Color Issue - Help

resolve technical issues related to use of Neat Video
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Silvestro
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Joined: Wed Oct 29, 2008 9:18 am

Color Issue - Help

Post by Silvestro » Wed Oct 29, 2008 10:05 am

Hi everybody.
I'm new to this forum as I bought NeatVideo Home just few weeks ago and I did not met any problem until now.
Until now I used NeatVideo to restore old video made with analog cameras (vhs and s-vhs) and I am very satisfied.
Yesterday, anyway, it occured a problem that I do not know how to solve.
When I apply the ReduceNoise effect in Premiere Pro CS3, the sky changes noticeably its color, turning from light blue to a greenish tone.
I set up many times at the best the device profile.
All the steps were made carefully.. I checked many times.. no way.
Please note that above ReduceNoise there is a ColorCorrection Effect from Matrox (I work with a RTX.2). Swapping the two effects doesn't change the situation.
I tried also to work in advanced mode, lowering the noise reduction amount on the Cb channel.. it doesn't work.
I tried to change workspace from YCrCb to RGB, then lowering the sensitivity of the blue channel.. it doesn't work.. the sky continues to aquire a greenish tone.
Maybe it is funny to say but the problem, until now, appeared only with a footage that I grabbed from a fragment of a cassette. The same combination of effects (MatroxColorCorrection + Noise reduction) worked very fine with footage grabbed with other similar analog cassettes (same videocamera was used).
I don't know what the cause could be, nor how to solve.
Anybody can help?

NVTeam
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Post by NVTeam » Wed Oct 29, 2008 11:23 am

I think the problem is not related to NV settings (profiles, filter settings, working color space, etc.). Neat Video itself never changes color tone of the video data, regarless of NV settings.
I guess there is something wrong with the footage itself, like incorrect order of fields. Or there is some unusual interference between two plug-ins, but again, if it only shows up on one clip then there must be something clip-specific, perhaps the clip is somehow incorrectly encoded or marked in its metadata.
Is the problem still present if you use only NV on this clip? If you use only ColorCorrection? If it disappears and if it is just one clip then perhaps it makes sense to render it twice: once with color correction and another with noise reduction. The actual problem may be in Color Correction plug-in and I guess it may be easier to avoid it than to fix that plug-in.

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

Silvestro
Posts: 4
Joined: Wed Oct 29, 2008 9:18 am

Post by Silvestro » Wed Oct 29, 2008 2:52 pm

Hi Vlad and thanks for the quick reply
NVTeam wrote:..... but again, if it only shows up on one clip then there must be something clip-specific, perhaps the clip is somehow incorrectly encoded or marked in its metadata.
Vlad
I think we can exclude this possibility because all the clips belong physically to the same file (capturing from from an analog cassette, Premiere aquires a unique clip, which in my case is about 45 minutes long). Once captured, I cut manually the gigantic clip in the timeline, splitting it in a serie of multiple fragments. Effects are then applyed in a fragment-by-fragment basis. So, the problem is somehow "fragment-specific" and is particularly evident only in some clips with sky visible.
NVTeam wrote:.....
Is the problem still present if you use only NV on this clip? If you use only ColorCorrection?
Vlad
No, the NV will not change the tone of the original clip without CC applyed.
CC itself is applyed because the color tone of the original pictures is not wonderful, and it also need contrast/brightness adjustment.
So, once CC is applied, the picture looks fine.. good contrast, fine blue sky.. etc.. but still noisy.
And here comes NV to "kill" noise.
After NV is applied, noise is finely removed, contrast preserved.. but the color tone goes back to the original situation.. greenish.. same as some of the function of CC were somehow affected by NV.
NVTeam wrote:.....
perhaps it makes sense to render it twice: once with color correction and another with noise reduction.
Vlad
It is exactely what I thought..
- I pre-rendered the clips with only the CC applied..
- then I reimported the new clips with the color corrected
- finally I applied to the new clips the NV noise killer. The result, unluckily, did not change.. the greenish sky came back.
All I can do, by this time, is to increase the blue level in highlights (through the CC effect).


Anyway.. I may still have a card to play :

1 - First, I will pre-render the footage with the Noise Reduction filter.
2 - I will reimport the "De-Noised" footage and then I will apply to it the CC effect... praying that this will not re-introduce some noise and that skyes will be definitely same as I want.

I'll update the topic as soon as this test is made

Silvestro
Posts: 4
Joined: Wed Oct 29, 2008 9:18 am

Post by Silvestro » Thu Oct 30, 2008 6:53 am

Hello,
as promised in the previous post, here me back after the last attempt. So, I rendered the clips with NZ, reimported them in Premiere and finally applied the CC. The problem still persists.
I checked more carefully everything and I must partially contradict what I previously stated in the previous post
Silvestro wrote: No, the NV will not change the tone of the original clip without CC applied.
Checking carefully, even when only the NZ is applied to the fragment (even without CC) the color tone changes. The CC effect will just make more evident the problem.

NVTeam
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Post by NVTeam » Thu Oct 30, 2008 8:54 am

I am not sure what NZ is :-), but anyway, could you send me a simple test project with a small clip that together produce this effect when rendered in Premiere? Once we reproduce it here, we can determine the source of the problem.

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

Silvestro
Posts: 4
Joined: Wed Oct 29, 2008 9:18 am

Post by Silvestro » Thu Oct 30, 2008 10:20 am

NVTeam wrote:I am not sure what NZ is :-)
Vlad
:shock: :oops: "NZ" is just the result of posting too early in the morning, when my brain is still blurry :D .. I meant NV
NVTeam wrote: could you send me a simple test project with a small clip that together produce this effect when rendered in Premiere? Once we reproduce it here, we can determine the source of the problem.
Vlad
That sounds great !
I'll send you a project with a single small clip this weekend, as soon as I'll be back home.
In the meantime.. thanks a lot.

churchillstudios
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Joined: Wed Aug 26, 2009 11:06 pm

Post by churchillstudios » Wed Aug 26, 2009 11:22 pm

I'm seeing the same issue. Best way to describe the problem is that it appears highlights (such as sky, etc.) are clipping. Hot spots appear to get cut, any details are flattened off. Assuming it's a clipping issue, I color corrected the clip so highlight details would be a lower IRE, yet applying this before the effect did not seem to improve the results and "clipping" still occured.

Coincidentally I too am editing on a Matrox system - in this case Axio HD - and currently I'm in in 10 bit mode so clipping should not be an issue. Was there ever a determination as to what Silvestro's problem was? Thanks in advance.

- BC

NVTeam
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Post by NVTeam » Thu Aug 27, 2009 8:00 am

As far as I know, Premiere (Silvestro wrote about Premiere) doesn't have a specifically 10-bit rendering mode. It is either 8-bit or max bitdepth (which is usually 16 or 32).

Anyway, we discussed this issue with Silvestro in Nov 2008 by e-mail and found the following:
1) the problem seems to be related to Matrox effects, codecs or hardware;
2) the problem may show up when you use Matrox effects AND non-Matrox effects;
3) not only Neat Video but several other effects like Premiere's "color correction > equalize" cause the effect that we observed with Silvestro (it may be the same or not the same effect that you observe);
4) according to Silvestro, it may be possible to limit or completely eliminate the problem by using an advanced primary color correction filter instead of the secondary cc filter.

Hope this helps,
Vlad
Image Image Neat Video team
noise reduction for video and photos

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