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Rating of same noise profile changes

Posted: Tue Dec 11, 2012 4:52 pm
by Lugarimo
I must fix noise samples with photoshop sometimes but when I then select the BMP image of only the noise profile the rating is much lower than when selected area from the video. Why?

When I select from video the noise it was 89% but when I select the whole BMP I open in Virtual dub its 75%.

Posted: Tue Dec 11, 2012 7:36 pm
by NVTeam
Because (as described in the user guide) Auto Profile analyzes the whole image / frame, not only the primary area shown in the selection. If you have only that primary area then Auto Profile does not receive all information from the rest of the image.

Vlad

Posted: Tue Dec 11, 2012 8:41 pm
by Lugarimo
Will the 89 and 75% profiles make any difference qualitywise when denoising?

Posted: Tue Dec 11, 2012 8:45 pm
by NVTeam
If the profiles are different then the quality of the noise reduction may be different.

Vlad

Posted: Tue Dec 11, 2012 10:25 pm
by Lugarimo
No they are exactly the same. One is just taken from the full frame and other is profiled from only the screenshot of the noise profile.

Posted: Tue Dec 11, 2012 10:35 pm
by NVTeam
Then they are not the same. Check the profile graphs (in Advanced mode), there should be some differences.

Vlad

Posted: Wed Dec 12, 2012 1:39 pm
by Lugarimo
Indeed there are, and a lower rating but the picture noise profile itself is the same. This would still make denoising less effective?

Then how do I fix noise profiles in photoshop?

Posted: Wed Dec 12, 2012 1:53 pm
by NVTeam
If the profiles are different, the noise reduction will be different too. Less or more effective is an open question, but different for sure.

Why not build a noise profile using the full image instead of just that small sample?

Vlad