A Gamut of Opinion
by Steve Atwood
When Martin Kytka, Senior Research Scientist with Uni-Pixel Displays, first approached me with the idea of writing an article that would tackle the complexities of dynamic range in displays, gamma correction, and viewer perception of brightness and luminance, I was really excited. While the current North American Digital TV standard provides for a maximum of 256 gray levels per primary color, there are many new TV displays capable of 1024 or more levels per primary. With some type of temporal dithering scheme in high-frame-rate systems, this dynamic range can be extended even further.
Many in the display industry, as well as those on the content creation side, think there is a real opportunity to create a better user experience with extended-dynamic-range systems. Author Walter Allen of WalVisions summarizes this point of view well in this month's opinion piece, "An Appeal for More Bit-Depth in Displays." So naturally, if we are going to design systems with wider dynamic range, how are we going to map those levels to luminance values that will provide the best viewer experience? Well, that's the question Kytka is attempting to answer with his article "Gamma, Brightness, and Luminance Considerations for HD Displays" in this issue. Drawing on his experience with the DICOM standard, which is used to calibrate medical radiology displays (with well over 2000 distinct gray levels) for diagnostic purposes, he proposes that the same standard has some distinct advantages as a potential baseline for commercial high-dynamic-range HDTV displays.
What I did not know when I first discussed the article with Kykta was the wide range of opinions that exist with regard to this topic. It is complex and encompasses several fundamental fields of science, ranging from classical signal processing and display optics to human vision science and psychophysics. The science itself, the math, the prior art, and the previously published experimental research all weave a complex fabric of understanding as well as misunderstanding, allowing for many differing interpretations. Because the end result boils down to what we "see" and how we feel about it, we cannot avoid attempting to personalize the science and draw on our own experiences, either professional or personal, to rationalize the data. A natural bias often emerges, and some aspects of the science are therefore harder to digest than others.
We asked many knowledge experts in this field, including our mutual colleagues, for their points of view and we got them! I am grateful to everyone who took the time to weigh in on this topic. Our subsequent goal was to present an analysis, draw some conclusions, and provide an opinion about how this information can help guide future system designs. I am very pleased with the result and I think it will help drive discussion for further development and possibly a new baseline for future work. Additional analysis and differing points of view are always welcome and I look forward to this being a continuing subject in future issues of ID.
Meanwhile, I've had a lot of other things keeping me awake lately, and contrary to what you might think, the recent DTV transition in the U.S. is not one of them. My thoughts are on a different aspect of TV – 3-D TV, in fact, because that is the topic of our cover feature stories for this month; two compelling articles addressing the future for 3-D entertainment in the home – your home, my home, and anywhere else you could envision. Guest Editor Brian Schowengerdt has worked with us before and we are grateful to welcome him back, and for his extraordinary effort this year in producing these articles. (Be sure to read his guest editorial on the state of the industry.) In "3-D Displays in the Home," author Andrew Woods, a consultant and research engineer at Curtin University's Centre for Marine Science & Technology in Perth, Australia, takes us through an excellent survey of the various television display systems available to consumers today that are capable of showing 3-D content. He also provides an educated glimpse of what may be coming soon. I was surprised to learn that there are a lot more options available right now than I was aware of and that the new innovations could make a compelling experience for consumers quite soon. Meanwhile, author William Zou, chairman of the Society of Motion Picture and Television Engineers Task Force on 3-D to the Home, presents "An Overview for Developing End-to-End Standards for 3-D TV to the Home," which describes in amazing completeness the entire landscape of 3-D content creation and standards to date. Rather than trying to summarize it for you, I'll suggest you dive in and appreciate the unique perspective he brings to the subject. Together, these two articles make me really excited about the prospects for a truly compelling home 3-D experience and I declare once again that there has never been a more exciting time to be in the display business!
With that along with our regular Industry News on developments announced in and around the Display Week Conference last month, this issue is a wrap. While we do not yet have a way to bring the magazine to you in 3-D, I hope you find it a unique experience nonetheless. As always, we welcome your feedback and suggestions on these or any other topics related to displays. You can reach us by email at email@example.com. •