Special effect device, key signal control device and key signal control method

摘要

A key signal control unit for controlling the level of a key signal corresponding to an arbitrary position within a frame area to a level corresponding to a minimum distance from an inner edge of the frame area on the basis of the level of a key signal on the inner edge of the frame area as a reference value so that the frame area appears along an outer circumference of an image corresponding to a video signal. A totally new image special effect is thus made on the video signal.