Building noise with NV4

questions about practical use of Neat Video, examples of use
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jpsdr
Posts: 199
Joined: Mon Aug 11, 2008 7:33 am

Building noise with NV4

Post by jpsdr » Wed Nov 04, 2015 10:10 pm

Finaly, i've try to test the v4. (VDub v4.0.9).

The video i'm using is an anime with very little noise.
Anime means a lot of flat area, but... Impossible to buid noise.
Each time there was always a message about Y and/or Cb or Cr being not uniforms... On perfect flat areas !!! On anime, digital production with only a very very little of noise.
I've switched to NV3, and, surprise ! All the perfect flat areas NV4 was bugging me not being uniform, absolutely no message with NV3.

Either there is some new kind of setting somewhere i didn't find, either there is something wrong.

NVTeam
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Post by NVTeam » Wed Nov 04, 2015 10:31 pm

Or perhaps NV4 is just trying harder to avoid poor areas?

If you see that the area is uniform and noiseless that means there is little or no noise but most likely still a lot of compression artifacts that are typically not uniform (try to increase the contrast in those areas, you will see that). That is what NV is detecting and reporting in such cases. That shouldn't be a problem though because you can just ignore that report (it is not some kind of critical error or something, just a warning) and proceed to build a noise profile and then filter the video.

If you do not want to receive those warnings at all, you can disable them in Neat Video Preferences. Then you are on your own and if you know how to build noise profiles then you should be good even without that assistance from NV.

Thank you,
Vlad
Image Image Neat Video team
noise reduction for video and photos

jpsdr
Posts: 199
Joined: Mon Aug 11, 2008 7:33 am

Post by jpsdr » Wed Nov 04, 2015 11:10 pm

It's a Blu-Ray m2ts file, so, some compression artefact, still possible, a lot of compression artefact... Always possible, but honestly probability very very low from my point of view (but it's also possible that my point of view is wrong. :wink: )
If i have time, is there an e-mail i can provide you informations (ftp server) to retrieve a small sample, to confirm it's realy because of "lot of compression artefact" ?

NVTeam
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Post by NVTeam » Wed Nov 04, 2015 11:20 pm

You can extract one frame and send it to our support by e-mail. Or just open it in an image editor and increase the contrast to maximum in the area used for profiling. That will show a maze of those artifacts.

Vlad
Image Image Neat Video team
noise reduction for video and photos

jpsdr
Posts: 199
Joined: Mon Aug 11, 2008 7:33 am

Post by jpsdr » Fri Nov 06, 2015 11:01 am

Doing tests, i've been able to found out frames where both NV3 and NV4 complain about not uniform. Even if area seems unform and even increasing contrast i don't realy see this famous "maze", i'm not the expert, you are, so for me it's good, subject is close.
Thanks for your support.

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