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Pixel patterns that distort color on whole pixel line

Posted: 13 Dec 2014, 18:31
by dclon
I encountered a strange problem, and I'm beginning to think it may be an inherent problem in some LCD panels.

When viewing something like this (must be viewed at 100% scaling to test):
Image

This is what I see:
Image

The more alternating colored/black pixels there are in a pixel line, the more the whole line color distorts, like in this video of the problem:
http://www.dailymotion.com/video/x2ca6aa

My findings so far are: it happens when there's a grid/checkerboard pattern, 1 pixel spacing. More grid, more distortion. It's worse with magenta, quite bad with white, more subtle with a few other colors. The distortion seems to be an addition of green color to all the pixels on the line, not only the grid area.

Any idea what that is?

Re: Pixel patterns that distort color on whole pixel line

Posted: 13 Dec 2014, 18:50
by Falkentyne
Inversion artifacts with voltages or something.
Doesn't even matter because that image makes the entire SCREEN get messed up. I'm talking about even the area OUTSIDE OF THE BROWSER, above and below the browser!

I don't think that's something to keep on a screen for long periods of time.
Even my desktop got screwed up with white and pink horizontal lines--ABOVE the browser-- until I closed that image.......

OLEDs and CRT's at least work correctly...

Re: Pixel patterns that distort color on whole pixel line

Posted: 13 Dec 2014, 19:05
by dclon
What monitor model do you have? Can you post a photo of the monitor showing that image? It won't damage the monitor.

I don't think this is about inversion since it happens on the whole line and it adds/changes color.

Re: Pixel patterns that distort color on whole pixel line

Posted: 13 Dec 2014, 19:11
by Falkentyne
Sorry I don't have a camera.
And its an XL2720Z.

Re: Pixel patterns that distort color on whole pixel line

Posted: 13 Dec 2014, 19:25
by dclon
What I know so far is that the grid pattern affects a whole horizontal line, not vertical. Are you using the display in portrait orientation?

Re: Pixel patterns that distort color on whole pixel line

Posted: 13 Dec 2014, 19:53
by Falkentyne
No, I'm just moving the browser window around.
I'm not talking about the image rectangle thing at the middle of the screen where it extends horizontally to the edges.
Basically the inversion is so intense that it literally corrupts the entire screen when you move the browser window around (have it not maximized).
I find that when I use the OSD on the lagom.nl inversion tests, the 'vertical' lines from the OSD actually extend upwards to the top edge of the screen.

Haven't tested on VG248QE, tired of constantly hooking it up.

Re: Pixel patterns that distort color on whole pixel line

Posted: 13 Dec 2014, 20:32
by Falkentyne
Ok I used my laptop to take a picture and it was VERY difficult to do this with a laptop and a TINY low resolution camera, with a "take a picture" option that doesn't even WORK 80% of the time you click it...

This is the image zoomed in (with the hourglass) fullscreen. You can see the corruption through the browser window at the top (aero transparent): Pay attention to the top right:

http://i.imgur.com/cKAI65D.jpg
Image

Here is what it looks like WITHOUT the image, on this forum:

http://i.imgur.com/64ABNTQ.jpg
Image

Re: Pixel patterns that distort color on whole pixel line

Posted: 14 Dec 2014, 07:41
by dclon
Thanks for the photo (no cellphone camera?). That's odd, seeing it go vertically.
If you move/resizing Notepad over the magenta grid, do you see a behavior similar to what happens in the video I posted above?

What did you mean by...?
image rectangle thing at the middle of the screen where it extends horizontally to the edges.
What's the "OSD" on lagom.nl?

Re: Pixel patterns that distort color on whole pixel line

Posted: 14 Dec 2014, 07:54
by Falkentyne
Monitor on screen display.
Since the OSD covers the lagom inversion screens, when I bring it up, I see lines extend all the way to the top of the screen, mirroring the OSD edges.

And um, when I move the browser window around, above it, I see a thick horizontal line pattern alternating light/dark (pink/gray'ish) or something, and it instantly goes away if I stop motion.

Re: Pixel patterns that distort color on whole pixel line

Posted: 14 Dec 2014, 08:26
by dclon
Oh. Yeah, the monitor GUI affects and responds to the same problem. It's the actual pixels that matter (can be seen in this video if you look carefully).

So besides the vertical smearing, do you also get it horizontally?