Image Processing Reference
In-Depth Information
Some of these artifacts also apply to video, but you don't have the frame edge to
track against. You can still track objects in the frame in order to remove camera wobble,
but there is no gate weave because the pictures are not imaged on a physically moving
Tools such as Adobe After Effects are useful for stabilizing the shots so that the cam-
era movement and telecine gate weave are eliminated. The cost here might be a few pix-
els around the edge of the shot. These would need to be cropped, but they are probably in
the over-scan region of the image so they would not have been visible anyway.
Well-stabilized, cleaned footage should compress much better than raw filmed shots.
This is also a good opportunity to grade and color-correct the footage. If the content
was imported from very old film stock it will have a purple cast to it. Applications such as
Final Cut Pro have very good color-correction facilities these days. If you use Windows,
then Adobe Premier is useful for this kind of work. There are also many useful plug-ins to
incorporate into your suite of tools to enhance the whole process.
Be careful not to oversharpen during the telecine transfer from film, as this
will compromise your compression efficiency.
If you have the money, then high-end tools such as Shake give you a lot of leverage
for applying complex processes to your footage. However, they are financially out of the
reach of most users.
Stabilization should be done before dust removal so that the chances of copying
pixels from adjacent frames to repair the damage are improved. Scratch removal may
be a bit more tricky, because the scratch is prone to move as the video is stabilized and
that might make it harder to eradicate. This kind of restoration needs to be done
painstakingly, and dealing with very specific artifacts might have to be done one step
at a time.
The tools listed in Table 34-1 may be useful alternatives to Shake or After Effects.
Table 34-1 Motion-Tracking and Stabilization Software
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