View Full Version : Fixing overly sharpened edges

Squished
12th July 2006, 23:29
I'm not sure exactly what to call the problem with the movie I'm cleaning up. Maybe it is ringing? It has the same appearance as velocity scan on a TV. Basically, the edges are overly sharp causing some pretty ugly artifacts that I would like to remove. Hopefully there is a filter, or scripting that might clean this up.

Attached is a cropped frame. The table edge shows the problem clearly, as does the neckline on the dress.

Any suggestions?

Thanks!
foxyshadis
12th July 2006, 23:54
Ringing (or haloing), yep. A quick and dirty solution is the script DeHalo_alpha() by residet scriptmeister Didée, or you can try to deconvolve it, but determining the precise kernel used is quite difficult. Unfilter may also help somewhat.
Chainmax
13th July 2006, 00:49
HQDering is also a good alternative, because it's a great halo remover and sharpens the picture as a side effect. It's downside is that it causes some aliasing, which according to Didée could be solved by modifying the masking process. Some supersampling would probably help with that too. Alas, no one seems interested in doing it :(.
scharfis_brain
13th July 2006, 05:11
looks like someone scaled up the DVD Release of 2001 - A Space Oddyssey to HDTV.
You'd better get the original DVD...
Squished
13th July 2006, 15:45
looks like someone scaled up the DVD Release of 2001 - A Space Oddyssey to HDTV.
You'd better get the original DVD...

Actually, the first post image is a small section of a 1920x1080 frame from 2001. The HD broadcast was actually a decent film transfer... other than being hard telecined, and the ringing problem.

I'll get that sorted though.
Squished
13th July 2006, 18:00
Ringing (or haloing), yep. A quick and dirty solution is the script DeHalo_alpha() by residet scriptmeister Didée, or you can try to deconvolve it, but determining the precise kernel used is quite difficult. Unfilter may also help somewhat.

I tinkered with DeHalo_alpha, and it does help in some scenes, but it has a great deal of difficulty when the ring is actually separated from the object... what I would call a ripple. The more dramatic the brightness change, the further the ripple is from the edge.

I can see this is going to be tough to do well.

Thanks.