Hi,
I love using neat video. But I have never liked the profiling process. Sometimes I wish I could just set the noise levels directly to have exact control over what happens to the image. I don't like wondering if the profile I have built is accurately representative of what I am currently filtering. I would prefer to just set the noise levels, apply the filter, and see if I get something I like.
I imagine you could trivially add this to neat video by just having a "standard noise profile" that users can select, that has "unit" noise levels for Y, Cr, Cb and High, Medium & Low. Then using the regular noise level sliders would be, in effect, setting the noise levels.
Cheers,
Landrew
Direct noise level control
Could you clarify why you prefer to work with absolute values instead of relative ones? When we have absolute values (the results of objective measurements) in the noise profile and relative values (the subjective adjustments by the user) in the filter settings then we can separate objective and subjective things. Users don't have to bother with absolute noise levels, their values, differences between them in different modes, etc., they can simply rely on the noise profile and when necessary they can "say", for example, 'there is more noise elements in this clip than the profile says' (which can be easily deduces by evaluating the preview results), by increasing the corresponding noise level(s).
Regarding the "standard noise profile" idea, if you don't know the actual noise levels in the video data, how can you set the sliders to any meaningful values? Isn't it a just trial and error? Please compare this with the currently used method: NV prepares an analysis of the video noise, (which is usually a pretty accurate guess of the actual noise levels of the video data) and you can further tweak parts of this analysis (different measured noise levels) up and down to see what happens. If you used the "standard noise profile", then you would have to estimate the noise levels without any meaningful initial value, just trial and error.
Could you clarify how these two things - (1) absolute values of noise levels instead of relative ones and (2) using the "standard noise profile" (with somehow fixed noise levels) - would help you achieve better filtration with NV? Perhaps I am missing the point.
Thank you,
Vlad
Regarding the "standard noise profile" idea, if you don't know the actual noise levels in the video data, how can you set the sliders to any meaningful values? Isn't it a just trial and error? Please compare this with the currently used method: NV prepares an analysis of the video noise, (which is usually a pretty accurate guess of the actual noise levels of the video data) and you can further tweak parts of this analysis (different measured noise levels) up and down to see what happens. If you used the "standard noise profile", then you would have to estimate the noise levels without any meaningful initial value, just trial and error.
Could you clarify how these two things - (1) absolute values of noise levels instead of relative ones and (2) using the "standard noise profile" (with somehow fixed noise levels) - would help you achieve better filtration with NV? Perhaps I am missing the point.
Thank you,
Vlad
In my work as a film maker, I set the noise levels up to the point where image details start to be affected. For luma, I watch texture in skin, carpet, fabric or wood grain, etc. For chroma, I check to make sure that color changes are not bleading across edges. For both luma & chroma, I then back off some just to be conservative.
Generally, I don't really care how much noise is in the actual images to begin with. If some scenes end up grainy, that's ok. Grainy is better than smeary. I only care that the actual content of the images is not significantly affeced. So, I don't really need to profile different film segements or different cameras, since the noise levels I want are dependent on the content of the scene (farbic, skin, etc), which are invarient. Carpet is always carpet, Wood grain is always wood grain. If I shot two of the exact same scene with different cameras, and one came out noisy, I would still want the noise levels in Neat Video to be the same.
That's my thinking at least. And being able to set noise level to absolute values would make my work easier, as I could get to know what absolute noise levels were appropriate for cleaning up to the point of removing detail.
Cheers,
Landrew
Generally, I don't really care how much noise is in the actual images to begin with. If some scenes end up grainy, that's ok. Grainy is better than smeary. I only care that the actual content of the images is not significantly affeced. So, I don't really need to profile different film segements or different cameras, since the noise levels I want are dependent on the content of the scene (farbic, skin, etc), which are invarient. Carpet is always carpet, Wood grain is always wood grain. If I shot two of the exact same scene with different cameras, and one came out noisy, I would still want the noise levels in Neat Video to be the same.
That's my thinking at least. And being able to set noise level to absolute values would make my work easier, as I could get to know what absolute noise levels were appropriate for cleaning up to the point of removing detail.
Cheers,
Landrew
Thank you for the clarifications.
I think NV already does the thing that you are trying to do by hand: set the noise levels up to the point where image details start to be affected and then back off some just to be conservative. This is how noise profiling is working now. And it is mostly automatic, all noise levels are measured automatically.
I understand that you also want to be able to use a profile with some fixed values for different clips from different cameras. This is also possible if you can build a profile with values that suit your needs. You can build such a profile in a regular NV way and then, if its noise levels are not producing good preview results without additional noise level adjustments in the filter settings, then you can adjust the profile noise levels by adjusting the equalizer values in all color channels and controlling the resulting noise levels using the Profile Viewer. This would be not so fast as adjusting only the noise levels in the filter settings in a normal workflow but it would work and you would get a noise profile with noise levels that work well even with default filter settings for you.
On the other hand, perhaps all the troubles above are not that much needed? - In the regular workflow, once you build a noise profile and adjust the filter settings to the point where noise reduction results look good to your eyes, you can save these profile and preset to the disk and later you can load them into new projects to process other clips. In this case, the noise reduction will be exactly the same in terms of noise levels and noise reduction amounts.
So, basically, you have at least two ways to set it once and use it many times without need to re-adjust anything. Of course if you are satisfied with the same filtration applied to different clips.
I understand that it would perhaps be easier to do the same using absolute noise level values only, but that is something not so frequently needed -- if I undestand you correctly, you don't want to repeat the procedure for every clip, you only want to do it for one.
Thank you for your comments. They help to understand how NV could also be used.
Vlad
I think NV already does the thing that you are trying to do by hand: set the noise levels up to the point where image details start to be affected and then back off some just to be conservative. This is how noise profiling is working now. And it is mostly automatic, all noise levels are measured automatically.
I understand that you also want to be able to use a profile with some fixed values for different clips from different cameras. This is also possible if you can build a profile with values that suit your needs. You can build such a profile in a regular NV way and then, if its noise levels are not producing good preview results without additional noise level adjustments in the filter settings, then you can adjust the profile noise levels by adjusting the equalizer values in all color channels and controlling the resulting noise levels using the Profile Viewer. This would be not so fast as adjusting only the noise levels in the filter settings in a normal workflow but it would work and you would get a noise profile with noise levels that work well even with default filter settings for you.
On the other hand, perhaps all the troubles above are not that much needed? - In the regular workflow, once you build a noise profile and adjust the filter settings to the point where noise reduction results look good to your eyes, you can save these profile and preset to the disk and later you can load them into new projects to process other clips. In this case, the noise reduction will be exactly the same in terms of noise levels and noise reduction amounts.
So, basically, you have at least two ways to set it once and use it many times without need to re-adjust anything. Of course if you are satisfied with the same filtration applied to different clips.
I understand that it would perhaps be easier to do the same using absolute noise level values only, but that is something not so frequently needed -- if I undestand you correctly, you don't want to repeat the procedure for every clip, you only want to do it for one.
Thank you for your comments. They help to understand how NV could also be used.
Vlad
Yes, in fact, I built a reference profile a long time ago by filming a color test card with colored & gray squares. And I use that as my fixed reference to set noise level sliders for everything I shoot. I have one for standard definition and one for high definition.
My point I was trying to make was indeed only that it would be easier if I hadn't had to film the card and build the profile. If I could have just checked a box to "use absolute values" that would be simpler.
Also, I have limited trust in the profile I built. Did the color balance of the light I used affect it? Did the noise spectrum in camera I used to have any biases that would make the profile behave strangely.
As to your comment about my situation being rare, I would actually imagine that lots of people would like to dispense with profiling and just say "remove up to this much absolute noise". Especially people how want precise control over what is done to the images.
As a final note, I may just go ahead and use Virtual Dub or some other tool to synthesize a film with white noise super-imposed on a color chart as a way to build a profile with uniform spectral power distribution in the noise to use with Neat Video as a fixed reference.
Cheers,
Landrew
My point I was trying to make was indeed only that it would be easier if I hadn't had to film the card and build the profile. If I could have just checked a box to "use absolute values" that would be simpler.
Also, I have limited trust in the profile I built. Did the color balance of the light I used affect it? Did the noise spectrum in camera I used to have any biases that would make the profile behave strangely.
As to your comment about my situation being rare, I would actually imagine that lots of people would like to dispense with profiling and just say "remove up to this much absolute noise". Especially people how want precise control over what is done to the images.
As a final note, I may just go ahead and use Virtual Dub or some other tool to synthesize a film with white noise super-imposed on a color chart as a way to build a profile with uniform spectral power distribution in the noise to use with Neat Video as a fixed reference.
Cheers,
Landrew