NLMeans question
Posted: Sat Oct 13, 2018 2:48 am
I am in the process of converting Walking Dead Blu-Ray rips to smaller sized backups. For those who don't remember or who haven't seen the show, I'd have to say Walking Dead is the GRAINIEST show I've ever seen. Various directors add film grain under the stupid illusion that their viewers actually like it, but in reality it's analogous to taking a perfectly clean audio recording and adding hiss all over the place to make people think the recording is somehow more authentic... ironically this is a very non-authentic, non-genuine thing to do to perfectly good film. When I watch Walking Dead in its original 1080p form, all I see are dancing pixels all over the screen. I can hardly even concentrate on the images sometimes because the dancing pixels are so absurd.
I've traditionally used hqdn3d smoothing filters to get rid of graininess, and it typically works. I'll use 2:2:3:4 with quality 21, 3:3:4:5 quality 22, 4:4:5:6 quality 23 and so on - this pattern usually works pretty well for keeping file sizes down. In fact, in my opinion, removing grain this way often makes the resulting picture look even better than the original.
But with Walking Dead, the graininess is just too much. I experimented with NLMeans (slows encoding down drastically, so I've been reluctant to use it), and it really surprised me that the setting that worked best wasn't "Grain," but instead "Film." (And I had to bump it all the way up to "strong" to actually make a real difference - you can still see graininess, but any stronger and I imagine it will start to remove some of the imagery along with the grain.)
I am hoping someone out there who intimately understands how the NLMeans filter settings work can explain to me why film works better than grain... and given this reality, what is the "grain" setting actually for?
To be clear, this is not a "support" issue - this is not a "trouble ticket." There is nothing wrong with Handbrake. I just want to understand it better in general terms, that's all.
Thanks!
I've traditionally used hqdn3d smoothing filters to get rid of graininess, and it typically works. I'll use 2:2:3:4 with quality 21, 3:3:4:5 quality 22, 4:4:5:6 quality 23 and so on - this pattern usually works pretty well for keeping file sizes down. In fact, in my opinion, removing grain this way often makes the resulting picture look even better than the original.
But with Walking Dead, the graininess is just too much. I experimented with NLMeans (slows encoding down drastically, so I've been reluctant to use it), and it really surprised me that the setting that worked best wasn't "Grain," but instead "Film." (And I had to bump it all the way up to "strong" to actually make a real difference - you can still see graininess, but any stronger and I imagine it will start to remove some of the imagery along with the grain.)
I am hoping someone out there who intimately understands how the NLMeans filter settings work can explain to me why film works better than grain... and given this reality, what is the "grain" setting actually for?
To be clear, this is not a "support" issue - this is not a "trouble ticket." There is nothing wrong with Handbrake. I just want to understand it better in general terms, that's all.
Thanks!