The Consumer Electronics Association has decided on a name for 4K resolution: Ultra HD. I guess this leaves room for future resolution increases, with names like Uber Ultra HD (UUHD), Super Ultra Definition (SUD), and, of course, Fantastic Ultra Brilliant Amazing Resolution (FUBAR).
But 4K is still largely just an increase in resolution, which is only one aspect of picture quality, and not the most important.
Here are three things more important than an increase in resolution.
What is 4K?
If you haven't read the announcement, Ultra HD is a minimum resolution of 3,840x2,160 pixels, or four times 1080p HD. This increase in resolution is largely irrelevant for the TV sizes most people buy, so don't worry about your new 1080p LED LCD being obsolete anytime soon (or within its likely lifespan). I outline the reasons in my "Why 4K TVs are stupid" and "4K TVs are stupid (still)" articles, so I won't regurgitate them here.
Instead, let's get on to three improvements to picture quality on both the hardware and software side that would have a far more noticeable and worthwhile impact for everyone.
This is, by far, the most important aspect of picture quality. Contrast ratio is the difference between the darkest part of the image and the brightest. It is what gives the image depth, punch, and is one of the main factors in making an image seem "real" and not just a TV. The current 4K TVs are still just LCDs, with their limited contrast ratios.
Plasmas and OLED (whenever we see it) offer far better contrast ratios than LCDs (though the better local-dimming LED LCDs come close). Future 4K plasmas and OLEDs will offer the best of both worlds, but all technologies could use improvement on this front. For more info on what contrast ratio actually means, check out "Contrast ratio (or how every TV manufacturer lies to you)."
Bottom line: Improved contrast ratios will offer a more realistic image than a low contrast, but higher resolution, image.
On the content side, Blu-ray is great, but it's not where most of us get the majority of our content. Cable, satellite, and streaming all offer far more shows/movies, but at a significant cost: compression.
In order to fit HD in as small a "pipe" as possible, providers heavily compress the HD signal. This usually results in an image far worse than a more lightly compressed image (like from Blu-ray or over the air). Potential issues include a softer image, noise, metablocking, and more. Even on smaller TVs, the difference between Blu-ray and streaming can be significant. For that matter, most streaming services still only stream 720p, not 1080i (which is the same resolution as 1080p)
Improving the compression techniques, or reducing the severity of the compression (most likely by improving bandwidth), will allow for a better signal to be transmitted, i.e., a better-looking image at all resolutions. For more on this, check out "When HD isn't HD."
In reality, this will have to happen. People with big, new Ultra HDTVs are going to be disgusted with the sorry state of 720p/1080i over cable/satellite, just as HD owners continue to rail against poorly upconverted standard definition programming.
Bottom line: Less compression (or better compression) will result in a better image across all resolutions and all TV technologies.
Of the three improvements here, color is the most likely to get addressed. The current HD spec allows for up to 16.7 million colors, but is fairly limited in many ways. There are many colors impossible to reproduce on modern HDTVs.
The problem is, unlike contrast ratio and compression, improving color involves a radical change in the current TV infrastructure. Cameras must be able to record the wider gamut/bit depth, it has to be stored/transmitted, and then, of course, your TV must be able to display it. Fortunately, a radical change is exactly what's necessary to transition to 4K/Ultra HD, so let's hope this opportunity isn't lost for more realistic color.
Bottom line: It needs a top-to-bottom (or more accurately, camera-to-home) upgrade, but more-accurate color is the next most important aspect of overall picture quality after contrast ratio. Making it better will do wonders for realism.
The three above things all would improve the image far more than just bumping up the resolution. However, higher resolution is easier to market, and by extension, easier to sell. With manufacturers already hyping (lying) about "zillion-to-one" contrast ratios, where is there to go? Color and compression need explaining (so that's out). That leaves "Ultra HD" or Sony's redundant "Ultra HD 4K" redundancy.
In huge screen sizes, 4K is great. For passive 3D, 4K is great. But like I've said before, in the TV sizes most people buy, and at the distances most people sit, 4K resolutions are overkill. And, of course, there's still no readily available 4K content, but like I've said before, that's the least of the problem.
Higher contrast ratios, less/better compression, and better color would all be far greater improvements in picture quality for everyone, regardless of screen size.
Got a question for Geoff? Send him an e-mail! If it's witty, amusing, and/or a good question, you may just see it in a post just like this one. No, he won't tell you which TV to buy. Yes, he'll probably truncate and/or clean up your e-mail. You can also send him a message on Twitter: @TechWriterGeoff.