LED 5 分钟阅读
In our previous post, we explained how we guarantee a seamless video wall with minimal effort. But then again, we’re talking about direct-view LED so that should be a given, right? Impressive image quality is a key feature of this technology. As you might imagine, even the concept of image quality exposes a big gap between theory and reality. We have seen some video walls that made us cringe – and you probably have as well. What is Barco TruePix’ secret here? Better processing!
Leaving the low-priced solutions on the market aside, you might be interested to know that the quality of the LEDs themselves don’t vary that much. But the image quality these diodes produce certainly does! When a display is dimmed, showing fast- or slow-moving content or many shades of the same color, etc., very big differences can be observed. The secret, and differentiator in LED displays, is indeed the processing. Because the performance of your video wall is only as good as the signal it receives.
Barco has a lot of experience with image processing, and our image processing products power some of the world’s largest events across numerous markets and applications. Our E2 processor for example is the absolute benchmark in the live entertainment market. And so is our Infinipix® solution for LED. For TruePix, we made it even better and introduced Infinipix Gen2.
90% of walls run at less than 1/3rd of their maximum brightness
LED video walls can operate at very high brightness levels, but almost no installation runs at these extreme levels. Did you know that 90% of walls run at less than 1/3rd of their maximum brightness? Because of that reality, you can imagine that being able to display perfect images even when drastically dimmed is a crucial asset of an LED video wall. In a control room, for example, the video wall is dimmed a lot (if not, operators would suffer eye damage after viewing very bright displays all day). Ergonomically, this is why we dim the displays but even so, it remains crucial to view every detail in an image or video. The only way to do this is to offer a very high bit depth, making sure all nuances are transferred to the wall. With Infinipix Gen2’s 23-bit color processing you can keep the same color accuracy, grey scale levels and details in both dimmed and full brightness mode.
This patented True Dynamic RangeTM technology ensures there is no visual loss from your content source. By the way, this doesn’t just ensure a perfect representation of dimmed content, but for all images that have many variations of the same color. In other words: whatever your content, it will look great on your TruePix wall regardless of the brightness level!
Contrary to most competitors, Barco does the video processing and hardware design in-house. This enables us to perfectly tune the processing on the hardware. This is impossible when using a third-party video processing solution.
The color gamut of an LED display is limited by the characteristics of the individual LEDs. This affects the video wall’s ability to display colorful images accurately. Barco’s unique Smart CalibrationTM recognizes and counters the limitations in color gamut of an LED display. It recognizes the video content characteristics and – using this information – maps this on the LED display. In this way, you unlock the support of wide color gamuts, including DCIP3 and even REC2020.
Large video walls have a corresponding large overall resolution. This exceeds the capacity of the interface standards (HDMI and DisplayPort). Therefore, multiple image processors need to be stacked together and they all work as a system to create one large image. Consequently, synchronization between these different processors needs to be impeccable: every slight inconsistency will result in ‘tearing’ on the screen (see video). Especially when displaying fast moving objects, even a difference of a single frame is clearly visible. Barco Infinipix Gen2 guarantees perfect synchronization on the input without sacrificing latency.
When looking at an LED screen for long periods of time, eye fatigue can be a serious issue. For control room operators, for example, this is a problem that can lead to loss of concentration and even eye problems. The cause is the perceivable flicker that originates from the scanline patterns. This is a result of the Pulse Width Modulation (PWM) of the LEDs. When the video wall is dimmed significantly, the dark time between the current pulses increases, which results in more flickering. This means that eye fatigue will be worse in darker environments.
Barco’s SteadyViewTM technology strongly counters this effect by applying a unique LED driving algorithm to effectively reduce fatigue. SteadyView has 4 settings in the user interface to reduce the scanline flicker, depending on the type of content and typical brightness level of the use case. Without lowering the image quality, SteadyView technology allows operators to do their jobs more ergonomically.
Staring at a screen all day is not 100% healthy for your eyes: that is not a secret. This not only applies for LED screens, but for all display types. But not the entire color spectrum is really an issue. It is especially the blue wavelength that can cause damage to the eye’s retina.
When we look at the wavelengths emitted by various displays, we see that all display types have a spike in the blue light spectrum. That is why Barco foresees a number of measures to prevent damage to the eyes. First of all, we ‘handpick’ the LEDs. We test the brightness properties of every batch of LEDs. If the hazardous blue light peak is too high, the batch is refused. Second, the excellent dimming capabilities of TruePix (as explained above) make sure you can limit the blue light emissions without sacrificing on image quality. And third, you can also easily adjust the white point of the display. When making this warmer – which means toning down the blue color – you automatically lower the intensity of the harmful blue light wavelength.
Be aware that natural light also contains blue light wavelengths! Although it doesn’t show the peak we see in display light outputs, we must warn that daylight is a lot brighter than displays. Where displays at 700 nit are perceived as extremely bright, a blue sky produces a staggering 1600 nit!
The image below was taken on 17 November 2022 on a semi-cloudy day. The graph shows the intensity per wavelength. You see that the white cloud is the brightest and is actually in the ‘danger zone’ for blue light emissions. The blue sky is also very bright, but less harmful. When looking at the TruePix results at 700 nit, you see that it is well below the dangerous threshold.
This concludes the highlights of the Infinipix Gen2 benefits. Next week, we will explore TruePix’ superiority in terms of ROI.