Surprising bahaviour

general questions about Neat Video
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Joined: Sat May 07, 2011 10:55 pm

Surprising bahaviour

Post by Imageman » Sun Dec 02, 2012 3:59 pm

There are some things in Neat Video that surprises me.

In the User Guide it clearly says that "It is important to select either Progressive or Interlaced because Neat Video works differently with these two scan types".
My clips are .m2ts Mpeg-2 transport stream, interlaced. I use Vegas Movie Studio HD 9.0 for
the noise removal,and I decided to test Progressive with these,and I can't see any difference whatever,even looking at close range.
I use that setting regularly now because it shows a bigger frame.
So I wonder of course why the result is the same?

Another thing is the stressing of how important it is to select a even,featureless area for the profiling.
In my video clip is a wooden frame with vertical narrow slats wich the Auto profile selects part of. The slats are clearly visible within the frame and it still gives me a 75% over all quality reading, no clipping detected,uniformity 100% for all (and the result was OK).
That is surprising.
I am not complaining though. Quite happy with the program now after I discovered how very important it is to use Best/full setting in preview when profiling.

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Post by NVTeam » Mon Dec 03, 2012 10:50 am

If there is little difference when an incorrect setting is used, you are simply lucky. In another clip, in another situation, there may be a significant difference between the correct and incorrect setting (progressive vs interlaced). What is important is to know which setting is right in each case. A clip may be interlaced but the project may be progressive and the host may already be doing deinterlacing of the clip before sending full frames to filters for processing. Then the right setting in NV in would be progressive. So it is important to know what you are working with, because you need to tell that to the filter. Vegas itself will not tell, so you need to help the filter.

> The slats are clearly visible within the frame and it still gives me a 75% over all quality reading
That is why you need not only check the quality figure but (actually most important) to visually check the area selected by Auto Profile. Auto Profile doesn't know if those elements are actual details or some sort of banding artifact. You know that they are details because you have more information about that image than the filter has, so you need to guide the filter, helping it select the right area for analysis.
It is not forbidden to select any area, even with details, but you must be aware of the possible consequences: a less accurate noise profile leading to less accurate noise reduction. Some people break that rule intentionally to get smoother results. Which is less accurate in absolute sense, but may look better for some particular (like artistic) purpose.

Image Image Neat Video team
noise reduction for video and photos

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Post by Imageman » Wed Dec 05, 2012 1:20 pm

Thank you Vlad - I had a look at the clip in question again,and I find that there is no other suitable area,it's a very short clip, so the Auto profile had found the best possible area after all.
And it seem that Auto profile usually gives the best result. That is if one look through the whole clip.

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