How I fixed over-sharpening on my TV

I did something rather unusual today. I fixed a problem actually caused by my TV. So I figured I might as well make it a guide - it may be a rare problem, but perhaps somebody else may find it useful.

Introduction & description of the problem

First, the problem I solved: My TV over-sharpens the image on the screen. If you have a problem similar to this, then my explanation of how I fixed it may help. Note that this fix is nVidia specific, as it relies on a feature of nVidia cards.

The TV I have supports up to 1080p. And I can drive it that far, and it works. But, there is a problem: It has a "sharpen" option. The sharpen option passes a filter over the entire image to sharpen it. Which sounds pretty cool to try to enhance the image, but has a side effect - if you over-sharpen an image, it can cause a "fringing" effect at the edges, making a noticeable and distracting outline around many objects.

Unfortunately, even at the lowest sharpness level on the TV, it still applies the filter; there is no "off" switch. It's very ugly, and I'd rather avoid it. So in order to deal with this limitation, I need a slight blur effect.

Here is a preview of what the problem may look like (left half is over-sharpened, right half is normal):

Dealing with the problem and the nVidia feature that fixes it

For a while, I dealt with it by going to a lower resolution level. Using a lower resolution does have a bit of a "blurring" effect, but at the expense of detail. My laptop detects the "native" resolution of the TV as 1360x768. This is likely intentional by the TV manufacturer, as this resolution does fix the fringe. I suppose they figure most consoles at the time were outputting at a similar resolution (although that is certainly not the case anymore).

But I re-discovered a feature that nVidia video cards have which really helps.

nVidia's video cards have an interesting feature called "DSR." There are two options related to DSR: Factors and Smoothness.

The DSR technology is quite simple: It draws the graphics at a higher resolution than your monitor supports, then scales it down to your monitor's native resolution. This may seem odd, but ultimately it's a way to fix aliasing, a problem games tend to have because when multiple objects cover a pixel, video cards usually select one object or the other to cover that pixel. This creates a "stairstep" effect that is generally ugly.

The "factors" part of DSR selects how much higher you want to render the image at. The particular factor I am interested in is 4.00x, which is the equivalent of a 4K monitor.

The other part of DSR is "smoothness." The purpose of this setting is to overcome some artifacts at different factors, when the factor isn't quite a multiple of the screen's native resolution. This is in fact a blur filter, which is exactly when I need to fix this problem when driving my resolution to full 1080p.

How to fix the problem

So, what do I do?

• I've enabled DSR factors 2 & 4. This allows me to use DSR and its smoothness effect. The 2 & 4 factors are multiples of the resolution that tend to work well. There is no 1 factor, unfortunately. But that's because nVidia wasn't expecting DSR to be used to fix this type of problem.
  
• I set the smoothness to a level I deem workable. Between 33% and 50% seems to work well. Too low, and it won't offset the TV's over-sharpening. Too high, and I get a blurry image.
  
• DSR does work with Windows! I can set the desktop resolution to be higher. In order to offset the increased resolution, I set Windows' scaling option to a comfortable level for my TV.
  
• In games, I can now set the graphics options to the DSR resolutions to get rid of the fringing.
  
• In American Truck Simulator and European Truck simulator, I set the scaling to 50%. This causes the game to render at the native resolution instead of the DSR resolution, which helps with performance (DSR is performance hungry, and my laptop really can't handle rendering the game at 4K). For Antialiasing, I use other techniques.

The costs of this fix

It is not without its costs, however.

• It is not perfect, and never will be. Over-sharpening an image then blurring it will always leave some defects. That said, it is much more tolerable and being able to play at full 1080p gives me much more detail.
  
• DSR is power hungry. I can't use it in all games without a significant performance hit. I may have to go back to the standby of reducing the resolution to 1360x768 in games that don't support it.

Games that work well with this technique

That said, there are some games that work well:

• Older games that don't tax my card to begin with.
  
• Newer games that allow for scaling the image independent of the screen's resolution. In this case, reducing the image to 50% makes it 1080p again. There is still a performance impact, but not as bad as leaving it at what is essentially a 4k resolution.

Note that in American Truck Simulator, this option is called "scaling." Its purpose is to allow you to adjust the rendered resolution independently of the resolution it sends to your monitor. Over 100% is often used to help with aliasing issues on low resolution screens. Lower than 100% is often used to run the game on low end machines with less power. For this particular technique, I'd recommend setting it to 50%, which offsets the increased resolution that DSR uses.

So I'm pretty happy now 🙂. There aren't a lot of games that I play on the TV, but something like American Truck Simulator is definitely something I'll play when I feel like playing a chill game.

[CobraA1]

Note that I no longer own this TV and have a new one. This guide will remain just in case somebody else encounters this problem, but I expect it to be super rare.