About some pixels and artifacts after processing

[Henox]

Hi guys,

I was trying some settings on a video which is full of grains and noise. I want to get rid of them without affecting the video. I was told by a guy that I have, on the result, some artefacts in the hair of the girl, like "lines of pixels" as he said. I asked another person why I got such thing and he answered it might be due to the way the video was filter.

Below is the first avisynth script i used to filter it :

Import("C:\Program Files\AviSynth 2.5\plugins\Antialiasing.avs")
LoadPlugin("C:\Users\....\Videos\DGIndex\dgdecode.dll")
LoadPlugin("C:\Program Files\AviSynth 2.5\plugins\External\denoise_25_dll_20051215\denoise.dll")
LoadPlugin("C:\Program Files\AviSynth 2.5\plugins\External\degrainmedian_25_dll_20051009\degrainmedian.dll")
LoadPlugin("C:\Program Files\AviSynth 2.5\plugins\External\addgrain_25_dll_20030618\AddGrain.dll")

AVISource("C:\Users\....\Videos\EXAMPLESVIDEO\stuck_test_lagarith.avi").DEEN ().sharpen(1.0).AddGrain(2, 0, 0)
hqdn3d(2.0)

Undot()
antialiasing(12,15)
crop( 8, 2, -8, -2)
LSFMod(smode=5,secure=true,lmode=2,undershoot=4,edgemode=2,strength=80,soothe=true)
Tweak(bright=+3)

Then this is too screenshot of the processed and unprocessed video :

- from the stuck_test_lagarith.avi unprocessed source which is only ivtced :

http://img199.imageshack.us/img199/9215/stacieunprocessed.jpg

- from the stuck_test-2nd.mkv processed source which is filteredwith the previous avs :

http://img3.imageshack.us/img3/1526/stacieprocessed.jpg

Then this is the too samples uploaded at sendspace :
http://www.sendspace.com/file/aelzhc
http://www.sendspace.com/file/k2nbxt

So you will see some pixels are trembling on the hair (they are not fixed like in the unprocessed video), how could I avoid that, is that due to the filters ? I precise that it is not visible in the whole video though.

[g-force]

So you will see some pixels are trembling on the hair (they are not fixed like in the unprocessed video), how could I avoid that, is that due to the filters ? I precise that it is not visible in the whole video though.

I'll say that it's due to the way the video was filtered. Here's what your script looks like to me:

AVISource().denoise.sharpen.addnoise
denoise

denoise
blur
crop
sharpen
brighten

Might consider something like:

AVISource()
crop
brighten
denoise
sharpen

The problem is that every one of those filters you apply has some positive effects, and some negative effects. String enough of them together and the negatives outweigh the positives.

BTW, getting rid of the Sharpen(1) will go a long way.

-G

[m3mbran3]

You could try removing filters and seeing what affect they have on the output. I'm pretty sure undot() just removes stray pixels so that is unlikely to have an effect, I'm guessing that it is likely to be caused by your sharpening. From the samples you provided the filtered version is way to sharp, almost unnaturally so.

[MatLz]

Hi guys. Maybe it's antialiasing.avs which do these pixels. If I remember, antialiasing.avs uses sangnom.dll, and I have noticed many times sangnom did the sames artifacts when I use it for deinterlacing.
Maybe...