Maybe bug, maybe not in degrainmedian filter

[Serbianboss]

I maybe found(maybe not) a bug in degrainmedian 0.8.2

My soure is Pal,interlaced,btt,YV12 film. I wanted little to clean because its grainy.

Firstly, i use DGIndex to make d2v file and than make this simple script:


LoadPlugin("degrainmedian.dll")
LoadPlugin("C:\Program Files\AviSynth 2.5\plugins\DGDecode.dll")
MPEG2Source("C:\Desktop\tst.d2v", cpu=0)
DeGrainMedian (limitY=5,limitUV=7,mode=0,interlaced=true)


And i have some green and white line(or spot) on pictures. This i have when work with degrainmedian. Whit FFT3d or vague denoiser i dont have that problems.

Here is the pics(you must zoom to see diference)

This is original
http://img296.imageshack.us/img296/9106/originalcm3.jpg (http://imageshack.us)

This is with degrain:
http://img329.imageshack.us/img329/5844/degraintr6.jpg (http://imageshack.us)

This is FFT3D:
http://img296.imageshack.us/img296/5944/fft3dfilterry8.jpg (http://imageshack.us)

Late i will upload more pics where you can see green spots.

[Didée]

The effect you're trying to show gets lost in the jpeg artefacts. Especially the ringing of the red arrows ...

Please post PNG screenshots.

Edit -
From what I might guess/pretend to see in the pic, it's not a bug, but rather a characteristic of the method. DegrainMedian after all is a median filter ... artefacts of temporal median clipping definetly can produce such artefacts. mode=0 is aggressive, and limitY=5 is in range of those faint artificial lines.

[Serbianboss]

News pic[png format]:

First picture, vertical white lines:
http://imagecloset.com/show.php/448898_degrain1.PNG.html

Second picture, green spot(s)
http://imagecloset.com/show.php/448906_degrain2.PNG.html

What you think. Maybe parametars is too high(5,7,0) but with FFT3d sigma=3 or with high vague parametars dosnt see any green spots.

[Daodan]

As Didee said, mode=0 is very agressive and together with the other settings does indeed give this sort of artefacts (if it's bug or normal I can't really say, but I want to point that you're not the only one). First saw this when testing usabilty of degrainmedian on anime, and got even worse artefacts in my case (and green was their color too ^^).
Each filter has its own uses. Seems turning into mush a video isn't degrainmedian's strong point.