The function "Extract Single Colour Pane" is not the reason why your video freezes. Even with an large image it just takes about 20ms (of course this is system dependent too) which would still enable you to play your video with rates of about 50 frames per second.
However, when "activating" this case structure your VI jumps into a untimed while loop and does the colour pane extraction for the same image as long as you "deactivate" the loop.
You should reconsider your architecture!
Christian
