4K TVs are everywhere, and they're getting bigger. In recent years, there has been a resolution revolution as Full HD TVs have all but disappeared to usher in the new age of TV technology and many upgraded 4K TVs.

4K may have been a cutting edge new television technology a few years ago, but now 4K TVs are really popular and make up nearly 50% of all TVs shipped worldwide. Each one has a resolution of 3.840 x 2.160 pixels, which is equivalent to eight megapixels. It's much more detailed than the measly two megapixels offered by Full HD TVs.

So why are some 4K TVs so disappointing?

That's because even if you have a 4K TV, that doesn't mean everything you watch is 4K.. In fact, unless you have an Ultra HD Blu-ray player, a premium subscription to Netflix, or 4K TV channels delivered to your TV through a 4K decoder, having a 4K TV makes no difference to the quality of your TV. what you are seeing. What this means is that most of us record the same quality of video that we used to watch.

This is where 4K upscaling comes into play, which all 4K TVs will have to some degree. This improves the appearance of standard definition and high definition television channels, DVDs and streaming videos when they are larger. Here's everything you need to know about 4K upscaling when buying a 4K TV.

Samsung q90t

(Image credit: Samsung)

Why do we need 4K upscaling?

Because there is a “content deficit”. While we are now firmly in the era of 4K television, we certainly don't all watch 4K content., and Full HD images on a 4K panel won't look better, just bigger, without the help of intelligent scaling.

"If you have a Full HD picture on your TV and you don't scale it, it will only take up a quarter of the screen," says Gavin McCarron, manager of technical product marketing and planning at Sony Europe. Then I'd be surrounded by a blank screen. What does the upscaling process do to ensure that the image fills the screen's 4K resolution? "

How does 4K upscaling work?

Adapting an HD image to a 4K screen involves several steps. “It starts with an analysis of the received signal to determine what type and resolution it is: live TV or streaming, HD or Full HD,” says Deep Halder, Senior TV/AV Product Manager, Samsung UK & Ireland. “Next is noise reduction. Edges, textures and details are analyzed and refined accordingly. Finally, the signal is converted to 4K to match the native resolution of the panel." It is an incredibly complex process that requires powerful processors.

"The picture comes to the TV first from streaming, Blu-ray, streaming service, etc., and its quality is analyzed," says McCarron. "Sony uses a system of databases that are used to compare the appearance of different elements in this image, and once that evaluation is made, the image is scaled to what we say is a quality" close to "4K" " .

Panasonic HZ1500 OLED

(Image credit: Panasonic)

Sony says its "lens to the living room" approach is unique in that it leverages Sony Picture's extensive experience in film and television production, as well as its expertise in manufacturing 4K video cameras used by the film industry. television and cinema.

"When you go from Full HD to 4K, there's a lot of guesswork and what we're trying to do is take the guesswork out as much as possible." Sony's 4K X-Reality PRO, like other image processors, scales at the pixel level. "It doesn't just look at the pixel in isolation, it looks at pixels around it and on each diagonal, and it will also look at pixels across multiple images, to give consistency in image quality," says McCarron.

It is also essential that scalers can differentiate between MPEG / noise artifacts and details, as the latter do not need to be scaled. Climbers are also looking to improve local contrast and color in video.

How to test 4K upscaling in the store

If you are considering buying a TV from a physical store, be careful. All the televisions you see in stores are turned up in brightness to "look better."

They're set to be much, much brighter than you'd ever want a TV to appear in your own home. So when you have removed the remote from the provider, immediately change the picture mode from "vivid" to "natural" or "cinema". Then ask to see something that isn't in 4K. The store really wants to show you what 4K looks like on a 4K TV, which makes sense to them, but since most of what you'll see won't be 4K, they insist on live TV.

Any high definition channel you find will probably look good. These are the non-HD channels you need to worry about; These may seem mediocre without a decent scale.

Sony Master TVs are equipped with the X1 Ultimate processor. Credit: Sony

Sony Master TVs are equipped with the X1 Ultimate processor. Credit: Sony

Which TV brands offer the best 4K upscaling?

Hard to call, but generally speaking, the cheaper the TV, the less likely it is to have advanced 4K upscaling. You can see this in posts from all the big brands, who are investing heavily in their various image processing engines, some of which are reserved for their flagship TVs. For example, Philips has Ultra Resolution and its P5 processor, while Sony has 4K X-Reality PRO for its regular 4K TVs, for its Master series, X1 Ultimate processing. Samsung offers the UHD picture engine, while LG has the Picture Master processor and, in its OLED TVs, the Alpha 9 processor.

How do you take into account the size of your television?

Well, all image processing suites are committed to making all kinds of video look good on 4K screens. So is it fair to say that the bigger the TV, the more advanced the scale needs to be and the more powerful the processor needs to be?

"It will make a big difference the bigger the television," says McCarron. "Pixel density is higher on smaller screens, so it's not as critical."

Samsung uses the 8K AI enhancement in its Q900R 8K TVs. Credit: Samsung

Samsung uses the 8K AI enhancement in its Q900R 8K TVs. Credit: Samsung

What about the 8K magnification?

If you think Full HD at 4K is tricky, the birth of 8K TVs just upped the ante.

So far, the 900-inch Samsung Q8R 85K QLED TV is all we've got to go, but it's fair to say that its so-called 8K AI Upscaling appears groundbreaking as it uses machine learning, a form of AI.

"Millions of samples are evaluated, often comparing good and bad quality images of the same objects," says Halder. "The differences between the two (noise, blur, compression, and artifacts) are analyzed (and) the result is an algorithm that accurately calculates how to improve the appearance of a low-quality image." This information is then placed in a database built into the TV processor for future use. "Regardless of the source of the image (SD, HD, UHD), the TV has the information it needs to determine for itself how the image should look on a native 8K screen."

So as screens get bigger in both size and pixel density, the future of scaling is definitely AI, but whatever TV you buy, be sure to check it out. 4K demo and your money back.