Blend dithering without unwanted artifacts?

RetroArch Additions Shaders
#1

It seems like every filtering method available is unable to blend dithering without introducing unwanted artifacts. Every shader I’ve tried falls into one of these two categories.

Gaussian blur - black lines lose all sharpness, destroying a lot of details in pixel art. Highlights get completely blown out. Too much detail is lost.

Lanczos, catmull-rom spline, others - black lines become way too bold, white lines become too thin and the image loses contrast. Ringing artifacts can be a problem.

Do any filtering methods blur dithering without the unwanted side effects?

1 Like
#2

No ordinary filtering can deal with dithering in a meaningful way i guess. Best to give the gdapt shaders a chance, they detect dithering patterns and return an averaged color instead of the pattern. I tried it with some games with heavy dithering and it was ok.

2 Likes
#3

NTSC filtering does it sort of (if you don’t mind the rainbows and blur), and jinc2 can do it with the right settings (it’s another windowed function, like lanczos, so it has the same issues), but anything that acts on all pixels regardless of whether it’s part of a dithering pattern or not is going to have a lot of unwanted effects.

Something targeted like mdapt/gdapt still has unwanted effects in the form of false-positives/negatives when the pattern-detection trips up, but they at least don’t come with the more generalized unwanted effects from filtering every single pixel.

2 Likes