Activity › Forums › Broadcasting › Chroma key
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Chroma key
Posted by Merete on April 13, 2005 at 1:03 pmDoes anyone know a good site about chroma keying? I need input…
Merete
Mark Suszko replied 21 years, 1 month ago 4 Members · 6 Replies -
6 Replies
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Charley King
April 13, 2005 at 3:04 pmIf you can tell us what systems you are using, what kind of invironment, I might be able to help, but I don’t know of any sites that explain everything about chroma Keying. Just about every project has it’s own little quirks that have to be overcome.
Charlie
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Mark Suszko
April 13, 2005 at 7:17 pmI would add the Ultimatte web site is often the first place for beginners to look up info on chromakeying.
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Jon Zanone
April 14, 2005 at 11:42 amDon’t use DV. As related by others much smarter than I in this very thread, DV is a bear to key. DV is a compressed format, and the part of the signal you need to make a good key is thrown away in the compression process.
Jon
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Charley King
April 14, 2005 at 3:09 pmFast movement will always cause problems, the blur between fields of thesource and background tend to mix together and as a result will either key out or leave greenish trail. That is where you either live with it, or paint it out frame by frame. I personally don’t know any other way to get rid of that problem, altho the better quality the camera you start with and the less compression you use the better the results.
Charlie
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Mark Suszko
April 14, 2005 at 3:43 pmI think you’re hosed, between the DV and the shutter action, you might be trying to key one field’s worth of image info in each of those motion frames. For the frames that are not working, You will need to hand-rotoscope those. You can export a frame movie into Photoshop, or use a paint program or compositor (hopefully with a wacom tablet and pen) to draw sharper mattes around the hand and finger, etc.
In DV, keying off green tends to work a little better than blue, as you have more luminance info with green. One other trick you might try is to do a luma key instead of a chrmakey, or combine the matte generated in luma over the chroma matte. Anything to avoid the tedious hand-roto work;-)
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