What is latency?

Latency is a time delay between the cause and the effect of a change. In visualization, latency refers to the amount of time it takes for an image to get from a source to its appearance on a screen.

How do you measure latency? 

Latency is the time it takes for a visualization system to process signals from external sources before displaying them on screen. It is the delay between a frame change on the source side and the same frame change reaching its destination and showing on the screen side. We measure this delay in frames or milliseconds (ms) from first pixel in to first pixel out. The closer your latency is to zero, the better. 

Why is latency important? 

Some lag is unavoidable due to the architecture, the processing, and the load time on both the input side and the output side. But reducing the latency is a design goal for any system where there is real-time interaction with the video content such as IMAG (image magnification) screens during live concerts, videoconferencing systems, or professional training simulators.

Lower latency is desirable to achieve a smooth viewing and user experience, ensuring that what you see on a screen or device is in sync with what is happening in real life in close to real time.

High latency can create noticeable delays, which can make watching the content and using interactive applications difficult. There is the nuisance of audio and video being out of sync. But the importance of low latency goes beyond lip sync issues. Imagine an fast jet pilot in a simulator not seeing the immediate and real-time effects of his steering actions. At the speed they are flying, every millisecond counts. And incorrect training is possibly even dangerous.

How do you enable low latency? 

Latency in a system depends on several aspects of all the devices in your chain and can vary if any of them is changed or a device is added/removed. If one product in the chain adds latency, the overall result will be impacted. Adding a device in the visualization chain potentially adds extra processing which adds additional lag.

Other factors influencing the system latency levels include:

  • Network performance and poor (internet) connection speeds (if streaming content)
  • Outdated hardware components such as cables or ports which do not meet current standards. The Barco projectors and image processing solutions, for instance, allow you to use the latest fiber optic cables to distribute video with minimal additional latency or compression.
  • Incorrect settings within software used.

To conclude, cleaning on a regular basis and ensuring a secure ambient environment can also work beneficial to your systems’ latency levels.

What is Barco Single-Step Processing? 

Every extra step (like adding an extra device to your system) can lead to an extra delay in your signal transport. The Barco Single-Step Processing (SSP™), part of the powerful Barco Pulse electronics in our Barco projectors, is a proprietary technology enabling all image processing being done in one single step.

Thanks to the SSP™, a Barco projector can efficiently pixel-shift the image to output higher resolutions than its inherent native resolution, like 4K UHD (Ultra High Definition) on a WQXGA projector, or 6K on a native 4K projector. Since the pixel-shift processing is done faster than any competing technology, the result is a sharper image with more details without adding extra latency to the projector.

In the same single step, the SSP™ projectors perform other demanding processing tasks and geometry corrections, like warping and blending the image - all in one single step, keeping the processing lag to a bare minimum. This is a huge advantage in a real-time processing environment. By doing all calculations in one single step, you also reduce the quality loss.

Adding a Barco Pulse projector to your system as an extra device, is the best choice you can make to avoid extra latency.