[Tig] Preventing banding artifacts

Rogerio Moraes rogermamo at gmail.com
Fri Oct 23 10:39:11 BST 2015


Hello

    I've been using for "noise" or "dither" a dpx sequence that's a scan from a35mm negative unexposed for grain. I have those for asthetc reasons, bit now I use it more to try to compensate banding onions. I don't consider this a final solution, since it does impact on the image and for practical reasons dealing every time with a 2k files, replicating it on a timeline ( it's just about 1 minute long) and rendering ( it does impact render times) is kind of frustrating, since I'm trying to correct an error that I don't even see! But I'm kind of glad to see I'm not the only one in the business with this problem... Let' me say that one once again: I really don't care anymore with 4K, 8k ,16k.... I do want better and greater  color resolutions! There, I said it.

Thank you all.

On the move

Em 23 de out de 2015, às 06:57, Chris Barnett via Tig <tig at colorist.org> escreveu:

> Sohonet www.sohonet.co.uk sponsors the TIG.
> =====
> 
> 
> I've also been meaning to ask this question for a while..
> 
> Going from 4K Prores 444 master (from RED raw camera files) down to 1080 H.264 8bit web versions creates shocking banding.
> 
> I've actually found that watching broadcast TV I don't see banding as much as I would expect, having experience of making it so often!!
> 
> I export either from Resolve, FCP7 or MPEG stream clip - all with same results (ish) - resolve seems best..
> 
> Could you explain how / which software you use to add dither? It works so well with audio but not found how to use it with video.
> 
> I'm having to use techniques based on individual clips that are worst offenders.. I cannot use blur on a vignette at all, it's basically just having to remove all fx or grades that offend. Or as you say add noise. Also projecting with data projectors as we do  for end of year screenings is a total nightmare.
> 
> Thanks 
> 
> Chris
> 
> 
> -----
> 
> Chris Barnett
> University of Bristol - associate teacher
> MA Film & Television
> 
> 
> 
> 
>> On 23 Oct 2015, at 03:06, David Mackenzie via Tig <tig at colorist.org> wrote:
>> 
>> Sohonet www.sohonet.co.uk sponsors the TIG.
>> =====
>> 
>> 
>> Hi Rogerio
>> I face a similar issue with 10-bit masters going to 8-bit Blu-ray, and as
>> you mentioned, the solution is to add dither. However, this can be
>> challenging to do at BD bitrates (up to 40mbps) with adjustable software
>> encoding, so I imagine for real time broadcast encoding you're out of
>> options. Happy to be proven wrong though!
>> 
>>> On Thu, Oct 22, 2015 at 9:54 PM, Rogério Moraes <tig at colorist.org> wrote:
>>> 
>>> Sohonet www.sohonet.co.uk sponsors the TIG.
>>> =====
>>> 
>>> 
>>> Hello all
>>> 
>>> 
>>> I'm trying to come up with solutions for this. I'm seeing a lot of banding
>>> artifacts on y when on air. Although we always output 10 bit prores minimum
>>> to all of our jobs, there's no way to forsee how that is going to be
>>> treated by the channel or network I think they all broadcast to 8 bit? Is
>>> that a plague with TVs or computer screens?. Frustating enough, we master
>>> thngs to be pristine only to see the all too familiar blooming onion on
>>> air. I try to minimize this by adding a very fine grain but it has
>>> drawback, mostly because adding this to all jobs seems impractical.. Is
>>> there a definitive or another solution for this? Any ideias?
>>> Thanks for the input
>>> 
>>> 
>>> --
>>> Rogério Moraes
>>> _______________________________________________
>>> http://colorist.org
>>> To change subscription options, see
>>> http://tig.colorist.org/mailman/listinfo/tig
>> 
>> 
>> 
>> 
>> -- 
>> -- 
>> David Mackenzie
>> DVD / Blu-ray Compression & Authoring
>> AV Calibration and Consulting
>> ISF Certified Calibrator
>> 
>> US: +1 914-902-8928
>> UK: +44 (0) 203-239-6816
>> _______________________________________________
>> http://colorist.org
>> To change subscription options, see http://tig.colorist.org/mailman/listinfo/tig
> _______________________________________________
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> To change subscription options, see http://tig.colorist.org/mailman/listinfo/tig



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