Backward compatibility is always appreciated, there's no doubt about it. However, sometimes a console's implementation can be lacklustre, either due to technical difficulties or laziness on the manufacturer's part. Depending on who you ask, the 3DS' DS/DSi mode can be said to fit in either: your only options are to either play games upscaled to the 3DS' screen resolution, which includes a blurry filter that cannot be turned off, or in native res mode, which is hardly ideal as it doesn't make use of the entire screens - thus introducing big black bars all around. Due to it, some people preferred playing DS(i) titles on past consoles as it made a number of games look significantly better without any compromises.

But things are finally starting to change with the release of TWPatch made by @Sono. After lots of research and reverse engineering, he made a patcher that is able to change how TWL_FIRM's image upscaling behaves. A total of nine different scaling filters are available (not counting Nintendo's default one), several of which are able to make your games look much sharper than before! In order to give you an idea of what to expect, here is a comparison taken from the thread (made by @youny43 - left: default / right: patched) :

​

For the curious, here's a list of the included filters:

• Nintendo default
• Sono's crisp (original patch)
• Sono's crisp (tweaked)
• Zero interpolation (double pixel)
• Linear interpolation 1
• Linear interpolation 2
• Sharpen test 1
• Linear sharpen 1
• Darken crisp
• Darken Nintendo

The patcher works on both Old and New 3DS models as long as they are running Luma CFW. You need to have enabled loading external FIRMs and modules in Luma's configuration menu, otherwise, the custom filters won't be applied. The process can take several minutes, so be sure to have enough battery charge (and patience) before proceeding. If you're unsure on which one to apply, you can preview how they'll look inside the homebrew app and compare it to Nintendo's default one.

If you want to try this yourself, make sure to read the instructions & remarks in @Sono's post before downloading (linked below).

Source

 

[The Real Jdbye]

See my post earlier on this page, I posted screenshots of every filter available in TWPatch right now. Again, the way they look on whatever device you're using to read GBATemp won't be the same as on a 3DS.

Thanks. Linear sharpen 1 looks very similar to the original, just with more sharpening applied. I think I prefer the original by just a tiny bit, since sharpening filters like that tend to result in a slight halo effect around edges and that is definitely apparent here. Some people might not mind that though.
Linear interpolation 1 is more blurry than Nintendo's own filter.

Looking at all this makes me think that Nintendo actually did think this through and try out different scaling options before settling on the one that was ultimately included. As most of these have jagged edges, and the ones that don't look very similar to Nintendo's own, to such a degree that on a real console I can't imagine you would be able to tell the difference between them at all.
But there is definitely room for improvement with more advanced scaling options being a real possibility, and I'm interested to see what improvements this project will get in the future. I'm not expecting xBRZ or anything (honestly wouldn't make sense on a screen this small/low res anyway), but intelligently detecting edges and contrasts, smoothing those out while upscaling everything else using a different filter, sort of a hybrid between 2 (or more) filters, could have very good results.

I took out my best camera, yet it's still not possible to capture the difference using it due to how subtle yet noticable it is in games. Sadly no matter how I try, I can't capture the differences using a camera, especially when comparing linear interpolation to linear interpolation with slightly more edge detect.

Spoiler: Nintendo's default

Spoiler: Linear sharpen

I could tell the difference just fine. Although the difference isn't great. I think the difference comes across better on screen captures like the ones @Vague Rant posted.
I might slightly prefer Linear sharpen over the default for 2D content like what you posted. For 3D content, I still prefer the original based on what I've seen. But then again for 3D content the filtering was never really an issue to me. It's 2D content that really suffers.

 

[Sono]

Thanks. Linear sharpen 1 looks very similar to the original, just with more sharpening applied. I think I prefer the original by just a tiny bit, since sharpening filters like that tend to result in a slight halo effect around edges and that is definitely apparent here. Some people might not mind that though.
Linear interpolation 1 is more blurry than Nintendo's own filter.

Looking at all this makes me think that Nintendo actually did think this through and try out different scaling options before settling on the one that was ultimately included. As most of these have jagged edges, and the ones that don't look very similar to Nintendo's own, to such a degree that on a real console I can't imagine you would be able to tell the difference between them at all.
But there is definitely room for improvement with more advanced scaling options being a real possibility, and I'm interested to see what improvements this project will get in the future. I'm not expecting xBRZ or anything (honestly wouldn't make sense on a screen this small/low res anyway), but intelligently detecting edges and contrasts, smoothing those out while upscaling everything else using a different filter, sort of a hybrid between 2 (or more) filters, could have very good results.

Yeah, in contrast they definitely did settle on a relatively good matrix.

Too bad it's not possible to use anything but symmetrical matrixes. I tried searching for upscale matrixes, but I only get results for Gaussian blur, which are the opposite of what I want. If you have any matrixes you know of then let me know, and I'll try porting it to the matrix hardware.

 

[Justinde75]

Wonder if there is one that stretches the game to the whole screen

 

[Sono]

Wonder if there is one that stretches the game to the whole screen

That has been requested a few times in the original thread, and it is already on my reverse engineering queue.

 

[Justinde75]

That has been requested a few times in the original thread, and it is already on my reverse engineering queue.

Great because I am one of these disgusting people that like have games stretched to the whole screen

 

[Sono]

Great because I am one of these disgusting people that like have games stretched to the whole screen

Sadly it's not possible to stretch it all the way to 400px, but 384px should be close enough, just 8-8 pixels on each side of the screen.

 

[Justinde75]

Sadly it's not possible to stretch it all the way to 400px, but 384px should be close enough, just 8-8 pixels on each side of the screen.

Hey its still something, always better than nothing!

 

[Foxi4]

Very nicely done. Stock scaling leaves a lot to be desired, it's good to see custom solutions popping up at long last.

 

[Flame]

well done to @Sono for this amazing project.

also well done to @RattletraPM for front paging this.

 

[SonicMC]

well if a picture doesn't really show differences. perhaps someone can upload a video No hurry by anyone to do so. Thanks @Sonos; always fun to have more features and options!

 

[ImLEBrAn]

Does this work with R4's or only legit DS cartridges?

 

[Vague Rant]

Does this work with R4's or only legit DS cartridges?

Anything at all that runs in DS or DSi mode. That means flash cards, DSiWare and anything in between.

 

[DSoryu]

well if a picture doesn't really show differences. perhaps someone can upload a video No hurry by anyone to do so. Thanks @Sonos; always fun to have more features and options!

I posted a video a while back in the original thread:



I tried to zoom as much as possible, it is running the first ever released patch, I believe it is:

• Sono's crisp (original patch)

 

[XDel]

If you want to try this yourself, make sure to read the instructions & remarks in @Sono's post before downloading (linked below).

Source

I can't go any lower, where is the link?

 

[RattletraPM]

I can't go any lower, where is the link?

Source

Spoiler

EDIT: Woosh.

 

[Sono]

I can't go any lower, where is the link?

Source

Spoiler

EDIT: Woosh.

Not all browsers seem to be able to scroll to that post, including mine.

https://sono.9net.org/hebrew/TWPatch/data/TWPatch.cia

 

[helltoast]

HONESTLY I CAN'T SEE any difference.......

you people must be blind. or just grossly unatentive. the difference is obvious even in the op, just look at the font, but Vague Rant made a great comparison.

default is essentially bilinear with a little sharpening, this shouldn't be surprising to anyone who's ever used an image editor before. crisp is nearest neighbor scaled unevenly and linear is just bilinear filtering. personally I think linear sharp looks the best if default is too blurry for you.

it's a shame the 3DS doesn't have a 384 resolution for pixel-perfect scaling. at least Sony got that right with the Vita. fantastic job nonetheless, @Sono.

 

[banjo2]

I don't have a 3DS, but hey, this is really cool! Good work @Sono

 

[kuwanger]

Thanks for all the work Sono. Wish I could help. Any chance in the future of subpixel scaling?

 

[Sono]

Thanks for all the work Sono. Wish I could help. Any chance in the future of subpixel scaling?

Thank you for this! I bookmarked the page so I can give it a read when I'm less tired and have time