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TV backlight compensation (2020)

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Re: TV backlight compensation (2020)

#61

Post by nottorp »

kevingadd wrote: post #51
nottorp wrote: post #33

Earlier quoted context omitted.

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 eit…

The first graphic design monitor I bought from Benq had a busted image processor so that you couldn't turn off the sharpening - only set it to -5% (blurry) or +5%. Eventually I complained enough that they sent me a different monitor that didn't have the problem. I've had bad experiences with some of Dell's pro-grade monitors too. It feels like modern displays are so complex firmware and hardware wise that it's just v…

Funny, when I bought my first designer-ish monitor I threw a (gaming) Benq into the trash.

Re: TV backlight compensation (2020)

#62

Post by nottorp »

deergomoo wrote: post #48
nottorp wrote: post #33

Earlier quoted context omitted.

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 eit…

> Asus ProArt I’m using one of these and I’m very happy with it. Reasonable price, 75Hz, supports USB-PD + has its own USB ports so I can one-cable it with my work laptop. Most importantly they come factory calibrated. I consider reasonable colour reproduction important even though I only use it for programming. I stare at this thing for 8 hours a day, it needs to look good. In fairness I also have a 165Hz LG UltraGe…

> I consider reasonable colour reproduction important

When I got my first I wasted 2 hours rewatching a movie I had seen recently. Just because i didn't know it can look that good on a monitor :)

Re: TV backlight compensation (2020)

#63

Post by pferdone »

When I installed my DIY backlight solution (ala AmbiLight) to my TV I also had a red shift for some of my LEDs. But that was mainly due to the fact that not enough voltage reached the later LEDs on the strip to power green/blue because they need higher voltage than red.

Re: TV backlight compensation (2020)

#64

Post by jiggawatts »

autoexec wrote: post #52
BoorishBears wrote: post #36

Earlier quoted context omitted.

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% su…

If you fill your entire screen with nothing but a single solid color (try #FF6400) does it show up correctly? That is, without any gradient or areas of the screen where the color appears darker or lighter (especially around the edges or in the corners?). I've yet to find a modern monitor that doesn't have a problem with that basic test, which is pretty disappointing considering accurately representing a single color…

Monitor? No.

But I just recently purchased a Sony A95K QD-OLED television, and holy cow the uniformity is just breathtaking. You start noticing the deficiencies in your own vision.

There's a similar panel available as a computer monitor, but unfortunately only curved and 1440p.

Re: TV backlight compensation (2020)

#65

Post by sorenjan »

Rygian wrote: post #24

This 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)…

Sounds like local contrast adjustment. There are several different ways of solving it, here's a couple that look like they work pretty well:

https://stackoverflow.com/questions/63251089/how-to-do-a-loc...

https://stackoverflow.com/questions/65666507/local-contrast-...

One possible preprocessing step could be to do a high pass filter on it, if the shadows vary slowly over the image.

There are also more specialized techniques specifically for removing shadows from documents, like these:

http://civc.ucsb.edu/graphics/Papers/ACCV2016_DocShadow/

https://faculty.iiit.ac.in/~vgandhi/papers/shadow_removal_ca...

I also found this, an image editor based approach if you just want to do a few images manually:

https://janithl.github.io/2021/12/remove-shadows-and-uneven-...

Re: TV backlight compensation (2020)

#66

Post by sorenjan »

This reminds me of the world cup in South Africa, where the spectators used vuvuzelas to make a unique sound that I found hard to endure. I figured it would be easy to use a notch filter to remove it, but I could never find a way to implement it it real or near real time, only as post processing.

Re: TV backlight compensation (2020)

#67

Post by washadjeffmad »

jagged-chisel wrote: post #55
drumdude wrote: post #21

I do this for a living. Sony digital cinema projectors use a type of LCD panel (SXRD) where the uniformity drifts over time. A special camera takes about 35 minutes to create a LUT to restore the projected image to a uniform white.

Is that 35 minutes spent collecting input, or calculating the LUT?

I imagine the process is Capture > Analyze > Generate > Apply > Repeat until all test images are within bounds and color matched, not stage 1: capture, stage 2: calculate, done. That's how it worked for our projection, at least.

Re: TV backlight compensation (2020)

#68

Post by bzzzt »

dontlaugh wrote: post #50
bzzzt wrote: post #17

Earlier quoted context omitted.

Calibrating color with an iPhone is already a feature in tvOS, so correcting for local errors looks like a nice improvement in that direction.

Sadly it only works with iPhones that have FaceID.

Probably related to the quality of the camera.

Re: TV backlight compensation (2020)

#69

Post by zepolen »

empiricus wrote: post #59
serd wrote: post #22

Earlier quoted context omitted.

Could you share a photo? I'd really like to see that.

https://i.postimg.cc/1Xy6V5wb/oledburn.jpg not the greatest picture (some reflections). should have used a gray background, but I used red because this color is the most affected. The burnin is mostly harmless, but the middle blob is very annoying; yellow parts of the image become greenish when they get to the middle of the screen.

Which tv is this?
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