Debunking “FSR is just Lanczos” claims

1 : Anonymous2021/08/07 22:11 ID: p02jd3

So I will start off by saying FSR is based on Lanczos however it is much faster which allows better performance and it also solves a few major issues from Lanczos, most notably the ringing artifacts.

I took some screenshot comparisons of FSR vs FSR + RIS vs Lanczos with FidelityFX Sharpening in Rift Breaker vs FSR with Magpie + FidelityFX Sharpening

All images except Native are 720p to 1440p upscaled. Ray Tracing was turned to Max.

Magpie seems to add way more sharpening than the real FSR was even after adding 60% RIS

But anyways lets get back to MagPie to inject fsr vs injecting Lanczos

A super zoomed in on the characters will show the biggest difference in Magpie Lanczos vs Magpie FSR

You can see insane amounts of artifacts on the Lanczos scaling (Right) with a much better impage on the MagPie FSR (Left)

Not to mention the performance impact on Lanczos is insane.

Because I did not disable Fidelity FX on the MagPie FSR there are some over sharpening artifacts however its still much better than the Lanczos especially on the edges of objects.


Alex is wrong by saying using Lanczos + Sharpening will give you the same image as FSR even when using Fidelity FX Sharpening on Lanczos its still no where near as good as FSR.

2 : Anonymous2021/08/07 22:34 ID: h83tdlw

People are always trying to cast dispersion of some kind, it seems. I think most people ignore the FUD out of hand, but still I certainly agree with you.

3 : Anonymous2021/08/07 23:14 ID: h83y46m

should add a native 720 to the comparisons

ID: h83yx6c

Point was more to compare Lanczos to FSR not comparing them both to native or both to unscaled but I should have yes good point.

ID: h840m23

yeah, would just give another point of comparison so you can see what kind of mistakes the scalers are making. kinda looks like FSR magpie isn't grabbing lossless frames for some reason, getting some edge block formations similar to sharpening a compressed image, though this doesn't show up in the lanczos + magpie image even though theres more sharpening and more artifacts.

4 : Anonymous2021/08/07 23:37 ID: h840siz

It's worth mentioning that the Lanczos from Magpie is actually drastically different from every single other implementation I have seen so far, it looks much better (and it's also insanely heavy). I made a similar comparison once using the FSR demo from Github and comparing it vs a screenshot of it I took at 1080p and upscaled through FFmpeg, madVR and Hybrid.

Saying that the FSR results were a lot better would be a big understatement, not only I got much better edges with FSR but also all the ringing around edges was gone. And I did disabled the sharpening pass to make it fair, because I only wanted to compare the upscaling.

I'll add an edit with the links to the albums if I manage to find that comment I made a while ago.


FFmpeg lanczos 1080p to 2160p

madVR lanczos 1080p to 2160p

FSR Performance with the sharpening disabled

Direct comparison 400% zoom

I didn't included the Hybrid results because it looked identical to the other two.

5 : Anonymous2021/08/07 22:49 ID: h83v514

Who the hell says FSR is just Lanczos. The source code shows it's clearly not. They optimized it, removed the common artifact associated with that method and then added a edge detection routine, to keep edges nice and defined.

You can see it clearly in your left vs right comparison, the edges of that unit and it's weapon is smooth and clear while the regular Lanczos is jagged and aliased.

Its almost as if FSR being good enough, somehow hurts these morons who worship DLSS, especially those who keep on claiming its better than native.

About DLSS, here's Hardware Canucks 2021 look into it, and they were not impressed at all.

Funny they mention all of the issues I had with my week's experience with DLSS on a 3070. It's blurry in motion, ruins textures, and had terrible ghosting problems. Yet when I said it, I had fanboys pile on claiming I was making it up, DLSS was "better in motion"! Like total bullshit.

Edit: Removed the bad language.

ID: h83vnji

Alex from Digital Foundry made the claim on twitter after he was angry that people were using MagPie and instead was telling people to use Nvidia Sharpening + GPU scaling in control panel for better results. And its been repeated by other people.

tl;dr, Not only did he claim its the same thing he claimed that Lanczos is superior

Same Lanczos upscale as FSR (with more taps for higher quality) with controllable sharpen.

/1422982316658413573" class="reddit-press-link" target="_blank" rel="noopener">

Its clearly something he doesn't believe as he refused to post pictures to support his claim.

It is still on the front page of /

ID: h840g9e

Did he implied NV's control panel up-scaling is either the same as FSR or better? lol

Man, Jensen could have just packaged that and launched it as DLSS 1.0 instead.

ID: h83wgpg

People still take DigitalClownery seriously?

EDIT: Also, Nvidia CP sharpening is utter garbage. It's worse than RIS. I can easily see over sharpening with Nvidia while there was none with RIS.

6 : Anonymous2021/08/07 23:25 ID: h83zg88

There have been threads of people in /

claiming FSR is simply a bilinear (or lanczos) upscale with CAS sharpening enabled. Utterly clueless, all you need to do is rtfm on gituib and see that's not true. Even if it were true, it's irrelevant!

It doesn't help that DF, who usually do great tech reviews, did an awul job with FSR.

There are to be a large number of people who, due to the fact that FSR is

Simple Includes no temporal data or motion vectors

Believe it must therefore be awful.

This is, of course, illogical, as the complexity of a tool has no bearing on it's efficacy.

If I could manufacture a quad core CPU on a 40nm process that was nearly as performant as a 5900x, at a fraction of the cost, that could magically fit any motherboard, that would be a good thing.

In the analogy, some are essentially arguing that the 40nm quad core is bad by virtue of the fact it has fewer cores and uses an old process.

7 : Anonymous2021/08/07 23:16 ID: h83yc8f

Even if it was, I wouldn't have any qualms about it.

8 : Anonymous2021/08/07 22:42 ID: h83udsu


ID: h83uu2f

Someone did and the thread was in frontpage of

with few counter arguments.

People were blindly agreeing.

ID: h83uuyj

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9 : Anonymous2021/08/07 23:32 ID: h84059e

Interesting write up, thanks for sharing! Love the benefit of an open source solution: no need to speculate when you can just find the answer!

10 : Anonymous2021/08/07 23:02 ID: h83wqtz

Why don't you just compare the source code ?

ID: h83x4wg

The source code is different than Lanczos it just has a mention that its based on Lanczos. I showed images comparing Lanczos to FSR here.

ID: h83xgcq

images are subjective. code does not lie.


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