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Comment by blkhp19 | Hacker News Reader

It’s not micro LED - it’s mini LED.

Mini LED uses an array of white LEDs to provide somewhat-localized dimming / illumination. You can get close to true blacks with this, but you might notice a halo around areas since the mini LED array resolution is lower than that of the RGB pixels.

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I'm not sure halo is an issue with modern miniLEDs. I've actually worked with research-grade local dimming algorithms and it's relatively easy to get a perceptually nearly perfect picture if you have a calibrated backlight and some image processing software. These algorithms have been known known for a while but it looks like only recently got to production due to need for efficient realtime implementation (they need to run at full 60 or 120 Hz after all).

And, maybe more important, let's not forget the glare effect in our eyes [0] that tends to mask smaller halos.

A couple papers for example, [1] describes one of the better classical algorithms, and [2] is about a modern NN-based approach.

[0] https://resources.mpi-inf.mpg.de/hdr/TemporalGlare/

[1] (2015, pdf) https://hal.archives-ouvertes.fr/hal-01362368/file/IVMSP2016...

[2] (2020) https://arxiv.org/abs/2008.08352v1

I apologize for not reading those papers first, but I don't see how this is possible. With miniLEDs you have a small area of the screen which has a single backlight - if half of that area is 100% white and half 100% black, you'll need the backlight 100% on.

How can that black be as black as in the neighboring area where the backlight is off?

I read the papers - it can't, they just seem to have novel ways of controlling the zones available. I supposed the smaller the miniLED array the more control you can have over the zones and the better it works. But there doesn't seem to be anything that really solves the bleeding issue.

The human eye perceives colors relative to their surroundings, so a black pixel next to a white pixel will look blacker. You can exploit this effect to enhance the perceived contrast ratio. How well this works in practice varies.

https://en.wikipedia.org/wiki/Checker_shadow_illusion

This, and in general setting LED brightness to minimum necessary to get target brightness with fully open LCD, taking into account interaction of nearby LEDs (light from one LED spreads to adjacent cells, thus you could minimize brightness of boundary LEDs even farther).

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