APPARATUS AND METHOD FOR NOISE REDUCTION OF VIDEO SIGNAL DEPENDENT UPON VIDEO GAIN

A circuit 8 reduces noise on a video signal from an imager 6 for a TV monitor 7. The noise reduction circuit includes a video frame store connected so as to integrate the corresponding picture elements of several frames in order to reduce noise. The amount of noise reduction applied depends on the noise on the incoming video signal but, whereas this has been assessed previously by comparing differences between incoming frames, in the invention it is assessed from the gain, information on which is encoded on the video signal. The gain of the imager gives a more accurate reflection of video noise than does comparing successive frames, since movements on the image can produce the same effect as noise fluctuations.