قالب وردپرس درنا توس
Home / Tips and Tricks / What is 4K resolution? An overview of Ultra HD

What is 4K resolution? An overview of Ultra HD



4K Ultra HD logo.
ahmetemre / Shutterstock

If you buy a TV or upgrade to the next generation console, you̵

7;ve probably seen terms like 4K and Ultra HD thrown around. Let’s cut through the jargon and get down to what these terms mean, and if they are even interchangeable.

It’s about resolution

Usually 4K and UHD refer to a resolution that is a step up from 1080p (or “full HD”). A 4K UHD screen has about four times the pixels from the previous generation, which creates a cleaner, more detailed image.

An ad for 4K Ultra HD Blu-ray.
Sony

A 1080p HD TV cannot take full advantage of a 4K UHD picture. To see the benefits, you need to make sure the media you consume is available in 4K UHD.

Fortunately, 4K UHD is everywhere, from movies and TV shows, to the latest video games. You can also buy a UHD 4K monitor for your computer for lots of screen properties and excellent image quality. Your smartphone will probably shoot in 4K, even if the massive video files are not worth it on a smaller screen.

4K and UHD are different

Although used interchangeably by manufacturers, retailers and consumers, 4K and Ultra HDR (UHD) are not the same. 4K is a production standard defined by Digital Cinema Initiatives (DCI), but UHD is only a screen resolution. Movies are produced in DCI 4K, while most TVs have a resolution that matches UHD.

The 4K production standard specifies a resolution of 4096 x 2160 pixels, twice the width and length of the previous standard 2048 x 1080 or 2K. As part of this production standard, 4K also specifies the type of compression to be used (JPEG2000), maximum bit rate (up to 250 Mbits per second) and color depth specifications (12-bit, 4: 4: 4).

A graph comparing pixels offered by DCI 4K, 4K UHD and DCI 2K resolutions.

Ultra HD has a screen resolution of 3840 x 2160 pixels and is used in most modern TVs – even those that are advertised as 4K compatible. Apart from the number of pixels on the screen, there are no additional specifications. The real differences between the two formats are the width of the images and the aspect ratios.

A movie produced in 4K can use a aspect ratio of up to 1.9: 1, but most filmmakers prefer 1.85: 1 or 2.39: 1. Video games rendered for consumer-level screens use the UHD aspect ratio of 1.78: 1 to fill the screen.

This is why you continue to see the mailbox format (black bars at the top and bottom of the screen) when watching movies on your brand new UHD TV. Because UHD does not specify any additional standards, older TVs with eight-bit panels are advertised as UHDs along with new 10-bit (and future 12-bit) UHD screens.

The areas of 8K Ultra HD, 4K Ultra HD, Full HD and SD were compared.

To make matters worse, Ultra HD is also used for so-called 8K content. Labeled as “8K UHD” (as opposed to 4K UHD), this refers to content with a resolution of 7680 x 4320 pixels. This leap in quality is huge in terms of the total number of pixels. However, it will be a while before we see extensive content produced for this format.

Simply put, many manufacturers use the term “2160p” to describe common UHD content, even if it is not strictly accurate in relation to production standards.

Things to keep in mind when upgrading to 4K

This is a great time to upgrade to a UHD TV that can play 4K, as the technology has matured considerably over the past five years. Not only are UHD screens now much cheaper, but they also have more features. There are 10-bit panels that can display highly dynamic content that also has powerful image processors on board.

For the leap to be worthwhile, you need to consider how big you want your screen to be and how far you sit from it. According to RTINGS, the upgrade is not worth it if you sit longer than six meters from a 50-inch screen. You can still not see the pixels from that distance, so you will not benefit from the increased resolution.

Another thing that is worth considering is if you even watch enough 4K content to justify the upgrade. Ultra-HD Blu-rays provide the best home experience, and there is a large catalog of them growing all the time. If you do not often buy expensive records, however, you can stay in streaming content instead.

This is where the speed of your internet connection can make or break your investment in a shiny new TV. Netflix claims that its customers need an internet speed of 25 Mbits per second or better to stream Ultra HD.

You can test your internet speed to find out how your screen will go. Keep in mind, though, that these speeds can drop significantly during hectic periods (like when everyone is streaming Netflix at the same time).

You must also pay for a premium subscription at a premium level to access the highest quality content. Netflix gates its UHD content behind a $ 15.99 monthly package. It might be worth it if you’re a fan of Netflix Originals, most of which streams in UHD resolution.

Unfortunately, many movies that have UHD editions in HD are still presented on Netflix.

Subscription levels on the Netflix website.

Do you have existing HD devices, such as a Roku or Apple TV? These can be a problem, as they can only deliver a 1080p image. You need a Chromecast Ultra or Apple TV 4K to take advantage of higher resolution and HDR playback. This is less of a problem for your TV, as long as it has a stable and responsive operating system, which many do.

Remember that 4K is lit on larger screens. Unfortunately, when you upgrade to a larger UHD TV, all 1080p content will look worse. However, this will be a minor problem in the future, and there are some solutions.

Upscaling to Ultra HD

Current TVs attach great importance to upscaling, which takes lower resolution content and scales it to fit a much larger screen. Remember that there are four times as many pixels on an Ultra HDR screen than there are on a regular Full HD TV.

Upscaling fortunately means more than just stretching an image. Modern TVs and playback devices process the image and try to reconstruct it so that it looks best with a higher resolution. This is done via a process called interpolation, during which missing pixels are generated on the fly. The intention is to create a smooth transition between contrasting parts of the image.

As TVs become more powerful, better interpolation and upscaling techniques will be used. NVIDIA Shield currently has some of the best upscaling on the market. It uses AI and machine learning to enhance different parts of the image using different techniques.

If you upgraded to an Ultra HD TV and have noticed lower performance with lower resolution content, a Shield may be just what you need.

PlayStation 4 Pro uses innovative scaling to reproduce images with a lower resolution (like 1,440p), which is then scaled to 4K via a technology called chessboarding.

NVIDIA has developed Deep Learning Super Sampling to do a similar thing on PC games. Some parts of the image are reproduced with lower resolutions and then scaled up in real time. This gives better performance than making the scene in the original resolution.

RELATED: What is “upscaling” on a TV and how does it work?

How about HDR?

HDR (High Dynamic Range) is also often advertised on movies and TVs, and it is a completely different technology. While 4K is a production standard and UHD is a resolution, HDR is a loosely defined term that refers to a wider color gamut and higher peak brightness.

While 1080p HDR may be available, HDR content was not widely produced during the “Full HD” age, so you will not find any TVs on the market that offer HDR at 1080p. However, the vast majority of 4K devices on the market support HDR in some form.

Do not worry about the terminology

Whether it’s called 4K or UHD does not matter. Your UHD TV is 4K compatible. The world has just adapted to the unclear conditions that manufacturers and marketers throw.

Netflix can advertise a movie in Ultra HD, while iTunes labels the same movie 4K. Your TV does not care and plays both well.

Before you go out and buy the new set, however, be sure to check out these common mistakes that people make when shopping for a TV.

RELATED: 6 Mistakes People Make When Buying A TV




Source link