Scenalyzer almost works, but not quite. It can record at fixed intervals, which lets you do time lapse. However, it does not let you record individual video frames at the moment of your own choosing. Stop motion lets you do this, and is used for animation movies, such as "Wallace and Gromit" or "Chicken Run."
It's not a "single" click of the mouse, but it CAN capture stills from tape. In the capture program, just move to the frame to be captured and go to Transport - Capture - Capture Still. As a shortcut, you can press CTRL-SHIFT-R instead.