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First post, by Holering

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I just find it hard to believe no emulators or filters implement oversampling. It's not exactly hard, and its been used in the audio realm for over 30 years at least. In this world of digital flat panel displays stuck at one resolution, it makes it even harder to believe. At least IMO; which is why I ask .

Here's an example of why oversampling is just so much needed it's not even funny. I'm going to use a homebrew game of Sonic for the SNES.

original 256x224 size
Sonic%20the%20Hedgehog%20-%20SNES-2.png

if you upscale to say, a native 1280x1024 size, you get this on a typical DFP:
8FfqVvF.png

Does that look bad to you? To me it obviously looks nothing how the original looked. It's been turned into a muddy-blurry look after being upscaled with typical bilinear filtering. This is what happens on most digital displays.

Watch what happens when you apply 5X oversampling (which is hardly oversampling for 256x224 to 1280x1024):
ephVDZE.png
That looks way better doesn't it? I didn't even use bicubic or lanczos filtering; it was mere linear filtering.

Even if you stretch it to a distorted widescreen 1280x800 resolution, it still looks really good IMO (besides being fat haha).
UYFXHTT.png

That doesn't even consider what happens when you add scanlines and other filters. Scanlines get really distorted lots of times, until you use filtering; but then you end up with blurry quality that looks nothing like a good display (IMO).

Would anyone even care to have oversampling?

Reply 1 of 11, by obobskivich

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My guess is that it's an overlooked feature - consider how small of a percentage of the population would even actually notice, let alone need, such functionality in their display. I'm not saying you're wrong (and it's actually very nice that you've provided illustrations as examples), just that it's small potatoes compared to such grand problems as stuffing more apps into the next iOS release or adding some new video codec to the next Windows platform. 🤣

Out of curiosity, don't the more recent nVidia drivers support this in a roundabout way?

Reply 3 of 11, by Gemini000

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DOSBox and MAME both support oversampling. :B

In DOSBox, simply make sure you set your output mode to ddraw or opengl and set the scaler to normal2x for high-resolution stuff, or normal3x for low-resolution stuff. If it doesn't work, add "forced" to the scaler selection, like: "normal3x forced"

In MAME, you just adjust the setting for pre-scaling.

I also use oversampling when I render my ADG episodes and I intend to use oversampling with my next game project following my current one as it's a game idea that will be using low-resolution graphics.

As for why it's not more prevalent, I couldn't tell you. It's one of the simplest things to do in terms of coding, so long as you're working with hardware acceleration: You just take your final render for the current frame, stretch it by an exact multiplier using nearest neighbour filtering, then switch to linear filtering and fit it into the window/screen with the appropriate aspect correction applied.

--- Kris Asick (Gemini)
--- Pixelmusement Website: www.pixelships.com
--- Ancient DOS Games Webshow: www.pixelships.com/adg

Reply 4 of 11, by Mau1wurf1977

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obobskivich wrote:

Out of curiosity, don't the more recent nVidia drivers support this in a roundabout way?

Yes I heard about that. I believe they use it as a form of AA.

I have always used 3x in DOSBox in combination with OpenGLnb (non bilinear). That gives nice sharp pixels. Can't stand the soft / washed out look.

@Gemini000

When you say you oversample for your show, do refer to your DOSBox footage? And if so, how?

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Reply 5 of 11, by Kreshna Aryaguna Nurzaman

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Sorry can't stay for long, but...

obobskivich wrote:

My guess is that it's an overlooked feature - consider how small of a percentage of the population would even actually notice, let alone need, such functionality in their display.

Wait, such functionality exists in display monitors? How to use it? The only feature I know is aspect ratio, to preserve 4:3 aspect ratio on wide screen.

Or maybe you're referring to this?

Holering wrote:

Wow! I just noticed Kreshna made a thread about fidelity vs enchancements. Would a freakin' coincidence. I swear I didn't even know 🤣! 😲

🤣

So I guess oversampling is an enhancement to preserve fidelity. 😉

Never thought this thread would be that long, but now, for something different.....
Kreshna Aryaguna Nurzaman.

Reply 6 of 11, by Gemini000

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Mau1wurf1977 wrote:

When you say you oversample for your show, do refer to your DOSBox footage? And if so, how?

When dealing with 320x200 footage, DOSBox records it at that resolution, so what I do is load up the footage in VirtualDub and apply two resizing filters. The first resizes by exactly 200% with nearest neighbour filtering, which results in pixelated 640x400 footage. The second resize brings it up to 640x480 using a bicubic resampler.

While I could theoretically upscale first by 300% to 960x600 then go down to 640x480, I find the results are identical to what I described above since 600 on the Y axis doesn't contain any extra information than 400 on the Y axis for matching up with 480, whereas going from 200 to 480 would result in gradients between each real pixel. In fact, if you know the exact resolutions you're aiming for, you can simply upscale with nearest neighbour filtering to the smallest size multiplier before you exceed the target resolution, then just upscale with linear filtering from there, but it's easier from a programming standpoint to just pick a single oversized upscale resolution and then scale that to whatever target resolution you need to hit. :B

--- Kris Asick (Gemini)
--- Pixelmusement Website: www.pixelships.com
--- Ancient DOS Games Webshow: www.pixelships.com/adg

Reply 7 of 11, by Mau1wurf1977

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Haven't used VirtualDub in ages! Some of my early DOSBox videos I upscaled it similar to yours. However I nearest neighbour upscaled to 1440 x 1080 and uploaded it to YT that way.

My website with reviews, demos, drivers, tutorials and more...
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Reply 8 of 11, by leileilol

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Personally I don't like the whole 'pixel scale' stuff when applied to console games and opt to prefer a NTSC + CRT shader where possible, because on real console hardware it's unlikely you'd get clear and colorful pixels as the "intended" first picture either. 😀

apsosig.png
long live PCem

Reply 9 of 11, by obobskivich

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Kreshna Aryaguna Nurzaman wrote:
Sorry can't stay for long, but... […]
Show full quote

Sorry can't stay for long, but...

obobskivich wrote:

My guess is that it's an overlooked feature - consider how small of a percentage of the population would even actually notice, let alone need, such functionality in their display.

Wait, such functionality exists in display monitors? How to use it? The only feature I know is aspect ratio, to preserve 4:3 aspect ratio on wide screen.

Or maybe you're referring to this?

No afiak there isn't a display that scales like this. But yeah that link is what I was thinking of with the nVidia thing. 😀

Reply 10 of 11, by Kreshna Aryaguna Nurzaman

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obobskivich wrote:
Kreshna Aryaguna Nurzaman wrote:
Sorry can't stay for long, but... […]
Show full quote

Sorry can't stay for long, but...

obobskivich wrote:

My guess is that it's an overlooked feature - consider how small of a percentage of the population would even actually notice, let alone need, such functionality in their display.

Wait, such functionality exists in display monitors? How to use it? The only feature I know is aspect ratio, to preserve 4:3 aspect ratio on wide screen.

Or maybe you're referring to this?

No afiak there isn't a display that scales like this. But yeah that link is what I was thinking of with the nVidia thing. 😀

I actually hoped there are displays that do SSAA on everything. 🤣

I mean, doesn't even have to be 3D; it merely renders the image in higher resolution and then scaled it down while smoothing the edges.

Never thought this thread would be that long, but now, for something different.....
Kreshna Aryaguna Nurzaman.

Reply 11 of 11, by Auzner

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The filters are too "dumb" and make the art look more vague. Breaks nostalgia, LCDs in general do that, which is why I still keep CRTs around. Smarter algorithms are needed to determine curves, islands, and shades. This research paper by Johannes Kopf and Dani Lischinski from a few years ago may change some people's minds about using pixel resampling.
http://research.microsoft.com/en-us/um/people … paper/pixel.pdf
https://www.youtube.com/watch?v=o2Fd-4NzB0w
As far as I know, this isn't used yet in any emulator.