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Old March 11th, 2005, 08:44 PM   #1
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Article on Sharpening Artifact Removal

Hi everyone,
I just finished writing up an article on a method I've developed which removes (or at least tries very hard to) those annoying halos or rings that you see in video footage.

I think this is probably the best place to post it, although if I'm mistaken please say so.

The article can be found below:
http://www.bargus.org/articles.html

It's probably most useful for those of you who use Canon cameras such as the GL1 or XL1.

Feedback is very welcome!

Adam Bowman
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Old March 11th, 2005, 10:49 PM   #2
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If you use Vegas, you might be able to achieve similar results by:

Unsharp mask
Amount = -50% (Type in a negative number and hit enter.)
*-100% does nothing as far as I know, and below -100% interesting things happen. -150% is another sweet spot.
Radius = 0.005 (or thereabouts... maybe 0.002/3)
Threshold- push it up a little to around 0.150

I'm not sure what exactly this does but it does reduce the contrast on fine high contrast transitions.
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Old March 12th, 2005, 12:10 AM   #3
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Wow! Kudos for working out such a complex procedure. What of just turning down "sharpness" or "detail" in the camera?
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Old March 12th, 2005, 07:23 AM   #4
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<<<-- Originally posted by Joshua Provost : Wow! Kudos for working out such a complex procedure. What of just turning down "sharpness" or "detail" in the camera? -->>>

I've been using the Canon XL1, which is not blessed with these controls.
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Old March 12th, 2005, 09:36 AM   #5
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Adam,

the results you are getting are excellent, I particularly like the way the rest of the image stays sharp after applying the de-ring

I just wonder if you can get the AE SDK (free from adobe site) and program a plug-in to do this more efficiently. Maybe a technique to just blur the edges which exceed a certain contrast threshold

I am guessing it takes quite a while to render frames with 2 gaussian blurs in the stack
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Old March 12th, 2005, 01:09 PM   #6
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Hi John,

I'll maybe look into the SDK, although I'm not a programmer at all I have friends who might be able to help. If anyone wants to make a Plug-In version based on my Preset and method and release it for free that'd be great as well!

As far as Render time, it takes about a second per frame, which I find to be adequate (just leaving AE to churn out footage overnight). I expect this can be streamlined and made more efficient if it was a created as bespoke plug-in.

Adam Bowman
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