Abstract: A video processing system for use in combining a first video image sequence comprising a number of image frames and a second sequence of video image frames to create a composite video image sequence is disclosed. The system comprises a stylus and touch tablet combination and is arranged to define on a frame-by-frame basis at least four reference points representing corners of a keyframe in three dimensional space notionally projected onto a monitor screen. A transforming circuit transforms the addresses of pixels in a frame of the first video image sequence so as to cause the pixels to represent the frame as projected onto the display screen from the same location in three dimensional space as the keyframe. A combiner combines the transformed frame with a corresponding frame of the second video sequence to produce the composite video image sequence.

Abstract: A flat picture is spatially transformed by moving selected reference points one-by-one and "pinning" them at new positions. The system comprises a source of picture video signals, (1, 2) representing picture points at respective addresses in a first picture projected on a viewing screen, addressing means (159) for providing address signals representing the addresses of at least four reference points defining corners of a polygon notionally projected on said screen, and operator-controlled means (14) for producing selective adjustment of said address signals to cause said reference points to define the corners of said polygon as projected on said screen after a movement of said polygon in 3D space. A transforming circuit 7 responds to said address signals after the selective adjustment by transforming the addresses of said picture video signals so as to cause the picture video signals to represent the picture as projected on said screen after undergoing the same movement in 3D space as said polygon.