View Full Version : Article on Sharpening Artifact Removal


Adam Bowman
March 11th, 2005, 08:44 PM
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

Glenn Chan
March 11th, 2005, 10:49 PM
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.

Joshua Provost
March 12th, 2005, 12:10 AM
Wow! Kudos for working out such a complex procedure. What of just turning down "sharpness" or "detail" in the camera?

Adam Bowman
March 12th, 2005, 07:23 AM
<<<-- 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.

John Jay
March 12th, 2005, 09:36 AM
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

Adam Bowman
March 12th, 2005, 01:09 PM
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