What is the "Halo" effect?

[20/20]

I always hear about "halo" because of sharpening.
Included a picture to see if I got it right.
That slight ghosting at the rigthside of the face/helmet.
Is that the "halo" effect?

Also, the window looking to the outside. It doesnt look too good.
How can I fix this?
I guess you cannot let a plugin specificaly do just 1 portion of a image.
Maybe using photoshop and frame by frame restauration? (that sounds tough)

http://i11.photobucket.com/albums/a158/alcappuccino/halo_.jpg

[manono]

Hi-

Haloing is sometimes called ringing, but most accurately edge enhancement:

http://www.videophile.info/Guide_EE/Page_01.htm

And, as you said, it's caused by sharpening. Yours in that pic doesn't quite look like what I've seen on DVDs before, but I guess that's it. Did you create that yourself, or is that an untouched cap from a DVD?

To get rid of it is tricky, without softening the rest of the picture too much. I use BlindDehalo3, although there are a host of other AviSynth filters that can do the job with greater or lesser success:

http://forum.doom9.org/showthread.php?t=74003
http://forum.doom9.org/showthread.php?t=102794

Also, the FFT3DFilter has a dehaloing component (pretty slow, though):

http://avisynth.org.ru/fft3dfilter/fft3dfilter.html

[20/20]

Am more curious as to wether or not "Haloing artifacts" will
give encoders a tough time. It's only on a few scenes.

And, well, I thought I saw the artifacts on the original
LaserDisc-rip too! (but not this bad)

[guns1inger]

Your example actually looks like poor effects work, where colour bleed as lead to some of the background showing through the edge of the helmet.

There are quite a few commercial discs that show very bad edge enhancement artifacts, some from large studio releases. Have a look at To Catch a Thief or The Guns of Navarone to see how badly some studios can do it.