View Full Version : 4:1:1 blocky (keying) in Premiere Pro


Nathan Petersen
July 7th, 2005, 10:23 AM
Hey guys,
I have not found another solution for smoothing the edges when keying with Premiere pro. However I have done: http://www.neopics.com/bluescreen/ (the photoshop method). This works great if only there was some way just to do it in Premiere PRO. The problem with it, is the film strip files are so huge and it takes forever to do. I know there are a lot of great keyers out there but is there any plugin or anything that will allow me to do this in Premiere Pro? Thanks again

Nathan Petersen
July 7th, 2005, 10:53 AM
anybody know of anything?

Jeremy Davidson
July 7th, 2005, 11:33 AM
AVISynth may be of use. I've never used it for keying, but some of the color adjustment filters for it are great. It does take some code skills, but it's very powerful.

Check it out here: http://www.avisynth.org
...and a couple of tutorials here: http://aqua-web.dyndns.org/film.php

I know there's a setting in Premiere 6.0 (yes, I'm outdated) that seems to help -- I think it's called Smoothing, but I don't remember exactly at the moment.

Nathan Petersen
July 7th, 2005, 12:34 PM
How would you got about doing that, im not sure?

Jeremy Davidson
July 7th, 2005, 01:23 PM
Well, my theory is that the method would look something like this:
1. Load DV AVI file
2. Separate out Luma and Chroma information
3. Apply "GeneralConvolution" to Chroma (the "4-pixel horizontal blur")
4. Stick Luma and Chroma back together
5. Output result

Like I said, I've never actually tried it, and I'm no expert on AVISynth by any means. So far I've used it mostly for Bob deinterlacing and some color correction curves. If I get some free time I'll see if I can come up with a script.

As for that Premiere option, I saw it last in the Transparency dialog box (where you tweak greenscreen threshold and such).

Jeremy

P.S. I've heard rumors that green works better than blue for DV keying. I built a 9'x7' greenscreen for my last composite project. It turned out well, but I could afford to let it look a little cheesy due to the nature of the project.

Nathan Petersen
July 7th, 2005, 01:54 PM
I have actually heard of it but I have never coded anything for it, the only coding I know really well is HTML/SHTML, took a few java classes so can't say im to good with that. Anyway if you could script somthing for avisynth that would be great!

Jeremy Davidson
July 22nd, 2005, 03:48 PM
OK, so I still haven't gotten an AVISynth script, but I ran across something else you may find useful. Virtualdub comes with a "Chroma Smoothing" filter that looks like it might do what you're looking for. I haven't tried any of my footage in it yet. If it works for you be sure to let us know!

I have version 1.6.1. 'Looks like it's already up to 1.6.8 now.
http://www.virtualdub.org

You'll have to use a codec besides DV when you export back out of vdub or else you'll still end up with 4:1:1 video that's just fuzzier than before. Uncompressed AVI is an option, though it is not friendly to small hard drives.