Interesting trivia: green-screen chromakey with DV is nearly as good as 4:2:2

riredale wrote on 6/20/2004, 4:41 PM

I came across this web site yesterday, and about halfway down they talk about strengths and weaknesses of DV chromakey versus BetacamSP and D1.

Turns out that the 4:1:1 used by DV (NTSC countries) is only about 15% worse than straight 4:2:2 that has been commonly used for chromakeys. The trick is to use green as the key color.

I've heard others say that Vegas chromakeys with green are surprisingly good; perhaps this helps explain why.

Comments

Spot|DSE wrote on 6/20/2004, 10:20 PM

Keep in mind that during the key process, Vegas samples at 4:4:4.
But yes, this is a good explanation of why green works well. Adam Wilt, Stephen Schliecher, and Steve Hullfish have written some good articles on this as well, that are slightly more up to date.
If you want to see the luma value of green vs other colors for your own eyes, create generated media using SMPTE color bars on the Vegas timeline.
Then drop on Black and White filter, remove all color. Look at the color that has the greatest value. It's green.