I could answer that with more than a few choice words, but I am too old to be bothered.
I think you are wrong there
Applying a blur will get what you want, but that will degrade the whole image. However you might get 2 pixels (one into the boundary / one out) from the Gimp plugin g'mic http://www.gmic.eu and the filter wavelet antialias.
This a snippet for before / after comparison from the full size image.
Filter looks like this: https://i.imgur.com/ihfdNXD.jpg
Quote:..I have never seen an image with 1px AA
I think you are wrong there
Applying a blur will get what you want, but that will degrade the whole image. However you might get 2 pixels (one into the boundary / one out) from the Gimp plugin g'mic http://www.gmic.eu and the filter wavelet antialias.
This a snippet for before / after comparison from the full size image.
Filter looks like this: https://i.imgur.com/ihfdNXD.jpg