You're upgrading your home entertainment system or your computer screen. But you're bombarded with meaningless jargon. One of them is "upscaling".

What is 4K UHD upscaling? How does it work? And do you need a special monitor or Blu-ray player to do it? Here's everything you need to know.

What Is Upscaling?

Upscaling converts low resolution material (most often video or images) into a higher definition. It's certainly nothing new: upscaling occurs when you output DVD footage to your Full HD television.

There are four primary resolutions you'll need to know before buying your next TV:

  • HD: 1280×720
  • Full HD: 1920×1080
  • Ultra HD/4K: 3840×2160
  • Ultra HD/8K: 7620×4380

However, only the first three are widely used. 8K televisions are huge and never took the market by storm. They look amazing, but prices are similarly incredible. Most consider 4K the best quality available for your home.

Note: There is a difference between Ultra HD (UHD) and 4K---but for all intents and purposes, these differences don't affect regular household consumers. Their disparities are typically only notable for those in video production.

differences between 4k UHD HD 1080p pixels DVD VCD aspect ratio
Image Credit: Wikimedia Commons.

Upscaling produces video that utilizes your monitor's maximum aspect ratio, even when playing a lower resolution video.

Most flat-screen TVs have a 1920x1080p resolution, resulting in 2,073,600 pixels in total---that's 1,920 across, multiplied by 1,080 rows of pixels. A 1280x720 HD movie doesn't use all the available pixels; it only uses 921,600 of them. That's a huge deficit. A device that supports upscaling, then, "fills in the blanks", effectively stretching the image across the entire screen.

It does so using an interpolation algorithm. This infers new data by extracting from known elements; it tells "blank" pixels what to do based on what those surrounding it display, and then duplicating that content.

This doesn't sound like a fair interpretation of a film. To counter this, many manufacturers apply sharpening software to market their products, thereby reducing pixelation or softening. Contrasts are often tampered with to make an image look more vivid.

Should You Buy an Upscaling Blu-ray Player or 4K TV?

Upscaling can be handled by either your TV or a capable device, i.e. a Blu-ray player. The PlayStation 4's upscaler is especially impressive too.

Naturally, Blu-ray players are the cheaper option. They're typically below $200, while a 4K TV can cost a lot more.

Suffice to say, any connected device can only upscale to the maximum resolution of your screen. There's no use buying a Blu-ray player that boasts 4K capabilities if you only have a Full HD monitor.

Indeed, most upscaling is implemented by your television. Don't be tricked by a player that boasts superior upscaling: in the end, your television is the limiting factor.

Marvel discs Avengers UltraHD HD

Your TV will be responsible for making that leap to higher definition. It does this with all signals, whether you're watching a DVD, Blu-ray, normal TV channels, or through a streaming service. Even if a Blu-ray player is capable of upscaling to an impressive 4K, if your TV doesn't support this, you'll simply get the highest resolution your set is confined to (often 1080p HD).

You're probably wondering if 4K TVs automatically upscale. If they didn't, lower resolution images would appear small on a big screen, likely surrounded by a large black border. However, the quality of the video resolution upscaler included will depend on how expensive the screen is.

The best 4K upscaler will be top of the range. You get what you pay for. But there is a decent medium to be reached. The cheapest option isn't necessarily the worst; vice versa, the more expensive won't be the best either.

Which Is Better: Upscaling or "True 4K"?

Is there a difference between content filmed in 4K and content upscaled to 4K? Absolutely. The latter will always be inferior.

Upscaling---sometimes known as upconversion---implies precision. But it can't add more detail than is already present. It's an educated guess made by your device. That's why Blu-rays aren't pointless. They give you the nearest definition to cinema without a 4K Ultra HD television (which has 3840x2160p); so yes, quality also naturally depends on the equipment used.

4K is what most movies are filmed in. That doesn't mean you'll be able to enjoy classics in UHD.

Former chair of the SMPTE Working Group on Professional and Studio Monitors, Joe Kane says that this has been common practice for at least two decades:

"As much as we've been producing in the 4K format, we didn't store it because nobody thought we were ever going to use it! We would shoot in legitimate 4096x2160, produce in 4K but then archive in 2K."

To watch Real 4K films, you'll need a 4K TV, UHD Blu-ray player, and a HDMI cable (ideally HDMI 2.0). 4K discs are more expensive than usual Blu-rays, but frequently come with a HD version too. If you're future-proofing your collection, these are a good option.

What Are the Downsides of 4K Upscaling?

Upscaling sounds like you're getting 4K video quality from 1080p video. That's not what it is. It's far from perfect. It stands to reason that there would be problems with technology that forces a picture into duplicating its pixels to create a fair estimation of a higher resolution.

The main problem with upscaling is the possibility of visual artifacts, increasingly an issue with fast-moving videos. While some material might appear stretched, one notable trouble is the ringing idiosyncrasy, which appears as a "ghost" or further outline around objects.

Blurring and distortion of any sort will be most noticeable the closer you are to your television or monitor.

In effect, upscaling can work against itself. In an effort to gain a higher resolution, older program can appear less sharp as they're stretched beyond the boundaries they were originally meant to be viewed in.

Better resolutions will always be desirable on desktop computers. That's why 4K computer monitors also upscale input to the full 3840x2160p resolution. Yet none of us use PCs or laptops to solely play movies, and the side-effect of a 4K screen is a very mixed performance. Icons, for example, appear ridiculously small.

In short, 4K computer monitors aren't worth it right now. If you want to play a game in all its detailed glory, you'll need a seriously good graphics processing unit (GPU), which can prove expensive!

Is Upscaling Worth It?

Not always. Sometimes, older content will be blurrier than intended. Nonetheless, many films were filmed in higher resolution and only stored in 1080p. That means the information originally captured on film was lost. Upscaling doesn't restore it. Upscaling merely infers data based on surrounding pixels.

If you're sitting at a sensible distance from the television, upscaled movies will appear clearer.

Upscaling from a Blu-ray player is a great option if you still love your extensive DVD collection; however, your television is the limiting factor. If it isn't a UHD TV, you won't get UHD content---so don't be fooled by showroom tricks that make screens look better than they will at home.