Abstract: A method of and apparatus for storing two scan lines of encoded video information for the purpose of writing said information into a main video memory such that the two lines may be transferred to main video memory during horizontal blanking periods when the main video memory is not being read for the purpose of forming a manipulated image on the screen. Two consecutive horizontal blanking periods are used to complete the transfer of each stored line. Further circuits are provided for altering addresses to the main video memory which is properly segmented for the purpose of extracting the target pixel information and the information of several surrounding pixels. The purpose of such access is to supply a pixel interpolator with enough information to construct a proper screen image of the target pixel.

Abstract: 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.