Chroma Keying with OpenCV Python

This is an individual work. It does not have any specific algorithm requirement. I just want to see how the code would look like when it works: Doing an opencv project to remove color behind a video in Python. It needs to be able to 1) pick up color by a mouse click on video playback, 2)adjust tolerance level with trackbar and see real time result from the same video. The video should be looping constantly. Implemented with highGUI and source code should be provided.