Creating Image manipulation scripts without unity pro

Questions & Answers
1

I Need a way to get a negative light effect form my camera in unity, is there any way to do this when you have Unity Free ? I have searched for functions that allow you to script image manipulation but I have come up dry, does anyone have any ideas ?

2

I might be possible to use a modified direct x that allow to use post-processing, like this:

http://www.enbdev.com/