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  1. Member brassplyer's Avatar
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    dv.avi from a Digital8 camcorder converted to HuffYuv.

    Wondering what can be done about these noticeable transitions in brightness level - seen in the halo around this torch - most noticeable around the outer fringes. This is after Denoising with Neat Video but it can be seen in the original DV file. It becomes more obvious when the Brightness/Contrast is adjusted as it has been here. I.e. why isn't it just a smooth transition from bright to dark? It's even more noticeable when the video is actually playing.

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    Last edited by brassplyer; 5th Jan 2015 at 02:58.
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  2. You might want to read up on (color) banding and dithering.
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    It's edge enhancement. Pretty much all electronic video cameras apply it to the image. Some more, some less, more professional ones have a menu setting for it. It's intentional, and supposed to increase the perceived sharpness of the image.

    Dehalo_alpha probably helps, but it'll also most likely kill fine details.
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    Originally Posted by Skiller View Post
    Edge "enhancement", once necessary in the old age of tiny CRTs nowadays completely unnecessary and harmful to the video.

    Unfortunately stuffy old engineers keep doing it, on DVDs and even on Blu-Rays.

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  5. Member brassplyer's Avatar
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    Originally Posted by Skiller View Post
    It's edge enhancement. Pretty much all electronic video cameras apply it to the image. Some more, some less, more professional ones have a menu setting for it. It's intentional, and supposed to increase the perceived sharpness of the image.

    Dehalo_alpha probably helps, but it'll also most likely kill fine details.
    I'm not sure we're talking about the same thing. What I'm referring to is how the brightness level as seen in the halo around the flame instead of being a smooth transition from brightest to darkest has obvious points where you can see edges or rings of brightness where it drops off to the next level of brightness, where in-between levels of brightness are skipped. There isn't an edge per se to be enhanced.

    From what I've been reading it's an issue with digital video and a common fix is to add noise to mask it, which I just removed with NeatVideo. And sure enough it's more prominent once the noise is peeled away. If it's a choice between noise or banding, I'll live with the banding.
    Last edited by brassplyer; 6th Jan 2015 at 20:19.
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    Originally Posted by brassplyer View Post
    Originally Posted by Skiller View Post
    It's edge enhancement. Pretty much all electronic video cameras apply it to the image. Some more, some less, more professional ones have a menu setting for it. It's intentional, and supposed to increase the perceived sharpness of the image.

    Dehalo_alpha probably helps, but it'll also most likely kill fine details.
    I'm not sure we're talking about the same thing. What I'm referring to is how the brightness level as seen in the halo around the flame instead of being a smooth transition from brightest to darkest has obvious points where you can see edges or rings of brightness where it drops off to the next level of brightness, where in-between levels of brightness are skipped.
    Actually the banding in the image you provided is not that bad. There are far worse examples.

    Video luminosity is only 8 bit (actually less and it is really luma - you need to ask "brilliant" engineers why these things are still an issue in 2015), for grey levels that is not that much of a problem but for color it is ("brilliant" engineers can explain why they coded color in such a way that banding is often worse for colors).

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  7. Yes, it's a choice of noise or banding. The number of possible colors in 8 bit YUV is too small to create smooth gradients. Even in 8 bit RGB it can be a problem. You can use 10 bit YUV instead but then you'll have problems with players that don't support 10 bit video.

    As was pointed out, the banding in that image isn't all that bad. Maybe your graphics card or display is misconfigured. Or your monitor can't distinguish 256 shades of gray.
    Last edited by jagabo; 6th Jan 2015 at 20:28.
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  8. Member brassplyer's Avatar
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    Originally Posted by jagabo View Post
    Yes, it's a choice of noise or banding. The number of possible colors in 8 bit YUV is too small to create smooth gradients. Even in 8 bit RGB it can be a problem. You can use 10 bit YUV instead but then you'll have problems with players that don't support 10 bit video.

    As was pointed out, the banding in that image isn't all that bad. Maybe your graphics card or display is misconfigured. Or your monitor can't distinguish 256 shades of gray.
    It looks worse on this end, gets smoothed out a bit going to jpeg but it's more pronounced when the video is playing.
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  9. Do you differences between the top, middle, and bottom rows of this video?
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  10. Member brassplyer's Avatar
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    Originally Posted by jagabo View Post
    Do you differences between the top, middle, and bottom rows of this video?
    Yes. The bands get progressively wider.
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    The image posted (and most of the videos you've been posting) are over filtered. Strong tempo-spatial filters like NeatVideo and tough degrainers don't just remove the noise we don't like, they also scrub away grain that makes up a lot of "detail", especially in VHS and movie-based sources. The result is banding, macroblocks, posterizing, and "plastic" effects. How it's handled might be easier to explain using one of your original sources (but you seem to have a morbid fear of posting original samples). You might be willing to take the word of many many many many many many many others who recommend to cut down on filtering strength, use different filtering methods to suit the source, and/or use various other ways of either retaining some of the original "noise" or adding controlled noise back into the work. Color Banding and Noise Removal.
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  12. Member brassplyer's Avatar
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    Originally Posted by LMotlow View Post
    The image posted (and most of the videos you've been posting) are over filtered. Strong tempo-spatial filters like NeatVideo and tough degrainers don't just remove the noise we don't like, they also scrub away grain that makes up a lot of "detail", especially in VHS and movie-based sources. The result is banding, macroblocks, posterizing, and "plastic" effects. How it's handled might be easier to explain using one of your original sources (but you seem to have a morbid fear of posting original samples). You might be willing to take the word of many many many many many many many others who recommend to cut down on filtering strength, use different filtering methods to suit the source, and/or use various other ways of either retaining some of the original "noise" or adding controlled noise back into the work. Color Banding and Noise Removal.
    No "morbid fear" but it's a pita to upload a clip when I find that doing so often doesn't result in a better answer to the question. I don't think it'll really help here. My use of NeatVideo isn't extreme - I'm definitely conscious of avoiding the "plasticized" look and not killing detail. As you can see from the screen shot there's certainly image detail there where the structure of the torch can be seen - there's as much detail as there is in the original which is from an SD Digital8 camera.

    Yes I've noticed that noise can create an illusion of detail - for example here in the trees, the noise makes it seem like there's more detail in the branches than there really is. At that distance there's not going to be fine detail with this camera even under ideal lighting, let alone at night like this.

    As I say - I'll live with the banding if the only solution is to retain a higher level of noise - which still won't eliminate the banding altogether since it's visible even in the original.
    Last edited by brassplyer; 8th Jan 2015 at 14:31.
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