A video special effects processing system for superimposing a key video picture on a reference video picture. A key video signal which corresponds to the key video picture is stored in digital form in a memory in locations which are addressable by data corresponding to coordinate pairs. In a preferred embodiment, the video data stored in the memory is read out in accordance with a manipulated coordinate pair, thereby achieving a predetermined type of displacement effect on a video screen. The manipulated coordinate pairs are produced in response to the original coordinate pairs which identify the memory addresses and function data provided by a central processing unit (CPU), which processes the data in accordance with a mathematical function which defines the special effect which is desired to be achieved. The original coordinate pair data and the function data are arithmetically manipulated in a hardware-implemented manipulator in accordance with a generalized video effects equation.