What version of avisynth do you use? depending on that you might need to use other masktools versions. The best you can do is test each part, especially the core of my script.
Test both of these, they should be working (blur for each dimension, you can also use blur(1,0) and blur(0,1) too)
clp=last uv=3
vblur = clp.mt_convolution("50 99 50","1",U=uv,V=uv)
hblur = clp.mt_convolution("1","50 99 50",U=uv,V=uv)
It’s not fair you criticize my script, this is not state of the art work, I’m not a programmer and it’s a mere 1 hour job. I simply wanted to picture that with some work it shouldn’t be too hard to get rid of the pseudo-transparency/vertical dither or whatever you want to name it. Bare CRT shaders don’t work on them as nicely as I wished, at least on crt-hyllian which is my default shader (awesome shader btw) as I showed above.
Here I show it again, easily explains my point: http://imgur.com/a/1Vrgh
I know there’s no “perfect” solution, but as a tradeoff I would rather have some forgivable errors shown in the vinverse method than the very dirty drop outs of the anti-dithering gdapt shader for checkerboard dithers. My opinion.