Measure the Right Thing the Right Way


by Thomas G. Fiske

At the beginning of 2009, we find ourselves facing challenging financial times and a troubling business climate. The free-wheeling fiscal orthodoxy of the past several years has fallen on hard times as we live through a disconcerting and unsettling period of turmoil in most of the world's financial markets and in many areas of business. And we are also in for a rethink in the world of politics, as a new U.S. administration and Congress take power in Washington this month. At the risk of overusing a tired phrase, we are in the midst of a paradigm shift of significant proportion – at least where money and politics are concerned.

In the field of electronic displays, we are constantly confronted with new technologies, applications, and manufacturing processes. While perhaps not as significant as the new realities in the financial and political spheres, the new technologies in the display world necessitate some new thinking in how we supply these new technologies, introduce new applications, and create and address new markets. One necessary part of this new thinking is the area of display-system evaluation and measurement – and how to relate those objective physical measurements to the human visual system in particular and the overall human experience in general.

In this issue of Information Display, we feature this year's installment on display measurement and characterization. We have contributions from experts in the rapidly expanding field of 3-D displays and high-dynamic-range (HDR) displays. There is a proposal about how to measure small-area character contrast, plus a timely suggestion regarding how to maximize your enjoyment of that new flat-panel HDTV you found under the tree last month.

Two articles in this issue address 3-D displays: one from a measurement perspective and one from the viewpoint of human perception. Nokia researchers Marja Salmimaa and Toni Järvenpää describe a preferred measurement methodology for autostereoscopic displays and review the status of several standardization efforts around 3-D display measurement and characterization. Professor Martin Banks and co-workers from the UC Berkeley School of Optometry and the Center for Neural Science at New York University discuss how the human observer perceives stereo pictures. They conclude that 3-D perception of stereo pictures depends on viewer position relative to the display screen. This position-related effect for 3-D perception is much stronger for 3-D pictures than for 2-D pictures and has significance for designers of stereo viewing systems. Digital 3-D cinema providers take note.

Anders Ballestad and his colleagues at Dolby Laboratories in Canada present an article about the characterization of HDR displays. The conventional metric of contrast ratio makes little sense when you are are essentially dividing by zero (unless, of course, you are in marketing, where the big, impressive contrast numbers look good on your product brochure). The engineers at Dolby present a more relevant and perceptually meaningful metric based on static- and dynamic-halo artifacts.

We are treated to another fine article from display-measurement expert Edward F. Kelley of NIST. Known for his engaging writing and speaking style, he relates some important (and doable) suggestions about how to obtain meaningful measurements for the contrast of small, dark characters on a light display surface.

Finally, HDTV expert, writer, and speaker Pete Putman offers eminently practical advice about the need for HDTV calibration. He provides the definitive answer to the age-old question: "Do I need to spend the extra cash to have my HDTV professionally calibrated?"

We've presented articles here that provide guidance for characterizing some of today's newest and most exciting display technologies from some of the best experts in their fields. I hope that you find this year's display measurement issue lively, compelling, informative, and relevant.

Have a happy and healthy New Year. Play hard, work safe, do good, and be well. •


Thomas G. Fiske is a Principal Systems Engineer at Rockwell Collins Display Systems in San Jose, CA; e-mail: tgfiske@rockwell His primary interest is in display technology development and metrology.