how to deal with posterization in anime animation

[zanzar]

this is a continue tread from the last one,just for different purpose.
i have anime dvds and i am trying to better their quality (i know some people hate this kind of thing here),and they will be posted and shared on a site.
i know you cant add detail (for that you need to hand draw each frame to add detail),and its NOT what i am trying to achieve.
since animation is so fundamentally different from video recordings,so also what applys to them is different
most times animation (with emphasis on anime) is just different colors seperated by black lines (or different color scemes).
now ill seperate it to 2 categories.

1.close up shots, in which you see most of the detail (lets say some charecter is talking and his size takes most of the frame)

2.far away shots, lets say seeing a crowd of pople each drawn like he is far away.

since the source is DVD and only 480x720 in resolution, the detail from afar will be much less, well detailed.
90% of the animation is number 1 (generally i think animators know that so they avoid as much as they can number 2)
for example a close shot dvdrip vs my attempt to better it with filters LINK
and here is what ill consider a far shot (the one pointing the sword) LINK
(ill note that this is relatively bad comparison and the result most time is better with different dvds i tested,i choose this because i have a blu-ray of it to compare to)

here is the bluray compared to the dvd LINK1 , LINK2

imo (and many others i asked) the attemt actually makes it more plesent to watch,the animation looks smoother and more clear,and there is much less noise or artifacts (its one thing to just compare shots and look at the whole result run), and in close shots it can par (a little bit) with the blu ray since essentially no detail was added in the first place because its "close" and there is nothing to add,unlike far ones where there is new detail added in the blu ray.

how i do it in short.
rip the source into frames with a script that cleans it a bit and sharpens the lines.
use waifu2x-caffe on them,then use linedarkening scripts like "hysteria" and increse the levels if the colors are to washed out then resize it to 720p and recombine them back into a video file.

now lets get to the point.
if i increse the levels (even some times if i dont) it causes the posterization become more visble and it varies in its strength (in different sences)
i uploaded a smaple for comparison

1.original

2.processed with the process i told you and this script

ImageSource("D:\pic\pic%06d.jpg", fps=23.976)

converttoyv12()
ColorMatrix(mode="rec.601->rec.709")
levels(30, 0.85, 246, 5, 255, coring=false)
tweak(sat=1.3, coring=false)
Hysteria(strength=1.0, maxchg=30,lowthresh=8)
Sharpen(0.25)
Hysteria(strength=1.0, maxchg=35,lowthresh=6)
Blur(0.35)
Hysteria(strength=1.0, maxchg=30,lowthresh=4, highthresh=60)
Blur(0.35)
Dehalo_alpha(rx=3, ry=3, darkstr=0.6, brightstr=0.6)
nnedi3_rpow2(2, cshift="spline64resize", fwidth=1280, fheight=720)

notice the posterization going crazy aroud his shirt collar

3.my attempt in fixing it with

converttoyv12()
ColorMatrix(mode="rec.601->rec.709")
smoothlevels(30, 0.9, 250, 5, 255)
Hysteria(strength=1.0, maxchg=30,lowthresh=8)
Sharpen(0.25)
Hysteria(strength=1.0, maxchg=35,lowthresh=6)
Blur(0.35)
Hysteria(strength=1.0, maxchg=30,lowthresh=4, highthresh=60)
Blur(0.35)
nnedi3_rpow2(2, cshift="spline64resize", fwidth=1280, fheight=720)
McTemporalDenoise(settings="medium")
GradFun3 ()
Dehalo_alpha(rx=3, ry=3, darkstr=0.5, brightstr=0.5)

also added 2 other samples- 1.with the first script 2.second with an attempt to fix it(didnt add the original)
i found out that "McTemporalDenoise" can take care of almost anything i throw at it (including this)the only problem it is slow. more so in 720p
if i try to increase the levels before the waifu2x, the source looses a lot of detail.

i am here to hear your suggestions on how to minimize the posterization (as you saw it can be minimized to berable extent).
also i am looking to by a new cpu because my cpu is old and is slow.
also does a multi threaded avisyth works well? (lets say 8 cores 16 threads) (i have 4 cores 4 threats...) and still virtualdub\Megui dont run at 100% with my cpu (why?)