As I'm on Ubuntu Hardy Heron (and Linux in general)
I'm not able to run the standard Processing Capture.
Testing GSCapture wasn't on top of my "todo list" but when I saw this great program (vimeo.com/1163538) I downloaded the GSCapture package and tried to manipulate pixels...
In few lines of code you can have this cheap result. I don't want to go further because this is not my project !