Take Neat Video to next level

suggest a way to improve Neat Video
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LeoB
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Joined: Mon Feb 24, 2014 8:47 pm

Take Neat Video to next level

Post by LeoB » Tue Feb 25, 2014 5:41 am

Hello,

Now that you've made NV the best software denoiser around, it would be logical to add a working VCR dropout corrector tool to NV.

Every analog VCR has some kind of DOC in their playback circuitry. But due to level differences of individual tape RF signal, the DOC circuit sensitivity cannot be fine-tuned by the operator. Besides, in most VCRs there aren't even internal adjustments for DOC sensitivity.

So, NV should have a feature that functions as a post-processing DOC, an extension to the one in a VCR.

I've worked with analog and digital VCRs for over four decades, so if you do decide to add a DOC filter to NV, I might have some ideas as how to apply it.

NVTeam
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Joined: Thu Sep 01, 2005 4:12 pm
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Post by NVTeam » Tue Feb 25, 2014 11:57 am

Thank you for the suggestion. Could you send us (to support [at] neatvideo.com) some small (short) sample clips showing the problem?

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

LeoB
Posts: 3
Joined: Mon Feb 24, 2014 8:47 pm

Post by LeoB » Sun Mar 02, 2014 3:11 pm

NVTeam wrote:Thank you for the suggestion. Could you send us (to support [at] neatvideo.com) some small (short) sample clips showing the problem?

Thank you,
Vlad
Hello,

I have no particular problem tape at the moment. But I think video dropouts are such a common thing that NV should include an additional filter for masking them. Especially, since almost no software-based NR tool has a DOC filter. More extensive DO concealment is available only in costly standalone devices like Snell&Wilcox.

First, unprocessed tape DOs are always modified by VCR's DOC circuits. Most of the 3 to 100-usec DOs are concealed. At the same time, however, each DOC action turns every longer DOs into twice or more short ones that remain in the PB picture. Those short DOs are the ones that could and should be addressed, I think.

So, after a VCR DOC circuit, nearly all of the remaining DOs are shorter than one horizontal TV line. They could be masked by taking the missing piece of signal from previous interlaced TV field.

With DOs more than 5 to 10 times longer than one H line (damaged tape), the software should fill the missing portion of the image with medium grey to make them less conspicuous.

Correcting chroma part of the signal is more difficult, especially in European PAL signal format. DOCs in most VCRs solve this by simply killing the chroma signal for the duration of each DO.

LeoB

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