Abstract: In order to process video images under control of a data processing system, a video signal processing device is described that can be coupled to a data processing system interface unit. The video signal processing device includes two image frame buffers and apparatus for transferring signals in a controllable manner between the two image frame buffers. The video signal processing device also includes apparatus for combining the output signals of the image frame buffers in a controllable manner. The control of the signal transfer between image frame buffers and the control for the combining of the output signals of the image frame buffers is provided by the data processing system. The data processing system loads a multiplicity of registers with information to provide the desired output signal and the video signal processing unit executes the functions determined by the register contents. In this manner, the data processing system can devote relatively few of the available resources to processing the image.