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So we're all wondering what the big breakthrough is, right? They're trying to play it off as being a combination of the front facing camera and 'mura correction' whatever that is. All we do know is they don't want to talk about it, and Chet himself has said it affects every aspect of the display hardware.
Well, I postulate that the front facing camera and the chaperone system were never part of the breakthrough. We know from the leaked images that the front facing camera has been in DK2 since September. And there's hardly anything revolutionary about running a high pass filter over an image to generate the outlines. So these are just smoke and mirrors.
The real breakthrough is this 'mura correction'. But what is it? I have a theory. And it is a breakthrough, but not of the kind we were hoping or expecting, and not one that Valve would want to crow about.
Wikipedia states that mura is a Japanese word meaning "unevenness; irregularity; lack of uniformity; nonuniformity; inequality".
And a month ago there was a purported leak on pastebin of insider info about problems with the Vive hardware.
In short, there were two problems:
The first was with the quality of the front facing camera. And what better way to hide issues with the camera's quality than by applying a high pass filter to the output to create a wireframe view of the scene?
The second was with the quality of the displays. The leaker claimed that the Vive and the Oculus use displays of identical resolution, but Oculus's displays have better pixel uniformity. In layman's terms, on a perfectly uniform display two pixels set to the same brightness would appear identical.
But no display is perfect, so there are variations in brightness between pixels. The Oculus team has managed to get displays which have a very high level of uniformity. The displays that HTC has been able to source however are not so uniform. And the problem with a non-uniform display is that as one looks around, particularly in darker scenes, one might see a rainbow pattern of speckles overlaid on the scene.
So how does mura correction fit into all this? Well, as any graphic designer knows, if you want accurate color rendering on your display you need to calibrate your screen. And the way professionals do this is with a little doodad with a light sensor that they stick to the screen with a suction cup before running a calibration app. This app then figures out how to adjust the gamma curves on your video card for red green and blue to correct the white balance, and to make sure the gray levels are where they should be all across the spectrum.
This sort of gamma correction however would be useless for fixing the Vive's display issues, because it operates on a global level, affecting all pixels equally. What Valve would need to implement is something more similar to what in the LED signage world is called dot correction.
Dot correction is adjusting the maximum brightness of individual LEDs to create a uniform display. And the same could be done for a display's pixels, and probably is done by display manufacturers.
But dot correction alone may not be sufficient to solve the problem. What if you reduce the brightness of one pixel to make it equal to another at maximum brightness, but when it's set to 50% brightness, there's still a difference? That's where you would need to take things to the next level and do gamma correction on a per-pixel basis. To correct the unevenness, or "mura".
So this is what I believe the real breakthrough is, and what Valve has done. They had some issues with their display quality and they found a way to correct it at the last minute which requires some tweak to the hardware. They could have shipped hardware without this fix, but then a whole lot of early adopters would have been screwed with inferior hardware.
At the same time, even though their intentions were honorable, this isn't exactly the sort of breakthrough they'd want to shout to the rooftops, because they'd be admitting that their devices have inferior displays, and even if their fix means there's now no perceptible difference in the final hardware, and even if it's better than the Rift, people might still have the seed of doubt sown in their minds.
So they downplay the real breakthrough and divert people's attention away from it to the camera and what that adds to the experience.
