How do you edit a green screen background?
What software do you use?
And how do you crop the specified thing in the greenscreen? This is because most youtube videos I watch change all the 'green' part, and it means, it doesn't show how to crop thing (if the greenscreen doesn't fit the whole screen of the video, the not-green won't be changed). Let me make an illustration using a picture ( http://img89.imageshack.us/img89/3052/gnkt.png ) --> how do you crop the person (and put it in another background), but not the red abstract line?
Update:@Tech Guy: Do you have any recommendation? I need the automatic one, not the manual cropping.
Answers & Comments
Verified answer
You didn't tell us what software you are using... Basically you manually crop away the parts outside the green screen. You would do this by adding a simple mask to your layer (how exactly to do this depends on the software).
For Adobe AfterEffects assume you would be using Keylight for removing the green screen. Then you can grab the pen tool (or even maybe the rectangle tool) and draw a quick mask on your layer (manually "cropping" it to only the area you want).
It only becomes problematic if the subject accidentally moves outside the greenscreen. If so, I highly recommend getting a larger greenscreen for the future as it can quickly become very labor-intensive.
You have to find a video cropping program. There are tons out there.