Special effect generator with limited read address calculation region

摘要

A special effect generator is arranged such that read address calculations for special effect processing of an original video image are limited only to the region within which the processed video image is located on the display screen, so that calculations of read addresses are simplified. The coordinates and image rotation information for several different video special effects are stored in a read-only-memory and are used to limit the address generation operation based on the coordinate boundaries of the image on the video screen, so that only those addresses actually required for the special effect are calculated.