Blurry upscaling on LG CX OLED

[kazaakas]

Hello folks,

 

So I'm a big fan of pixel-art graphics games, some of which only run on 1080p, or I play on my switch that can only output at most 1080p.

When I output a 1080p signal to my LG CX OLED (in game mode, with instant game response on), the way the image is upscaled to 4k, it loses its sharp lines and adjacent pixels start affecting one another.

This is most visible on sharpness tests like this one: http://www.lagom.nl/lcd-test/img/sharpness-d.png. On my pc monitor, this looks perfect, on the OLED at 1080p, there appears gray in between the white and the black. So clearly there is some interpolation going on. I understand this is the most desirable upscaling method when displaying most content, such as movies, or 3D games, but content that relies on sharp lines loses its sharpness.

 

Peculiarly, I normally strongly dislike super high sharpness settings, but when I max out the sharpness on the display this test image looks a lot more like the original (still not perfect) when outputted at 1080p.

 

Ideally I'd just let the TV do 1:2x2 pixel mapping (e.g. pixel doubling) when displaying 1080p content. Does anyone know the best way of achieving something (close to) this? Or am I just expecting something way too specific from a general purpose TV?

 

Thanks!

[Chris Pratt]

Game mode actually disables all post processing by the TV. That's how it's able to achieve higher refresh. You're basically just getting the standard bilinear upscaling you get trying to stretch any image to a larger amount of pixels.

[porina]

What GPU? I think Intel were first to implement integer scaling with the others following, but it isn't something I tried. Look in your GPU settings for that.

[leclod]

I thought Windows was the master. So if windows is run at 4k then the tv always thinks it shows 4k even if the 4k only contains fullHD data.

[porina]

1 minute ago, leclod said:

I thought Windows was the master. So if windows is run at 4k then the tv always thinks it shows 4k even if the 4k only contains fullHD data.

There are multiple interfaces at play here. At software level it supports certain resolutions and might be able to scale between them (render scale, DLSS, FSR, DSR), then you have the output resolution set in the GPU, and whatever resolutions the display supports. Generally speaking it is nice to have the GPU output match the display native resolution. Any scaling can be done in software or GPU. 

 

 

I just realised I missed a comment in OP, that they use a Switch. If PC GPU there would be more options, but I don't know what's possible using the TV only.

[KaitouX]

On PC you can just change the scaling method to nearest neighbor/integer scaling, on Nvidia GPUs from the 1000 series and newer: Go to the Nvidia Control Panel > Adjust desktop size and position > select "Integer Scaling" and "Perform Scaling on: GPU", on Intel and AMD GPUs there should be an equivalent on their respective control panel, for older Nvidia GPUs you need third party software to force integer scaling(search for IntegerScaler to find the options). On consoles that support 4K output the Devs might be able to make the console upscale using the desired method, but I don't think the TV itself can do it, it's probably limited to the method the manufacturer selected.

[Stahlmann]

Use integer scaling like @KaitouX mentioned. That basically makes every 4 pixels of your 4K screen act like 1 pixel of a 1080p input. Every halfway modern GPU has this option somewhere in their drivers.