| 摘要 |
PURPOSE:To apply special effect only to a portion of a video signal corresponding to a portion where an input key signal exists by providing a 1st A/D converter, a picture storage device, a write address generator, a readout address generator and a D/A converter. CONSTITUTION:An input video signal 1 and an input key signal 2 are coded into a digital signal by A/D converters 3, 6 respectively and written in a picture storage device 4 and a readout address generator 9 by an output of a write address generator 5 respectively. Then the readout address generator 9 discriminates the presence of the key signal and decides the video signal to be read. Moreover, a background is added to the video signal read by the picture storage device 4 with an effective range command signal outputted from the readout address generator 9 at a background adder 10. Then the resulting signal is decoded by a D/A converter 12 and outputted from an output terminal 14 via a synchronizing signal adder 13. Thus, special effect is applied only to a portion of the video signal corresponding to the portion where the input key signal exists. |
