Hello!
It has been a long time since I didn't try something new, because in fact, I thought that I was face to a wall.
But these last times were hard for me with my job and so I decided to relax and I got some new inspiration...
In fact, the thing which bothered me was always that I had in mind a feeling, a souvenir that the aliasing was particular on CRT TVs with the old 2D games, whereas on a modern screen, it doesn't match this souvenir, but not only because the pixels are more visible and bigger.
It's something else. And it's actually definitely the black lines between scanlines which gave this particular look with the aliasing, as you can see here:
If we squint, we can definitely see that all is blending together, giving this particular aliasing that is so different from the way it looks with the raw image on a modern screen.
And so, I tried to understand: why?
Fot me, it's simple: something that is missing is adding some informations!
It's a paradox and a trick with the brain.
It's why I tried to do the exact opposite...
Or in fact, in a different way, with some kind of blur
If it's only a trick with the brain and that we can add information with something missing (the blank lines between scanlines), I supposed that we can to the same thing by adding some blur, whereas we already had doubled the resolution twice.
Theoretically, the same exact pixels than in the original image are still here. But I add an information by blurring them a bit, like the black scanlines do with no information.
But no, in fact, no information is a information too! Here is the logic!
So I tried to find a correct value for the horizontal blur at first in my AviSynth script with the Blur function.
And I found a value that is between 0.25 and 0.50. The average value is:
(0.25 + 0.50) / 2 = 0.375
But it was more complicated vertically, because there should be black scanlines = information with no information.
In fact, with the same value, there would be the same information. So I add something (sharpness, but in fact not, because we are only blurring the image, we are not adding sharpness), with less information (still by blurring the image).
I know that it's a strange logic, maybe this even madness...

But with the half of blur vertically... so:
0.375 / 2 = 0.1875
... I was surprise to see that there is something similar to the effect of the black scanlines, but without them.
I think it's simillar, but in an other way, with an opposite idea.
If we compare closely:
You will not be necessarily agree, but if we think one second how the trick operates with scanlines, we can suppose that it's the same kind of think, but in a different way.
In any case, I think that it's great in movement.
I think that I won't try other things, or for other kind of contents, but I think, I understood how the illusion works.
Know, we only have 2 choices: do something similar with CRT shaders or something different with the same intention, but with another trick.
Have a nice day!