SCANCONVERTER SYSTEM WITH SUPERIMPOSING APPARATUS

摘要

A scanconverter system with a superimposing apparatus for converting an interlaced video signal to a non-interlaced video signal and forming desired image data by superimposing a computer generated image on another image reproduced from a laser disc or the like. The system comprises a write clock generator for generating a write clock of a predetermined frequency, a read clock generator for generating a read clock of a double frequency, a line memory unit (3) for storing a horizontal line of an interlaced digital video signal and outputting a first non-interlaced digital video signal, a frame memory unit (8) for storing a frame of the interlaced digital video signal and outputting a second non-interlaced digital video signal, a detector (10) for detecting whether the interlaced digital video signal represents a still picture or not, and a selector (9) for selecting one of the first and second non-interlaced digital video signals according to the output of the detector. Selection of the first or second non-interlaced digital video signal depends on whether the interlaced digital video signal represents a still picture or not.