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What is the Difference Between 4K and UltraHD

August 15, 2014
Alina Krukova

Alina Krukova

Categories: Reviews

What is the difference between 4K and Full HD, which is better?

Having worked in the video technology industry for over a decade, I’ve witnessed the evolution of video resolutions firsthand. When Ultra high definition made its debut, many of us in the field were left pondering: What’s the real difference between “4K” and “UltraHD”? I remember the days when FullHD was the definition of clarity, and many of us were skeptical about any further enhancements. But technology always finds a way to surprise us.

In 2012, I had the privilege of attending a tech conference where the new UltraHD definition was unveiled. This groundbreaking development was released by the renowned Japanese broadcasting corporation NHK. Their presentation, backed by years of research and development, was a testament to the steps we were making in video technology.

During my time working with video resolutions, I’ve often encountered the terms UltraHD and 4K used interchangeably. It’s a common misconception that they represent different technologies. Drawing from my hands-on experience with these displays, I can clarify that they refer to the same technology. The term ‘4K’ is derived from the approximately 4000 pixels in its horizontal resolution.

Brief Summary

UltraHD is an ultra high definition format with a resolution of 3840×2160 pixels. Comparing with FullHD, where the resolution is 1920×1080, we can see that UltraHD resolution has 4 times more pixels, delivering more bright, realistic and detailed picture.

The difference between 4K and Full HD

Such number of pixels provides very high definition of the image. UltraHD also provides for the increased number of the displayable colors and more details in the lightest and darkest colors. Combined, this gives us the image as close to reality as possible.

Displaying 4K video requires special equipment — a screen that supports UltraHD resolution.

UltraHD Video Conferencing in TrueConf

TrueConf 4K video conference

  • 4K video conferencing for 1,000 participants
  • Easily integrates with Active Directory and H.323/SIP endpoints
  • 100% local video conferencing software for Windows and Linux
  • Cross-platform native applications for all major platforms
  • Built for security and privacy
  • Scalable SVC architecture

Download free version

Video Conferencing Modes UltraHD Possibility
Multipoint Video Conferencing, Video Lecture — 9 participants Up to 3840×2160 total
Multipoint Video Conferencing, Video Lecture — 16 participants Up to 5120×2880 total
Multipoint Video Conferencing, Video Lecture — 25 participants Up to 6400×3600 total

Using SVC (Scalable Video Coding) technology allows TrueConf video conferences to support UltraHD mode.

This happens as follows:
During a multipoint conference for 9 participants, the resolution of all their video windows adds up to 3840×2160 pixels, which means that, on average, each of the 9 video windows has about 960 pixels.

When TrueConf is used in fullscreen mode on an UltraHD screen, the total of the video resolutions is increased to 3840×2160.

This occurs because the server adjusts the video stream to the 4K screen. Even if your partner has joined the conference from a mobile device, you’ll still be getting the quality supported by your hardware (the quality is limited by the possibilities of the participants’s camera). And vice versa – in a conference with a 4K screen, the participant with a mobile device will receive the stream, adapted to his tablet or smartphone.


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