| 摘要 |
PURPOSE:To reduce noise by using a frame memory small in capacity by writing a noise rejection video signal into a memory during a video signal period and avoiding the signal from being written into the memory during the other period so as to output the input video signal to the next stage as it is. CONSTITUTION:The input video signal is inputted to substruction circuits 1, 3 and a switching circuit 5. A delayed video signal 201 retarded by one frame time from the frame memory 4 is inputted to the subtraction circuit 1 and the signal is subtracted from the input video signal and a frame difference signal 300 is outputted to an extraction circuit 2. The extraction circuit 2 separates the noise component and the video component to extract the noise component 400, which is supplied to the subtraction circuit 3. The noise component 400 is subtracted from the input video signal 100 and the video signal 200 being the result of noise component rejection is fed to a terminal (b) of the switching circuit 5. A control circuit 6 switches the switching circuit 5 so as to change over the video image part and the other parts and the input video signal 100 is outputted as it is for the parts other than the video image part.
|
