs, it will have a difficult time seeing more value from >8K. But everyone must realize there is more stimulation the eye can sense, and it is imperative that we as an industry provide that greater stimulation; taking advantage of sensory systems and the true-life of the display. High Dynamic Range High Dynamic Range (HDR) image capture exits and is ready to be exploited. Although, HDR replication on a display that matches nature is still out of reach, it is moving forward quickly. Demonstrated capabilities will continue to evolve and change the visual world in display visualization and both Augmented and Virtual Reality (AR VR). Innovation is moving rapidly. The human visual system can detect stars in the sky with brightness over 1 million times dimmer than the light a person experiences in a normal room. The human visual system can also support creating visible images in outside bright sun-lite environments that are 10,000 times brighter than a normal room. This incredible capability leads to great opportunity as well as great challenges in attempting to create displays that stimulate the eye sufficiently and recreate natural or true- life images. However that said, the current displays do not produce images as dark as the eye can manage, and do not produce images as bright as the eye can manage. Much of the eye’s capability is not even being activated. Researchers have determined that a range of 4 to 6 orders of magnitude referenced in candelas/meter squared (cd/m2), is possible to be experienced at one time by the eye in normal room lighting. True HDR displays for digital Signage solutions will be created by capturing content with High Dynamic Range imaging systems and presenting that image to a display with a High Dynamic Range reproduction capability. HDR experiences can be accomplished when two ends of the system can support each other, capturing and displaying the wider dynamic range. The systems of greatest applicability are 10 bits and 12 bits for RGB. There are displays in LCD and OLED currently in development, and they come very close to capturing and reproducing HDR in a large area display system for the consumer. Now we must extend that capability to LED. Netflix and Amazon have enabled these HDR video bit streams, and recently VUDU joined with their offerings. The name of the two standards have been adjusted by manufacturers, but are generically called HDR10 with specific names of HD1000 by Samsung and Dolby Vision by Dolby. Both standards can be encoded from the original master copy of the content created in production by the studios. One uses 10 bit encoding for their steps of gray scale, while the other uses 12 bits of encoding for the grayscale. HDR10 will possess 4X the bit depth (grayscale steps) of the content you normally watch on your HD TV. And so for every pixel in the TV, whether it is 2K or 4K, the pixel will have adjustments of 4 times as many steps. Dolby went a step further. Dolby Vision encoded content will have 4X the grayscale of the HD10 solution. Before you panic on standards differences, both are compatible with the SMPTE 2084 standards. Also, UHD TV chips with HDR that handle all standards are already deployed into high-end televisions. Remember that HDR10 was one standard; and for that standard the display is expected to support 1000 nits. That is 2-3X the brightness of a typical LCD TV or OLED TV. The major differences are in 10 bits and 12 bits, and the maximum peak brightness of the display. With those 2 extra bits, Dolby is able to maintain all the beauty in the darker images as HDR10, but it also has 2 extra bits to tell the display to reproduce even brighter white, at ~4000 nits (4X brighter than HDR10). For consumers, while display inputs may be 100% compatible with either standard, the more important issue is the display peak brightness. Commercial LED displays can currently meet the brightness capabilities in 4K resolution. Designs are being implemented to support true linear grayscale as well as peak brightness from this LED emissive display solution from theater systems, replacing projection to high-end consumer products. The future of HDR is now certain to expand into all large screen entertainment displays, especially tiled seamless LED. The SMPTE industry standards are set, and the rich infrastructure of hardware and content allows all product developers to move as quickly as possible to bring new products to market that impact the consumer. Industry leaders in content and display will join in collaboration to have solutions in the market for theaters and executive boardrooms. The time for HDR is today. The impact to the consumer and now the commercial industrial market is moving toward true life images in everything we view. Innovation has brought us another revolution in impact; a display that can really stimulate our senses.