Python Record Information

Hi, I am trying to capture an image from a webcam video stream. The python logic is very simple:

If button pressed, store the current frame; then, output the frame that was stored.

if 'image' not in globals():
    image = None

if Capture == True:
    #extract an image
    image = bmp

#output image
snapshot = image

The problem is that, once my button is not pressed, the frame keeps on updating even though I am not storing a new 'image' from my snapshot output. I have attached the GH example file, so that you can see what I mean. 

Any help or advice would be greatly appreciated!

Thanks everyone,

Jake