GPU Dithering
Would be great to know if Chrome or Firefox do something while Full RGB is on. As the current versions give some of us eye strain on known-good cards.
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Seagull I tried on Windows 10 1909 yesterday, and frankly, it seemed no different, but i just used for a couple minutes. My daily pc is other Windows 8.1, which is fine. I think there is subpixel rendering on Windows 10. Because fonts seem fuzzy, and sometimes i find difficult to focus on. I also think there is something different about color temperature or color space that changed with latest updates.
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tfouto No subpixel font smoothing in Windows 10. It's greyscale anti-aliasing.
You know, it's funny.. my work managed laptop is a T480 on windows 10 build 1803. Funny thing is, I also have the usb dock it came with, so usb-c to the dock, displayport output from the dock to an old HP displayport to DVI active adapter to my old CCFL monitor, and the backlight looks more stable than on my regular PC which is Win 7, mini-displayport out to active vga adapter to same monitor. The image is fine and I'm confident you all can use it, but there's this subtle background shimmer that isn't there with the T480 setup as-is. One of these days I should look for a mini-displayport to displayport adapter, so I can plug in the same HP to DVI and see how it looks on the Win 7 machine.
I was just now playing with a laptop from 2005, was a good one back then. Amazing how fast it is with a SSD drive in it, even after all these years. Anyway the hardware isn't that healthy anymore unfortunately. The screen isn't that good today. There's this shimmer or fuzz that's hard to quantify, almost a snowy moire effect. I think it might actually be the backlight beginning to fail because in one corner of the screen there's a crack (not on the glass, but behind it) from someone having dropped or crushed it. CCFLs don't last forever unfortunately.
I'm going to slap OpenBSD on the antique laptop tomorrow probably and see how it compares to XP and Linux which I've already viewed on it.
Seagull I changed the colour setting for the GTX660 from default to the other options available: RGB Full, RGB Limited, and YCC444. That screen should look familiar to windows Nvidia users.
Very curious, on my GTX970, I only have Desktop Colour Depth on #3. My connection is DVI so perhaps that has something to do with it.
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So, any conclusions to be drawn here? Is HDMI and a lower/different colour depth worth further trials?
All I can really say is that its worth trying different colour formats on the cards you have if you are having a problem. Whilst my gtx 660 does not dither on full RGB, I can't say if it will be the same for other Nvidia cards. But, I personally would be fairly confident that if I bought a new card I'd be able to find a setting that did not dither.
The other, and in my opinion, more important conclusion is that dithering frequency depends upon the colour being displayed. I think this is why people have problems when software updates or changes, steam and chrome for example. The software itself isn't dithering, but if the colours have been changed slightly that will affect how the GPU is dithering and might produce symptoms.
This is brilliant work!
Seagull Thanks for the offer of the card, but there isn't anything else I can think of to test for.
I guess I (selfishly?!) would love to know if there's a colour profile for this card that doesn't use dithering, as it appears that every card you have tested has been different. It would be a great to have a database of non-dithering settings for different Nvidia cards.
Seagull I've since moved on to biohacking!
Very curious to hear about this. Keep up the good work and keep us in the loop with your experiments!
Funny you should say that - I've just bought an ATEM Mini Pro, and it can capture direct to USB which is quite handy. I'd need to look as to whether it applies any kind of processing but it might even be interesting to test if it can be used to negate the dithering by acting as an active HDMI processor between the computer and the monitor.
If you're able to provide your software I'd really appreciate it and could continue to post dithering tests of different cards as and when I get my hands on them. I'd be tempted even to order cards from Amazon, test them and return them and post the results to try to find a 'safe' list.
si_edgey If you're able to provide your software I'd really appreciate it and could continue to post dithering tests of different cards as and when I get my hands on them. I'd be tempted even to order cards from Amazon, test them and return them and post the results to try to find a 'safe' list.
@Slacor and I have "our" project too
Setup isn't exactly trivial because it was a) developed on Linux, b) requires a Python runtime, OpenCV and parts of ffmpeg
https://github.com/ledstrain/videodiff
Expect some more features in the future
How programming literate are you? My software works, but its written badly, and requires editing the source code to change anything (file name, frame to start and end on etc). I can either give you the code, or the whole MS Visual Studio project file. The later might be easier to work with if you are unsure. The graphs are made in Matlab, which I can give you the scripts for aswell.
Real time removal of dithering is an interesting concept. Thinking about it now, the easiest way to do it will be to drop the colour depth. That way most dithering will be lost as 2/256 blue and 3/256 blue will both become say 0/16 blue. Edge cases like 15/256 and 16/256 that could flicker between 0/16 and 1/16 could be filtered out with a few frames held back to say look for scenarios where: frame 1 = 0/16; frame 2 = 1/16; frame 3 = 0/16, to change frame 2 to 0/16. The latter could be quite computationally demanding though, can't say if you could do that in real time.