How much does backlight drift over time? I have a few calibrated monitors with "uniform compensation" that has gotten decidely less uniform over the years.
TV backlight compensation (2020)
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Re: TV backlight compensation (2020)
#32This is almost identical to a problem I'm trying to solve, which is to turn a potato-quality picture of a sheet of paper into a clean scan, turning whatever levels of gray conform the paper background become a uniform #ffffff white. The obvious solutions (equalizing, converting to bitmap, …) don't work because what's white in the top left (say #ccc) is wildly different from what's white in the bottom right (say #888)…
A common alternative solution in this case would be to use an adaptive thresholding technique such as Otsu’s method.
Otsu's method finds a single threshold value in an adaptive way. This can't solve a scanned document thresholding problem.
btw: The iOS Notes app has quite a capable document scanning tool. It's cleverly hidden though.
Re: TV backlight compensation (2020)
#33The quality of computer monitors is appalling - after buying and returning several monitors because of quality issues, I briefly considered doing this system-wide to fix colour uniformity problems. Eventually I chose to keep my old monitor instead. It has uniformity problems as well but it doesn't cost me $1000 extra to keep. But it's a damn shame that you can't throw enough money at manufacturers to make them make m…
You talking about mainstream "gaming" monitors? I'm just a programmer and gave up on those long ago. Getting entry level monitors targeted at graphic designers now. Namely Asus ProArt and I think Dell has similar stuff?
They don't have 240 Hz and sub 0.01 ms response times though, so if you're buying your hardware based on bigger numbers in specs they won't do.
They're probably not that great for actual designers either, but they're good enough for me.
Re: TV backlight compensation (2020)
#34This is almost identical to a problem I'm trying to solve, which is to turn a potato-quality picture of a sheet of paper into a clean scan, turning whatever levels of gray conform the paper background become a uniform #ffffff white. The obvious solutions (equalizing, converting to bitmap, …) don't work because what's white in the top left (say #ccc) is wildly different from what's white in the bottom right (say #888)…
A common alternative solution in this case would be to use an adaptive thresholding technique such as Otsu’s method.
Thanks, I was not aware of Otsu's method.
From the Wikipedia article, "Otsu's method performs badly in case of heavy noise, small objects size, inhomogeneous lighting and larger intra-class than inter-class variance." (Emphasis mine.)
Right now my solution is at the stage of local thresholds with a configurable block size.
Thanks to your pointer, I know now that my next steps will be to review the Niblack or the Bernsen algorithms. (Or just integrate ImageJ.)
Re: TV backlight compensation (2020)
#35Gnome (Ubuntu, Linux) allows a custom shader to be applied to the whole desktop, including fullscreen apps. Here is an up to date fork with some example shaders: https://github.com/Hello1024/gse-shader I use it to make sure a 'sensitive' pixel on my screen never turns on (it's a row of pixels which, if the difference between it and the pixels to the side have more than a certain difference in brightness, the whole sc…
I want to be able to edit anything on my screen in ways defined by me:
"hide any faces"
"put a red circle around any animal"
"hide any word under three letters"
Re: TV backlight compensation (2020)
#36The quality of computer monitors is appalling - after buying and returning several monitors because of quality issues, I briefly considered doing this system-wide to fix colour uniformity problems. Eventually I chose to keep my old monitor instead. It has uniformity problems as well but it doesn't cost me $1000 extra to keep. But it's a damn shame that you can't throw enough money at manufacturers to make them make m…
My XDR has been pretty flawless, and on the less exorbitantly priced end, I've had good experiences with a few business oriented IPS models (most recently the Samsung UR55).
My main gripe is gaming monitors seem to be consistently the worst panels they can get their hands on.
It seems like they realize gamers will put up with a lot of garbage in exchange for raw "power" and take full advantage of the fact. I'm 99% sure that's why we saw brands like Wasabi Mango (who used to take B grade panels and sell them on the cheap) disappeared... the manufacturers just started shipping them as gaming models.
Re: TV backlight compensation (2020)
#37Earlier quoted context omitted.
A common alternative solution in this case would be to use an adaptive thresholding technique such as Otsu’s method.
Otsu's method finds a single threshold value in an adaptive way. This can't solve a scanned document thresholding problem. btw: The iOS Notes app has quite a capable document scanning tool. It's cleverly hidden though.
I'm pretty happy with the scanning feature of Evernote, and I think there are some other nice apps in the Android app store, but my goal is to have a solution that is not captive (either to a specific vendor or to a SaaS solution).
Re: TV backlight compensation (2020)
#38Gnome (Ubuntu, Linux) allows a custom shader to be applied to the whole desktop, including fullscreen apps. Here is an up to date fork with some example shaders: https://github.com/Hello1024/gse-shader I use it to make sure a 'sensitive' pixel on my screen never turns on (it's a row of pixels which, if the difference between it and the pixels to the side have more than a certain difference in brightness, the whole sc…
How did you manage to find the issue?
Re: TV backlight compensation (2020)
#39Gnome (Ubuntu, Linux) allows a custom shader to be applied to the whole desktop, including fullscreen apps. Here is an up to date fork with some example shaders: https://github.com/Hello1024/gse-shader I use it to make sure a 'sensitive' pixel on my screen never turns on (it's a row of pixels which, if the difference between it and the pixels to the side have more than a certain difference in brightness, the whole sc…
I want to be able to edit anything on my screen in ways defined by me: "hide any faces" "put a red circle around any animal" "hide any word under three letters" http://zeroprecedent.com/lore/flipside.html
Well now you have all the building blocks to implement it...
Re: TV backlight compensation (2020)
#40I have the same idea each time I read something about backlights;
How easy would be to place a cheap LCD at the back of the main screen and mirror the same output (in horizontally inverted mode)?
Technically it might require synchronizing the frame latency differences between the two devices, but would such a hack improve the perceived quality?