While the mainstream and not-so-mainstream press may be all aflutter over 4K, there still is no consumer or home standard. At best, early 4K adopters, on both the manufacturing and the consumer sides, may have to contend with growing pains. While it’s almost certain that our consumer 4K resolution will not be the same as true cinema 4K, instead defaulting to a more 16:9 aspect ratio-friendly Quad Full HD or QFHD, there is more to the 4K equation than resolution (man, am I starting to sound like a broken record).
It’s true: there is more to 4K than resolution. In fact, resolution is the weakest argument for 4K that I can think of. In a recent test, from reasonable distances (six or more feet) on a 100-inch screen, there was little to no difference in perceived quality when viewing 4K content over 1080p. What did make a difference in perceived quality were light output, color fidelity and contrast. Well, the 4K standard calls for higher bit-depth, 12 over our current eight, which allows for a broader color space and heightened contrast. For example, viewers of modern HD are no doubt used to suffering through banding, either in a film’s subtle color or low-light gradations, which is a direct result of HD’s 8-bit scheme. With 4K banding should be all but eliminated due to its 12-bit scheme and CIE color space, which, if I’m not mistaken, run the gamut of what the human eye can perceive in terms of color and contrast. But again, no consumer 4K standard has been ratified … yet.
One of the things that has to get hashed out is which compression standard to use. When it comes to digital cinema, the compression standard is JPEG2000, which is a fantastic compression method for high bit-rate transmissions, such as cinema 4K. However, JPEG2000 encoded content, in this case, the visual package of a film, is rather large, too large in some cases for Blu-ray and much too large for streaming, which is our future. As a result, much of what we view in our HD world today, including Blu-ray, is encoded using the compression standard H.264. H.264’s aim is to maintain high perceivable video quality while lowering bit rates, thus allowing more data to fit onto a disc and/or be streamed more easily. H.264 has permeated the marketplace and can be seen/used everywhere from YouTube to Blu-ray discs. H.264 is a good standard, though it lacks the chops to deliver 4K with the same fidelity as, say, JPEG2000.
Enter the next evolution of h.264, H.265. H.265 (or High Efficiency Video Coding, HEVC) is currently under development by both ISO/IEC Moving Picture Experts Group (MPEG) and ITU-T Video Coding Experts Group (VCEG). H.265 is said to improve perceivable video quality by effectively doubling the data compression ratio compared to H.264, without resulting in too large a file size. H.265 also will have support for resolutions up to 7680 x 4320, i.e., well over 4K resolution. H.265 is said to also allow for improved picture quality through the use of lower noise levels, wider color gamut (good news) and greater dynamic range (also good news).
H.265 is still under development, though a standard is said to be looming on the horizon, with some putting it as early as January or February of 2013. H.265 is sure to play an important role in the formation of a consumer 4K standard, as well as improving our streaming video experience. However, since H.265 isn’t scheduled to be complete until early next year, it may help put a home or consumer 4K standard into better perspective – i.e., a feasible delivery date. It is possible for a 4K standard to be ushered into existence under the current H.264 standard(s), but doing so would no doubt rob the viewer of much of the viewing experience, since H.264 lacks H.265’s ability to encompass higher bit rates, broader color spaces and increased dynamic range (contrast). There’s a lot still up in the air and no doubt plenty left to be mucked up. After all, we have never been treated to a full HD experience, even with the advent of Blu-ray disc, but I’m still hopeful that 4K can be brought to market correctly. However, if it turns out to be a simply a higher resolution version of what we currently have with Blu-ray, I may explode. 4K has so much more to offer than that, yet somehow corporate politics and egos tend to get in the way of doing the right thing when it comes to setting AV format standards.