Can it improve image quality besides the usual aliasing? (I know that nothing can truly replace real pixels)
It also improves the texture AF quality (moire reduction on high-frequency textures), by "pushing back" the kernel filter due to the higher render resolution -- a natural byproduct, sort of.
I've also seen cases where some distant objects weren't even rendered at 1080p. I'd say you get higher detailed scene overall.
The gaussian filter included with DSR supposedly uses similar tech as bokeh DOF. In most games DSR adds a nice soften effect to background noise and doesn't just fix aliasing. This is especially true when combined with SMAA/FXAA. Old games can look a bit more modern with DSR compared to just downsampling or throwing on tons of AA. I spent a while comparing image quality between DSR and just heavy AA, and DSR IQ always came out on top for me. Correct me if I'm wrong.
Nothing to do with bokeh DOF. A "13-tap gaussian filter" I'm sure can be used with bokeh DOF, but a filter can be used on just about anything. It's just a filter. You're probably getting that from some Crysis promotional material.
That's.. not quite it. Gaussian algorithm has many uses especially for image manipulation but DSR doesn't have anything to do with adding DoF (especially fancy looking bokeh). You can use gaussian algorithm to create blur filter too but gaussian filter but in this case you can just adjust the resizing filter a bit. DSR is not pixel resize with gaussian blur filter applied to it.
Ah, that sounds about right. I wasn't claiming it added DoF, only that I read somewhere that it has similar technology as Bokeh does. I hold no claims of knowing exactly how DSR works, only from a personal experience how well it works.
I've done lots of testing with DSR or downsampling in general compared to using all forms of AA. In the end, DSR or downsampling improved image quality. The Gaussian blur is just added to soften the overall image because the image quality can appear too sharp due to not actually having the pixels you are trying to display. It does improve everything and is superior to any form of AA. It also renders objects in the background much better than standard 1080p with AA.
It's not that it's too sharp, it's that unless you do the 4x mode which doubles resolution on width and height, when it's downscaled you'll get effects like bumps or waves in straight edges (especially diagonals) as there is literally missing information. The Gaussian filter is applied at the upscaled resolution before downscaling, and blends pixels (or rather blurs them, hence the Smoothness setting) so that when downscaled, more pixels can be used to represent the edges and this effect is minimised. If you can afford to do 4x in game, set Smoothness to 0 for the best image quality. Anything less however and some smoothness usually helps. Edit: the other major advantage for downscaling (be it Gedosato or DSR) is increased resolution in the quality of textures. Even though the end result is downscaled to your resolution, there is increased fidelity to the detail on textures. In an ideal world, you'd run DSR at 4x on everything. However, we simply don't have the GPU grunt to do that with most games, even with SLI.
Question regarding DSR and Smoothing.. I installed Tomb Raider (newer version) and I set DSR to 1.2x. It automatically set smoothing to 33%.. Is it best to leave the smoothing factor set according to how it gets set up automatically? Or is it better to keep it at 0%? Or 50%? Etc...
I use an HDTV also. What does Smoothing do exactly? Whats the difference from setting it to 0% to 100%?
It adds a gaussian blur to the images to smoothen them out. With HDTVs you typically need more to compensate for the lack of pixel density vs a large screen (1080 native on a 42inch is a lot more pixelated than a 22inch for example). For me, and I game on a 42inch, 45% works really well. Play around with it. Try default and slowly bump it up. Martigen said it best: "The Gaussian filter is applied at the upscaled resolution before downscaling, and blends pixels (or rather blurs them, hence the Smoothness setting) so that when downscaled, more pixels can be used to represent the edges and this effect is minimised."
