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Here’s a challenge. Ground Glass Artifact Removal.
Well, I’ve warped my mind around this alone for long enough. Welcome to the problem.
We shot this footage on an HVX200 using a protechnik 35mm adapter. We discovered shortly into the shoot (during first download) that the ground glass was not spinning every time we rolled.
We now have a fair amount of footage with a static ground-glass overlay on it.
The overlay is a static, mottled-noise-like overlay that is consistent within each shot (but not between all shots unfortunately).
Obviously, the goal is to either remove the artifact or make it significantly less noticeable.
Tactics and demo packages tried so far:
AE:
Dust and Scratches filter (at a high enough radius will remove the effect but at the cost of the making the shot look highly processed and blurry)
Various operations involving blurring and then mathematically merging (add,sub,mult,tried em all) it with an unaffected layer in order to create a mask of the noise.
Red Giant Film Fix (dust removal)Nuke:
Dustbuster
Furnace plugin: Grain Removal, Dust Removal, Noise RemovalShake:
Various blur/merge operations.
A couple of de-graining macros.And also, adding grain/noise to try and cover up the effect. Despite added noise, the oddness of the overlay is still clear.
It’s so frustrating, because at the brain level, you can clearly see the effect of the foreground overlay. The question is, how do I make it mathematical?
Here is a 30 frame section from one of the shots (pngs in a RAR). (about 50M). Link.
I have yet to have the privilege of tapping the great minds in here. I keenly await your responses. Thanks in advance.
Raza
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2 Replies
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The voice of reason is not welcome here!
But seriously, I appreciate your advice, and in the end, what you say is right. I think at a gut level I have already reconciled to that, but at a curiosity level, I am still intrigued by this problem, both its uniqueness and the sheer frustrating nature of it.
Thanks again,
Raza
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Hey, I wonder, what did you decide in the end? I am curious as to which of the techniques worked closest to something acceptable (or which was the least worse). I had a really silly idea looking at the stills (probably a in stop-motion/rotoscoping mindset). Given that the grain is constant, completely static, you could manually create a mask in photoshop for the subtle light variations and try to compensate them as such. Because it doesn’t move, it would be a pain, but you would only have to do it once and maybe do slight moving corrections in after affects, but the relative position of the grain would never move. Also, even for a static GG, that image looks pretty grainy. I’ve shot static GG on SD in the past (for experimentations) and it didn’t look as grainy. But maybe it’s just the HD working as a stronger delator. Another option in this highly artisan approach would be to film a static white surface with the same GG as a guide to the photoshoping madness.
But I would be curious as to the what yielded better results anyway.
Peace.
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